Merge branch 'master' into libuv-0.10-headless-display

Conflicts:
	common/curl_request.cpp
	common/glfw_view.cpp
	common/glfw_view.hpp
	include/mbgl/platform/request.hpp
	ios/mapbox-gl-cocoa
	setup-libraries.sh
	src/map/map.cpp
	src/platform/request.cpp
	test/fixtures/fixture_request.cpp

115 files changed, 5031 insertions, 862 deletions

diff --git a/Makefile b/Makefile
index b7aa397e1a..584fe2a2e4 100644
--- a/Makefile
+++ b/Makefile
@@ -108,4 +108,4 @@ distclean: clean
 	-rm -rf ./mapnik-packaging/osx/out/universal
 	-find ./mapnik-packaging/osx/out/packages -type d ! -name 'packages' -maxdepth 1 -exec rm -rf {} \;
 
-.PHONY: mbgl test linux
+.PHONY: mbgl test linux build/test/Makefile
diff --git a/common/Reachability.h b/common/Reachability.h
new file mode 100644
index 0000000000..1cf7d2ecea
--- /dev/null
+++ b/common/Reachability.h
@@ -0,0 +1,112 @@
+/*
+ Copyright (c) 2011, Tony Million.
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ 1. Redistributions of source code must retain the above copyright notice, this
+ list of conditions and the following disclaimer.
+
+ 2. Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions and the following disclaimer in the documentation
+ and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#import <Foundation/Foundation.h>
+#import <SystemConfiguration/SystemConfiguration.h>
+
+#import <sys/socket.h>
+#import <netinet/in.h>
+#import <netinet6/in6.h>
+#import <arpa/inet.h>
+#import <ifaddrs.h>
+#import <netdb.h>
+
+/**
+ * Does ARC support GCD objects?
+ * It does if the minimum deployment target is iOS 6+ or Mac OS X 8+
+ *
+ * @see http://opensource.apple.com/source/libdispatch/libdispatch-228.18/os/object.h
+ **/
+#if OS_OBJECT_USE_OBJC
+#define NEEDS_DISPATCH_RETAIN_RELEASE 0
+#else
+#define NEEDS_DISPATCH_RETAIN_RELEASE 1
+#endif
+
+/**
+ * Create NS_ENUM macro if it does not exist on the targeted version of iOS or OS X.
+ *
+ * @see http://nshipster.com/ns_enum-ns_options/
+ **/
+#ifndef NS_ENUM
+#define NS_ENUM(_type, _name) enum _name : _type _name; enum _name : _type
+#endif
+
+extern NSString *const kReachabilityChangedNotification;
+
+typedef NS_ENUM(NSInteger, NetworkStatus) {
+    // Apple NetworkStatus Compatible Names.
+    NotReachable = 0,
+    ReachableViaWiFi = 2,
+    ReachableViaWWAN = 1
+};
+
+@class Reachability;
+
+typedef void (^NetworkReachable)(Reachability * reachability);
+typedef void (^NetworkUnreachable)(Reachability * reachability);
+
+@interface Reachability : NSObject
+
+@property (nonatomic, copy) NetworkReachable    reachableBlock;
+@property (nonatomic, copy) NetworkUnreachable  unreachableBlock;
+
+
+@property (nonatomic, assign) BOOL reachableOnWWAN;
+
++(Reachability*)reachabilityWithHostname:(NSString*)hostname;
+// This is identical to the function above, but is here to maintain
+//compatibility with Apples original code. (see .m)
++(Reachability*)reachabilityWithHostName:(NSString*)hostname;
++(Reachability*)reachabilityForInternetConnection;
++(Reachability*)reachabilityWithAddress:(const struct sockaddr_in*)hostAddress;
++(Reachability*)reachabilityForLocalWiFi;
+
+-(Reachability *)initWithReachabilityRef:(SCNetworkReachabilityRef)ref;
+
+-(BOOL)startNotifier;
+-(void)stopNotifier;
+
+-(BOOL)isReachable;
+-(BOOL)isReachableViaWWAN;
+-(BOOL)isReachableViaWiFi;
+
+// WWAN may be available, but not active until a connection has been established.
+// WiFi may require a connection for VPN on Demand.
+-(BOOL)isConnectionRequired; // Identical DDG variant.
+-(BOOL)connectionRequired; // Apple's routine.
+// Dynamic, on demand connection?
+-(BOOL)isConnectionOnDemand;
+// Is user intervention required?
+-(BOOL)isInterventionRequired;
+
+-(NetworkStatus)currentReachabilityStatus;
+-(SCNetworkReachabilityFlags)reachabilityFlags;
+-(NSString*)currentReachabilityString;
+-(NSString*)currentReachabilityFlags;
+
+@end
diff --git a/common/Reachability.m b/common/Reachability.m
new file mode 100644
index 0000000000..c6f6388f52
--- /dev/null
+++ b/common/Reachability.m
@@ -0,0 +1,527 @@
+/*
+ Copyright (c) 2011, Tony Million.
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ 1. Redistributions of source code must retain the above copyright notice, this
+ list of conditions and the following disclaimer.
+
+ 2. Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions and the following disclaimer in the documentation
+ and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#import "Reachability.h"
+
+
+NSString *const kReachabilityChangedNotification = @"kReachabilityChangedNotification";
+
+@interface Reachability ()
+
+@property (nonatomic, assign) SCNetworkReachabilityRef  reachabilityRef;
+
+
+#if NEEDS_DISPATCH_RETAIN_RELEASE
+@property (nonatomic, assign) dispatch_queue_t          reachabilitySerialQueue;
+#else
+@property (nonatomic, strong) dispatch_queue_t          reachabilitySerialQueue;
+#endif
+
+
+@property (nonatomic, strong) id reachabilityObject;
+
+-(void)reachabilityChanged:(SCNetworkReachabilityFlags)flags;
+-(BOOL)isReachableWithFlags:(SCNetworkReachabilityFlags)flags;
+
+@end
+
+static NSString *reachabilityFlags(SCNetworkReachabilityFlags flags)
+{
+    return [NSString stringWithFormat:@"%c%c %c%c%c%c%c%c%c",
+#if	TARGET_OS_IPHONE
+            (flags & kSCNetworkReachabilityFlagsIsWWAN)               ? 'W' : '-',
+#else
+            'X',
+#endif
+            (flags & kSCNetworkReachabilityFlagsReachable)            ? 'R' : '-',
+            (flags & kSCNetworkReachabilityFlagsConnectionRequired)   ? 'c' : '-',
+            (flags & kSCNetworkReachabilityFlagsTransientConnection)  ? 't' : '-',
+            (flags & kSCNetworkReachabilityFlagsInterventionRequired) ? 'i' : '-',
+            (flags & kSCNetworkReachabilityFlagsConnectionOnTraffic)  ? 'C' : '-',
+            (flags & kSCNetworkReachabilityFlagsConnectionOnDemand)   ? 'D' : '-',
+            (flags & kSCNetworkReachabilityFlagsIsLocalAddress)       ? 'l' : '-',
+            (flags & kSCNetworkReachabilityFlagsIsDirect)             ? 'd' : '-'];
+}
+
+// Start listening for reachability notifications on the current run loop
+static void TMReachabilityCallback(SCNetworkReachabilityRef target, SCNetworkReachabilityFlags flags, void* info)
+{
+#pragma unused (target)
+#if __has_feature(objc_arc)
+    Reachability *reachability = ((__bridge Reachability*)info);
+#else
+    Reachability *reachability = ((Reachability*)info);
+#endif
+
+    // We probably don't need an autoreleasepool here, as GCD docs state each queue has its own autorelease pool,
+    // but what the heck eh?
+    @autoreleasepool
+    {
+        [reachability reachabilityChanged:flags];
+    }
+}
+
+
+@implementation Reachability
+
+@synthesize reachabilityRef;
+@synthesize reachabilitySerialQueue;
+
+@synthesize reachableOnWWAN;
+
+@synthesize reachableBlock;
+@synthesize unreachableBlock;
+
+@synthesize reachabilityObject;
+
+#pragma mark - Class Constructor Methods
+
++(Reachability*)reachabilityWithHostName:(NSString*)hostname
+{
+    return [Reachability reachabilityWithHostname:hostname];
+}
+
++(Reachability*)reachabilityWithHostname:(NSString*)hostname
+{
+    SCNetworkReachabilityRef ref = SCNetworkReachabilityCreateWithName(NULL, [hostname UTF8String]);
+    if (ref)
+    {
+        id reachability = [[self alloc] initWithReachabilityRef:ref];
+
+#if __has_feature(objc_arc)
+        return reachability;
+#else
+        return [reachability autorelease];
+#endif
+
+    }
+
+    return nil;
+}
+
++(Reachability *)reachabilityWithAddress:(const struct sockaddr_in *)hostAddress
+{
+    SCNetworkReachabilityRef ref = SCNetworkReachabilityCreateWithAddress(kCFAllocatorDefault, (const struct sockaddr*)hostAddress);
+    if (ref)
+    {
+        id reachability = [[self alloc] initWithReachabilityRef:ref];
+
+#if __has_feature(objc_arc)
+        return reachability;
+#else
+        return [reachability autorelease];
+#endif
+    }
+
+    return nil;
+}
+
++(Reachability *)reachabilityForInternetConnection
+{
+    struct sockaddr_in zeroAddress;
+    bzero(&zeroAddress, sizeof(zeroAddress));
+    zeroAddress.sin_len = sizeof(zeroAddress);
+    zeroAddress.sin_family = AF_INET;
+
+    return [self reachabilityWithAddress:&zeroAddress];
+}
+
++(Reachability*)reachabilityForLocalWiFi
+{
+    struct sockaddr_in localWifiAddress;
+    bzero(&localWifiAddress, sizeof(localWifiAddress));
+    localWifiAddress.sin_len            = sizeof(localWifiAddress);
+    localWifiAddress.sin_family         = AF_INET;
+    // IN_LINKLOCALNETNUM is defined in <netinet/in.h> as 169.254.0.0
+    localWifiAddress.sin_addr.s_addr    = htonl(IN_LINKLOCALNETNUM);
+
+    return [self reachabilityWithAddress:&localWifiAddress];
+}
+
+
+// Initialization methods
+
+-(Reachability *)initWithReachabilityRef:(SCNetworkReachabilityRef)ref
+{
+    self = [super init];
+    if (self != nil)
+    {
+        self.reachableOnWWAN = YES;
+        self.reachabilityRef = ref;
+    }
+
+    return self;
+}
+
+-(void)dealloc
+{
+    [self stopNotifier];
+
+    if(self.reachabilityRef)
+    {
+        CFRelease(self.reachabilityRef);
+        self.reachabilityRef = nil;
+    }
+
+	self.reachableBlock		= nil;
+	self.unreachableBlock	= nil;
+
+#if !(__has_feature(objc_arc))
+    [super dealloc];
+#endif
+
+
+}
+
+#pragma mark - Notifier Methods
+
+// Notifier
+// NOTE: This uses GCD to trigger the blocks - they *WILL NOT* be called on THE MAIN THREAD
+// - In other words DO NOT DO ANY UI UPDATES IN THE BLOCKS.
+//   INSTEAD USE dispatch_async(dispatch_get_main_queue(), ^{UISTUFF}) (or dispatch_sync if you want)
+
+-(BOOL)startNotifier
+{
+    SCNetworkReachabilityContext    context = { 0, NULL, NULL, NULL, NULL };
+
+    // this should do a retain on ourself, so as long as we're in notifier mode we shouldn't disappear out from under ourselves
+    // woah
+    self.reachabilityObject = self;
+
+
+
+    // First, we need to create a serial queue.
+    // We allocate this once for the lifetime of the notifier.
+    self.reachabilitySerialQueue = dispatch_queue_create("com.tonymillion.reachability", NULL);
+    if(self.reachabilitySerialQueue == nil)
+    {
+        return NO;
+    }
+
+#if __has_feature(objc_arc)
+    context.info = (__bridge void *)self;
+#else
+    context.info = (void *)self;
+#endif
+
+    if (!SCNetworkReachabilitySetCallback(self.reachabilityRef, TMReachabilityCallback, &context))
+    {
+#ifdef DEBUG
+        NSLog(@"SCNetworkReachabilitySetCallback() failed: %s", SCErrorString(SCError()));
+#endif
+
+        // Clear out the dispatch queue
+        if(self.reachabilitySerialQueue)
+        {
+#if NEEDS_DISPATCH_RETAIN_RELEASE
+            dispatch_release(self.reachabilitySerialQueue);
+#endif
+            self.reachabilitySerialQueue = nil;
+        }
+
+        self.reachabilityObject = nil;
+
+        return NO;
+    }
+
+    // Set it as our reachability queue, which will retain the queue
+    if(!SCNetworkReachabilitySetDispatchQueue(self.reachabilityRef, self.reachabilitySerialQueue))
+    {
+#ifdef DEBUG
+        NSLog(@"SCNetworkReachabilitySetDispatchQueue() failed: %s", SCErrorString(SCError()));
+#endif
+
+        // UH OH - FAILURE!
+
+        // First stop, any callbacks!
+        SCNetworkReachabilitySetCallback(self.reachabilityRef, NULL, NULL);
+
+        // Then clear out the dispatch queue.
+        if(self.reachabilitySerialQueue)
+        {
+#if NEEDS_DISPATCH_RETAIN_RELEASE
+            dispatch_release(self.reachabilitySerialQueue);
+#endif
+            self.reachabilitySerialQueue = nil;
+        }
+
+        self.reachabilityObject = nil;
+
+        return NO;
+    }
+
+    return YES;
+}
+
+-(void)stopNotifier
+{
+    // First stop, any callbacks!
+    SCNetworkReachabilitySetCallback(self.reachabilityRef, NULL, NULL);
+
+    // Unregister target from the GCD serial dispatch queue.
+    SCNetworkReachabilitySetDispatchQueue(self.reachabilityRef, NULL);
+
+    if(self.reachabilitySerialQueue)
+    {
+#if NEEDS_DISPATCH_RETAIN_RELEASE
+        dispatch_release(self.reachabilitySerialQueue);
+#endif
+        self.reachabilitySerialQueue = nil;
+    }
+
+    self.reachabilityObject = nil;
+}
+
+#pragma mark - reachability tests
+
+// This is for the case where you flick the airplane mode;
+// you end up getting something like this:
+//Reachability: WR ct-----
+//Reachability: -- -------
+//Reachability: WR ct-----
+//Reachability: -- -------
+// We treat this as 4 UNREACHABLE triggers - really apple should do better than this
+
+#define testcase (kSCNetworkReachabilityFlagsConnectionRequired | kSCNetworkReachabilityFlagsTransientConnection)
+
+-(BOOL)isReachableWithFlags:(SCNetworkReachabilityFlags)flags
+{
+    BOOL connectionUP = YES;
+
+    if(!(flags & kSCNetworkReachabilityFlagsReachable))
+        connectionUP = NO;
+
+    if( (flags & testcase) == testcase )
+        connectionUP = NO;
+
+#if	TARGET_OS_IPHONE
+    if(flags & kSCNetworkReachabilityFlagsIsWWAN)
+    {
+        // We're on 3G.
+        if(!self.reachableOnWWAN)
+        {
+            // We don't want to connect when on 3G.
+            connectionUP = NO;
+        }
+    }
+#endif
+
+    return connectionUP;
+}
+
+-(BOOL)isReachable
+{
+    SCNetworkReachabilityFlags flags;
+
+    if(!SCNetworkReachabilityGetFlags(self.reachabilityRef, &flags))
+        return NO;
+
+    return [self isReachableWithFlags:flags];
+}
+
+-(BOOL)isReachableViaWWAN
+{
+#if	TARGET_OS_IPHONE
+
+    SCNetworkReachabilityFlags flags = 0;
+
+    if(SCNetworkReachabilityGetFlags(reachabilityRef, &flags))
+    {
+        // Check we're REACHABLE
+        if(flags & kSCNetworkReachabilityFlagsReachable)
+        {
+            // Now, check we're on WWAN
+            if(flags & kSCNetworkReachabilityFlagsIsWWAN)
+            {
+                return YES;
+            }
+        }
+    }
+#endif
+
+    return NO;
+}
+
+-(BOOL)isReachableViaWiFi
+{
+    SCNetworkReachabilityFlags flags = 0;
+
+    if(SCNetworkReachabilityGetFlags(reachabilityRef, &flags))
+    {
+        // Check we're reachable
+        if((flags & kSCNetworkReachabilityFlagsReachable))
+        {
+#if	TARGET_OS_IPHONE
+            // Check we're NOT on WWAN
+            if((flags & kSCNetworkReachabilityFlagsIsWWAN))
+            {
+                return NO;
+            }
+#endif
+            return YES;
+        }
+    }
+
+    return NO;
+}
+
+
+// WWAN may be available, but not active until a connection has been established.
+// WiFi may require a connection for VPN on Demand.
+-(BOOL)isConnectionRequired
+{
+    return [self connectionRequired];
+}
+
+-(BOOL)connectionRequired
+{
+    SCNetworkReachabilityFlags flags;
+
+	if(SCNetworkReachabilityGetFlags(reachabilityRef, &flags))
+    {
+		return (flags & kSCNetworkReachabilityFlagsConnectionRequired);
+	}
+
+    return NO;
+}
+
+// Dynamic, on demand connection?
+-(BOOL)isConnectionOnDemand
+{
+	SCNetworkReachabilityFlags flags;
+
+	if (SCNetworkReachabilityGetFlags(reachabilityRef, &flags))
+    {
+		return ((flags & kSCNetworkReachabilityFlagsConnectionRequired) &&
+				(flags & (kSCNetworkReachabilityFlagsConnectionOnTraffic | kSCNetworkReachabilityFlagsConnectionOnDemand)));
+	}
+
+	return NO;
+}
+
+// Is user intervention required?
+-(BOOL)isInterventionRequired
+{
+    SCNetworkReachabilityFlags flags;
+
+	if (SCNetworkReachabilityGetFlags(reachabilityRef, &flags))
+    {
+		return ((flags & kSCNetworkReachabilityFlagsConnectionRequired) &&
+				(flags & kSCNetworkReachabilityFlagsInterventionRequired));
+	}
+
+	return NO;
+}
+
+
+#pragma mark - reachability status stuff
+
+-(NetworkStatus)currentReachabilityStatus
+{
+    if([self isReachable])
+    {
+        if([self isReachableViaWiFi])
+            return ReachableViaWiFi;
+
+#if	TARGET_OS_IPHONE
+        return ReachableViaWWAN;
+#endif
+    }
+
+    return NotReachable;
+}
+
+-(SCNetworkReachabilityFlags)reachabilityFlags
+{
+    SCNetworkReachabilityFlags flags = 0;
+
+    if(SCNetworkReachabilityGetFlags(reachabilityRef, &flags))
+    {
+        return flags;
+    }
+
+    return 0;
+}
+
+-(NSString*)currentReachabilityString
+{
+	NetworkStatus temp = [self currentReachabilityStatus];
+
+	if(temp == reachableOnWWAN)
+	{
+        // Updated for the fact that we have CDMA phones now!
+		return NSLocalizedString(@"Cellular", @"");
+	}
+	if (temp == ReachableViaWiFi)
+	{
+		return NSLocalizedString(@"WiFi", @"");
+	}
+
+	return NSLocalizedString(@"No Connection", @"");
+}
+
+-(NSString*)currentReachabilityFlags
+{
+    return reachabilityFlags([self reachabilityFlags]);
+}
+
+#pragma mark - Callback function calls this method
+
+-(void)reachabilityChanged:(SCNetworkReachabilityFlags)flags
+{
+    if([self isReachableWithFlags:flags])
+    {
+        if(self.reachableBlock)
+        {
+            self.reachableBlock(self);
+        }
+    }
+    else
+    {
+        if(self.unreachableBlock)
+        {
+            self.unreachableBlock(self);
+        }
+    }
+
+    // this makes sure the change notification happens on the MAIN THREAD
+    dispatch_async(dispatch_get_main_queue(), ^{
+        [[NSNotificationCenter defaultCenter] postNotificationName:kReachabilityChangedNotification
+                                                            object:self];
+    });
+}
+
+#pragma mark - Debug Description
+
+- (NSString *) description
+{
+    NSString *description = [NSString stringWithFormat:@"<%@: %#x>",
+                             NSStringFromClass([self class]), (unsigned int) self];
+    return description;
+}
+
+@end
diff --git a/common/foundation_request.h b/common/foundation_request.h
deleted file mode 100644
index 0b8c4b8fb0..0000000000
--- a/common/foundation_request.h
+++ /dev/null
@@ -1 +0,0 @@
-#import <Foundation/Foundation.h>
diff --git a/common/foundation_request.mm b/common/foundation_request.mm
deleted file mode 100644
index b7eafdb96c..0000000000
--- a/common/foundation_request.mm
+++ /dev/null
@@ -1,115 +0,0 @@
-#import "foundation_request.h"
-
-#include "TargetConditionals.h"
-#if TARGET_OS_IPHONE
-#import <UIKit/UIKit.h>
-#include <atomic>
-#endif
-
-#include <memory>
-#include <string>
-#include <functional>
-#include <mbgl/platform/request.hpp>
-#include <mbgl/platform/platform.hpp>
-#include <mbgl/util/std.hpp>
-#include <mbgl/util/uv.hpp>
-
-dispatch_once_t request_initialize = 0;
-NSURLSession *session = nullptr;
-
-#if TARGET_OS_IPHONE
-std::atomic<int> active_tasks;
-#endif
-
-
-// We're using a child class to make sure ARC is working correctly, as well as to add activity
-// indicators on iOS.
-class FoundationRequest : public mbgl::platform::Request {
-public:
-    FoundationRequest(const std::string &url,
-                      std::function<void(mbgl::platform::Response *)> callback,
-                      std::shared_ptr<uv::loop> loop)
-        : Request(url, callback, loop) {
-#if TARGET_OS_IPHONE
-        active_tasks++;
-        dispatch_async(dispatch_get_main_queue(), ^(void) {
-            [[UIApplication sharedApplication]
-                setNetworkActivityIndicatorVisible:(active_tasks > 0)];
-        });
-#endif
-    }
-
-    ~FoundationRequest() {
-#if TARGET_OS_IPHONE
-        active_tasks--;
-        dispatch_async(dispatch_get_main_queue(), ^(void) {
-            [[UIApplication sharedApplication]
-                setNetworkActivityIndicatorVisible:(active_tasks > 0)];
-        });
-#endif
-    }
-
-    NSURLSessionDataTask *task = nullptr;
-};
-
-std::shared_ptr<mbgl::platform::Request>
-mbgl::platform::request_http(const std::string &url,
-                             std::function<void(Response *)> callback,
-                             std::shared_ptr<uv::loop> loop) {
-    dispatch_once(&request_initialize, ^{
-        NSURLSessionConfiguration *sessionConfig =
-            [NSURLSessionConfiguration defaultSessionConfiguration];
-        sessionConfig.timeoutIntervalForResource = 30;
-        sessionConfig.HTTPMaximumConnectionsPerHost = 8;
-        sessionConfig.requestCachePolicy = NSURLRequestUseProtocolCachePolicy;
-
-        session = [NSURLSession sessionWithConfiguration:sessionConfig];
-
-#if TARGET_OS_IPHONE
-        active_tasks = 0;
-#endif
-    });
-
-    std::shared_ptr<FoundationRequest> req =
-        std::make_shared<FoundationRequest>(url, callback, loop);
-
-    // Note that we are creating a new shared_ptr pointer(!) to make sure there is at least one
-    // shared_ptr in existence while the NSURLSession is loading our data. We are making sure in the
-    // callback that this pointer gets destroyed again.
-    std::shared_ptr<Request> *req_ptr = new std::shared_ptr<Request>(req);
-
-    NSURLSessionDataTask *task = [session
-                                  dataTaskWithURL:[NSURL URLWithString:@(url.c_str())]
-                                  completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
-        if ([error code] == NSURLErrorCancelled) {
-            // We intentionally cancelled this request. Make sure we clear the shared_ptr to resolve
-            // the circular reference. We're referencing this shared_ptr by value so that the object
-            // stays around until this completion handler is invoked.
-            delete req_ptr;
-
-            return;
-        }
-
-        if (!error && [response isKindOfClass:[NSHTTPURLResponse class]]) {
-            (*req_ptr)->res->code = [(NSHTTPURLResponse *)response statusCode];
-            (*req_ptr)->res->body = {(const char *)[data bytes], [data length]};
-        } else {
-            (*req_ptr)->res->error_message = [[error localizedDescription] UTF8String];
-        }
-
-        (*req_ptr)->complete();
-
-        delete req_ptr;
-    }];
-
-    req->task = task;
-
-    [task resume];
-    return req;
-}
-
-void mbgl::platform::cancel_request_http(const std::shared_ptr<Request> &req) {
-    if (req) {
-        [((FoundationRequest *)(req.get()))->task cancel];
-    }
-}
diff --git a/common/glfw_view.cpp b/common/glfw_view.cpp
index 0908786bb6..120faf4df1 100644
--- a/common/glfw_view.cpp
+++ b/common/glfw_view.cpp
@@ -186,7 +186,9 @@ int GLFWView::run() {
         glfwWaitEvents();
     }
 
-    map->stop();
+    map->stop([](void *) {
+        glfwWaitEvents();
+    });
 
     return 0;
 }
@@ -199,6 +201,10 @@ void GLFWView::make_inactive() {
     glfwMakeContextCurrent(nullptr);
 }
 
+void GLFWView::notify() {
+    glfwPostEmptyEvent();
+}
+
 void GLFWView::swap() {
     glfwPostEmptyEvent();
 
diff --git a/common/glfw_view.hpp b/common/glfw_view.hpp
index 04085f7750..6e91c1125e 100644
--- a/common/glfw_view.hpp
+++ b/common/glfw_view.hpp
@@ -18,6 +18,7 @@ public:
     void swap();
     void make_active();
     void make_inactive();
+    void notify();
     void notify_map_change(mbgl::MapChange change, mbgl::timestamp delay = 0);
 
     static void key(GLFWwindow *window, int key, int scancode, int action, int mods);
diff --git a/common/headless_view.cpp b/common/headless_view.cpp
index 3f945ee6aa..c2084ac90d 100644
--- a/common/headless_view.cpp
+++ b/common/headless_view.cpp
@@ -161,6 +161,10 @@ HeadlessView::~HeadlessView() {
 #endif
 }
 
+void HeadlessView::notify() {
+    // no-op
+}
+
 void HeadlessView::notify_map_change(mbgl::MapChange /*change*/, mbgl::timestamp /*delay*/) {
     // no-op
 }
diff --git a/common/headless_view.hpp b/common/headless_view.hpp
index 600e9d51fa..d2fe75382a 100644
--- a/common/headless_view.hpp
+++ b/common/headless_view.hpp
@@ -28,6 +28,7 @@ public:
     void resize(uint16_t width, uint16_t height, float pixelRatio);
     const std::unique_ptr<uint32_t[]> readPixels();
 
+    void notify();
     void notify_map_change(MapChange change, timestamp delay = 0);
     void make_active();
     void make_inactive();
diff --git a/common/http_request_baton_cocoa.mm b/common/http_request_baton_cocoa.mm
new file mode 100644
index 0000000000..a9992fad8c
--- /dev/null
+++ b/common/http_request_baton_cocoa.mm
@@ -0,0 +1,149 @@
+#include <mbgl/storage/http_request_baton.hpp>
+#include <mbgl/util/std.hpp>
+#include <mbgl/util/parsedate.h>
+
+#include <uv.h>
+
+#include <mbgl/util/uv.hpp>
+
+#import <Foundation/Foundation.h>
+#include <ctime>
+#include <xlocale.h>
+
+namespace mbgl {
+
+dispatch_once_t request_initialize = 0;
+NSURLSession *session = nullptr;
+
+void HTTPRequestBaton::start(const util::ptr<HTTPRequestBaton> &ptr) {
+    assert(uv_thread_self() == ptr->thread_id);
+
+    // Starts the request.
+    util::ptr<HTTPRequestBaton> baton = ptr;
+
+    // Create a C locale
+    static locale_t locale = newlocale(LC_ALL_MASK, nullptr, nullptr);
+
+    dispatch_once(&request_initialize, ^{
+        NSURLSessionConfiguration *sessionConfig = [NSURLSessionConfiguration defaultSessionConfiguration];
+        sessionConfig.timeoutIntervalForResource = 30;
+        sessionConfig.HTTPMaximumConnectionsPerHost = 8;
+        sessionConfig.requestCachePolicy = NSURLRequestReloadIgnoringLocalCacheData;
+        sessionConfig.URLCache = nil;
+
+        session = [NSURLSession sessionWithConfiguration:sessionConfig];
+    });
+
+    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:[NSURL URLWithString:@(baton->path.c_str())]];
+    if (baton->response) {
+        if (!baton->response->etag.empty()) {
+            [request addValue:@(baton->response->etag.c_str()) forHTTPHeaderField:@"If-None-Match"];
+        } else if (baton->response->modified) {
+            const time_t modified = baton->response->modified;
+            struct tm *timeinfo = std::gmtime(&modified);
+            char buffer[32];
+            strftime_l(buffer, 32, "%a, %d %b %Y %H:%M:%S GMT", timeinfo, locale);
+            [request addValue:@(buffer) forHTTPHeaderField:@"If-Modified-Since"];
+        }
+    }
+
+    NSURLSessionDataTask *task = [session dataTaskWithRequest:request
+                                            completionHandler:^(NSData *data, NSURLResponse *res, NSError *error) {
+        if (error) {
+            if ([error code] == NSURLErrorCancelled) {
+                // The response code remains at 0 to indicate cancelation.
+                // In addition, we don't need any response object.
+                baton->response.reset();
+                baton->type = HTTPResponseType::Canceled;
+            } else {
+                // TODO: Use different codes for host not found, timeout, invalid URL etc.
+                // These can be categorized in temporary and permanent errors.
+                baton->response = std::make_unique<Response>();
+                baton->response->code = [(NSHTTPURLResponse *)res statusCode];
+                baton->response->message = [[error localizedDescription] UTF8String];
+
+                switch ([error code]) {
+                    case NSURLErrorBadServerResponse: // 5xx errors
+                        baton->type = HTTPResponseType::TemporaryError;
+                        break;
+
+                    case NSURLErrorTimedOut:
+                    case NSURLErrorUserCancelledAuthentication:
+                        baton->type = HTTPResponseType::SingularError; // retry immediately
+                        break;
+
+                    case NSURLErrorNetworkConnectionLost:
+                    case NSURLErrorCannotFindHost:
+                    case NSURLErrorCannotConnectToHost:
+                    case NSURLErrorDNSLookupFailed:
+                    case NSURLErrorNotConnectedToInternet:
+                    case NSURLErrorInternationalRoamingOff:
+                    case NSURLErrorCallIsActive:
+                    case NSURLErrorDataNotAllowed:
+                        baton->type = HTTPResponseType::ConnectionError;
+                        break;
+
+                    default:
+                        baton->type = HTTPResponseType::PermanentError;
+                }
+            }
+        } else if ([res isKindOfClass:[NSHTTPURLResponse class]]) {
+            const long code = [(NSHTTPURLResponse *)res statusCode];
+            if (code == 304) {
+                // Assume a Response object already exists.
+                assert(baton->response);
+            } else {
+                baton->response = std::make_unique<Response>();
+                baton->response->code = code;
+                baton->response->data = {(const char *)[data bytes], [data length]};
+            }
+
+            if (code == 304) {
+                baton->type = HTTPResponseType::NotModified;
+            } else if (code == 200) {
+                baton->type = HTTPResponseType::Successful;
+            } else {
+                baton->type = HTTPResponseType::PermanentError;
+            }
+
+            NSDictionary *headers = [(NSHTTPURLResponse *)res allHeaderFields];
+            NSString *cache_control = [headers objectForKey:@"Cache-Control"];
+            if (cache_control) {
+                baton->response->expires = Response::parseCacheControl([cache_control UTF8String]);
+            }
+
+            NSString *last_modified = [headers objectForKey:@"Last-Modified"];
+            if (last_modified) {
+                baton->response->modified = parse_date([last_modified UTF8String]);
+            }
+
+            NSString *etag = [headers objectForKey:@"ETag"];
+            if (etag) {
+                baton->response->etag = [etag UTF8String];
+            }
+        } else {
+            // This should never happen.
+            baton->type = HTTPResponseType::PermanentError;
+            baton->response = std::make_unique<Response>();
+            baton->response->code = -1;
+            baton->response->message = "response class is not NSHTTPURLResponse";
+        }
+
+        uv_async_send(baton->async);
+    }];
+
+    [task resume];
+
+    baton->ptr = const_cast<void *>(CFBridgingRetain(task));
+}
+
+void HTTPRequestBaton::stop(const util::ptr<HTTPRequestBaton> &ptr) {
+    assert(uv_thread_self() == ptr->thread_id);
+    assert(ptr->ptr);
+
+    NSURLSessionDataTask *task = CFBridgingRelease(ptr->ptr);
+    ptr->ptr = nullptr;
+    [task cancel];
+}
+
+}
diff --git a/common/http_request_baton_curl.cpp b/common/http_request_baton_curl.cpp
new file mode 100644
index 0000000000..772aeb86e1
--- /dev/null
+++ b/common/http_request_baton_curl.cpp
@@ -0,0 +1,465 @@
+#include <mbgl/storage/http_request_baton.hpp>
+#include <mbgl/util/uv-messenger.h>
+#include <mbgl/util/std.hpp>
+#include <mbgl/util/ptr.hpp>
+
+#include <uv.h>
+#include <curl/curl.h>
+
+#include <queue>
+#include <cassert>
+#include <cstring>
+#include <ctime>
+#include <xlocale.h>
+
+// This file contains code from http://curl.haxx.se/libcurl/c/multi-uv.html:
+
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2013, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+/* Example application code using the multi socket interface to download
+   multiple files at once, but instead of using curl_multi_perform and
+   curl_multi_wait, which uses select(), we use libuv.
+   It supports epoll, kqueue, etc. on unixes and fast IO completion ports on
+   Windows, which means, it should be very fast on all platforms..
+
+   Written by Clemens Gruber, based on an outdated example from uvbook and
+   some tests from libuv.
+
+   Requires libuv and (of course) libcurl.
+
+   See http://nikhilm.github.com/uvbook/ for more information on libuv.
+*/
+
+// Handles the request thread + messaging to the thread.
+static uv_once_t once;
+static uv_loop_t loop;
+static uv_messenger_t start_messenger;
+static uv_messenger_t stop_messenger;
+static uv_thread_t thread;
+static unsigned long thread_id;
+
+// Used as the CURL timer function to periodically check for socket updates.
+static uv_timer_t timeout;
+
+// CURL multi handle that we use to request multiple URLs at the same time, without having to block
+// and spawn threads.
+static CURLM *multi = nullptr;
+
+// CURL share handles are used for sharing session state (e.g.)
+static uv_mutex_t share_mutex;
+static CURLSH *share = nullptr;
+
+// A queue that we use for storing resuable CURL easy handles to avoid creating and destroying them
+// all the time.
+static std::queue<CURL *> handles;
+
+namespace mbgl {
+
+struct CURLContext {
+    util::ptr<HTTPRequestBaton> baton;
+    uv_poll_t *poll_handle = nullptr;
+    curl_socket_t sockfd = 0;
+    curl_slist *headers = nullptr;
+
+    CURLContext(const util::ptr<HTTPRequestBaton> &baton_) : baton(baton_) {
+    }
+
+    ~CURLContext() {
+        // We are destructing the poll handle in a CURL callback already.
+        assert(!poll_handle);
+
+        // Once the CURLContext gets destroyed, CURL doesn't need any headers anymore.
+        if (headers) {
+            curl_slist_free_all(headers);
+            headers = nullptr;
+        }
+    }
+};
+
+// Locks the CURL share handle
+void curl_share_lock(CURL *, curl_lock_data, curl_lock_access, void *) {
+    uv_mutex_lock(&share_mutex);
+}
+
+// Unlocks the CURL share handle
+void curl_share_unlock(CURL *, curl_lock_data, void *) {
+    uv_mutex_unlock(&share_mutex);
+}
+
+// This function must run in the CURL thread.
+// It is either called when the request is completed, or when we try to cancel the request.
+void finish_request(const util::ptr<HTTPRequestBaton> &baton) {
+    assert(uv_thread_self() == thread_id);
+    if (baton->ptr) {
+        CURL *handle = (CURL *)baton->ptr;
+        CURLMcode error = curl_multi_remove_handle(multi, handle);
+        if (error != CURLM_OK) {
+            baton->response = std::make_unique<Response>();
+            baton->response->code = -1;
+            baton->response->message = curl_multi_strerror(error);
+        }
+
+        // Destroy the shared pointer. We still have one pointing to it
+        CURLContext *context = nullptr;
+        curl_easy_getinfo(handle, CURLINFO_PRIVATE, (char *)&context);
+        curl_easy_setopt(handle, CURLOPT_PRIVATE, nullptr);
+        delete context;
+
+        // TODO: delete the headers object again.
+
+        curl_easy_reset(handle);
+        handles.push(handle);
+        baton->ptr = nullptr;
+    }
+}
+
+void curl_perform(uv_poll_t *req, int, int events) {
+    int running_handles;
+    int flags = 0;
+    CURLContext *context = (CURLContext *)req->data;
+    CURLMsg *message;
+    int pending;
+
+    uv_timer_stop(&timeout);
+
+    if (events & UV_READABLE) {
+        flags |= CURL_CSELECT_IN;
+    }
+    if (events & UV_WRITABLE) {
+        flags |= CURL_CSELECT_OUT;
+    }
+
+    curl_multi_socket_action(multi, context->sockfd, flags, &running_handles);
+
+    while ((message = curl_multi_info_read(multi, &pending))) {
+        switch (message->msg) {
+        case CURLMSG_DONE: {
+            CURLContext *context = nullptr;
+            curl_easy_getinfo(message->easy_handle, CURLINFO_PRIVATE, (char *)&context);
+
+            // Make a copy so that the Baton stays around even after we are calling finish_request
+            util::ptr<HTTPRequestBaton> baton = context->baton;
+
+            // Add human-readable error code
+            if (message->data.result != CURLE_OK) {
+                baton->response->message = curl_easy_strerror(message->data.result);
+                baton->response->code = -1;
+
+                switch (message->data.result) {
+                    case CURLE_COULDNT_RESOLVE_PROXY:
+                    case CURLE_COULDNT_RESOLVE_HOST:
+                    case CURLE_COULDNT_CONNECT:
+                        baton->type = HTTPResponseType::ConnectionError;
+                        break;
+
+                    case CURLE_OPERATION_TIMEDOUT:
+                        baton->type = HTTPResponseType::TemporaryError;
+                        break;
+
+                    default:
+                        baton->type = HTTPResponseType::PermanentError;
+                }
+            } else {
+                long code = 0;
+                curl_easy_getinfo(message->easy_handle, CURLINFO_RESPONSE_CODE, &code);
+
+                if (code != 304) {
+                    baton->response->code = code;
+                }
+
+                if (code == 304) {
+                    baton->type = HTTPResponseType::NotModified;
+                } else if (code == 200) {
+                    baton->type = HTTPResponseType::Successful;
+                } else if (code >= 500 && code < 600) {
+                    baton->type = HTTPResponseType::TemporaryError;
+                } else if (code >= 400 && code < 500) {
+                    baton->type = HTTPResponseType::PermanentError;
+                } else {
+                    assert(!"code must be either 200 or 304");
+                }
+            }
+
+            // We're currently in the CURL request thread.
+            finish_request(baton);
+
+            if (baton->async) {
+                uv_async_send(baton->async);
+                baton->async = nullptr;
+            }
+
+            break;
+        }
+
+        default:
+            // This should never happen, because there are no other message types.
+            throw std::runtime_error("CURLMSG returned unknown message type");
+        }
+    }
+}
+
+int handle_socket(CURL *handle, curl_socket_t sockfd, int action, void *, void *socketp) {
+    CURLContext *context = nullptr;
+    curl_easy_getinfo(handle, CURLINFO_PRIVATE, (char *)&context);
+
+    if (!socketp && action != CURL_POLL_REMOVE) {
+        // We haven't initialized the socket yet, so we need to do this now.
+        assert(context->sockfd == 0);
+        context->sockfd = sockfd;
+        assert(!context->poll_handle);
+        context->poll_handle = new uv_poll_t;
+        uv_poll_init_socket(&loop, context->poll_handle, sockfd);
+        context->poll_handle->data = context;
+        curl_multi_assign(multi, sockfd, context);
+    }
+
+    if (context) {
+        if (action == CURL_POLL_IN || action == CURL_POLL_INOUT) {
+            uv_poll_start(context->poll_handle, UV_READABLE, curl_perform);
+        }
+        if (action == CURL_POLL_OUT || action == CURL_POLL_INOUT) {
+            uv_poll_start(context->poll_handle, UV_WRITABLE, curl_perform);
+        }
+        if (action == CURL_POLL_REMOVE && socketp) {
+            uv_poll_stop(context->poll_handle);
+            uv_close((uv_handle_t *)context->poll_handle, [](uv_handle_t *handle) {
+                delete (uv_poll_t *)handle;
+            });
+            context->poll_handle = nullptr;
+            curl_multi_assign(multi, sockfd, NULL);
+        }
+    }
+
+    return 0;
+}
+
+void on_timeout(uv_timer_t *) {
+    int running_handles;
+    CURLMcode error = curl_multi_socket_action(multi, CURL_SOCKET_TIMEOUT, 0, &running_handles);
+    if (error != CURLM_OK) {
+        throw std::runtime_error(std::string("CURL multi error: ") + curl_multi_strerror(error));
+    }
+}
+
+void start_timeout(CURLM *, long timeout_ms, void *) {
+    if (timeout_ms <= 0) {
+        on_timeout(&timeout);
+    } else {
+        uv_timer_start(&timeout, on_timeout, timeout_ms, 0);
+    }
+}
+
+void thread_init(void *) {
+#ifdef __APPLE__
+    pthread_setname_np("CURL");
+#endif
+    thread_id = uv_thread_self();
+
+    uv_timer_init(&loop, &timeout);
+
+    CURLSHcode share_error;
+    share = curl_share_init();
+
+    share_error = curl_share_setopt(share, CURLSHOPT_LOCKFUNC, curl_share_lock);
+    if (share_error != CURLSHE_OK) {
+        throw std::runtime_error(std::string("CURL share error: ") + curl_share_strerror(share_error));
+    }
+
+    share_error = curl_share_setopt(share, CURLSHOPT_UNLOCKFUNC, curl_share_unlock);
+    if (share_error != CURLSHE_OK) {
+        throw std::runtime_error(std::string("CURL share error: ") + curl_share_strerror(share_error));
+    }
+
+
+    CURLMcode multi_error;
+    multi = curl_multi_init();
+
+    multi_error = curl_multi_setopt(multi, CURLMOPT_SOCKETFUNCTION, handle_socket);
+    if (multi_error != CURLM_OK) {
+        throw std::runtime_error(std::string("CURL multi error: ") + curl_multi_strerror(multi_error));
+    }
+    multi_error = curl_multi_setopt(multi, CURLMOPT_TIMERFUNCTION, start_timeout);
+    if (multi_error != CURLM_OK) {
+        throw std::runtime_error(std::string("CURL multi error: ") + curl_multi_strerror(multi_error));
+
+    }
+
+    // Main event loop. This will not return until the request loop is terminated.
+    uv_run(&loop, UV_RUN_DEFAULT);
+
+    curl_multi_cleanup(multi);
+    multi = nullptr;
+
+    curl_share_cleanup(share);
+    share = nullptr;
+
+    thread_id = -1;
+}
+
+// This function is called when we have new data for a request. We just append it to the string
+// containing the previous data.
+size_t curl_write_cb(void *const contents, const size_t size, const size_t nmemb, void *const userp) {
+    ((std::string *)userp)->append((char *)contents, size * nmemb);
+    return size * nmemb;
+}
+
+// Compares the beginning of the (non-zero-terminated!) data buffer with the (zero-terminated!)
+// header string. If the data buffer contains the header string at the beginning, it returns
+// the length of the header string == begin of the value, otherwise it returns npos.
+// The comparison of the header is ASCII-case-insensitive.
+size_t header_matches(const char *const header, const char *const buffer, const size_t length) {
+    const size_t header_length = strlen(header);
+    if (length < header_length) return std::string::npos;
+    size_t i = 0;
+    while (i < length && i < header_length && std::tolower(buffer[i]) == header[i]) {
+        i++;
+    }
+    return i == header_length ? i : std::string::npos;
+}
+
+size_t curl_header_cb(char * const buffer, const size_t size, const size_t nmemb, void *const userp) {
+    const size_t length = size * nmemb;
+
+    Response *response = static_cast<Response *>(userp);
+
+    size_t begin = std::string::npos;
+    if ((begin = header_matches("last-modified: ", buffer, length)) != std::string::npos) {
+        // Always overwrite the modification date; We might already have a value here from the
+        // Date header, but this one is more accurate.
+        const std::string value { buffer + begin, length - begin - 2 }; // remove \r\n
+        response->modified = curl_getdate(value.c_str(), nullptr);
+    } else if ((begin = header_matches("etag: ", buffer, length)) != std::string::npos) {
+        response->etag = { buffer + begin, length - begin - 2 }; // remove \r\n
+    } else if ((begin = header_matches("cache-control: ", buffer, length)) != std::string::npos) {
+        const std::string value { buffer + begin, length - begin - 2 }; // remove \r\n
+        response->expires = Response::parseCacheControl(value.c_str());
+    }
+
+    return length;
+}
+
+// This function must run in the CURL thread.
+void start_request(void *const ptr) {
+    assert(uv_thread_self() == thread_id);
+    std::unique_ptr<util::ptr<HTTPRequestBaton>> baton_guard { (util::ptr<HTTPRequestBaton> *)ptr };
+    util::ptr<HTTPRequestBaton> &baton = *baton_guard.get();
+    assert(baton);
+
+    // Create a C locale
+    static locale_t locale = newlocale(LC_ALL_MASK, nullptr, nullptr);
+
+    CURL *handle = nullptr;
+    if (!handles.empty()) {
+        handle = handles.front();
+        handles.pop();
+    } else {
+        handle = curl_easy_init();
+    }
+
+    baton->ptr = handle;
+
+    // Wrap this in a unique_ptr for now so that it destructs until we assign it the the CURL handle.
+    std::unique_ptr<CURLContext> context = std::make_unique<CURLContext>(baton);
+
+    if (baton->response) {
+        if (!baton->response->etag.empty()) {
+            const std::string header = std::string("If-None-Match: ") + baton->response->etag;
+            context->headers = curl_slist_append(context->headers, header.c_str());
+        } else if (baton->response->modified) {
+            const time_t modified = baton->response->modified;
+            struct tm *timeinfo = std::gmtime(&modified);
+            char buffer[64];
+            strftime_l(buffer, 64, "If-Modified-Since: %a, %d %b %Y %H:%M:%S GMT", timeinfo, locale);
+            context->headers = curl_slist_append(context->headers, buffer);
+        }
+    }
+
+    if (context->headers) {
+        curl_easy_setopt(handle, CURLOPT_HTTPHEADER, context->headers);
+    }
+
+    if (!baton->response) {
+        baton->response = std::make_unique<Response>();
+    }
+
+    // Carry on the shared pointer in the private information of the CURL handle.
+    curl_easy_setopt(handle, CURLOPT_PRIVATE, context.release());
+    curl_easy_setopt(handle, CURLOPT_CAINFO, "ca-bundle.crt");
+    curl_easy_setopt(handle, CURLOPT_URL, baton->path.c_str());
+    curl_easy_setopt(handle, CURLOPT_WRITEFUNCTION, curl_write_cb);
+    curl_easy_setopt(handle, CURLOPT_WRITEDATA, &baton->response->data);
+    curl_easy_setopt(handle, CURLOPT_HEADERFUNCTION, curl_header_cb);
+    curl_easy_setopt(handle, CURLOPT_HEADERDATA, baton->response.get());
+    curl_easy_setopt(handle, CURLOPT_ACCEPT_ENCODING, "gzip, deflate");
+    curl_easy_setopt(handle, CURLOPT_SHARE, share);
+
+    // Start requesting the information.
+    curl_multi_add_handle(multi, handle);
+}
+
+// This function must run in the CURL thread.
+void stop_request(void *const ptr) {
+    assert(uv_thread_self() == thread_id);
+    std::unique_ptr<util::ptr<HTTPRequestBaton>> baton_guard { (util::ptr<HTTPRequestBaton> *)ptr };
+    util::ptr<HTTPRequestBaton> &baton = *baton_guard.get();
+    assert(baton);
+
+    if (baton->async) {
+        baton->type = HTTPResponseType::Canceled;
+
+        // We can still stop the request because it is still in progress.
+        finish_request(baton);
+
+        uv_async_send(baton->async);
+        baton->async = nullptr;
+    } else {
+        // If the async handle is gone, it means that the actual request has been completed before
+        // we got a chance to cancel it. In this case, this is a no-op. It is likely that
+        // the pointer below is the last lifeline of the HTTPRequestBaton. This means we're going
+        // to delete the HTTPRequestBaton in the current (CURL) thread.
+    }
+}
+
+void create_thread() {
+    uv_mutex_init(&share_mutex);
+    uv_loop_init(&loop);
+    uv_messenger_init(&loop, &start_messenger, start_request);
+    uv_messenger_init(&loop, &stop_messenger, stop_request);
+    uv_thread_create(&thread, thread_init, nullptr);
+}
+
+// This function must be run from the main thread (== where the HTTPRequestBaton was created)
+void HTTPRequestBaton::start(const util::ptr<HTTPRequestBaton> &ptr) {
+    assert(uv_thread_self() == ptr->thread_id);
+    uv_once(&once, create_thread);
+    uv_messenger_send(&start_messenger, new util::ptr<HTTPRequestBaton>(ptr));
+}
+
+// This function must be run from the main thread (== where the HTTPRequestBaton was created)
+void HTTPRequestBaton::stop(const util::ptr<HTTPRequestBaton> &ptr) {
+    assert(uv_thread_self() == ptr->thread_id);
+    uv_once(&once, create_thread);
+    uv_messenger_send(&stop_messenger, new util::ptr<HTTPRequestBaton>(ptr));
+}
+
+}
diff --git a/common/ios.mm b/common/ios.mm
new file mode 100644
index 0000000000..7989e73a4e
--- /dev/null
+++ b/common/ios.mm
@@ -0,0 +1,21 @@
+#import <Foundation/Foundation.h>
+
+#include <mbgl/platform/platform.hpp>
+
+namespace mbgl {
+namespace platform {
+
+// Returns the path to the default cache database on this system.
+std::string defaultCacheDatabase() {
+    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES);
+    if ([paths count] == 0) {
+        // Disable the cache if we don't have a location to write.
+        return "";
+    }
+
+    NSString *libraryDirectory = [paths objectAtIndex:0];
+    return [[libraryDirectory stringByAppendingPathComponent:@"cache.db"] UTF8String];
+}
+
+}
+}
diff --git a/common/linux.cpp b/common/linux.cpp
new file mode 100644
index 0000000000..6132ace692
--- /dev/null
+++ b/common/linux.cpp
@@ -0,0 +1,12 @@
+#include <mbgl/platform/platform.hpp>
+
+namespace mbgl {
+namespace platform {
+
+// Returns the path to the default cache database on this system.
+std::string defaultCacheDatabase() {
+    return "/tmp/mbgl-cache.db";
+}
+
+}
+}
diff --git a/common/osx.mm b/common/osx.mm
new file mode 100644
index 0000000000..974ea537cb
--- /dev/null
+++ b/common/osx.mm
@@ -0,0 +1,31 @@
+#import <Foundation/Foundation.h>
+
+#include <mbgl/platform/platform.hpp>
+
+namespace mbgl {
+namespace platform {
+
+// Returns the path to the default cache database on this system.
+std::string defaultCacheDatabase() {
+    NSArray *paths =
+        NSSearchPathForDirectoriesInDomains(NSApplicationSupportDirectory, NSUserDomainMask, YES);
+    if ([paths count] == 0) {
+        // Disable the cache if we don't have a location to write.
+        return "";
+    }
+
+    NSString *path = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"Mapbox GL"];
+
+    if (![[NSFileManager defaultManager] createDirectoryAtPath:path
+                                   withIntermediateDirectories:YES
+                                                    attributes:nil
+                                                         error:nil]) {
+        // Disable the cache if we couldn't create the directory.
+        return "";
+    }
+
+    return [[path stringByAppendingPathComponent:@"cache.db"] UTF8String];
+}
+
+}
+}
diff --git a/configure b/configure
index e8f880b543..b92f97758b 100755
--- a/configure
+++ b/configure
@@ -107,6 +107,14 @@ def configure_curl(o):
   o['variables']['curl_libraries'] = ret[0].split()
   o['variables']['curl_cflags'] = ret[1].split()
 
+def configure_sqlite3(o):
+  ret = pkg_config('sqlite3', options.pkgconfig_root)
+  if not ret:
+      sys.stderr.write('could not find sqlite3 with pkg-config')
+      sys.exit(-1)
+  o['variables']['sqlite3_libraries'] = ret[0].split()
+  o['variables']['sqlite3_cflags'] = ret[1].split()
+
 def write(filename, data):
   filename = os.path.join(root_dir, filename)
   print "creating ", filename
@@ -129,6 +137,7 @@ if __name__ == '__main__':
   configure_uv(output)
   configure_png(output)
   configure_curl(output)
+  configure_sqlite3(output)
   pprint.pprint(output, indent=2)
 
   write('config.gypi', "# Do not edit. Generated by the configure script.\n" +
diff --git a/include/mbgl/map/map.hpp b/include/mbgl/map/map.hpp
index ac33dba0ef..7e4687ea6f 100644
--- a/include/mbgl/map/map.hpp
+++ b/include/mbgl/map/map.hpp
@@ -7,11 +7,11 @@
 #include <mbgl/util/noncopyable.hpp>
 #include <mbgl/util/time.hpp>
 #include <mbgl/util/uv.hpp>
+#include <mbgl/util/ptr.hpp>
 
 #include <cstdint>
 #include <atomic>
 #include <iosfwd>
-#include <memory>
 #include <set>
 #include <vector>
 
@@ -31,21 +31,31 @@ class FileSource;
 class View;
 
 class Map : private util::noncopyable {
+    typedef void (*stop_callback)(void *);
+
 public:
     explicit Map(View &view);
     ~Map();
 
-    // Start/stop the map render thread
+    // Start the map render thread. It is asynchronous.
     void start();
-    void stop();
 
-    // Runs the map event loop.
+    // Stop the map render thread. This call will block until the map rendering thread stopped.
+    // The optional callback function will be invoked repeatedly until the map thread is stopped.
+    // The callback function should wait until it is woken up again by view.notify(), otherwise
+    // this will be a busy waiting loop. The optional data parameter will be passed to the callback
+    // function.
+    void stop(stop_callback cb = nullptr, void *data = nullptr);
+
+    // Runs the map event loop. ONLY run this function when you want to get render a single frame
+    // with this map object. It will *not* spawn a separate thread and instead block until the
+    // frame is completely rendered.
     void run();
 
     // Triggers a lazy rerender: only performs a render when the map is not clean.
     void rerender();
 
-    void renderLayer(std::shared_ptr<StyleLayer> layer_desc, RenderPass pass, const Tile::ID* id = nullptr, const mat4* matrix = nullptr);
+    void renderLayer(util::ptr<StyleLayer> layer_desc, RenderPass pass, const Tile::ID* id = nullptr, const mat4* matrix = nullptr);
 
     // Forces a map update: always triggers a rerender.
     void update();
@@ -65,7 +75,7 @@ public:
     void resize(uint16_t width, uint16_t height, float ratio, uint16_t fb_width, uint16_t fb_height);
 
     // Styling
-    const std::set<std::shared_ptr<StyleSource>> getActiveSources() const;
+    const std::set<util::ptr<StyleSource>> getActiveSources() const;
     void setAppliedClasses(const std::vector<std::string> &classes);
     void toggleClass(const std::string &name);
     const std::vector<std::string> &getAppliedClasses() const;
@@ -116,16 +126,20 @@ public:
     void toggleDebug();
     bool getDebug() const;
 
+    // Call this when the network reachability changed.
+    void setReachability(bool status);
+
 public:
     inline const TransformState &getState() const { return state; }
-    inline std::shared_ptr<FileSource> getFileSource() const { return fileSource; }
-    inline std::shared_ptr<Style> getStyle() const { return style; }
-    inline std::shared_ptr<GlyphAtlas> getGlyphAtlas() { return glyphAtlas; }
-    inline std::shared_ptr<GlyphStore> getGlyphStore() { return glyphStore; }
-    inline std::shared_ptr<SpriteAtlas> getSpriteAtlas() { return spriteAtlas; }
-    std::shared_ptr<Sprite> getSprite();
-    inline std::shared_ptr<Texturepool> getTexturepool() { return texturepool; }
-    inline std::shared_ptr<uv::loop> getLoop() { return loop; }
+    inline util::ptr<FileSource> getFileSource() const { return fileSource; }
+    inline util::ptr<Style> getStyle() const { return style; }
+    inline util::ptr<GlyphAtlas> getGlyphAtlas() { return glyphAtlas; }
+    inline util::ptr<GlyphStore> getGlyphStore() { return glyphStore; }
+    inline util::ptr<SpriteAtlas> getSpriteAtlas() { return spriteAtlas; }
+    util::ptr<Sprite> getSprite();
+    inline util::ptr<Texturepool> getTexturepool() { return texturepool; }
+    inline util::ptr<uv::loop> getLoop() { return loop; }
+    uv::worker &getWorker();
     inline timestamp getAnimationTime() const { return animationTime; }
     inline timestamp getTime() const { return animationTime; }
     void updateTiles();
@@ -141,7 +155,7 @@ private:
     void setup();
 
     void updateSources();
-    void updateSources(const std::shared_ptr<StyleLayerGroup> &group);
+    void updateSources(const util::ptr<StyleLayerGroup> &group);
 
     void updateRenderState();
 
@@ -154,15 +168,16 @@ private:
 
     // Unconditionally performs a render with the current map state.
     void render();
-    void renderLayers(std::shared_ptr<StyleLayerGroup> group);
+    void renderLayers(util::ptr<StyleLayerGroup> group);
 
 private:
     bool async = false;
-    std::shared_ptr<uv::loop> loop;
+    util::ptr<uv::loop> loop;
+    std::unique_ptr<uv::worker> workers;
     std::unique_ptr<uv::thread> thread;
-    uv_async_t *async_terminate = nullptr;
-    uv_async_t *async_render = nullptr;
-    uv_async_t *async_cleanup = nullptr;
+    std::unique_ptr<uv_async_t> async_terminate;
+    std::unique_ptr<uv_async_t> async_render;
+    std::unique_ptr<uv_async_t> async_cleanup;
 
 private:
     // If cleared, the next time the render thread attempts to render the map, it will *actually*
@@ -177,24 +192,33 @@ private:
     // ready for rendering.
     std::atomic_flag is_rendered = ATOMIC_FLAG_INIT;
 
+    // Stores whether the map thread has been stopped already.
+    std::atomic_bool is_stopped;
+
 public:
     View &view;
 
 private:
+#ifndef NDEBUG
+    const unsigned long main_thread;
+    unsigned long map_thread = -1;
+#endif
+
     Transform transform;
     TransformState state;
 
-    std::shared_ptr<FileSource> fileSource;
+    util::ptr<FileSource> fileSource;
 
-    std::shared_ptr<Style> style;
-    std::shared_ptr<GlyphAtlas> glyphAtlas;
-    std::shared_ptr<GlyphStore> glyphStore;
-    std::shared_ptr<SpriteAtlas> spriteAtlas;
-    std::shared_ptr<Sprite> sprite;
-    std::shared_ptr<Texturepool> texturepool;
+    util::ptr<Style> style;
+    util::ptr<GlyphAtlas> glyphAtlas;
+    util::ptr<GlyphStore> glyphStore;
+    util::ptr<SpriteAtlas> spriteAtlas;
+    util::ptr<Sprite> sprite;
+    util::ptr<Texturepool> texturepool;
 
     Painter painter;
 
+    std::string styleURL;
     std::string styleJSON = "";
     std::string accessToken = "";
 
@@ -203,7 +227,7 @@ private:
 
     int indent = 0;
 
-    std::set<std::shared_ptr<StyleSource>> activeSources;
+    std::set<util::ptr<StyleSource>> activeSources;
 
 };
 
diff --git a/include/mbgl/map/raster_tile_data.hpp b/include/mbgl/map/raster_tile_data.hpp
index 98aa3baaf5..14833c0d84 100644
--- a/include/mbgl/map/raster_tile_data.hpp
+++ b/include/mbgl/map/raster_tile_data.hpp
@@ -5,8 +5,6 @@
 #include <mbgl/map/tile_data.hpp>
 #include <mbgl/renderer/raster_bucket.hpp>
 
-#include <memory>
-
 namespace mbgl {
 
 class Map;
@@ -18,12 +16,12 @@ class RasterTileData : public TileData {
     friend class TileParser;
 
 public:
-    RasterTileData(Tile::ID id, Map &map, const SourceInfo &source);
+    RasterTileData(Tile::ID id, Map &map, const util::ptr<SourceInfo> &source);
     ~RasterTileData();
 
     virtual void parse();
-    virtual void render(Painter &painter, std::shared_ptr<StyleLayer> layer_desc, const mat4 &matrix);
-    virtual bool hasData(std::shared_ptr<StyleLayer> layer_desc) const;
+    virtual void render(Painter &painter, util::ptr<StyleLayer> layer_desc, const mat4 &matrix);
+    virtual bool hasData(util::ptr<StyleLayer> layer_desc) const;
 
 protected:
     StyleBucketRaster properties;
diff --git a/include/mbgl/map/source.hpp b/include/mbgl/map/source.hpp
index cb069db272..e74ddb9902 100644
--- a/include/mbgl/map/source.hpp
+++ b/include/mbgl/map/source.hpp
@@ -8,12 +8,12 @@
 #include <mbgl/util/noncopyable.hpp>
 #include <mbgl/util/time.hpp>
 #include <mbgl/util/mat4.hpp>
+#include <mbgl/util/ptr.hpp>
 
 #include <cstdint>
 #include <forward_list>
 #include <iosfwd>
 #include <map>
-#include <memory>
 
 namespace mbgl {
 
@@ -25,7 +25,7 @@ struct box;
 
 class Source : public std::enable_shared_from_this<Source>, private util::noncopyable {
 public:
-    Source(SourceInfo& info);
+    Source(const util::ptr<SourceInfo>& info);
 
     void load(Map &map);
 
@@ -33,8 +33,8 @@ public:
     void updateMatrices(const mat4 &projMatrix, const TransformState &transform);
     void drawClippingMasks(Painter &painter);
     size_t getTileCount() const;
-    void render(Painter &painter, std::shared_ptr<StyleLayer> layer_desc);
-    void render(Painter &painter, std::shared_ptr<StyleLayer> layer_desc, const Tile::ID &id, const mat4 &matrix);
+    void render(Painter &painter, util::ptr<StyleLayer> layer_desc);
+    void render(Painter &painter, util::ptr<StyleLayer> layer_desc, const Tile::ID &id, const mat4 &matrix);
     void finishRender(Painter &painter);
 
     std::forward_list<Tile::ID> getIDs() const;
@@ -54,7 +54,7 @@ private:
 
     double getZoom(const TransformState &state) const;
 
-    SourceInfo& info;
+    util::ptr<SourceInfo> info;
     bool loaded = false;
 
     // Stores the time when this source was most recently updated.
diff --git a/include/mbgl/map/sprite.hpp b/include/mbgl/map/sprite.hpp
index 6461a5e33d..454ebd8886 100644
--- a/include/mbgl/map/sprite.hpp
+++ b/include/mbgl/map/sprite.hpp
@@ -3,11 +3,11 @@
 
 #include <mbgl/util/image.hpp>
 #include <mbgl/util/noncopyable.hpp>
+#include <mbgl/util/ptr.hpp>
 
 #include <cstdint>
 #include <atomic>
 #include <iosfwd>
-#include <memory>
 #include <string>
 #include <unordered_map>
 #include <future>
@@ -34,11 +34,11 @@ public:
 class Sprite : public std::enable_shared_from_this<Sprite>, private util::noncopyable {
 private:
     struct Key {};
-    void load(const std::shared_ptr<FileSource> &fileSource);
+    void load(const util::ptr<FileSource> &fileSource);
 
 public:
     Sprite(const Key &, const std::string& base_url, float pixelRatio);
-    static std::shared_ptr<Sprite> Create(const std::string& base_url, float pixelRatio, const std::shared_ptr<FileSource> &fileSource);
+    static util::ptr<Sprite> Create(const std::string& base_url, float pixelRatio, const util::ptr<FileSource> &fileSource);
 
     const SpritePosition &getSpritePosition(const std::string& name) const;
 
diff --git a/include/mbgl/map/tile.hpp b/include/mbgl/map/tile.hpp
index 75ced7e384..b9f0556add 100644
--- a/include/mbgl/map/tile.hpp
+++ b/include/mbgl/map/tile.hpp
@@ -3,6 +3,7 @@
 
 #include <mbgl/util/mat4.hpp>
 #include <mbgl/util/noncopyable.hpp>
+#include <mbgl/util/ptr.hpp>
 
 #include <cstdint>
 #include <bitset>
@@ -10,7 +11,6 @@
 #include <cstdint>
 #include <forward_list>
 #include <iosfwd>
-#include <memory>
 #include <string>
 
 namespace mbgl {
@@ -78,7 +78,7 @@ public:
     const Tile::ID id;
     ClipID clip;
     mat4 matrix;
-    std::shared_ptr<TileData> data;
+    util::ptr<TileData> data;
 };
 
 }
diff --git a/include/mbgl/map/tile_data.hpp b/include/mbgl/map/tile_data.hpp
index 9aaef84e04..07cf19c5c8 100644
--- a/include/mbgl/map/tile_data.hpp
+++ b/include/mbgl/map/tile_data.hpp
@@ -6,11 +6,11 @@
 #include <mbgl/geometry/debug_font_buffer.hpp>
 
 #include <mbgl/util/noncopyable.hpp>
+#include <mbgl/util/ptr.hpp>
 
 #include <atomic>
 #include <exception>
 #include <iosfwd>
-#include <memory>
 #include <string>
 
 namespace mbgl {
@@ -19,8 +19,7 @@ class Map;
 class Painter;
 class SourceInfo;
 class StyleLayer;
-
-namespace platform { class Request; }
+class Request;
 
 class TileData : public std::enable_shared_from_this<TileData>,
              private util::noncopyable {
@@ -29,7 +28,7 @@ public:
     struct geometry_too_long_exception : exception {};
 
 public:
-    typedef std::shared_ptr<TileData> Ptr;
+    typedef util::ptr<TileData> Ptr;
 
     enum class State {
         invalid,
@@ -41,7 +40,7 @@ public:
     };
 
 public:
-    TileData(Tile::ID id, Map &map, const SourceInfo &source);
+    TileData(Tile::ID id, Map &map, const util::ptr<SourceInfo> &source);
     ~TileData();
 
     void request();
@@ -57,8 +56,8 @@ public:
     virtual void beforeParse();
     virtual void parse() = 0;
     virtual void afterParse();
-    virtual void render(Painter &painter, std::shared_ptr<StyleLayer> layer_desc, const mat4 &matrix) = 0;
-    virtual bool hasData(std::shared_ptr<StyleLayer> layer_desc) const = 0;
+    virtual void render(Painter &painter, util::ptr<StyleLayer> layer_desc, const mat4 &matrix) = 0;
+    virtual bool hasData(util::ptr<StyleLayer> layer_desc) const = 0;
 
 
 public:
@@ -69,10 +68,10 @@ protected:
     Map &map;
 
 public:
-    const SourceInfo &source;
+    util::ptr<SourceInfo> source;
 
 protected:
-    std::weak_ptr<platform::Request> req;
+    std::unique_ptr<Request> req;
     std::string data;
 
     // Contains the tile ID string for painting debug information.
diff --git a/include/mbgl/map/tile_parser.hpp b/include/mbgl/map/tile_parser.hpp
index fa64dad6d5..ddb4b98820 100644
--- a/include/mbgl/map/tile_parser.hpp
+++ b/include/mbgl/map/tile_parser.hpp
@@ -4,10 +4,10 @@
 #include <mbgl/map/vector_tile.hpp>
 #include <mbgl/style/filter_expression.hpp>
 #include <mbgl/text/glyph.hpp>
+#include <mbgl/util/ptr.hpp>
 
 #include <cstdint>
 #include <iosfwd>
-#include <memory>
 #include <string>
 
 namespace mbgl {
@@ -32,11 +32,11 @@ class Collision;
 class TileParser {
 public:
     TileParser(const std::string &data, VectorTileData &tile,
-               const std::shared_ptr<const Style> &style,
-               const std::shared_ptr<GlyphAtlas> &glyphAtlas,
-               const std::shared_ptr<GlyphStore> &glyphStore,
-               const std::shared_ptr<SpriteAtlas> &spriteAtlas,
-               const std::shared_ptr<Sprite> &sprite);
+               const util::ptr<const Style> &style,
+               const util::ptr<GlyphAtlas> &glyphAtlas,
+               const util::ptr<GlyphStore> &glyphStore,
+               const util::ptr<SpriteAtlas> &spriteAtlas,
+               const util::ptr<Sprite> &sprite);
     ~TileParser();
 
 public:
@@ -44,11 +44,11 @@ public:
 
 private:
     bool obsolete() const;
-    void parseStyleLayers(std::shared_ptr<StyleLayerGroup> group);
-    std::unique_ptr<Bucket> createBucket(std::shared_ptr<StyleBucket> bucket_desc);
+    void parseStyleLayers(util::ptr<StyleLayerGroup> group);
+    std::unique_ptr<Bucket> createBucket(util::ptr<StyleBucket> bucket_desc);
 
     std::unique_ptr<Bucket> createFillBucket(const VectorTileLayer& layer, const FilterExpression &filter, const StyleBucketFill &fill);
-    std::unique_ptr<Bucket> createRasterBucket(const std::shared_ptr<Texturepool> &texturepool, const StyleBucketRaster &raster);
+    std::unique_ptr<Bucket> createRasterBucket(const util::ptr<Texturepool> &texturepool, const StyleBucketRaster &raster);
     std::unique_ptr<Bucket> createLineBucket(const VectorTileLayer& layer, const FilterExpression &filter, const StyleBucketLine &line);
     std::unique_ptr<Bucket> createSymbolBucket(const VectorTileLayer& layer, const FilterExpression &filter, const StyleBucketSymbol &symbol);
 
@@ -59,12 +59,12 @@ private:
     VectorTileData& tile;
 
     // Cross-thread shared data.
-    std::shared_ptr<const Style> style;
-    std::shared_ptr<GlyphAtlas> glyphAtlas;
-    std::shared_ptr<GlyphStore> glyphStore;
-    std::shared_ptr<SpriteAtlas> spriteAtlas;
-    std::shared_ptr<Sprite> sprite;
-    std::shared_ptr<Texturepool> texturePool;
+    util::ptr<const Style> style;
+    util::ptr<GlyphAtlas> glyphAtlas;
+    util::ptr<GlyphStore> glyphStore;
+    util::ptr<SpriteAtlas> spriteAtlas;
+    util::ptr<Sprite> sprite;
+    util::ptr<Texturepool> texturePool;
 
     std::unique_ptr<Collision> collision;
 };
diff --git a/include/mbgl/map/transform.hpp b/include/mbgl/map/transform.hpp
index d0f56b7fba..5404f333c1 100644
--- a/include/mbgl/map/transform.hpp
+++ b/include/mbgl/map/transform.hpp
@@ -98,10 +98,10 @@ private:
     // cache values for spherical mercator math
     double Bc, Cc;
 
-    std::forward_list<std::shared_ptr<util::transition>> transitions;
-    std::shared_ptr<util::transition> scale_timeout;
-    std::shared_ptr<util::transition> rotate_timeout;
-    std::shared_ptr<util::transition> pan_timeout;
+    std::forward_list<util::ptr<util::transition>> transitions;
+    util::ptr<util::transition> scale_timeout;
+    util::ptr<util::transition> rotate_timeout;
+    util::ptr<util::transition> pan_timeout;
 };
 
 }
diff --git a/include/mbgl/map/vector_tile_data.hpp b/include/mbgl/map/vector_tile_data.hpp
index deb628e485..9de666c84f 100644
--- a/include/mbgl/map/vector_tile_data.hpp
+++ b/include/mbgl/map/vector_tile_data.hpp
@@ -26,14 +26,14 @@ class VectorTileData : public TileData {
     friend class TileParser;
 
 public:
-    VectorTileData(Tile::ID id, Map &map, const SourceInfo &source);
+    VectorTileData(Tile::ID id, Map &map, const util::ptr<SourceInfo> &source);
     ~VectorTileData();
 
     virtual void beforeParse();
     virtual void parse();
     virtual void afterParse();
-    virtual void render(Painter &painter, std::shared_ptr<StyleLayer> layer_desc, const mat4 &matrix);
-    virtual bool hasData(std::shared_ptr<StyleLayer> layer_desc) const;
+    virtual void render(Painter &painter, util::ptr<StyleLayer> layer_desc, const mat4 &matrix);
+    virtual bool hasData(util::ptr<StyleLayer> layer_desc) const;
 
 protected:
     // Holds the actual geometries in this tile.
diff --git a/include/mbgl/map/view.hpp b/include/mbgl/map/view.hpp
index 3e2f1a4b5a..395a05d435 100644
--- a/include/mbgl/map/view.hpp
+++ b/include/mbgl/map/view.hpp
@@ -45,6 +45,8 @@ public:
         return 0;
     }
 
+    virtual void notify() = 0;
+
     // Notifies a watcher of map x/y/scale/rotation changes.
     // Must only be called from the same thread that caused the change.
     // Must not be called from the render thread.
diff --git a/include/mbgl/platform/event.hpp b/include/mbgl/platform/event.hpp
index 1676f40d2c..d2a06618a3 100644
--- a/include/mbgl/platform/event.hpp
+++ b/include/mbgl/platform/event.hpp
@@ -29,6 +29,7 @@ enum class Event : uint8_t {
     ParseStyle,
     ParseTile,
     Render,
+    Database,
     HttpRequest,
     Sprite,
 };
@@ -40,6 +41,7 @@ MBGL_DEFINE_ENUM_CLASS(EventClass, Event, {
     { Event::ParseStyle, "ParseStyle" },
     { Event::ParseTile, "ParseTile" },
     { Event::Render, "Render" },
+    { Event::Database, "Database" },
     { Event::HttpRequest, "HttpRequest" },
     { Event::Sprite, "Sprite" },
     { Event(-1), "Unknown" },
diff --git a/include/mbgl/platform/platform.hpp b/include/mbgl/platform/platform.hpp
index 22405a4cfd..b7107bb9cd 100644
--- a/include/mbgl/platform/platform.hpp
+++ b/include/mbgl/platform/platform.hpp
@@ -4,7 +4,6 @@
 #include <mbgl/util/uv.hpp>
 
 #include <memory>
-#include <functional>
 #include <string>
 
 namespace mbgl {
@@ -12,30 +11,14 @@ namespace platform {
 
 class Request;
 
-struct Response {
-    Response(std::function<void(Response *)> callback) : callback(callback) {}
-    int16_t code = -1;
-    std::string body;
-    std::string error_message;
-    std::function<void(Response *)> callback;
-};
-
-// Makes an HTTP request of a URL, preferrably on a background thread, and calls a function with the
-// results in the original thread (which runs the libuv loop).
-// If the loop pointer is NULL, the callback function will be called on an arbitrary thread.
-// Returns a cancellable request.
-std::shared_ptr<Request> request_http(const std::string &url,
-                                      std::function<void(Response *)> callback,
-                                      std::shared_ptr<uv::loop> loop = nullptr);
-
 // Uppercase a string, potentially using platform-specific routines.
 std::string uppercase(const std::string &string);
 
 // Lowercase a string, potentially using platform-specific routines.
 std::string lowercase(const std::string &string);
 
-// Cancels an HTTP request.
-void cancel_request_http(const std::shared_ptr<Request> &req);
+// Returns the path to the default cache database on this system.
+std::string defaultCacheDatabase();
 
 // Shows an alpha image with the specified dimensions in a named window.
 void show_debug_image(std::string name, const char *data, size_t width, size_t height);
diff --git a/include/mbgl/platform/request.hpp b/include/mbgl/platform/request.hpp
deleted file mode 100644
index 2a231769c1..0000000000
--- a/include/mbgl/platform/request.hpp
+++ /dev/null
@@ -1,41 +0,0 @@
-#ifndef MBGL_PLATFORM_REQUEST
-#define MBGL_PLATFORM_REQUEST
-
-#include <string>
-#include <functional>
-#include <memory>
-#include <atomic>
-
-#include <mbgl/util/noncopyable.hpp>
-#include <mbgl/util/uv.hpp>
-
-namespace mbgl {
-namespace platform {
-
-struct Response;
-
-class Request : public std::enable_shared_from_this<Request>, private util::noncopyable {
-public:
-    Request(const std::string &url,
-            std::function<void(Response *)> callback,
-            std::shared_ptr<uv::loop> loop);
-    ~Request();
-
-    void complete();
-
-private:
-    static void complete(uv_async_t *async, int status);
-
-public:
-    const std::string url;
-    std::unique_ptr<Response> res;
-    std::atomic<bool> cancelled;
-
-public:
-    uv_async_t *async = nullptr;
-    std::shared_ptr<uv::loop> loop;
-};
-}
-}
-
-#endif
diff --git a/include/mbgl/renderer/bucket.hpp b/include/mbgl/renderer/bucket.hpp
index 1391f6e3e3..696bfb1110 100644
--- a/include/mbgl/renderer/bucket.hpp
+++ b/include/mbgl/renderer/bucket.hpp
@@ -1,11 +1,11 @@
 #ifndef MBGL_RENDERER_BUCKET
 #define MBGL_RENDERER_BUCKET
 
-#include <string>
-#include <memory>
 #include <mbgl/map/tile.hpp>
 #include <mbgl/util/noncopyable.hpp>
 
+#include <string>
+
 namespace mbgl {
 
 class Painter;
@@ -13,7 +13,7 @@ class StyleLayer;
 
 class Bucket : private util::noncopyable {
 public:
-    virtual void render(Painter& painter, std::shared_ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix) = 0;
+    virtual void render(Painter& painter, util::ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix) = 0;
     virtual bool hasData() const = 0;
     virtual ~Bucket() {}
 
diff --git a/include/mbgl/renderer/debug_bucket.hpp b/include/mbgl/renderer/debug_bucket.hpp
index 660b7fcba8..fb6cfb4cae 100644
--- a/include/mbgl/renderer/debug_bucket.hpp
+++ b/include/mbgl/renderer/debug_bucket.hpp
@@ -6,7 +6,6 @@
 #include <mbgl/geometry/vao.hpp>
 
 #include <vector>
-#include <memory>
 
 #ifndef BUFFER_OFFSET
 #define BUFFER_OFFSET(i) ((char *)nullptr + (i))
@@ -20,7 +19,7 @@ class DebugBucket : public Bucket {
 public:
     DebugBucket(DebugFontBuffer& fontBuffer);
 
-    virtual void render(Painter& painter, std::shared_ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix);
+    virtual void render(Painter& painter, util::ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix);
     virtual bool hasData() const;
 
     void drawLines(PlainShader& shader);
diff --git a/include/mbgl/renderer/fill_bucket.hpp b/include/mbgl/renderer/fill_bucket.hpp
index 15868e4092..ae766ec28d 100644
--- a/include/mbgl/renderer/fill_bucket.hpp
+++ b/include/mbgl/renderer/fill_bucket.hpp
@@ -44,7 +44,7 @@ public:
                const StyleBucketFill& properties);
     ~FillBucket();
 
-    virtual void render(Painter& painter, std::shared_ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix);
+    virtual void render(Painter& painter, util::ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix);
     virtual bool hasData() const;
 
     void addGeometry(pbf& data);
diff --git a/include/mbgl/renderer/line_bucket.hpp b/include/mbgl/renderer/line_bucket.hpp
index 8babb734ed..7337ca80ad 100644
--- a/include/mbgl/renderer/line_bucket.hpp
+++ b/include/mbgl/renderer/line_bucket.hpp
@@ -1,13 +1,12 @@
 #ifndef MBGL_RENDERER_LINEBUCKET
 #define MBGL_RENDERER_LINEBUCKET
 
-#include "bucket.hpp"
+#include <mbgl/renderer/bucket.hpp>
 #include <mbgl/geometry/vao.hpp>
 #include <mbgl/geometry/elements_buffer.hpp>
 #include <mbgl/geometry/line_buffer.hpp>
 #include <mbgl/style/style_bucket.hpp>
 
-#include <memory>
 #include <vector>
 
 namespace mbgl {
@@ -30,7 +29,7 @@ public:
                PointElementsBuffer& pointElementsBuffer,
                const StyleBucketLine& properties);
 
-    virtual void render(Painter& painter, std::shared_ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix);
+    virtual void render(Painter& painter, util::ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix);
     virtual bool hasData() const;
 
     void addGeometry(pbf& data);
diff --git a/include/mbgl/renderer/painter.hpp b/include/mbgl/renderer/painter.hpp
index 15331b9b67..0f9bd79173 100644
--- a/include/mbgl/renderer/painter.hpp
+++ b/include/mbgl/renderer/painter.hpp
@@ -22,6 +22,7 @@
 #include <mbgl/shader/gaussian_shader.hpp>
 
 #include <mbgl/map/transform_state.hpp>
+#include <mbgl/util/ptr.hpp>
 
 #include <map>
 #include <unordered_map>
@@ -73,7 +74,7 @@ public:
     void changeMatrix();
 
     // Renders a particular layer from a tile.
-    void renderTileLayer(const Tile& tile, std::shared_ptr<StyleLayer> layer_desc, const mat4 &matrix);
+    void renderTileLayer(const Tile& tile, util::ptr<StyleLayer> layer_desc, const mat4 &matrix);
 
     // Renders debug information for a tile.
     void renderTileDebug(const Tile& tile);
@@ -83,11 +84,11 @@ public:
 
     void renderDebugText(DebugBucket& bucket, const mat4 &matrix);
     void renderDebugText(const std::vector<std::string> &strings);
-    void renderFill(FillBucket& bucket, std::shared_ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix);
-    void renderLine(LineBucket& bucket, std::shared_ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix);
-    void renderSymbol(SymbolBucket& bucket, std::shared_ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix);
-    void renderRaster(RasterBucket& bucket, std::shared_ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix);
-    void renderBackground(std::shared_ptr<StyleLayer> layer_desc);
+    void renderFill(FillBucket& bucket, util::ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix);
+    void renderLine(LineBucket& bucket, util::ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix);
+    void renderSymbol(SymbolBucket& bucket, util::ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix);
+    void renderRaster(RasterBucket& bucket, util::ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix);
+    void renderBackground(util::ptr<StyleLayer> layer_desc);
 
     float saturationFactor(float saturation);
     float contrastFactor(float contrast);
@@ -97,7 +98,7 @@ public:
 
     void renderPrerenderedTexture(RasterBucket &bucket, const mat4 &matrix, const RasterProperties& properties);
 
-    void createPrerendered(RasterBucket& bucket, std::shared_ptr<StyleLayer> layer_desc, const Tile::ID& id);
+    void createPrerendered(RasterBucket& bucket, util::ptr<StyleLayer> layer_desc, const Tile::ID& id);
 
     void resize();
 
@@ -111,7 +112,7 @@ public:
     // Configures the painter strata that is used for early z-culling of fragments.
     void setStrata(float strata);
 
-    void drawClippingMasks(const std::set<std::shared_ptr<StyleSource>> &sources);
+    void drawClippingMasks(const std::set<util::ptr<StyleSource>> &sources);
     void drawClippingMask(const mat4& matrix, const ClipID& clip);
 
     void resetFramebuffer();
diff --git a/include/mbgl/renderer/raster_bucket.hpp b/include/mbgl/renderer/raster_bucket.hpp
index 66cceac8e7..794da3b143 100644
--- a/include/mbgl/renderer/raster_bucket.hpp
+++ b/include/mbgl/renderer/raster_bucket.hpp
@@ -16,9 +16,9 @@ class VertexArrayObject;
 
 class RasterBucket : public Bucket {
 public:
-    RasterBucket(const std::shared_ptr<Texturepool> &texturepool, const StyleBucketRaster& properties);
+    RasterBucket(const util::ptr<Texturepool> &texturepool, const StyleBucketRaster& properties);
 
-    virtual void render(Painter& painter, std::shared_ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix);
+    virtual void render(Painter& painter, util::ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix);
     virtual bool hasData() const;
 
     bool setImage(const std::string &data);
diff --git a/include/mbgl/renderer/symbol_bucket.hpp b/include/mbgl/renderer/symbol_bucket.hpp
index c71d276456..42682401ef 100644
--- a/include/mbgl/renderer/symbol_bucket.hpp
+++ b/include/mbgl/renderer/symbol_bucket.hpp
@@ -56,7 +56,7 @@ class SymbolBucket : public Bucket {
 public:
     SymbolBucket(const StyleBucketSymbol &properties, Collision &collision);
 
-    virtual void render(Painter &painter, std::shared_ptr<StyleLayer> layer_desc, const Tile::ID &id, const mat4 &matrix);
+    virtual void render(Painter &painter, util::ptr<StyleLayer> layer_desc, const Tile::ID &id, const mat4 &matrix);
     virtual bool hasData() const;
     virtual bool hasTextData() const;
     virtual bool hasIconData() const;
diff --git a/include/mbgl/storage/base_request.hpp b/include/mbgl/storage/base_request.hpp
new file mode 100644
index 0000000000..16ff24faa3
--- /dev/null
+++ b/include/mbgl/storage/base_request.hpp
@@ -0,0 +1,62 @@
+#ifndef MBGL_STORAGE_BASE_REQUEST
+#define MBGL_STORAGE_BASE_REQUEST
+
+#include <mbgl/storage/request_callback.hpp>
+#include <mbgl/util/ptr.hpp>
+
+#include <string>
+#include <forward_list>
+#include <functional>
+
+
+typedef struct uv_loop_s uv_loop_t;
+typedef struct uv_async_s uv_async_t;
+
+namespace mbgl {
+
+class Response;
+class Request;
+
+class BaseRequest {
+private:
+    // Make noncopyable and immovable
+    BaseRequest(const BaseRequest &) = delete;
+    BaseRequest(BaseRequest &&) = delete;
+    BaseRequest& operator=(const BaseRequest &) = delete;
+    BaseRequest& operator=(BaseRequest &&) = delete;
+
+public:
+    BaseRequest(const std::string &path);
+    virtual ~BaseRequest();
+
+    Callback *add(Callback &&callback, const util::ptr<BaseRequest> &request);
+    void remove(Callback *callback);
+
+    // Must be called by subclasses when a valid Response object is available. It will notify
+    // all listeners.
+    void notify();
+
+    // This function is called when the request ought to be stopped. Any subclass must make sure this
+    // is also called in its destructor. Calling this function repeatedly must be safe.
+    // This function must call notify().
+    virtual void cancel() = 0;
+
+    // This function is called when the request should be reattempted immediately. This is typically
+    // reaction to a network status change.
+    virtual void retryImmediately();
+
+public:
+    const unsigned long thread_id;
+    const std::string path;
+    std::unique_ptr<Response> response;
+
+protected:
+    // This object may hold a shared_ptr to itself. It does this to prevent destruction of this object
+    // while a request is in progress.
+    util::ptr<BaseRequest> self;
+    std::forward_list<std::unique_ptr<Callback>> callbacks;
+};
+
+}
+
+#endif
diff --git a/include/mbgl/storage/file_request.hpp b/include/mbgl/storage/file_request.hpp
new file mode 100644
index 0000000000..2f883728ff
--- /dev/null
+++ b/include/mbgl/storage/file_request.hpp
@@ -0,0 +1,27 @@
+#ifndef MBGL_STORAGE_FILE_REQUEST
+#define MBGL_STORAGE_FILE_REQUEST
+
+#include <mbgl/storage/base_request.hpp>
+
+namespace mbgl {
+
+typedef struct uv_loop_s uv_loop_t;
+
+struct FileRequestBaton;
+
+class FileRequest : public BaseRequest {
+public:
+    FileRequest(const std::string &path, uv_loop_t *loop);
+    ~FileRequest();
+
+    void cancel();
+
+private:
+    FileRequestBaton *ptr = nullptr;
+
+    friend struct FileRequestBaton;
+};
+
+}
+
+#endif
\ No newline at end of file
diff --git a/include/mbgl/storage/file_request_baton.hpp b/include/mbgl/storage/file_request_baton.hpp
new file mode 100644
index 0000000000..0f1968ca13
--- /dev/null
+++ b/include/mbgl/storage/file_request_baton.hpp
@@ -0,0 +1,35 @@
+#ifndef MBGL_STORAGE_FILE_REQUEST_BATON
+#define MBGL_STORAGE_FILE_REQUEST_BATON
+
+#include <mbgl/storage/file_request.hpp>
+
+#include <uv.h>
+
+namespace mbgl {
+
+struct FileRequestBaton {
+    FileRequestBaton(FileRequest *request_, const std::string &path, uv_loop_t *loop);
+    ~FileRequestBaton();
+
+    void cancel();
+    static void file_opened(uv_fs_t *req);
+    static void file_stated(uv_fs_t *req);
+    static void file_read(uv_fs_t *req);
+    static void file_closed(uv_fs_t *req);
+    static void notify_error(uv_fs_t *req);
+    static void cleanup(uv_fs_t *req);
+
+    const unsigned long thread_id;
+    FileRequest *request = nullptr;
+    uv_fs_t req;
+    uv_file fd = -1;
+    bool canceled = false;
+    std::string body;
+    uv_buf_t buffer;
+};
+
+
+}
+
+
+#endif
diff --git a/include/mbgl/storage/file_source.hpp b/include/mbgl/storage/file_source.hpp
new file mode 100644
index 0000000000..4b17cd29a7
--- /dev/null
+++ b/include/mbgl/storage/file_source.hpp
@@ -0,0 +1,55 @@
+#ifndef MBGL_STORAGE_FILE_SOURCE
+#define MBGL_STORAGE_FILE_SOURCE
+
+#include <mbgl/storage/resource_type.hpp>
+#include <mbgl/storage/request.hpp>
+
+#include <string>
+#include <unordered_map>
+#include <functional>
+
+typedef struct uv_loop_s uv_loop_t;
+typedef struct uv_messenger_s uv_messenger_t;
+
+namespace mbgl {
+
+class BaseRequest;
+class SQLiteStore;
+
+class FileSource {
+private:
+    FileSource(const FileSource &) = delete;
+    FileSource(FileSource &&) = delete;
+    FileSource& operator=(const FileSource &) = delete;
+    FileSource& operator=(FileSource &&) = delete;
+
+public:
+    FileSource(uv_loop_t *loop, const std::string &path);
+    ~FileSource();
+
+public:
+    // Stores and retrieves the base path/URL for relative requests
+    void setBase(const std::string &value);
+    const std::string &getBase() const;
+
+    std::unique_ptr<Request> request(ResourceType type, const std::string &url);
+
+    void prepare(std::function<void()> fn);
+
+    void retryAllPending();
+
+private:
+    const unsigned long thread_id;
+
+    // Stores a URL that is used as a base for loading resources with relative path.
+    std::string base;
+
+    std::unordered_map<std::string, std::weak_ptr<BaseRequest>> pending;
+    util::ptr<SQLiteStore> store;
+    uv_loop_t *loop = nullptr;
+    uv_messenger_t *queue = nullptr;
+};
+
+}
+
+#endif
diff --git a/include/mbgl/storage/http_request.hpp b/include/mbgl/storage/http_request.hpp
new file mode 100644
index 0000000000..ec76f1147c
--- /dev/null
+++ b/include/mbgl/storage/http_request.hpp
@@ -0,0 +1,57 @@
+#ifndef MBGL_STORAGE_HTTP_REQUEST
+#define MBGL_STORAGE_HTTP_REQUEST
+
+#include <mbgl/storage/resource_type.hpp>
+#include <mbgl/storage/base_request.hpp>
+#include <mbgl/storage/http_request_baton.hpp>
+
+#include <string>
+#include <memory>
+#include <cassert>
+
+typedef struct uv_loop_s uv_loop_t;
+typedef struct uv_timer_s uv_timer_t;
+
+namespace mbgl {
+
+struct CacheRequestBaton;
+struct HTTPRequestBaton;
+struct CacheEntry;
+class SQLiteStore;
+
+class HTTPRequest : public BaseRequest {
+public:
+    HTTPRequest(ResourceType type, const std::string &path, uv_loop_t *loop, util::ptr<SQLiteStore> store);
+    ~HTTPRequest();
+
+    void cancel();
+    void retryImmediately();
+
+private:
+    void startCacheRequest();
+    void handleCacheResponse(std::unique_ptr<Response> &&response);
+    void startHTTPRequest(std::unique_ptr<Response> &&res);
+    void handleHTTPResponse(HTTPResponseType responseType, std::unique_ptr<Response> &&response);
+
+    void retryHTTPRequest(std::unique_ptr<Response> &&res, uint64_t timeout);
+
+    void removeCacheBaton();
+    void removeHTTPBaton();
+    void removeBackoffTimer();
+
+private:
+    const unsigned long thread_id;
+    uv_loop_t *const loop;
+    CacheRequestBaton *cache_baton = nullptr;
+    util::ptr<HTTPRequestBaton> http_baton;
+    uv_timer_t *backoff_timer = nullptr;
+    util::ptr<SQLiteStore> store;
+    const ResourceType type;
+    uint8_t attempts = 0;
+
+    friend struct HTTPRequestBaton;
+};
+
+}
+
+#endif
\ No newline at end of file
diff --git a/include/mbgl/storage/http_request_baton.hpp b/include/mbgl/storage/http_request_baton.hpp
new file mode 100644
index 0000000000..279784ec25
--- /dev/null
+++ b/include/mbgl/storage/http_request_baton.hpp
@@ -0,0 +1,73 @@
+#ifndef MBGL_STORAGE_HTTP_REQUEST_BATON
+#define MBGL_STORAGE_HTTP_REQUEST_BATON
+
+#include <mbgl/storage/response.hpp>
+#include <mbgl/util/ptr.hpp>
+
+#include <string>
+
+typedef struct uv_async_s uv_async_t;
+
+namespace mbgl {
+
+class HTTPRequest;
+
+enum class HTTPResponseType : int8_t {
+    // This error probably won't be resolved by retrying anytime soon. We are giving up.
+    PermanentError = -5,
+
+    // This error might be resolved by waiting some time (e.g. server issues).
+    // We are going to do an exponential back-off and will try again in a few seconds.
+    TemporaryError = -4,
+
+    // This error was caused by a temporary error and it is likely that it will be resolved
+    // immediately. We are going to try again right away. This is like the TemporaryError, except
+    // that we will not perform exponential back-off.
+    SingularError = -3,
+
+    // This error might be resolved once the network reachability status changes.
+    // We are going to watch the network status for changes and will retry as soon as the operating
+    // system notifies us of a network status change.
+    ConnectionError = -2,
+
+    // The request was canceled programatically.
+    Canceled = -1,
+
+    // The request is still in progress.
+    Unknown = 0,
+
+    // The request returned data successfully. We retrieved and decoded the data successfully.
+    Successful = 1,
+
+    // The request confirmed that the data wasn't changed. We already have the data.
+    NotModified = 2,
+};
+
+struct HTTPRequestBaton {
+    HTTPRequestBaton(const std::string &path);
+    ~HTTPRequestBaton();
+
+    const unsigned long thread_id;
+    const std::string path;
+
+    HTTPRequest *request = nullptr;
+    uv_async_t *async = nullptr;
+
+    HTTPResponseType type = HTTPResponseType::Unknown;
+    std::unique_ptr<Response> response;
+
+    // Implementation specific use.
+    void *ptr = nullptr;
+
+    // IMPLEMENT THESE 3 PLATFORM SPECIFIC FUNCTIONS:
+
+    // Begin the HTTP request. Platform-specific implementation.
+    static void start(const util::ptr<HTTPRequestBaton> &ptr);
+
+    // This will be called to stop/cancel the HTTP request (if possible). Platform-specific implementation.
+    static void stop(const util::ptr<HTTPRequestBaton> &ptr);
+};
+
+}
+
+#endif
diff --git a/include/mbgl/storage/request.hpp b/include/mbgl/storage/request.hpp
new file mode 100644
index 0000000000..e603ee527a
--- /dev/null
+++ b/include/mbgl/storage/request.hpp
@@ -0,0 +1,39 @@
+#ifndef MBGL_STORAGE_REQUEST
+#define MBGL_STORAGE_REQUEST
+
+#include <mbgl/storage/request_callback.hpp>
+#include <mbgl/storage/response.hpp>
+#include <mbgl/util/ptr.hpp>
+
+#include <forward_list>
+
+typedef struct uv_loop_s uv_loop_t;
+
+namespace mbgl {
+
+class BaseRequest;
+
+class Request {
+private:
+    Request(const Request &) = delete;
+    Request(Request &&) = delete;
+    Request& operator=(const Request &) = delete;
+    Request& operator=(Request &&) = delete;
+
+public:
+    Request(const util::ptr<BaseRequest> &base);
+    ~Request();
+
+    void onload(CompletedCallback cb);
+    void oncancel(AbortedCallback cb);
+    void cancel();
+
+private:
+    const unsigned long thread_id;
+    util::ptr<BaseRequest> base;
+    std::forward_list<Callback *> callbacks;
+};
+
+}
+
+#endif
\ No newline at end of file
diff --git a/include/mbgl/storage/request_callback.hpp b/include/mbgl/storage/request_callback.hpp
new file mode 100644
index 0000000000..01427bd96d
--- /dev/null
+++ b/include/mbgl/storage/request_callback.hpp
@@ -0,0 +1,22 @@
+#ifndef MBGL_STORAGE_REQUEST_CALLBACK
+#define MBGL_STORAGE_REQUEST_CALLBACK
+
+#include <mbgl/util/variant.hpp>
+
+#include <functional>
+
+namespace mbgl {
+
+class Response;
+
+using CompletedCallback = std::function<void(const Response &)>;
+using AbortedCallback = std::function<void()>;
+
+using Callback = mapbox::util::variant<
+    CompletedCallback,
+    AbortedCallback
+>;
+
+}
+
+#endif
diff --git a/include/mbgl/storage/resource_type.hpp b/include/mbgl/storage/resource_type.hpp
new file mode 100644
index 0000000000..b7204a9fa1
--- /dev/null
+++ b/include/mbgl/storage/resource_type.hpp
@@ -0,0 +1,18 @@
+#ifndef MBGL_STORAGE_RESOURCE_TYPE
+#define MBGL_STORAGE_RESOURCE_TYPE
+
+#include <cstdint>
+
+namespace mbgl {
+
+enum class ResourceType : uint8_t {
+    Unknown = 0,
+    Tile = 1,
+    Glyphs = 2,
+    Image = 3,
+    JSON = 4
+};
+
+}
+
+#endif
diff --git a/include/mbgl/storage/response.hpp b/include/mbgl/storage/response.hpp
new file mode 100644
index 0000000000..9357ad3c63
--- /dev/null
+++ b/include/mbgl/storage/response.hpp
@@ -0,0 +1,26 @@
+#ifndef MBGL_STORAGE_RESPONSE
+#define MBGL_STORAGE_RESPONSE
+
+#include <string>
+#include <ctime>
+
+namespace mbgl {
+
+
+
+class Response {
+public:
+    long code = 0;
+    int64_t modified = 0;
+    int64_t expires = 0;
+    std::string etag;
+    std::string data;
+
+    std::string message;
+
+    static int64_t parseCacheControl(const char *value);
+};
+
+}
+
+#endif
\ No newline at end of file
diff --git a/include/mbgl/storage/sqlite_store.hpp b/include/mbgl/storage/sqlite_store.hpp
new file mode 100644
index 0000000000..cb7730d0bf
--- /dev/null
+++ b/include/mbgl/storage/sqlite_store.hpp
@@ -0,0 +1,47 @@
+#ifndef MBGL_STORAGE_SQLITE_STORE
+#define MBGL_STORAGE_SQLITE_STORE
+
+#include <mbgl/storage/file_source.hpp>
+#include <mbgl/storage/response.hpp>
+
+#include <uv.h>
+
+#include <string>
+
+typedef struct uv_worker_s uv_worker_t;
+
+namespace mapbox {
+namespace sqlite {
+class Database;
+}
+}
+
+namespace mbgl {
+
+class SQLiteStore {
+public:
+    SQLiteStore(uv_loop_t *loop, const std::string &path);
+    ~SQLiteStore();
+
+    typedef void (*GetCallback)(std::unique_ptr<Response> &&entry, void *ptr);
+
+    void get(const std::string &path, GetCallback cb, void *ptr);
+    void put(const std::string &path, ResourceType type, const Response &entry);
+    void updateExpiration(const std::string &path, int64_t expires);
+
+private:
+    void createSchema();
+    void closeDatabase();
+    static void runGet(uv_work_t *req);
+    static void runPut(uv_work_t *req);
+    static void deliverResult(uv_work_t *req, int status);
+
+private:
+    const unsigned long thread_id;
+    util::ptr<mapbox::sqlite::Database> db;
+    uv_worker_t *worker = nullptr;
+};
+
+}
+
+#endif
diff --git a/include/mbgl/style/style.hpp b/include/mbgl/style/style.hpp
index c09de6ebba..56f318ecbb 100644
--- a/include/mbgl/style/style.hpp
+++ b/include/mbgl/style/style.hpp
@@ -6,6 +6,7 @@
 
 #include <mbgl/util/time.hpp>
 #include <mbgl/util/uv.hpp>
+#include <mbgl/util/ptr.hpp>
 
 #include <cstdint>
 #include <map>
@@ -13,7 +14,6 @@
 #include <unordered_map>
 #include <vector>
 #include <set>
-#include <memory>
 
 namespace mbgl {
 
@@ -49,7 +49,7 @@ public:
     const std::string &getSpriteURL() const;
 
 public:
-    std::shared_ptr<StyleLayerGroup> layers;
+    util::ptr<StyleLayerGroup> layers;
     std::vector<std::string> appliedClasses;
     std::string glyph_url;
 
diff --git a/include/mbgl/style/style_bucket.hpp b/include/mbgl/style/style_bucket.hpp
index c2cde52aa5..c4a8f6037e 100644
--- a/include/mbgl/style/style_bucket.hpp
+++ b/include/mbgl/style/style_bucket.hpp
@@ -8,8 +8,8 @@
 #include <mbgl/util/vec.hpp>
 #include <mbgl/util/variant.hpp>
 #include <mbgl/util/noncopyable.hpp>
+#include <mbgl/util/ptr.hpp>
 
-#include <memory>
 #include <forward_list>
 
 namespace mbgl {
@@ -93,12 +93,12 @@ typedef mapbox::util::variant<StyleBucketFill, StyleBucketLine, StyleBucketSymbo
 
 class StyleBucket {
 public:
-    typedef std::shared_ptr<StyleBucket> Ptr;
+    typedef util::ptr<StyleBucket> Ptr;
 
     StyleBucket(StyleLayerType type);
 
     std::string name;
-    std::shared_ptr<StyleSource> style_source;
+    util::ptr<StyleSource> style_source;
     std::string source_layer;
     FilterExpression filter;
     StyleBucketRender render = std::false_type();
diff --git a/include/mbgl/style/style_layer.hpp b/include/mbgl/style/style_layer.hpp
index 84981e3fb4..641dc1e71c 100644
--- a/include/mbgl/style/style_layer.hpp
+++ b/include/mbgl/style/style_layer.hpp
@@ -6,8 +6,9 @@
 #include <mbgl/style/style_properties.hpp>
 #include <mbgl/style/applied_class_properties.hpp>
 
+#include <mbgl/util/ptr.hpp>
+
 #include <vector>
-#include <memory>
 #include <string>
 #include <map>
 #include <set>
@@ -64,7 +65,7 @@ public:
 
     // Bucket information, telling the renderer how to generate the geometries
     // for this layer (feature property filters, tessellation instructions, ...).
-    std::shared_ptr<StyleBucket> bucket;
+    util::ptr<StyleBucket> bucket;
 
     // Contains all style classes that can be applied to this layer.
     const std::map<ClassID, ClassProperties> styles;
@@ -80,7 +81,7 @@ public:
     StyleProperties properties;
 
     // Child layer array (if this layer has child layers).
-    std::shared_ptr<StyleLayerGroup> layers;
+    util::ptr<StyleLayerGroup> layers;
 };
 
 }
diff --git a/include/mbgl/style/style_layer_group.hpp b/include/mbgl/style/style_layer_group.hpp
index 983dd136f0..1af6e23bd7 100644
--- a/include/mbgl/style/style_layer_group.hpp
+++ b/include/mbgl/style/style_layer_group.hpp
@@ -15,7 +15,7 @@ public:
 
     bool hasTransitions() const;
 public:
-    std::vector<std::shared_ptr<StyleLayer>> layers;
+    std::vector<util::ptr<StyleLayer>> layers;
 };
 
 }
diff --git a/include/mbgl/style/style_parser.hpp b/include/mbgl/style/style_parser.hpp
index e4e1b7f632..fc253bb1dd 100644
--- a/include/mbgl/style/style_parser.hpp
+++ b/include/mbgl/style/style_parser.hpp
@@ -27,7 +27,7 @@ public:
 
     void parse(JSVal document);
 
-    std::shared_ptr<StyleLayerGroup> getLayers() {
+    util::ptr<StyleLayerGroup> getLayers() {
         return root;
     }
 
@@ -46,14 +46,14 @@ private:
     void parseSources(JSVal value);
 
     std::unique_ptr<StyleLayerGroup> createLayers(JSVal value);
-    std::shared_ptr<StyleLayer> createLayer(JSVal value);
+    util::ptr<StyleLayer> createLayer(JSVal value);
     void parseLayers();
-    void parseLayer(std::pair<JSVal, std::shared_ptr<StyleLayer>> &pair);
+    void parseLayer(std::pair<JSVal, util::ptr<StyleLayer>> &pair);
     void parseStyles(JSVal value, std::map<ClassID, ClassProperties> &styles);
     void parseStyle(JSVal, ClassProperties &properties);
-    void parseReference(JSVal value, std::shared_ptr<StyleLayer> &layer);
-    void parseBucket(JSVal value, std::shared_ptr<StyleLayer> &layer);
-    void parseRender(JSVal value, std::shared_ptr<StyleLayer> &layer);
+    void parseReference(JSVal value, util::ptr<StyleLayer> &layer);
+    void parseBucket(JSVal value, util::ptr<StyleLayer> &layer);
+    void parseRender(JSVal value, util::ptr<StyleLayer> &layer);
     void parseSprite(JSVal value);
     void parseGlyphURL(JSVal value);
 
@@ -94,13 +94,13 @@ private:
 private:
     std::unordered_map<std::string, const rapidjson::Value *> constants;
 
-    std::unordered_map<std::string, const std::shared_ptr<StyleSource>> sources;
+    std::unordered_map<std::string, const util::ptr<StyleSource>> sources;
 
     // This stores the root layer.
-    std::shared_ptr<StyleLayerGroup> root;
+    util::ptr<StyleLayerGroup> root;
 
     // This maps ids to Layer objects, with all items being at the root level.
-    std::unordered_map<std::string, std::pair<JSVal, std::shared_ptr<StyleLayer>>> layers;
+    std::unordered_map<std::string, std::pair<JSVal, util::ptr<StyleLayer>>> layers;
 
     // Store a stack of layers we're parsing right now. This is to prevent reference cycles.
     std::forward_list<StyleLayer *> stack;
diff --git a/include/mbgl/style/style_source.hpp b/include/mbgl/style/style_source.hpp
index b598550c65..00c48431a1 100644
--- a/include/mbgl/style/style_source.hpp
+++ b/include/mbgl/style/style_source.hpp
@@ -2,18 +2,18 @@
 #define MBGL_STYLE_STYLE_SOURCE
 
 #include <mbgl/style/types.hpp>
+#include <mbgl/util/ptr.hpp>
+#include <mbgl/util/noncopyable.hpp>
+#include <rapidjson/document.h>
 
-#include <memory>
 #include <vector>
 #include <string>
 
-#include <rapidjson/document.h>
-
 namespace mbgl {
 
 class Source;
 
-class SourceInfo {
+class SourceInfo : private util::noncopyable {
 public:
     SourceType type = SourceType::Vector;
     std::string url;
@@ -31,12 +31,12 @@ public:
 
 class StyleSource : public std::enable_shared_from_this<StyleSource> {
 public:
-    SourceInfo info;
+    util::ptr<SourceInfo> info;
 
     bool enabled = false;
-    std::shared_ptr<Source> source;
+    util::ptr<Source> source;
 
-    StyleSource(const SourceInfo &info)
+    StyleSource(const util::ptr<SourceInfo> &info)
         : info(info)
     {}
 };
diff --git a/include/mbgl/text/glyph_store.hpp b/include/mbgl/text/glyph_store.hpp
index e0c0391c73..f8a7cb4d0c 100644
--- a/include/mbgl/text/glyph_store.hpp
+++ b/include/mbgl/text/glyph_store.hpp
@@ -4,6 +4,7 @@
 #include <mbgl/text/glyph.hpp>
 #include <mbgl/util/pbf.hpp>
 #include <mbgl/util/vec.hpp>
+#include <mbgl/util/ptr.hpp>
 
 #include <cstdint>
 #include <vector>
@@ -47,8 +48,15 @@ private:
 
 class GlyphPBF {
 public:
-    GlyphPBF(const std::string &glyphURL, const std::string &fontStack, GlyphRange glyphRange, const std::shared_ptr<FileSource> &fileSource);
+    GlyphPBF(const std::string &glyphURL, const std::string &fontStack, GlyphRange glyphRange, const util::ptr<FileSource> &fileSource);
 
+private:
+    GlyphPBF(const GlyphPBF &) = delete;
+    GlyphPBF(GlyphPBF &&) = delete;
+    GlyphPBF &operator=(const GlyphPBF &) = delete;
+    GlyphPBF &operator=(GlyphPBF &&) = delete;
+
+public:
     void parse(FontStack &stack);
 
     std::shared_future<GlyphPBF &> getFuture();
@@ -63,7 +71,7 @@ private:
 // Manages Glyphrange PBF loading.
 class GlyphStore {
 public:
-    GlyphStore(const std::shared_ptr<FileSource> &fileSource);
+    GlyphStore(const util::ptr<FileSource> &fileSource);
 
     // Block until all specified GlyphRanges of the specified font stack are loaded.
     void waitForGlyphRanges(const std::string &fontStack, const std::set<GlyphRange> &glyphRanges);
@@ -82,7 +90,7 @@ public:
     std::string glyphURL;
 
 private:
-    const std::shared_ptr<FileSource> fileSource;
+    const util::ptr<FileSource> fileSource;
     std::unordered_map<std::string, std::map<GlyphRange, std::unique_ptr<GlyphPBF>>> ranges;
     std::unordered_map<std::string, std::unique_ptr<FontStack>> stacks;
     std::mutex mtx;
diff --git a/include/mbgl/util/compression.hpp b/include/mbgl/util/compression.hpp
new file mode 100644
index 0000000000..a33b2476a7
--- /dev/null
+++ b/include/mbgl/util/compression.hpp
@@ -0,0 +1,15 @@
+#ifndef MBGL_UTIL_COMPRESSION
+#define MBGL_UTIL_COMPRESSION
+
+#include <string>
+
+namespace mbgl {
+namespace util {
+
+std::string compress(const std::string &raw);
+std::string decompress(const std::string &raw);
+
+}
+}
+
+#endif
diff --git a/include/mbgl/util/filesource.hpp b/include/mbgl/util/filesource.hpp
deleted file mode 100644
index 18c63ddfeb..0000000000
--- a/include/mbgl/util/filesource.hpp
+++ /dev/null
@@ -1,43 +0,0 @@
-#ifndef MBGL_UTIL_FILESOURCE
-#define MBGL_UTIL_FILESOURCE
-
-#include <mbgl/util/uv.hpp>
-
-#include <string>
-#include <memory>
-#include <functional>
-
-namespace mbgl {
-
-namespace platform {
-struct Response;
-}
-
-enum class ResourceType : uint8_t {
-    Unknown,
-    Tile,
-    Glyphs,
-    Image,
-    JSON
-};
-
-class FileSource {
-public:
-    FileSource();
-
-    void setBase(const std::string &value);
-    const std::string &getBase() const;
-
-    void load(ResourceType type, const std::string &url, std::function<void(platform::Response *)> callback, const std::shared_ptr<uv::loop> loop = nullptr);
-
-private:
-    // Stores a URL that is used as a base for loading resources with relative path.
-    std::string base;
-
-    // Stores the absolute path to the cache directory.
-    const std::string cache;
-};
-
-}
-
-#endif
diff --git a/include/mbgl/util/interpolate.hpp b/include/mbgl/util/interpolate.hpp
index e8c3389350..c9232db4eb 100644
--- a/include/mbgl/util/interpolate.hpp
+++ b/include/mbgl/util/interpolate.hpp
@@ -1,6 +1,8 @@
 #ifndef MBGL_UTIL_INTERPOLATE
 #define MBGL_UTIL_INTERPOLATE
 
+#include <array>
+
 namespace mbgl {
 namespace util {
 
diff --git a/include/mbgl/util/parsedate.h b/include/mbgl/util/parsedate.h
new file mode 100644
index 0000000000..6905e361d4
--- /dev/null
+++ b/include/mbgl/util/parsedate.h
@@ -0,0 +1,38 @@
+#ifndef HEADER_PARSEDATE_H
+#define HEADER_PARSEDATE_H
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <time.h>
+
+time_t parse_date(const char *p);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* HEADER_PARSEDATE_H */
diff --git a/include/mbgl/util/ptr.hpp b/include/mbgl/util/ptr.hpp
new file mode 100644
index 0000000000..6e02f956f3
--- /dev/null
+++ b/include/mbgl/util/ptr.hpp
@@ -0,0 +1,29 @@
+#ifndef MBGL_UTIL_PTR
+#define MBGL_UTIL_PTR
+
+#include <memory>
+#include <cassert>
+
+namespace mbgl {
+namespace util {
+
+template <typename T>
+class ptr : public ::std::shared_ptr<T> {
+public:
+    template <typename... Args>
+    inline ptr(Args &&... args)
+        : ::std::shared_ptr<T>(::std::forward<Args>(args)...) {}
+
+    inline auto operator->() const -> decltype(this->::std::shared_ptr<T>::operator->()) {
+        assert(*this);
+        return ::std::shared_ptr<T>::operator->();
+    }
+    inline auto operator*() const -> decltype(this->::std::shared_ptr<T>::operator*()) {
+        assert(*this);
+        return ::std::shared_ptr<T>::operator*();
+    }
+};
+}
+}
+
+#endif
\ No newline at end of file
diff --git a/include/mbgl/util/queue.h b/include/mbgl/util/queue.h
new file mode 100644
index 0000000000..fe02b454ea
--- /dev/null
+++ b/include/mbgl/util/queue.h
@@ -0,0 +1,92 @@
+/* Copyright (c) 2013, Ben Noordhuis <info@bnoordhuis.nl>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef QUEUE_H_
+#define QUEUE_H_
+
+typedef void *QUEUE[2];
+
+/* Private macros. */
+#define QUEUE_NEXT(q)       (*(QUEUE **) &((*(q))[0]))
+#define QUEUE_PREV(q)       (*(QUEUE **) &((*(q))[1]))
+#define QUEUE_PREV_NEXT(q)  (QUEUE_NEXT(QUEUE_PREV(q)))
+#define QUEUE_NEXT_PREV(q)  (QUEUE_PREV(QUEUE_NEXT(q)))
+
+/* Public macros. */
+#define QUEUE_DATA(ptr, type, field)                                          \
+  ((type *) ((char *) (ptr) - ((char *) &((type *) 0)->field)))
+
+#define QUEUE_FOREACH(q, h)                                                   \
+  for ((q) = QUEUE_NEXT(h); (q) != (h); (q) = QUEUE_NEXT(q))
+
+#define QUEUE_EMPTY(q)                                                        \
+  ((const QUEUE *) (q) == (const QUEUE *) QUEUE_NEXT(q))
+
+#define QUEUE_HEAD(q)                                                         \
+  (QUEUE_NEXT(q))
+
+#define QUEUE_INIT(q)                                                         \
+  do {                                                                        \
+    QUEUE_NEXT(q) = (q);                                                      \
+    QUEUE_PREV(q) = (q);                                                      \
+  }                                                                           \
+  while (0)
+
+#define QUEUE_ADD(h, n)                                                       \
+  do {                                                                        \
+    QUEUE_PREV_NEXT(h) = QUEUE_NEXT(n);                                       \
+    QUEUE_NEXT_PREV(n) = QUEUE_PREV(h);                                       \
+    QUEUE_PREV(h) = QUEUE_PREV(n);                                            \
+    QUEUE_PREV_NEXT(h) = (h);                                                 \
+  }                                                                           \
+  while (0)
+
+#define QUEUE_SPLIT(h, q, n)                                                  \
+  do {                                                                        \
+    QUEUE_PREV(n) = QUEUE_PREV(h);                                            \
+    QUEUE_PREV_NEXT(n) = (n);                                                 \
+    QUEUE_NEXT(n) = (q);                                                      \
+    QUEUE_PREV(h) = QUEUE_PREV(q);                                            \
+    QUEUE_PREV_NEXT(h) = (h);                                                 \
+    QUEUE_PREV(q) = (n);                                                      \
+  }                                                                           \
+  while (0)
+
+#define QUEUE_INSERT_HEAD(h, q)                                               \
+  do {                                                                        \
+    QUEUE_NEXT(q) = QUEUE_NEXT(h);                                            \
+    QUEUE_PREV(q) = (h);                                                      \
+    QUEUE_NEXT_PREV(q) = (q);                                                 \
+    QUEUE_NEXT(h) = (q);                                                      \
+  }                                                                           \
+  while (0)
+
+#define QUEUE_INSERT_TAIL(h, q)                                               \
+  do {                                                                        \
+    QUEUE_NEXT(q) = (h);                                                      \
+    QUEUE_PREV(q) = QUEUE_PREV(h);                                            \
+    QUEUE_PREV_NEXT(q) = (q);                                                 \
+    QUEUE_PREV(h) = (q);                                                      \
+  }                                                                           \
+  while (0)
+
+#define QUEUE_REMOVE(q)                                                       \
+  do {                                                                        \
+    QUEUE_PREV_NEXT(q) = QUEUE_NEXT(q);                                       \
+    QUEUE_NEXT_PREV(q) = QUEUE_PREV(q);                                       \
+  }                                                                           \
+  while (0)
+
+#endif /* QUEUE_H_ */
diff --git a/include/mbgl/util/raster.hpp b/include/mbgl/util/raster.hpp
index e526ffa5ac..7051c30091 100644
--- a/include/mbgl/util/raster.hpp
+++ b/include/mbgl/util/raster.hpp
@@ -4,11 +4,11 @@
 #include <mbgl/util/transition.hpp>
 #include <mbgl/util/texturepool.hpp>
 #include <mbgl/util/image.hpp>
+#include <mbgl/util/ptr.hpp>
 #include <mbgl/renderer/prerendered_texture.hpp>
 
 #include <string>
 #include <mutex>
-#include <memory>
 
 typedef struct uv_loop_s uv_loop_t;
 
@@ -17,7 +17,7 @@ namespace mbgl {
 class Raster : public std::enable_shared_from_this<Raster> {
 
 public:
-    Raster(const std::shared_ptr<Texturepool> &texturepool);
+    Raster(const util::ptr<Texturepool> &texturepool);
     ~Raster();
 
     // load image data
@@ -57,7 +57,7 @@ private:
     bool loaded = false;
 
     // shared texture pool
-    std::shared_ptr<Texturepool> texturepool;
+    util::ptr<Texturepool> texturepool;
 
     // min/mag filter
     uint32_t filter = 0;
@@ -66,7 +66,7 @@ private:
     std::unique_ptr<util::Image> img;
 
     // fade in transition
-    std::shared_ptr<util::transition> fade_transition = nullptr;
+    util::ptr<util::transition> fade_transition = nullptr;
 };
 
 }
diff --git a/include/mbgl/util/sqlite3.hpp b/include/mbgl/util/sqlite3.hpp
new file mode 100644
index 0000000000..3e324f7ce1
--- /dev/null
+++ b/include/mbgl/util/sqlite3.hpp
@@ -0,0 +1,74 @@
+#pragma once
+
+#include <string>
+#include <stdexcept>
+
+typedef struct sqlite3 sqlite3;
+typedef struct sqlite3_stmt sqlite3_stmt;
+
+namespace mapbox {
+namespace sqlite {
+
+enum OpenFlag : int {
+    ReadOnly = 0x00000001,
+    ReadWrite = 0x00000002,
+    Create = 0x00000004,
+    NoMutex = 0x00008000,
+    FullMutex = 0x00010000,
+    SharedCache = 0x00020000,
+    PrivateCache = 0x00040000,
+};
+
+struct Exception : std::runtime_error {
+    inline Exception(int err, const char *msg) : std::runtime_error(msg), code(err) {}
+    const int code = 0;
+};
+
+class Statement;
+
+class Database {
+private:
+    Database(const Database &) = delete;
+    Database &operator=(const Database &) = delete;
+
+public:
+    Database(const std::string &filename, int flags = 0);
+    Database(Database &&);
+    ~Database();
+    Database &operator=(Database &&);
+
+    operator bool() const;
+
+    void exec(const std::string &sql);
+    Statement prepare(const char *query);
+
+private:
+    sqlite3 *db = nullptr;
+};
+
+class Statement {
+private:
+    Statement(const Statement &) = delete;
+    Statement &operator=(const Statement &) = delete;
+
+public:
+    Statement(sqlite3 *db, const char *sql);
+    Statement(Statement &&);
+    ~Statement();
+    Statement &operator=(Statement &&);
+
+    operator bool() const;
+
+    template <typename T> void bind(int offset, T value);
+    void bind(int offset, const std::string &value, bool retain = true);
+    template <typename T> T get(int offset);
+
+    bool run();
+    void reset();
+
+private:
+    sqlite3_stmt *stmt = nullptr;
+};
+
+}
+}
diff --git a/include/mbgl/util/uv-channel.h b/include/mbgl/util/uv-channel.h
new file mode 100644
index 0000000000..ea5c279f65
--- /dev/null
+++ b/include/mbgl/util/uv-channel.h
@@ -0,0 +1,29 @@
+#ifndef MBGL_UTIL_UV_CHANNEL
+#define MBGL_UTIL_UV_CHANNEL
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <uv.h>
+
+// Taken from http://navaneeth.github.io/blog/2013/08/02/channels-in-libuv/
+
+typedef struct uv_chan_s uv_chan_t;
+
+struct uv_chan_s {
+    uv_mutex_t mutex;
+    uv_cond_t cond;
+    void *q[2];
+};
+
+int uv_chan_init(uv_chan_t *chan);
+void uv_chan_send(uv_chan_t *chan, void *data);
+void *uv_chan_receive(uv_chan_t *chan);
+void uv_chan_destroy(uv_chan_t *chan);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/include/mbgl/util/uv-messenger.h b/include/mbgl/util/uv-messenger.h
new file mode 100644
index 0000000000..82b8ef2d9c
--- /dev/null
+++ b/include/mbgl/util/uv-messenger.h
@@ -0,0 +1,32 @@
+#ifndef MBGL_UTIL_UV_MESSENGER
+#define MBGL_UTIL_UV_MESSENGER
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <uv.h>
+
+typedef struct uv_messenger_s uv_messenger_t;
+typedef void (*uv_messenger_cb)(void *arg);
+typedef void (*uv_messenger_stop_cb)(uv_messenger_t *msgr);
+
+struct uv_messenger_s {
+    uv_mutex_t mutex;
+    uv_async_t async;
+    uv_messenger_cb callback;
+    void *data;
+    void *queue[2];
+};
+
+int uv_messenger_init(uv_loop_t *loop, uv_messenger_t *msgr, uv_messenger_cb callback);
+void uv_messenger_send(uv_messenger_t *msgr, void *arg);
+void uv_messenger_stop(uv_messenger_t *msgr);
+void uv_messenger_ref(uv_messenger_t *msgr);
+void uv_messenger_unref(uv_messenger_t *msgr);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/include/mbgl/util/uv-worker.h b/include/mbgl/util/uv-worker.h
new file mode 100644
index 0000000000..451b6fb04d
--- /dev/null
+++ b/include/mbgl/util/uv-worker.h
@@ -0,0 +1,42 @@
+#ifndef MBGL_UTIL_UV_WORKER
+#define MBGL_UTIL_UV_WORKER
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct uv_messenger_s uv_messenger_t;
+
+#include <mbgl/util/uv-channel.h>
+
+#include <stdlib.h>
+
+typedef struct uv_worker_s uv_worker_t;
+
+typedef void (*uv_worker_cb)(void *data);
+typedef void (*uv_worker_after_cb)(void *data);
+typedef void (*uv_worker_close_cb)(uv_worker_t *worker);
+
+struct uv_worker_s {
+#ifndef NDEBUG
+    unsigned long thread_id;
+#endif
+    uv_loop_t *loop;
+    uv_messenger_t *msgr;
+    uv_chan_t chan;
+    const char *name;
+    int count;
+    uv_worker_close_cb close_cb;
+    unsigned int active_items;
+};
+
+int uv_worker_init(uv_worker_t *worker, uv_loop_t *loop, int count, const char *name);
+void uv_worker_send(uv_worker_t *worker, void *data, uv_worker_cb work_cb,
+                    uv_worker_after_cb after_work_cb);
+void uv_worker_close(uv_worker_t *worker, uv_worker_close_cb close_cb);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/include/mbgl/util/uv.hpp b/include/mbgl/util/uv.hpp
index 4ceb8b873f..3c533cfbf8 100644
--- a/include/mbgl/util/uv.hpp
+++ b/include/mbgl/util/uv.hpp
@@ -4,6 +4,7 @@
 #include <string>
 
 typedef struct uv_async_s uv_async_t;
+typedef struct uv_timer_s uv_timer_t;
 typedef struct uv_handle_s uv_handle_t;
 typedef struct uv_loop_s uv_loop_t;
 
@@ -11,9 +12,15 @@ namespace uv {
 
 std::string cwd();
 
+struct deleter {
+    void operator()(uv_async_t *async);
+    void operator()(uv_timer_t *timer);
+};
+
 class thread;
 class rwlock;
 class loop;
+class worker;
 
 }
 
diff --git a/include/mbgl/util/uv_detail.hpp b/include/mbgl/util/uv_detail.hpp
index b3fdbb3719..a80423f822 100644
--- a/include/mbgl/util/uv_detail.hpp
+++ b/include/mbgl/util/uv_detail.hpp
@@ -1,21 +1,13 @@
 #ifndef MBGL_UTIL_UV_DETAIL
 #define MBGL_UTIL_UV_DETAIL
 
+#include <mbgl/util/ptr.hpp>
+#include <mbgl/util/uv-worker.h>
+
 #include <uv.h>
+
 #include <functional>
 #include <cassert>
-
-#ifdef __clang__
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wunused-parameter"
-#endif
-
-#include <boost/lockfree/queue.hpp>
-
-#ifdef __clang__
-#pragma clang diagnostic pop
-#endif
-
 #include <string>
 
 
@@ -112,6 +104,24 @@ private:
     uv_once_t o = UV_ONCE_INIT;
 };
 
+class worker {
+public:
+    inline worker(uv_loop_t *loop, unsigned int count, const char *name = nullptr) : w(new uv_worker_t) {
+        uv_worker_init(w, loop, count, name);
+    }
+    inline ~worker() {
+        uv_worker_close(w, [](uv_worker_t *worker) {
+            delete worker;
+        });
+    }
+    inline void add(void *data, uv_worker_cb work_cb, uv_worker_after_cb after_work_cb) {
+        uv_worker_send(w, data, work_cb, after_work_cb);
+    }
+
+private:
+    uv_worker_t *w;
+};
+
 template <typename T>
 class work {
 public:
@@ -119,30 +129,26 @@ public:
     typedef void (*after_work_callback)(T &object);
 
     template<typename... Args>
-    work(const std::shared_ptr<loop> &loop, work_callback work_cb, after_work_callback after_work_cb, Args&&... args)
-        : loop(loop),
-          data(std::forward<Args>(args)...),
+    work(worker &worker, work_callback work_cb, after_work_callback after_work_cb, Args&&... args)
+        : data(std::forward<Args>(args)...),
           work_cb(work_cb),
           after_work_cb(after_work_cb) {
-        req.data = this;
-        uv_queue_work(**loop, &req, do_work, after_work);
+        worker.add(this, do_work, after_work);
     }
 
 private:
-    static void do_work(uv_work_t *req) {
-        work<T> *w = static_cast<work<T> *>(req->data);
+    static void do_work(void *data) {
+        work<T> *w = reinterpret_cast<work<T> *>(data);
         w->work_cb(w->data);
     }
 
-    static void after_work(uv_work_t *req, int) {
-        work<T> *w = static_cast<work<T> *>(req->data);
+    static void after_work(void *data) {
+        work<T> *w = reinterpret_cast<work<T> *>(data);
         w->after_work_cb(w->data);
         delete w;
     }
 
 private:
-    std::shared_ptr<uv::loop> loop;
-    uv_work_t req;
     T data;
     work_callback work_cb;
     after_work_callback after_work_cb;
diff --git a/linux/mapboxgl-app.gyp b/linux/mapboxgl-app.gyp
index e19768caf9..dac1934d31 100644
--- a/linux/mapboxgl-app.gyp
+++ b/linux/mapboxgl-app.gyp
@@ -15,7 +15,8 @@
         '../common/platform_default.cpp',
         '../common/glfw_view.hpp',
         '../common/glfw_view.cpp',
-        '../common/curl_request.cpp',
+        '../common/http_request_baton_curl.cpp',
+        '../common/linux.cpp',
         '../common/stderr_log.hpp',
         '../common/stderr_log.cpp',
       ],
@@ -32,7 +33,6 @@
             ],
             'OTHER_LDFLAGS': [
               '<@(glfw3_libraries)',
-              '<@(curl_libraries)',
             ],
           }
         },
@@ -46,7 +46,6 @@
           'link_settings': {
             'libraries': [
               '<@(glfw3_libraries)',
-              '<@(curl_libraries)',
               '-lboost_regex'
             ],
           },
diff --git a/macosx/main.mm b/macosx/main.mm
index 9ecc307c05..aeb49225cb 100644
--- a/macosx/main.mm
+++ b/macosx/main.mm
@@ -1,9 +1,12 @@
 #include "../common/settings_nsuserdefaults.hpp"
 #include "../common/glfw_view.hpp"
 #include "../common/nslog_log.hpp"
+#include "../common/Reachability.h"
 
 #import <Foundation/Foundation.h>
 
+#include <uv.h>
+
 @interface URLHandler : NSObject
 @property (nonatomic) mbgl::Map *map;
 
@@ -68,16 +71,25 @@
 @end
 
 int main() {
+    fprintf(stderr, "main thread: 0x%lx\n", uv_thread_self());
     mbgl::Log::Set<mbgl::NSLogBackend>();
 
     GLFWView view;
     mbgl::Map map(view);
+    mbgl::Map *map_ptr = &map;
 
     URLHandler *handler = [[URLHandler alloc] init];
     [handler setMap:&map];
     NSAppleEventManager *appleEventManager = [NSAppleEventManager sharedAppleEventManager];
     [appleEventManager setEventHandler:handler andSelector:@selector(handleGetURLEvent:withReplyEvent:) forEventClass:kInternetEventClass andEventID:kAEGetURL];
 
+    // Notify map object when network reachability status changes.
+    Reachability* reachability = [Reachability reachabilityForInternetConnection];
+    reachability.reachableBlock = ^(Reachability *reachability) {
+        map_ptr->setReachability(true);
+    };
+    [reachability startNotifier];
+
     // Load settings
     mbgl::Settings_NSUserDefaults settings;
     map.setLonLatZoom(settings.longitude, settings.latitude, settings.zoom);
@@ -97,6 +109,8 @@ int main() {
 
     int ret = view.run();
 
+    [reachability stopNotifier];
+
     // Save settings
     map.getLonLatZoom(settings.longitude, settings.latitude, settings.zoom);
     settings.bearing = map.getBearing();
diff --git a/macosx/mapboxgl-app.gyp b/macosx/mapboxgl-app.gyp
index da5c68ea35..51f591fdd0 100644
--- a/macosx/mapboxgl-app.gyp
+++ b/macosx/mapboxgl-app.gyp
@@ -15,8 +15,10 @@
         '../common/platform_nsstring.mm',
         '../common/glfw_view.hpp',
         '../common/glfw_view.cpp',
-        '../common/foundation_request.h',
-        '../common/foundation_request.mm',
+        '../common/reachability.h',
+        '../common/reachability.m',
+        '../common/http_request_baton_cocoa.mm',
+        '../common/osx.mm',
         '../common/nslog_log.hpp',
         '../common/nslog_log.mm',
       ],
@@ -33,6 +35,7 @@
         ],
         'OTHER_LDFLAGS': [
           '<@(glfw3_libraries)',
+          '-framework SystemConfiguration',
         ],
         'SDKROOT': 'macosx',
         'INFOPLIST_FILE': 'Info.plist',
diff --git a/mapboxgl.gyp b/mapboxgl.gyp
index dcd89f3a76..68434bf2ba 100644
--- a/mapboxgl.gyp
+++ b/mapboxgl.gyp
@@ -31,7 +31,7 @@
             '<(SHARED_INTERMEDIATE_DIR)/src/shader/shaders_gl.cpp',
             '<(SHARED_INTERMEDIATE_DIR)/src/shader/shaders_gles2.cpp'
         ],
-        'include_dirs':[
+        'include_dirs': [
           '<(SHARED_INTERMEDIATE_DIR)/include/',
         ]
       }
@@ -126,53 +126,70 @@
         '<!@(find src -name "*.glsl")',
         'bin/style.json'
       ],
-      'xcode_settings': {
-        'SDKROOT': 'macosx',
-        'SUPPORTED_PLATFORMS':['macosx'],
-        'MACOSX_DEPLOYMENT_TARGET':'10.9',
-        'PUBLIC_HEADERS_FOLDER_PATH': 'include',
-        'OTHER_CPLUSPLUSFLAGS':[
-          '<@(png_cflags)',
-          '<@(uv_cflags)',
-          '-I<(boost_root)/include',
-        ]
-      },
-      'include_dirs':[
-          './include'
-      ],
-      'cflags': [
-          '<@(png_cflags)',
-          '-I<(boost_root)/include',
+      'include_dirs': [
+        './include'
       ],
-      'direct_dependent_settings': {
-          'include_dirs':[
-              './include',
-          ],
-          'cflags': [
+      'conditions': [
+        ['OS == "mac"', {
+          'xcode_settings': {
+            'SDKROOT': 'macosx',
+            'SUPPORTED_PLATFORMS': ['macosx'],
+            'MACOSX_DEPLOYMENT_TARGET': '10.9',
+            'PUBLIC_HEADERS_FOLDER_PATH': 'include',
+            'OTHER_CPLUSPLUSFLAGS': [
               '<@(png_cflags)',
               '<@(uv_cflags)',
+              '<@(curl_cflags)',
+              '<@(sqlite3_cflags)',
+              '-I<(boost_root)/include',
+            ],
+            'OTHER_CFLAGS': [
+              '<@(uv_cflags)',
+            ],
+          },
+        }, {
+          'cflags': [
+            '<@(png_cflags)',
+            '<@(uv_cflags)',
+            '<@(curl_cflags)',
+            '<@(sqlite3_cflags)',
+            '-I<(boost_root)/include',
           ],
-          'xcode_settings': {
-            'OTHER_CPLUSPLUSFLAGS':[
-                '<@(png_cflags)',
+        }]
+      ],
+      'direct_dependent_settings': {
+        'include_dirs': [
+          './include',
+        ],
+        'conditions': [
+          ['OS == "mac"', {
+            'xcode_settings': {
+              'OTHER_CPLUSPLUSFLAGS': [
                 '<@(uv_cflags)',
-            ]
-          },
-          'conditions': [
-            ['OS == "mac"', {
-              'xcode_settings': {
-                'OTHER_LDFLAGS': [
-                    '<@(png_libraries)',
-                    '<@(uv_libraries)',
-                ]
-              }
-            }, {
-              'libraries': [
+                '<@(curl_cflags)',
+                '-I<(boost_root)/include',
+              ],
+              'OTHER_LDFLAGS': [
                 '<@(png_libraries)',
                 '<@(uv_libraries)',
+                '<@(curl_libraries)',
+                '<@(sqlite3_libraries)',
               ]
-            }]
-          ]
+            }
+          }, {
+            'cflags': [
+              '<@(uv_cflags)',
+              '<@(curl_cflags)',
+              '-I<(boost_root)/include',
+            ],
+            'libraries': [
+              '<@(png_libraries)',
+              '<@(uv_libraries)',
+              '<@(curl_libraries)',
+              '<@(sqlite3_libraries)',
+            ]
+          }]
+        ]
       }
     },
     {
@@ -181,7 +198,7 @@
       'type': 'static_library',
       'hard_dependency': 1,
       'dependencies': [
-          'shaders',
+        'shaders',
       ],
       'sources': [
         '<!@(find src/ \( -name "*.cpp" ! -name shaders.hpp ! -name shaders_gles2.cpp ! -name shaders_gl.cpp \))',
@@ -195,56 +212,42 @@
       ],
       'xcode_settings': {
         'SDKROOT': 'iphoneos',
-        'SUPPORTED_PLATFORMS':['iphonesimulator','iphoneos'],
+        'SUPPORTED_PLATFORMS': ['iphonesimulator','iphoneos'],
         'ARCHS': [ "armv7", "armv7s", "arm64", "i386", "x86_64" ],
         'TARGETED_DEVICE_FAMILY': '1,2',
         'CODE_SIGN_IDENTITY': 'iPhone Developer',
         'IPHONEOS_DEPLOYMENT_TARGET': '7.0',
         'PUBLIC_HEADERS_FOLDER_PATH': 'include',
-        'GCC_INPUT_FILETYPE':'sourcecode.cpp.cpp',
-        'OTHER_CPLUSPLUSFLAGS':[
+        'GCC_INPUT_FILETYPE': 'sourcecode.cpp.cpp',
+        'OTHER_CPLUSPLUSFLAGS': [
           '<@(png_cflags)',
           '<@(uv_cflags)',
+          '<@(curl_cflags)',
+          '<@(sqlite3_cflags)',
           '-I<(boost_root)/include',
-        ]
+        ],
       },
-      'include_dirs':[
-          './include'
-      ],
-      'cflags': [
-          '<@(png_cflags)',
-          '<@(uv_cflags)',
-          '-I<(boost_root)/include',
+      'include_dirs': [
+        './include'
       ],
       'direct_dependent_settings': {
-          'include_dirs':[
-              './include'
+        'include_dirs': [
+          './include',
+        ],
+        'xcode_settings': {
+          'OTHER_LDFLAGS': [
+            '<@(png_libraries)',
+            '<@(uv_libraries)',
+            '<@(curl_libraries)',
+            '<@(sqlite3_libraries)',
           ],
-          'cflags': [
-              '<@(png_cflags)',
-              '<@(uv_cflags)',
+          'OTHER_CPLUSPLUSFLAGS': [
+            '<@(uv_cflags)',
           ],
-          'xcode_settings': {
-            'OTHER_CPLUSPLUSFLAGS':[
-                '<@(png_cflags)',
-                '<@(uv_cflags)',
-            ]
-          },
-          'conditions': [
-            ['OS == "mac"', {
-              'xcode_settings': {
-                'OTHER_LDFLAGS': [
-                    '<@(png_libraries)',
-                    '<@(uv_libraries)',
-                ]
-              }
-            }, {
-              'libraries': [
-                '<@(png_libraries)',
-                '<@(uv_libraries)'
-              ]
-            }]
-          ]
+          'OTHER_CFLAGS': [
+            '<@(uv_cflags)',
+          ],
+        }
       }
     }
   ]
diff --git a/scripts/flags.sh b/scripts/flags.sh
index 0c0981cdc1..58aee18a04 100755
--- a/scripts/flags.sh
+++ b/scripts/flags.sh
@@ -16,12 +16,12 @@ if [[ ${TRAVIS_OS_NAME} == "linux" ]]; then
     # some limited coverage
     if [[ ${BUILDTYPE} == "Debug" ]]; then
         if [[ ${CXX} == "g++" ]]; then
-            export CXXFLAGS="-fsanitize=address ${CXXFLAGS}"
-            export CFLAGS="-fsanitize=address ${CFLAGS}"
+            export CXXFLAGS="-fsanitize=address -g ${CXXFLAGS}"
+            export CFLAGS="-fsanitize=address -g ${CFLAGS}"
             export LDFLAGS="-fsanitize=address  ${LDFLAGS}"
         elif [[ ${CXX} == "clang++" ]]; then
-            export CXXFLAGS="-fsanitize=thread -fPIC ${CXXFLAGS}"
-            export CFLAGS="-fsanitize=thread ${CFLAGS}"
+            export CXXFLAGS="-fsanitize=thread -g -fPIC ${CXXFLAGS}"
+            export CFLAGS="-fsanitize=thread -g ${CFLAGS}"
             export LDFLAGS="-fsanitize=thread -pie ${LDFLAGS}"
         fi
     fi
diff --git a/setup-libraries.sh b/setup-libraries.sh
index ce0a230bcd..dc1b1643fa 100755
--- a/setup-libraries.sh
+++ b/setup-libraries.sh
@@ -53,6 +53,7 @@ NPM=$(which npm)
 
 MP_HASH="e82e6c00ea5a0cda147e4c121a3c7751cae69ff8"
 DIR_HASH=$(echo `pwd` | git hash-object --stdin)
+
 if [ ! -d 'mapnik-packaging/' ]; then
   git clone https://github.com/mapnik/mapnik-packaging.git
 fi
@@ -66,7 +67,7 @@ export CXX11=true
 
 if [ ${UNAME} = 'Darwin' ]; then
 
-if [ ! -z "${TRAVIS:-}" ]; then
+if [[ $TRAVIS ]]; then
     if aws s3 cp s3://${AWS_S3_BUCKET}/dependencies/build-cpp11-libcpp-osx_${MP_HASH}_${DIR_HASH}.tar.gz ./out/ ; then
         if aws s3 cp s3://${AWS_S3_BUCKET}/dependencies/build-cpp11-libcpp-ios_${MP_HASH}_${DIR_HASH}.tar.gz ./out/ ; then
             rm -rf out/build-cpp11-libcpp-x86_64-macosx
@@ -83,30 +84,40 @@ source iPhoneOS.sh
 export LIBUV_VERSION=0.10.28
     if [ ! -f out/build-cpp11-libcpp-armv7-iphoneos/lib/libpng.a ] ; then ./scripts/build_png.sh ; fi
     if [ ! -f out/build-cpp11-libcpp-armv7-iphoneos/lib/libuv.a ] ; then ./scripts/build_libuv.sh ; fi
+    if [ ! -f out/build-cpp11-libcpp-armv7-iphoneos/lib/libcurl.a ] ; then ./scripts/build_curl.sh ; fi
+    if [ ! -f out/build-cpp11-libcpp-armv7-iphoneos/lib/libsqlite3.a ] ; then ./scripts/build_sqlite.sh ; fi
     echo '     ...done'
 
 source iPhoneOSs.sh
 export LIBUV_VERSION=0.10.28
     if [ ! -f out/build-cpp11-libcpp-armv7s-iphoneoss/lib/libpng.a ] ; then ./scripts/build_png.sh ; fi
     if [ ! -f out/build-cpp11-libcpp-armv7s-iphoneoss/lib/libuv.a ] ; then ./scripts/build_libuv.sh ; fi
+    if [ ! -f out/build-cpp11-libcpp-armv7s-iphoneoss/lib/libcurl.a ] ; then ./scripts/build_curl.sh ; fi
+    if [ ! -f out/build-cpp11-libcpp-armv7s-iphoneoss/lib/libsqlite3.a ] ; then ./scripts/build_sqlite.sh ; fi
     echo '     ...done'
 
 source iPhoneOS64.sh
 export LIBUV_VERSION=0.10.28
     if [ ! -f out/build-cpp11-libcpp-arm64-iphoneos64/lib/libpng.a ] ; then ./scripts/build_png.sh ; fi
     if [ ! -f out/build-cpp11-libcpp-arm64-iphoneos64/lib/libuv.a ] ; then ./scripts/build_libuv.sh ; fi
+    if [ ! -f out/build-cpp11-libcpp-arm64-iphoneos64/lib/libcurl.a ] ; then ./scripts/build_curl.sh ; fi
+    if [ ! -f out/build-cpp11-libcpp-arm64-iphoneos64/lib/libsqlite3.a ] ; then ./scripts/build_sqlite.sh ; fi
     echo '     ...done'
 
 source iPhoneSimulator.sh
 export LIBUV_VERSION=0.10.28
     if [ ! -f out/build-cpp11-libcpp-i386-iphonesimulator/lib/libpng.a ] ; then ./scripts/build_png.sh ; fi
     if [ ! -f out/build-cpp11-libcpp-i386-iphonesimulator/lib/libuv.a ] ; then ./scripts/build_libuv.sh ; fi
+    if [ ! -f out/build-cpp11-libcpp-i386-iphonesimulator/lib/libcurl.a ] ; then ./scripts/build_curl.sh ; fi
+    if [ ! -f out/build-cpp11-libcpp-i386-iphonesimulator/lib/libsqlite3.a ] ; then ./scripts/build_sqlite.sh ; fi
     echo '     ...done'
 
 source iPhoneSimulator64.sh
 export LIBUV_VERSION=0.10.28
    if [ ! -f out/build-cpp11-libcpp-x86_64-iphonesimulator/lib/libpng.a ] ; then ./scripts/build_png.sh ; fi
    if [ ! -f out/build-cpp11-libcpp-x86_64-iphonesimulator/lib/libuv.a ] ; then ./scripts/build_libuv.sh ; fi
+   if [ ! -f out/build-cpp11-libcpp-x86_64-iphonesimulator/lib/libcurl.a ] ; then ./scripts/build_curl.sh ; fi
+   if [ ! -f out/build-cpp11-libcpp-x86_64-iphonesimulator/lib/libsqlite3.a ] ; then ./scripts/build_sqlite.sh ; fi
    echo '     ...done'
 
 source MacOSX.sh
@@ -114,6 +125,7 @@ export LIBUV_VERSION=0.10.28
     if [ ! -f out/build-cpp11-libcpp-x86_64-macosx/lib/libpng.a ] ; then ./scripts/build_png.sh ; fi
     if [ ! -f out/build-cpp11-libcpp-x86_64-macosx/lib/libglfw3.a ] ; then ./scripts/build_glfw.sh ; fi
     if [ ! -f out/build-cpp11-libcpp-x86_64-macosx/lib/libuv.a ] ; then ./scripts/build_libuv.sh ; fi
+    if [ ! -f out/build-cpp11-libcpp-x86_64-macosx/lib/libsqlite3.a ] ; then ./scripts/build_sqlite.sh ; fi
     if [ ! -f out/build-cpp11-libcpp-x86_64-macosx/lib/libssl.a ] ; then ./scripts/build_openssl.sh ; fi
     if [ ! -f out/build-cpp11-libcpp-x86_64-macosx/lib/libcurl.a ] ; then ./scripts/build_curl.sh ; fi
     if [ ! -d out/build-cpp11-libcpp-x86_64-macosx/include/boost ] ; then ./scripts/build_boost.sh `pwd`/../../src/ `pwd`/../../include/ `pwd`/../../linux/ `pwd`/../../common/ ; fi
@@ -121,8 +133,10 @@ export LIBUV_VERSION=0.10.28
 
 # setup iOS universal libs
 ./scripts/make_universal.sh
+patch -p0 --forward < patches/curl-ios.diff || true
+echo "NOTE: One patch FAILURE is expected. The other should have been applied or ignored."
 
-if [ ! -z "${TRAVIS:-}" ] && [ ! -z "${AWS_ACCESS_KEY_ID}" ] && [ ! -z "${AWS_SECRET_ACCESS_KEY}" ] ; then
+if [[ $TRAVIS && $AWS_ACCESS_KEY_ID && $AWS_SECRET_ACCESS_KEY ]] ; then
     tar -zcf out/build-cpp11-libcpp-ios_${MP_HASH}_${DIR_HASH}.tar.gz out/build-cpp11-libcpp-universal
     aws s3 cp --acl public-read out/build-cpp11-libcpp-ios_${MP_HASH}_${DIR_HASH}.tar.gz s3://${AWS_S3_BUCKET}/dependencies/
     tar -zcf out/build-cpp11-libcpp-osx_${MP_HASH}_${DIR_HASH}.tar.gz out/build-cpp11-libcpp-x86_64-macosx
@@ -138,7 +152,7 @@ cd ../../
 
 elif [ ${UNAME} = 'Linux' ]; then
 
-if [ ! -z "${TRAVIS:-}" ]; then
+if [[ $TRAVIS ]]; then
     if aws s3 cp s3://${AWS_S3_BUCKET}/dependencies/build-cpp11-libstdcpp-gcc-x86_64-linux_${MP_HASH}_${DIR_HASH}.tar.gz ./out/ ; then
         rm -rf out/build-cpp11-libstdcpp-gcc-x86_64-linux
         tar -xzf out/build-cpp11-libstdcpp-gcc-x86_64-linux_${MP_HASH}_${DIR_HASH}.tar.gz
@@ -150,11 +164,12 @@ export LIBUV_VERSION=0.10.28
     if [ ! -f out/build-cpp11-libstdcpp-gcc-x86_64-linux/lib/libglfw3.a ] ; then ./scripts/build_glfw.sh ; fi
     if [ ! -f out/build-cpp11-libstdcpp-gcc-x86_64-linux/lib/libpng.a ] ; then ./scripts/build_png.sh ; fi
     if [ ! -f out/build-cpp11-libstdcpp-gcc-x86_64-linux/lib/libuv.a ] ; then ./scripts/build_libuv.sh ; fi
+    if [ ! -f out/build-cpp11-libstdcpp-gcc-x86_64-linux/lib/libsqlite3.a ] ; then ./scripts/build_sqlite.sh ; fi
     if [ ! -f out/build-cpp11-libstdcpp-gcc-x86_64-linux/lib/libssl.a ] ; then ./scripts/build_openssl.sh ; fi
     if [ ! -f out/build-cpp11-libstdcpp-gcc-x86_64-linux/lib/libcurl.a ] ; then ./scripts/build_curl.sh ; fi
     if [ ! -f out/build-cpp11-libstdcpp-gcc-x86_64-linux/lib/libboost_regex.a ] ; then ./scripts/build_boost.sh --with-regex ; fi
 
-if [ ! -z "${TRAVIS:-}" ] && [ ! -z "${AWS_ACCESS_KEY_ID}" ] && [ ! -z "${AWS_SECRET_ACCESS_KEY}" ] ; then
+if [[ $TRAVIS && $AWS_ACCESS_KEY_ID && $AWS_SECRET_ACCESS_KEY ]] ; then
     if ! tar --compare -zf out/build-cpp11-libstdcpp-gcc-x86_64-linux.tar.gz ; then
         tar -zcf out/build-cpp11-libstdcpp-gcc-x86_64-linux_${MP_HASH}_${DIR_HASH}.tar.gz out/build-cpp11-libstdcpp-gcc-x86_64-linux
         aws s3 cp --acl public-read out/build-cpp11-libstdcpp-gcc-x86_64-linux_${MP_HASH}_${DIR_HASH}.tar.gz s3://${AWS_S3_BUCKET}/dependencies/
diff --git a/src/map/map.cpp b/src/map/map.cpp
index ad8749ff08..9034c6d5ac 100644
--- a/src/map/map.cpp
+++ b/src/map/map.cpp
@@ -19,11 +19,10 @@
 #include <mbgl/style/style_bucket.hpp>
 #include <mbgl/util/texturepool.hpp>
 #include <mbgl/geometry/sprite_atlas.hpp>
-#include <mbgl/util/filesource.hpp>
+#include <mbgl/storage/file_source.hpp>
 #include <mbgl/platform/log.hpp>
 
 #include <algorithm>
-#include <memory>
 #include <iostream>
 
 #define _USE_MATH_DEFINES
@@ -34,12 +33,15 @@ using namespace mbgl;
 Map::Map(View& view)
     : loop(std::make_shared<uv::loop>()),
       thread(std::make_unique<uv::thread>()),
+      async_terminate(new uv_async_t()),
+      async_render(new uv_async_t()),
+      async_cleanup(new uv_async_t()),
       view(view),
+#ifndef NDEBUG
+      main_thread(uv_thread_self()),
+#endif
       transform(view),
-      fileSource(std::make_shared<FileSource>()),
-      style(std::make_shared<Style>()),
       glyphAtlas(std::make_shared<GlyphAtlas>(1024, 1024)),
-      glyphStore(std::make_shared<GlyphStore>(fileSource)),
       spriteAtlas(std::make_shared<SpriteAtlas>(512, 512)),
       texturepool(std::make_shared<Texturepool>()),
       painter(*this) {
@@ -53,49 +55,93 @@ Map::Map(View& view)
 }
 
 Map::~Map() {
-    // Clear the style first before the rest of the constructor deletes members of this object.
-    // This is required because members of the style reference the Map object in their destructors.
-    style.reset();
-
     if (async) {
         stop();
     }
+
+    // Explicitly reset all pointers.
+    texturepool.reset();
+    sprite.reset();
+    spriteAtlas.reset();
+    glyphStore.reset();
+    glyphAtlas.reset();
+    style.reset();
+    fileSource.reset();
+    workers.reset();
+
+    uv_run(**loop, UV_RUN_DEFAULT);
+}
+
+uv::worker &Map::getWorker() {
+    if (!workers) {
+        workers = std::make_unique<uv::worker>(**loop, 4, "Tile Worker");
+    }
+    return *workers;
 }
 
 void Map::start() {
+    assert(uv_thread_self() == main_thread);
+    assert(!async);
+
     // When starting map rendering in another thread, we perform async/continuously
     // updated rendering. Only in these cases, we attach the async handlers.
     async = true;
 
+    // Reset the flag.
+    is_stopped = false;
+
     // Setup async notifications
-    async_terminate = new uv_async_t();
-    uv_async_init(**loop, async_terminate, terminate);
-    async_terminate->data = **loop;
+    uv_async_init(**loop, async_terminate.get(), terminate);
+    async_terminate->data = this;
 
-    async_render = new uv_async_t();
-    uv_async_init(**loop, async_render, render);
+    uv_async_init(**loop, async_render.get(), render);
     async_render->data = this;
 
-    async_cleanup = new uv_async_t();
-    uv_async_init(**loop, async_cleanup, cleanup);
+    uv_async_init(**loop, async_cleanup.get(), cleanup);
     async_cleanup->data = this;
 
     uv_thread_create(*thread, [](void *arg) {
         Map *map = static_cast<Map *>(arg);
+#ifndef NDEBUG
+        map->map_thread = uv_thread_self();
+#endif
+#ifdef __APPLE__
+        pthread_setname_np("Map");
+#endif
         map->run();
+#ifndef NDEBUG
+        map->map_thread = -1;
+#endif
+
+        // Make sure that the stop() function knows when to stop invoking the callback function.
+        map->is_stopped = true;
+        map->view.notify();
     }, this);
 }
 
-void Map::stop() {
-    if (async_terminate != nullptr) {
-        uv_async_send(async_terminate);
+void Map::stop(stop_callback cb, void *data) {
+    assert(uv_thread_self() == main_thread);
+    assert(main_thread != map_thread);
+    assert(async);
+
+    uv_async_send(async_terminate.get());
+
+    if (cb) {
+        // Wait until the render thread stopped. We are using this construct instead of plainly
+        // relying on the thread_join because the system might need to run things in the current
+        // thread that is required for the render thread to terminate correctly. This is for example
+        // the case with Cocoa's NSURLRequest. Otherwise, we will eventually deadlock because this
+        // thread (== main thread) is blocked. The callback function should use an efficient waiting
+        // function to avoid a busy waiting loop.
+        while (!is_stopped) {
+            cb(data);
+        }
     }
 
+    // If a callback function was provided, this should return immediately because the thread has
+    // already finished executing.
     uv_thread_join(*thread);
 
-    // Run the event loop once to make sure our async delete handlers are called.
-    uv_run(**loop, UV_RUN_ONCE);
-
     async = false;
 }
 
@@ -104,22 +150,35 @@ void Map::delete_async(uv_handle_t *handle, int status) {
 }
 
 void Map::run() {
+#ifndef NDEBUG
+    if (!async) {
+        map_thread = main_thread;
+    }
+#endif
+    assert(uv_thread_self() == map_thread);
+
     setup();
     prepare();
     uv_run(**loop, UV_RUN_DEFAULT);
 
+    // Run the event loop once more to make sure our async delete handlers are called.
+    uv_run(**loop, UV_RUN_ONCE);
+
     // If the map rendering wasn't started asynchronously, we perform one render
     // *after* all events have been processed.
     if (!async) {
         render();
+#ifndef NDEBUG
+        map_thread = -1;
+#endif
     }
 }
 
 void Map::rerender() {
     // We only send render events if we want to continuously update the map
     // (== async rendering).
-    if (async && async_render != nullptr) {
-        uv_async_send(async_render);
+    if (async) {
+        uv_async_send(async_render.get());
     }
 }
 
@@ -139,7 +198,7 @@ void Map::swapped() {
 
 void Map::cleanup() {
     if (async_cleanup != nullptr) {
-        uv_async_send(async_cleanup);
+        uv_async_send(async_cleanup.get());
     }
 }
 
@@ -153,9 +212,20 @@ void Map::terminate() {
     painter.terminate();
 }
 
+void Map::setReachability(bool reachable) {
+    // Note: This function may be called from *any* thread.
+    if (reachable) {
+        if (fileSource) {
+            fileSource->prepare([&]() {
+                fileSource->retryAllPending();
+            });
+        }
+    }
+}
+
 void Map::render(uv_async_t *async, int status) {
     Map *map = static_cast<Map *>(async->data);
-
+    assert(uv_thread_self() == map->map_thread);
 
     if (map->state.hasSize()) {
         if (map->is_rendered.test_and_set() == false) {
@@ -175,44 +245,48 @@ void Map::render(uv_async_t *async, int status) {
 
 void Map::terminate(uv_async_t *async, int status) {
     // Closes all open handles on the loop. This means that the loop will automatically terminate.
-    uv_loop_t *loop = static_cast<uv_loop_t *>(async->data);
-    uv_walk(loop, [](uv_handle_t *handle, void */*arg*/) {
-        if (!uv_is_closing(handle)) {
-            uv_close(handle, NULL);
-        }
-    }, NULL);
+    Map *map = static_cast<Map *>(async->data);
+    assert(uv_thread_self() == map->map_thread);
+
+    // Remove all of these to make sure they are destructed in the correct thread.
+    map->glyphStore.reset();
+    map->fileSource.reset();
+    map->style.reset();
+    map->workers.reset();
+    map->activeSources.clear();
+
+    uv_close((uv_handle_t *)map->async_cleanup.get(), nullptr);
+    uv_close((uv_handle_t *)map->async_render.get(), nullptr);
+    uv_close((uv_handle_t *)map->async_terminate.get(), nullptr);
 }
 
 #pragma mark - Setup
 
 void Map::setup() {
+    assert(uv_thread_self() == map_thread);
     view.make_active();
     painter.setup();
     view.make_inactive();
 }
 
 void Map::setStyleURL(const std::string &url) {
-    fileSource->load(ResourceType::JSON, url, [&](platform::Response *res) {
-        if (res->code == 200) {
-            // Calculate the base
-            const size_t pos = url.rfind('/');
-            std::string base = "";
-            if (pos != std::string::npos) {
-                base = url.substr(0, pos + 1);
-            }
-
-            this->setStyleJSON(res->body, base);
-        } else {
-            Log::Error(Event::Setup, "loading style failed: %d (%s)", res->code, res->error_message.c_str());
-        }
-    }, loop);
+    // TODO: Make threadsafe.
+    styleURL = url;
 }
 
 
 void Map::setStyleJSON(std::string newStyleJSON, const std::string &base) {
+    // TODO: Make threadsafe.
     styleJSON.swap(newStyleJSON);
     sprite.reset();
+    if (!style) {
+        style = std::make_shared<Style>();
+    }
     style->loadJSON((const uint8_t *)styleJSON.c_str());
+    if (!fileSource) {
+        fileSource = std::make_shared<FileSource>(**loop, platform::defaultCacheDatabase());
+        glyphStore = std::make_shared<GlyphStore>(fileSource);
+    }
     fileSource->setBase(base);
     glyphStore->setURL(util::mapbox::normalizeGlyphsURL(style->glyph_url, getAccessToken()));
     update();
@@ -223,6 +297,7 @@ std::string Map::getStyleJSON() const {
 }
 
 void Map::setAccessToken(std::string access_token) {
+    // TODO: Make threadsafe.
     accessToken.swap(access_token);
 }
 
@@ -230,7 +305,7 @@ std::string Map::getAccessToken() const {
     return accessToken;
 }
 
-std::shared_ptr<Sprite> Map::getSprite() {
+util::ptr<Sprite> Map::getSprite() {
     const float pixelRatio = state.getPixelRatio();
     const std::string &sprite_url = style->getSpriteURL();
     if (!sprite || sprite->pixelRatio != pixelRatio) {
@@ -460,8 +535,10 @@ void Map::setDefaultTransitionDuration(uint64_t duration_milliseconds) {
 }
 
 void Map::updateSources() {
+    assert(uv_thread_self() == map_thread);
+
     // First, disable all existing sources.
-    for (const std::shared_ptr<StyleSource> &source : activeSources) {
+    for (const util::ptr<StyleSource> &source : activeSources) {
         source->enabled = false;
     }
 
@@ -469,7 +546,7 @@ void Map::updateSources() {
     updateSources(style->layers);
 
     // Then, construct or destroy the actual source object, depending on enabled state.
-    for (const std::shared_ptr<StyleSource> &style_source : activeSources) {
+    for (const util::ptr<StyleSource> &style_source : activeSources) {
         if (style_source->enabled) {
             if (!style_source->source) {
                 style_source->source = std::make_shared<Source>(style_source->info);
@@ -481,20 +558,20 @@ void Map::updateSources() {
     }
 
     // Finally, remove all sources that are disabled.
-    util::erase_if(activeSources, [](std::shared_ptr<StyleSource> source){
+    util::erase_if(activeSources, [](util::ptr<StyleSource> source){
         return !source->enabled;
     });
 }
 
-const std::set<std::shared_ptr<StyleSource>> Map::getActiveSources() const {
+const std::set<util::ptr<StyleSource>> Map::getActiveSources() const {
     return activeSources;
 }
 
-void Map::updateSources(const std::shared_ptr<StyleLayerGroup> &group) {
+void Map::updateSources(const util::ptr<StyleLayerGroup> &group) {
     if (!group) {
         return;
     }
-    for (const std::shared_ptr<StyleLayer> &layer : group->layers) {
+    for (const util::ptr<StyleLayer> &layer : group->layers) {
         if (!layer) continue;
         if (layer->bucket) {
             if (layer->bucket->style_source) {
@@ -507,7 +584,7 @@ void Map::updateSources(const std::shared_ptr<StyleLayerGroup> &group) {
 }
 
 void Map::updateTiles() {
-    for (const std::shared_ptr<StyleSource> &source : getActiveSources()) {
+    for (const util::ptr<StyleSource> &source : getActiveSources()) {
         source->source->update(*this);
     }
 }
@@ -515,13 +592,37 @@ void Map::updateTiles() {
 void Map::updateRenderState() {
     // Update all clipping IDs.
     ClipIDGenerator generator;
-    for (const std::shared_ptr<StyleSource> &source : getActiveSources()) {
+    for (const util::ptr<StyleSource> &source : getActiveSources()) {
         generator.update(source->source->getLoadedTiles());
         source->source->updateMatrices(painter.projMatrix, state);
     }
 }
 
 void Map::prepare() {
+    if (!fileSource) {
+        fileSource = std::make_shared<FileSource>(**loop, platform::defaultCacheDatabase());
+        glyphStore = std::make_shared<GlyphStore>(fileSource);
+    }
+
+    if (!style) {
+        style = std::make_shared<Style>();
+
+        fileSource->request(ResourceType::JSON, styleURL)->onload([&](const Response &res) {
+            if (res.code == 200) {
+                // Calculate the base
+                const size_t pos = styleURL.rfind('/');
+                std::string base = "";
+                if (pos != std::string::npos) {
+                    base = styleURL.substr(0, pos + 1);
+                }
+
+                setStyleJSON(res.data, base);
+            } else {
+                Log::Error(Event::Setup, "loading style failed: %ld (%s)", res.code, res.message.c_str());
+            }
+        });
+    }
+
     // Update transform transitions.
     animationTime = util::now();
     if (transform.needsTransition()) {
@@ -568,7 +669,7 @@ void Map::render() {
     // This guarantees that we have at least one function per tile called.
     // When only rendering layers via the stylesheet, it's possible that we don't
     // ever visit a tile during rendering.
-    for (const std::shared_ptr<StyleSource> &source : getActiveSources()) {
+    for (const util::ptr<StyleSource> &source : getActiveSources()) {
         source->source->finishRender(painter);
     }
 
@@ -582,7 +683,7 @@ void Map::render() {
     view.make_inactive();
 }
 
-void Map::renderLayers(std::shared_ptr<StyleLayerGroup> group) {
+void Map::renderLayers(util::ptr<StyleLayerGroup> group) {
     if (!group) {
         // Make sure that we actually do have a layer group.
         return;
@@ -625,7 +726,7 @@ void Map::renderLayers(std::shared_ptr<StyleLayerGroup> group) {
     }
 }
 
-void Map::renderLayer(std::shared_ptr<StyleLayer> layer_desc, RenderPass pass, const Tile::ID* id, const mat4* matrix) {
+void Map::renderLayer(util::ptr<StyleLayer> layer_desc, RenderPass pass, const Tile::ID* id, const mat4* matrix) {
     if (layer_desc->type == StyleLayerType::Background) {
         // This layer defines a background color/image.
 
diff --git a/src/map/raster_tile_data.cpp b/src/map/raster_tile_data.cpp
index 182a614393..e7725b7abd 100644
--- a/src/map/raster_tile_data.cpp
+++ b/src/map/raster_tile_data.cpp
@@ -5,7 +5,7 @@
 using namespace mbgl;
 
 
-RasterTileData::RasterTileData(Tile::ID id, Map &map, const SourceInfo &source)
+RasterTileData::RasterTileData(Tile::ID id, Map &map, const util::ptr<SourceInfo> &source)
     : TileData(id, map, source),
     bucket(map.getTexturepool(), properties) {
 }
@@ -25,10 +25,10 @@ void RasterTileData::parse() {
     }
 }
 
-void RasterTileData::render(Painter &painter, std::shared_ptr<StyleLayer> layer_desc, const mat4 &matrix) {
+void RasterTileData::render(Painter &painter, util::ptr<StyleLayer> layer_desc, const mat4 &matrix) {
     bucket.render(painter, layer_desc, id, matrix);
 }
 
-bool RasterTileData::hasData(std::shared_ptr<StyleLayer> /*layer_desc*/) const {
+bool RasterTileData::hasData(util::ptr<StyleLayer> /*layer_desc*/) const {
     return bucket.hasData();
 }
diff --git a/src/map/source.cpp b/src/map/source.cpp
index 083e931b7a..36f1a71c84 100644
--- a/src/map/source.cpp
+++ b/src/map/source.cpp
@@ -6,7 +6,7 @@
 #include <mbgl/util/raster.hpp>
 #include <mbgl/util/string.hpp>
 #include <mbgl/util/texturepool.hpp>
-#include <mbgl/util/filesource.hpp>
+#include <mbgl/storage/file_source.hpp>
 #include <mbgl/util/vec.hpp>
 #include <mbgl/util/math.hpp>
 #include <mbgl/util/std.hpp>
@@ -20,7 +20,7 @@
 
 namespace mbgl {
 
-Source::Source(SourceInfo& info)
+Source::Source(const util::ptr<SourceInfo>& info)
     : info(info)
 {
 }
@@ -29,32 +29,33 @@ Source::Source(SourceInfo& info)
 // The reason this isn't part of the constructor is that calling shared_from_this() in
 // the constructor fails.
 void Source::load(Map& map) {
-    if (info.url.empty()) {
+    if (info->url.empty()) {
         loaded = true;
         return;
     }
 
-    std::string url = util::mapbox::normalizeSourceURL(info.url, map.getAccessToken());
-    std::shared_ptr<Source> source = shared_from_this();
+    std::string url = util::mapbox::normalizeSourceURL(info->url, map.getAccessToken());
+    util::ptr<Source> source = shared_from_this();
 
-    map.getFileSource()->load(ResourceType::JSON, url, [source, &map](platform::Response *res) {
-        if (res->code != 200) {
+    map.getFileSource()->request(ResourceType::JSON, url)->onload([source, &map](const Response &res) {
+        if (res.code != 200) {
             Log::Warning(Event::General, "failed to load source TileJSON");
             return;
         }
 
         rapidjson::Document d;
-        d.Parse<0>(res->body.c_str());
+        d.Parse<0>(res.data.c_str());
 
         if (d.HasParseError()) {
             Log::Warning(Event::General, "invalid source TileJSON");
             return;
         }
 
-        source->info.parseTileJSONProperties(d);
+        source->info->parseTileJSONProperties(d);
         source->loaded = true;
 
         map.update();
+
     });
 }
 
@@ -98,7 +99,7 @@ void Source::drawClippingMasks(Painter &painter) {
     }
 }
 
-void Source::render(Painter &painter, std::shared_ptr<StyleLayer> layer_desc) {
+void Source::render(Painter &painter, util::ptr<StyleLayer> layer_desc) {
     gl::group group(std::string("layer: ") + layer_desc->id);
     for (const std::pair<const Tile::ID, std::unique_ptr<Tile>> &pair : tiles) {
         Tile &tile = *pair.second;
@@ -108,7 +109,7 @@ void Source::render(Painter &painter, std::shared_ptr<StyleLayer> layer_desc) {
     }
 }
 
-void Source::render(Painter &painter, std::shared_ptr<StyleLayer> layer_desc, const Tile::ID &id, const mat4 &matrix) {
+void Source::render(Painter &painter, util::ptr<StyleLayer> layer_desc, const Tile::ID &id, const mat4 &matrix) {
     auto it = tiles.find(id);
     if (it != tiles.end() && it->second->data && it->second->data->state == TileData::State::parsed) {
         painter.renderTileLayer(*it->second, layer_desc, matrix);
@@ -183,9 +184,9 @@ TileData::State Source::addTile(Map &map, const Tile::ID& id) {
 
     if (!new_tile.data) {
         // If we don't find working tile data, we're just going to load it.
-        if (info.type == SourceType::Vector) {
+        if (info->type == SourceType::Vector) {
             new_tile.data = std::make_shared<VectorTileData>(normalized_id, map, info);
-        } else if (info.type == SourceType::Raster) {
+        } else if (info->type == SourceType::Raster) {
             new_tile.data = std::make_shared<RasterTileData>(normalized_id, map, info);
         } else {
             throw std::runtime_error("source type not implemented");
@@ -199,7 +200,7 @@ TileData::State Source::addTile(Map &map, const Tile::ID& id) {
 }
 
 double Source::getZoom(const TransformState& state) const {
-    double offset = std::log(util::tileSize / info.tile_size) / std::log(2);
+    double offset = std::log(util::tileSize / info->tile_size) / std::log(2);
     offset += (state.getPixelRatio() > 1.0 ? 1 :0);
     return state.getZoom() + offset;
 }
@@ -211,8 +212,8 @@ int32_t Source::coveringZoomLevel(const TransformState& state) const {
 std::forward_list<Tile::ID> Source::coveringTiles(const TransformState& state) const {
     int32_t z = coveringZoomLevel(state);
 
-    if (z < info.min_zoom) return {{}};
-    if (z > info.max_zoom) z = info.max_zoom;
+    if (z < info->min_zoom) return {{}};
+    if (z > info->max_zoom) z = info->max_zoom;
 
     // Map four viewport corners to pixel coordinates
     box points = state.cornersToBox(z);
@@ -285,8 +286,8 @@ bool Source::updateTiles(Map &map) {
     std::forward_list<Tile::ID> required = coveringTiles(map.getState());
 
     // Determine the overzooming/underzooming amounts.
-    int32_t minCoveringZoom = util::clamp<int32_t>(zoom - 10, info.min_zoom, info.max_zoom);
-    int32_t maxCoveringZoom = util::clamp<int32_t>(zoom + 1,  info.min_zoom, info.max_zoom);
+    int32_t minCoveringZoom = util::clamp<int32_t>(zoom - 10, info->min_zoom, info->max_zoom);
+    int32_t maxCoveringZoom = util::clamp<int32_t>(zoom + 1,  info->min_zoom, info->max_zoom);
 
     // Retain is a list of tiles that we shouldn't delete, even if they are not
     // the most ideal tile for the current viewport. This may include tiles like
@@ -333,7 +334,7 @@ bool Source::updateTiles(Map &map) {
 
     // Remove all the expired pointers from the set.
     util::erase_if(tile_data, [&retain_data](std::pair<const Tile::ID, std::weak_ptr<TileData>> &pair) {
-        const std::shared_ptr<TileData> tile = pair.second.lock();
+        const util::ptr<TileData> tile = pair.second.lock();
         if (!tile) {
             return true;
         }
diff --git a/src/map/sprite.cpp b/src/map/sprite.cpp
index af9413a0e3..c069ece45a 100644
--- a/src/map/sprite.cpp
+++ b/src/map/sprite.cpp
@@ -5,7 +5,7 @@
 
 #include <string>
 #include <mbgl/platform/platform.hpp>
-#include <mbgl/util/filesource.hpp>
+#include <mbgl/storage/file_source.hpp>
 #include <mbgl/util/uv_detail.hpp>
 #include <mbgl/util/std.hpp>
 
@@ -22,8 +22,8 @@ SpritePosition::SpritePosition(uint16_t x, uint16_t y, uint16_t width, uint16_t
       sdf(sdf) {
 }
 
-std::shared_ptr<Sprite> Sprite::Create(const std::string& base_url, float pixelRatio, const std::shared_ptr<FileSource> &fileSource) {
-    std::shared_ptr<Sprite> sprite(std::make_shared<Sprite>(Key(), base_url, pixelRatio));
+util::ptr<Sprite> Sprite::Create(const std::string& base_url, float pixelRatio, const util::ptr<FileSource> &fileSource) {
+    util::ptr<Sprite> sprite(std::make_shared<Sprite>(Key(), base_url, pixelRatio));
     sprite->load(fileSource);
     return sprite;
 }
@@ -51,7 +51,7 @@ Sprite::operator bool() const {
 // Note: This is a separate function that must be called exactly once after creation
 // The reason this isn't part of the constructor is that calling shared_from_this() in
 // the constructor fails.
-void Sprite::load(const std::shared_ptr<FileSource> &fileSource) {
+void Sprite::load(const util::ptr<FileSource> &fileSource) {
     if (!valid) {
         // Treat a non-existent sprite as a successfully loaded empty sprite.
         loadedImage = true;
@@ -60,30 +60,30 @@ void Sprite::load(const std::shared_ptr<FileSource> &fileSource) {
         return;
     }
 
-    std::shared_ptr<Sprite> sprite = shared_from_this();
+    util::ptr<Sprite> sprite = shared_from_this();
 
-    fileSource->load(ResourceType::JSON, jsonURL, [sprite](platform::Response *res) {
-        if (res->code == 200) {
-            sprite->body.swap(res->body);
+    fileSource->request(ResourceType::JSON, jsonURL)->onload([sprite](const Response &res) {
+        if (res.code == 200) {
+            sprite->body = res.data;
             sprite->parseJSON();
             sprite->complete();
         } else {
-            Log::Warning(Event::Sprite, "Failed to load sprite info: Error %d: %s", res->code, res->error_message.c_str());
+            Log::Warning(Event::Sprite, "Failed to load sprite info: Error %d: %s", res.code, res.message.c_str());
             if (!sprite->future.valid()) {
-                sprite->promise.set_exception(std::make_exception_ptr(std::runtime_error(res->error_message)));
+                sprite->promise.set_exception(std::make_exception_ptr(std::runtime_error(res.message)));
             }
         }
     });
 
-    fileSource->load(ResourceType::Image, spriteURL, [sprite](platform::Response *res) {
-        if (res->code == 200) {
-            sprite->image.swap(res->body);
+    fileSource->request(ResourceType::Image, spriteURL)->onload([sprite](const Response &res) {
+        if (res.code == 200) {
+            sprite->image = res.data;
             sprite->parseImage();
             sprite->complete();
         } else {
-            Log::Warning(Event::Sprite, "Failed to load sprite image: Error %d: %s", res->code, res->error_message.c_str());
+            Log::Warning(Event::Sprite, "Failed to load sprite image: Error %d: %s", res.code, res.message.c_str());
             if (!sprite->future.valid()) {
-                sprite->promise.set_exception(std::make_exception_ptr(std::runtime_error(res->error_message)));
+                sprite->promise.set_exception(std::make_exception_ptr(std::runtime_error(res.message)));
             }
         }
     });
diff --git a/src/map/tile_data.cpp b/src/map/tile_data.cpp
index 57afb8dadb..44e3826bf5 100644
--- a/src/map/tile_data.cpp
+++ b/src/map/tile_data.cpp
@@ -4,12 +4,12 @@
 
 #include <mbgl/util/token.hpp>
 #include <mbgl/util/string.hpp>
-#include <mbgl/util/filesource.hpp>
+#include <mbgl/storage/file_source.hpp>
 #include <mbgl/util/uv_detail.hpp>
 
 using namespace mbgl;
 
-TileData::TileData(Tile::ID id, Map &map, const SourceInfo &source)
+TileData::TileData(Tile::ID id, Map &map, const util::ptr<SourceInfo> &source)
     : id(id),
       state(State::initial),
       map(map),
@@ -29,10 +29,10 @@ const std::string TileData::toString() const {
 }
 
 void TileData::request() {
-    if (source.tiles.empty())
+    if (source->tiles.empty())
         return;
 
-    std::string url = source.tiles[(id.x + id.y) % source.tiles.size()];
+    std::string url = source->tiles[(id.x + id.y) % source->tiles.size()];
     url = util::replaceTokens(url, [&](const std::string &token) -> std::string {
         if (token == "z") return std::to_string(id.z);
         if (token == "x") return std::to_string(id.x);
@@ -45,21 +45,28 @@ void TileData::request() {
 
     // Note: Somehow this feels slower than the change to request_http()
     std::weak_ptr<TileData> weak_tile = shared_from_this();
-    map.getFileSource()->load(ResourceType::Tile, url, [weak_tile, url](platform::Response *res) {
-        std::shared_ptr<TileData> tile = weak_tile.lock();
+    req = map.getFileSource()->request(ResourceType::Tile, url);
+    req->onload([weak_tile, url](const Response &res) {
+        util::ptr<TileData> tile = weak_tile.lock();
         if (!tile || tile->state == State::obsolete) {
             // noop. Tile is obsolete and we're now just waiting for the refcount
             // to drop to zero for destruction.
-        } else if (res->code == 200) {
+            return;
+        }
+
+        // Clear the request object.
+        tile->req.reset();
+
+        if (res.code == 200) {
             tile->state = State::loaded;
 
-            tile->data.swap(res->body);
+            tile->data = res.data;
 
             // Schedule tile parsing in another thread
             tile->reparse();
         } else {
 #if defined(DEBUG)
-            fprintf(stderr, "[%s] tile loading failed: %d, %s\n", url.c_str(), res->code, res->error_message.c_str());
+            fprintf(stderr, "[%s] tile loading failed: %ld, %s\n", url.c_str(), res.code, res.message.c_str());
 #endif
         }
     });
@@ -68,7 +75,7 @@ void TileData::request() {
 void TileData::cancel() {
     if (state != State::obsolete) {
         state = State::obsolete;
-        platform::cancel_request_http(req.lock());
+        req.reset();
     }
 }
 
@@ -79,12 +86,12 @@ void TileData::reparse() {
 
     // We're creating a new work request. The work request deletes itself after it executed
     // the after work handler
-    new uv::work<std::shared_ptr<TileData>>(
-        map.getLoop(),
-        [](std::shared_ptr<TileData> &tile) {
+    new uv::work<util::ptr<TileData>>(
+        map.getWorker(),
+        [](util::ptr<TileData> &tile) {
             tile->parse();
         },
-        [](std::shared_ptr<TileData> &tile) {
+        [](util::ptr<TileData> &tile) {
             tile->afterParse();
             tile->map.update();
         },
diff --git a/src/map/tile_parser.cpp b/src/map/tile_parser.cpp
index 6923c1a422..3dc5cb9cef 100644
--- a/src/map/tile_parser.cpp
+++ b/src/map/tile_parser.cpp
@@ -38,19 +38,26 @@ namespace mbgl {
 TileParser::~TileParser() = default;
 
 TileParser::TileParser(const std::string &data, VectorTileData &tile,
-                       const std::shared_ptr<const Style> &style,
-                       const std::shared_ptr<GlyphAtlas> &glyphAtlas,
-                       const std::shared_ptr<GlyphStore> &glyphStore,
-                       const std::shared_ptr<SpriteAtlas> &spriteAtlas,
-                       const std::shared_ptr<Sprite> &sprite)
+                       const util::ptr<const Style> &style_,
+                       const util::ptr<GlyphAtlas> &glyphAtlas_,
+                       const util::ptr<GlyphStore> &glyphStore_,
+                       const util::ptr<SpriteAtlas> &spriteAtlas_,
+                       const util::ptr<Sprite> &sprite_)
     : vector_data(pbf((const uint8_t *)data.data(), data.size())),
       tile(tile),
-      style(style),
-      glyphAtlas(glyphAtlas),
-      glyphStore(glyphStore),
-      spriteAtlas(spriteAtlas),
-      sprite(sprite),
-      collision(std::make_unique<Collision>(tile.id.z, 4096, tile.source.tile_size, tile.depth)) {
+      style(style_),
+      glyphAtlas(glyphAtlas_),
+      glyphStore(glyphStore_),
+      spriteAtlas(spriteAtlas_),
+      sprite(sprite_),
+      collision(std::make_unique<Collision>(tile.id.z, 4096, tile.source->tile_size, tile.depth)) {
+    assert(&tile != nullptr);
+    assert(style);
+    assert(glyphAtlas);
+    assert(glyphStore);
+    assert(spriteAtlas);
+    assert(sprite);
+    assert(collision);
 }
 
 void TileParser::parse() {
@@ -59,12 +66,12 @@ void TileParser::parse() {
 
 bool TileParser::obsolete() const { return tile.state == TileData::State::obsolete; }
 
-void TileParser::parseStyleLayers(std::shared_ptr<StyleLayerGroup> group) {
+void TileParser::parseStyleLayers(util::ptr<StyleLayerGroup> group) {
     if (!group) {
         return;
     }
 
-    for (const std::shared_ptr<StyleLayer> &layer_desc : group->layers) {
+    for (const util::ptr<StyleLayer> &layer_desc : group->layers) {
         // Cancel early when parsing.
         if (obsolete()) {
             return;
@@ -96,14 +103,14 @@ void TileParser::parseStyleLayers(std::shared_ptr<StyleLayerGroup> group) {
     }
 }
 
-std::unique_ptr<Bucket> TileParser::createBucket(std::shared_ptr<StyleBucket> bucket_desc) {
+std::unique_ptr<Bucket> TileParser::createBucket(util::ptr<StyleBucket> bucket_desc) {
     if (!bucket_desc) {
         fprintf(stderr, "missing bucket desc\n");
         return nullptr;
     }
 
     // Skip this bucket if we are to not render this
-    if (tile.id.z < std::floor(bucket_desc->min_zoom) && std::floor(bucket_desc->min_zoom) < tile.source.max_zoom) return nullptr;
+    if (tile.id.z < std::floor(bucket_desc->min_zoom) && std::floor(bucket_desc->min_zoom) < tile.source->max_zoom) return nullptr;
     if (tile.id.z >= std::ceil(bucket_desc->max_zoom)) return nullptr;
 
     auto layer_it = vector_data.layers.find(bucket_desc->source_layer);
@@ -157,7 +164,7 @@ std::unique_ptr<Bucket> TileParser::createFillBucket(const VectorTileLayer& laye
     return obsolete() ? nullptr : std::move(bucket);
 }
 
-std::unique_ptr<Bucket> TileParser::createRasterBucket(const std::shared_ptr<Texturepool> &texturepool, const StyleBucketRaster &raster) {
+std::unique_ptr<Bucket> TileParser::createRasterBucket(const util::ptr<Texturepool> &texturepool, const StyleBucketRaster &raster) {
     std::unique_ptr<RasterBucket> bucket = std::make_unique<RasterBucket>(texturepool, raster);
     return obsolete() ? nullptr : std::move(bucket);
 }
diff --git a/src/map/transform.cpp b/src/map/transform.cpp
index 6c5e70cc2f..baa615b94a 100644
--- a/src/map/transform.cpp
+++ b/src/map/transform.cpp
@@ -466,7 +466,7 @@ bool Transform::needsTransition() const {
 void Transform::updateTransitions(const timestamp now) {
     uv::writelock lock(mtx);
 
-    transitions.remove_if([now](const std::shared_ptr<util::transition> &transition) {
+    transitions.remove_if([now](const util::ptr<util::transition> &transition) {
         return transition->update(now) == util::transition::complete;
     });
 }
diff --git a/src/map/vector_tile_data.cpp b/src/map/vector_tile_data.cpp
index 1f74cab1d7..48b46059a5 100644
--- a/src/map/vector_tile_data.cpp
+++ b/src/map/vector_tile_data.cpp
@@ -8,13 +8,13 @@
 
 using namespace mbgl;
 
-VectorTileData::VectorTileData(Tile::ID id, Map &map, const SourceInfo &source)
+VectorTileData::VectorTileData(Tile::ID id, Map &map, const util::ptr<SourceInfo> &source)
     : TileData(id, map, source),
-      depth(id.z >= source.max_zoom ? map.getMaxZoom() - id.z : 1) {
+      depth(id.z >= source->max_zoom ? map.getMaxZoom() - id.z : 1) {
 }
 
 VectorTileData::~VectorTileData() {
-    std::shared_ptr<GlyphAtlas> glyphAtlas = map.getGlyphAtlas();
+    util::ptr<GlyphAtlas> glyphAtlas = map.getGlyphAtlas();
     if (glyphAtlas) {
         glyphAtlas->removeGlyphs(id.to_uint64());
     }
@@ -52,7 +52,7 @@ void VectorTileData::afterParse() {
     parser.reset();
 }
 
-void VectorTileData::render(Painter &painter, std::shared_ptr<StyleLayer> layer_desc, const mat4 &matrix) {
+void VectorTileData::render(Painter &painter, util::ptr<StyleLayer> layer_desc, const mat4 &matrix) {
     if (state == State::parsed && layer_desc->bucket) {
         auto databucket_it = buckets.find(layer_desc->bucket->name);
         if (databucket_it != buckets.end()) {
@@ -62,7 +62,7 @@ void VectorTileData::render(Painter &painter, std::shared_ptr<StyleLayer> layer_
     }
 }
 
-bool VectorTileData::hasData(std::shared_ptr<StyleLayer> layer_desc) const {
+bool VectorTileData::hasData(util::ptr<StyleLayer> layer_desc) const {
     if (state == State::parsed && layer_desc->bucket) {
         auto databucket_it = buckets.find(layer_desc->bucket->name);
         if (databucket_it != buckets.end()) {
diff --git a/src/platform/request.cpp b/src/platform/request.cpp
deleted file mode 100644
index 82e80b9a7c..0000000000
--- a/src/platform/request.cpp
+++ /dev/null
@@ -1,54 +0,0 @@
-#include <mbgl/platform/request.hpp>
-#include <mbgl/platform/platform.hpp>
-#include <mbgl/util/std.hpp>
-#include <mbgl/util/uv_detail.hpp>
-
-using namespace mbgl::platform;
-
-Request::Request(const std::string &url,
-                 std::function<void(Response *)> callback,
-                 std::shared_ptr<uv::loop> loop)
-    : url(url),
-      res(std::make_unique<Response>(callback)),
-      cancelled(false),
-      loop(loop) {
-    if (loop) {
-        // Add a check handle without a callback to keep the default loop running.
-        // We don't have a real handler attached to the default loop right from the
-        // beginning, because we're using asynchronous messaging to perform the actual
-        // request in the request thread. Only after the request is complete, we
-        // create an actual work request that is attached to the default loop.
-        async = new uv_async_t();
-        async->data = new std::unique_ptr<Response>();
-        uv_async_init(**loop, async, &complete);
-    }
-}
-
-Request::~Request() {
-}
-
-void Request::complete() {
-    if (loop) {
-        // We're scheduling the response callback to be invoked in the event loop.
-        // Since the Request object will be deleted before the callback is invoked,
-        // we move over the Response object to be owned by the async handle.
-        ((std::unique_ptr<Response> *)async->data)->swap(res);
-        uv_async_send(async);
-    } else {
-        // We're calling the response callback immediately. We're currently on an
-        // arbitrary thread, but that's okay.
-        res->callback(res.get());
-    }
-}
-
-void Request::complete(uv_async_t *async, int status) {
-    Response *res = static_cast<std::unique_ptr<Response> *>(async->data)->get();
-
-    res->callback(res);
-
-    // We need to remove our async handle again to allow the main event loop to exit.
-    uv_close((uv_handle_t *)async, [](uv_handle_t *handle) {
-        delete static_cast<std::unique_ptr<Response> *>(handle->data);
-        delete (uv_async_t *)handle;
-    });
-}
diff --git a/src/renderer/debug_bucket.cpp b/src/renderer/debug_bucket.cpp
index a3ac329f49..699c1c1db9 100644
--- a/src/renderer/debug_bucket.cpp
+++ b/src/renderer/debug_bucket.cpp
@@ -14,7 +14,7 @@ DebugBucket::DebugBucket(DebugFontBuffer& fontBuffer)
     : fontBuffer(fontBuffer) {
 }
 
-void DebugBucket::render(Painter& painter, std::shared_ptr<StyleLayer> /*layer_desc*/, const Tile::ID& /*id*/, const mat4 &matrix) {
+void DebugBucket::render(Painter& painter, util::ptr<StyleLayer> /*layer_desc*/, const Tile::ID& /*id*/, const mat4 &matrix) {
     painter.renderDebugText(*this, matrix);
 }
 
diff --git a/src/renderer/fill_bucket.cpp b/src/renderer/fill_bucket.cpp
index 875cc279b9..5358cae0b2 100644
--- a/src/renderer/fill_bucket.cpp
+++ b/src/renderer/fill_bucket.cpp
@@ -204,7 +204,7 @@ void FillBucket::tessellate() {
     lineGroup.vertex_length += total_vertex_count;
 }
 
-void FillBucket::render(Painter& painter, std::shared_ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix) {
+void FillBucket::render(Painter& painter, util::ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix) {
     painter.renderFill(*this, layer_desc, id, matrix);
 }
 
diff --git a/src/renderer/line_bucket.cpp b/src/renderer/line_bucket.cpp
index 2e89a7c35d..3ef7411be6 100644
--- a/src/renderer/line_bucket.cpp
+++ b/src/renderer/line_bucket.cpp
@@ -341,7 +341,7 @@ void LineBucket::addGeometry(const std::vector<Coordinate>& vertices) {
     }
 }
 
-void LineBucket::render(Painter& painter, std::shared_ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix) {
+void LineBucket::render(Painter& painter, util::ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix) {
     painter.renderLine(*this, layer_desc, id, matrix);
 }
 
diff --git a/src/renderer/painter.cpp b/src/renderer/painter.cpp
index 0d01fd1662..8988112585 100644
--- a/src/renderer/painter.cpp
+++ b/src/renderer/painter.cpp
@@ -197,7 +197,7 @@ void Painter::prepareTile(const Tile& tile) {
     glStencilFunc(GL_EQUAL, ref, mask);
 }
 
-void Painter::renderTileLayer(const Tile& tile, std::shared_ptr<StyleLayer> layer_desc, const mat4 &matrix) {
+void Painter::renderTileLayer(const Tile& tile, util::ptr<StyleLayer> layer_desc, const mat4 &matrix) {
     assert(tile.data);
     if (tile.data->hasData(layer_desc) || layer_desc->type == StyleLayerType::Raster) {
         gl::group group(util::sprintf<32>("render %d/%d/%d\n", tile.id.z, tile.id.y, tile.id.z));
@@ -206,7 +206,7 @@ void Painter::renderTileLayer(const Tile& tile, std::shared_ptr<StyleLayer> laye
     }
 }
 
-void Painter::renderBackground(std::shared_ptr<StyleLayer> layer_desc) {
+void Painter::renderBackground(util::ptr<StyleLayer> layer_desc) {
     const BackgroundProperties& properties = layer_desc->getProperties<BackgroundProperties>();
 
     Color color = properties.color;
diff --git a/src/renderer/painter_clipping.cpp b/src/renderer/painter_clipping.cpp
index 45b14a2f78..dc625ded4e 100644
--- a/src/renderer/painter_clipping.cpp
+++ b/src/renderer/painter_clipping.cpp
@@ -6,7 +6,7 @@
 
 using namespace mbgl;
 
-void Painter::drawClippingMasks(const std::set<std::shared_ptr<StyleSource>> &sources) {
+void Painter::drawClippingMasks(const std::set<util::ptr<StyleSource>> &sources) {
     gl::group group("clipping masks");
 
     useProgram(plainShader->program);
@@ -17,7 +17,7 @@ void Painter::drawClippingMasks(const std::set<std::shared_ptr<StyleSource>> &so
 
     coveringPlainArray.bind(*plainShader, tileStencilBuffer, BUFFER_OFFSET(0));
 
-    for (const std::shared_ptr<StyleSource> &source : sources) {
+    for (const util::ptr<StyleSource> &source : sources) {
         source->source->drawClippingMasks(*this);
     }
 
diff --git a/src/renderer/painter_fill.cpp b/src/renderer/painter_fill.cpp
index 6d56b9077e..6c17ab037a 100644
--- a/src/renderer/painter_fill.cpp
+++ b/src/renderer/painter_fill.cpp
@@ -10,7 +10,7 @@
 
 using namespace mbgl;
 
-void Painter::renderFill(FillBucket& bucket, std::shared_ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix) {
+void Painter::renderFill(FillBucket& bucket, util::ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix) {
     // Abort early.
     if (!bucket.hasData()) return;
 
diff --git a/src/renderer/painter_line.cpp b/src/renderer/painter_line.cpp
index 161abcd6ff..cd973b46d6 100644
--- a/src/renderer/painter_line.cpp
+++ b/src/renderer/painter_line.cpp
@@ -8,7 +8,7 @@
 
 using namespace mbgl;
 
-void Painter::renderLine(LineBucket& bucket, std::shared_ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix) {
+void Painter::renderLine(LineBucket& bucket, util::ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix) {
     // Abort early.
     if (pass == RenderPass::Opaque) return;
     if (!bucket.hasData()) return;
@@ -62,7 +62,7 @@ void Painter::renderLine(LineBucket& bucket, std::shared_ptr<StyleLayer> layer_d
         bucket.drawPoints(*linejoinShader);
     }
 
-    const std::shared_ptr<Sprite> &sprite = map.getSprite();
+    const util::ptr<Sprite> &sprite = map.getSprite();
     if (properties.image.size() && sprite) {
         SpriteAtlasPosition imagePos = map.getSpriteAtlas()->getPosition(properties.image, *sprite);
 
diff --git a/src/renderer/painter_raster.cpp b/src/renderer/painter_raster.cpp
index 7f7afc3e84..c362042e55 100644
--- a/src/renderer/painter_raster.cpp
+++ b/src/renderer/painter_raster.cpp
@@ -9,7 +9,7 @@
 
 using namespace mbgl;
 
-void Painter::renderRaster(RasterBucket& bucket, std::shared_ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix) {
+void Painter::renderRaster(RasterBucket& bucket, util::ptr<StyleLayer> layer_desc, const Tile::ID& id, const mat4 &matrix) {
     if (pass != RenderPass::Translucent) return;
 
     const RasterProperties &properties = layer_desc->getProperties<RasterProperties>();
@@ -34,7 +34,7 @@ void Painter::renderRaster(RasterBucket& bucket, std::shared_ptr<StyleLayer> lay
             // call updateTiles to get parsed data for sublayers
             map.updateTiles();
 
-            for (const std::shared_ptr<StyleLayer> &layer : layer_desc->layers->layers) {
+            for (const util::ptr<StyleLayer> &layer : layer_desc->layers->layers) {
                 setOpaque();
                 map.renderLayer(layer, RenderPass::Opaque, &id, &preMatrix);
                 setTranslucent();
diff --git a/src/renderer/painter_symbol.cpp b/src/renderer/painter_symbol.cpp
index 4fce66217f..415dead70e 100644
--- a/src/renderer/painter_symbol.cpp
+++ b/src/renderer/painter_symbol.cpp
@@ -112,7 +112,7 @@ void Painter::renderSDF(SymbolBucket &bucket,
     }
 }
 
-void Painter::renderSymbol(SymbolBucket &bucket, std::shared_ptr<StyleLayer> layer_desc, const Tile::ID &id, const mat4 &matrix) {
+void Painter::renderSymbol(SymbolBucket &bucket, util::ptr<StyleLayer> layer_desc, const Tile::ID &id, const mat4 &matrix) {
     // Abort early.
     if (pass == RenderPass::Opaque) {
         return;
diff --git a/src/renderer/raster_bucket.cpp b/src/renderer/raster_bucket.cpp
index 492eea980d..fc5e3dd3c8 100644
--- a/src/renderer/raster_bucket.cpp
+++ b/src/renderer/raster_bucket.cpp
@@ -3,13 +3,13 @@
 
 using namespace mbgl;
 
-RasterBucket::RasterBucket(const std::shared_ptr<Texturepool> &texturepool, const StyleBucketRaster& properties)
+RasterBucket::RasterBucket(const util::ptr<Texturepool> &texturepool, const StyleBucketRaster& properties)
 : properties(properties),
   texture(properties),
   raster(texturepool) {
 }
 
-void RasterBucket::render(Painter &painter, std::shared_ptr<StyleLayer> layer_desc, const Tile::ID &id, const mat4 &matrix) {
+void RasterBucket::render(Painter &painter, util::ptr<StyleLayer> layer_desc, const Tile::ID &id, const mat4 &matrix) {
     painter.renderRaster(*this, layer_desc, id, matrix);
 }
 
diff --git a/src/renderer/symbol_bucket.cpp b/src/renderer/symbol_bucket.cpp
index 374ea2dc26..3a4b017ef3 100644
--- a/src/renderer/symbol_bucket.cpp
+++ b/src/renderer/symbol_bucket.cpp
@@ -22,7 +22,7 @@ namespace mbgl {
 SymbolBucket::SymbolBucket(const StyleBucketSymbol &properties, Collision &collision)
     : properties(properties), collision(collision) {}
 
-void SymbolBucket::render(Painter &painter, std::shared_ptr<StyleLayer> layer_desc,
+void SymbolBucket::render(Painter &painter, util::ptr<StyleLayer> layer_desc,
                           const Tile::ID &id, const mat4 &matrix) {
     painter.renderSymbol(*this, layer_desc, id, matrix);
 }
diff --git a/src/storage/base_request.cpp b/src/storage/base_request.cpp
new file mode 100644
index 0000000000..e87679ae1b
--- /dev/null
+++ b/src/storage/base_request.cpp
@@ -0,0 +1,86 @@
+#include <mbgl/storage/base_request.hpp>
+#include <mbgl/storage/response.hpp>
+#include <mbgl/storage/request.hpp>
+
+#include <uv.h>
+
+#include <cassert>
+
+namespace mbgl {
+
+template <typename T, typename ...Args>
+void invoke(const std::forward_list<std::unique_ptr<Callback>> &list, Args&& ...args) {
+    for (const std::unique_ptr<Callback> &callback : list) {
+        assert(callback);
+        if (callback->is<T>()) {
+            callback->get<T>()(::std::forward<Args>(args)...);
+        }
+    }
+}
+
+BaseRequest::BaseRequest(const std::string &path_) : thread_id(uv_thread_self()), path(path_) {
+}
+
+// A base request can only be "canceled" by destroying the object. In that case, we'll have to
+// notify all cancel callbacks.
+BaseRequest::~BaseRequest() {
+    assert(thread_id == uv_thread_self());
+    notify();
+}
+
+void BaseRequest::retryImmediately() {
+    // no-op. override in child class.
+}
+
+void BaseRequest::notify() {
+    assert(thread_id == uv_thread_self());
+
+    // The parameter exists solely so that any calls to ->remove()
+    // are not going to cause deallocation of this object while this call is in progress.
+    util::ptr<BaseRequest> retain = self;
+
+    // Swap the lists so that it's safe for callbacks to call ->cancel()
+    // on the request object, which would modify the list.
+    const std::forward_list<std::unique_ptr<Callback>> list = std::move(callbacks);
+    callbacks.clear();
+
+    if (response) {
+        invoke<CompletedCallback>(list, *response);
+    } else {
+        invoke<AbortedCallback>(list);
+    }
+
+    self.reset();
+}
+
+Callback *BaseRequest::add(Callback &&callback, const util::ptr<BaseRequest> &request) {
+    assert(thread_id == uv_thread_self());
+    assert(this == request.get());
+
+    if (response) {
+        // We already have a response. Notify right away.
+        if (callback.is<CompletedCallback>()) {
+            callback.get<CompletedCallback>()(*response);
+        } else {
+            // We already know that this request was successful. The AbortedCallback will be discarded
+            // here since it would never be called.
+        }
+        return nullptr;
+    } else {
+        self = request;
+        callbacks.push_front(std::unique_ptr<Callback>(new Callback(std::move(callback))));
+        return callbacks.front().get();
+    }
+}
+
+void BaseRequest::remove(Callback *callback) {
+    assert(thread_id == uv_thread_self());
+    callbacks.remove_if([=](const std::unique_ptr<Callback> &cb) {
+        return cb.get() == callback;
+    });
+    if (callbacks.empty()) {
+        self.reset();
+    }
+}
+
+}
diff --git a/src/storage/file_request.cpp b/src/storage/file_request.cpp
new file mode 100644
index 0000000000..33398d5ef1
--- /dev/null
+++ b/src/storage/file_request.cpp
@@ -0,0 +1,37 @@
+#include <mbgl/storage/file_request.hpp>
+#include <mbgl/storage/file_request_baton.hpp>
+#include <mbgl/storage/response.hpp>
+
+#include <uv.h>
+
+#include <cassert>
+
+#include <unistd.h>
+
+namespace mbgl {
+
+FileRequest::FileRequest(const std::string &path_, uv_loop_t *loop)
+    : BaseRequest(path_), ptr(new FileRequestBaton(this, path, loop)) {
+}
+
+void FileRequest::cancel() {
+    assert(thread_id == uv_thread_self());
+
+    if (ptr) {
+        ptr->cancel();
+
+        // When deleting a FileRequest object with a uv_fs_* call is in progress, we are making sure
+        // that the callback doesn't accidentally reference this object again.
+        ptr->request = nullptr;
+        ptr = nullptr;
+    }
+
+    notify();
+}
+
+FileRequest::~FileRequest() {
+    assert(thread_id == uv_thread_self());
+    cancel();
+}
+
+}
diff --git a/src/storage/file_request_baton.cpp b/src/storage/file_request_baton.cpp
new file mode 100644
index 0000000000..127c78f3e5
--- /dev/null
+++ b/src/storage/file_request_baton.cpp
@@ -0,0 +1,142 @@
+#include <mbgl/storage/file_request_baton.hpp>
+#include <mbgl/storage/file_request.hpp>
+#include <mbgl/storage/response.hpp>
+
+namespace mbgl {
+
+FileRequestBaton::FileRequestBaton(FileRequest *request_, const std::string &path, uv_loop_t *loop)
+    : thread_id(uv_thread_self()), request(request_) {
+    req.data = this;
+    uv_fs_open(loop, &req, path.c_str(), O_RDONLY, S_IRUSR, file_opened);
+}
+
+FileRequestBaton::~FileRequestBaton() {
+}
+
+void FileRequestBaton::cancel() {
+    canceled = true;
+
+    // uv_cancel fails frequently when the request has already been started.
+    // In that case, we have to let it complete and check the canceled bool
+    // instead.
+    uv_cancel((uv_req_t *)&req);
+}
+
+void FileRequestBaton::notify_error(uv_fs_t *req) {
+    FileRequestBaton *ptr = (FileRequestBaton *)req->data;
+    assert(ptr->thread_id == uv_thread_self());
+
+    if (ptr->request && req->result < 0 && !ptr->canceled && req->result != UV_ECANCELED) {
+        ptr->request->response = std::unique_ptr<Response>(new Response);
+        ptr->request->response->code = req->result == UV_ENOENT ? 404 : 500;
+        ptr->request->response->message = uv_strerror(int(req->result));
+        ptr->request->notify();
+    }
+}
+
+void FileRequestBaton::file_opened(uv_fs_t *req) {
+    FileRequestBaton *ptr = (FileRequestBaton *)req->data;
+    assert(ptr->thread_id == uv_thread_self());
+
+    if (req->result < 0) {
+        // Opening failed or was canceled. There isn't much left we can do.
+        notify_error(req);
+        cleanup(req);
+    } else {
+        const uv_file fd = uv_file(req->result);
+
+        // We're going to reuse this handle, so we need to cleanup first.
+        uv_fs_req_cleanup(req);
+
+        if (ptr->canceled || !ptr->request) {
+            // Either the FileRequest object has been destructed, or the
+            // request was canceled.
+            uv_fs_close(req->loop, req, fd, file_closed);
+        } else {
+            ptr->fd = fd;
+            uv_fs_fstat(req->loop, req, fd, file_stated);
+        }
+    }
+}
+
+void FileRequestBaton::file_stated(uv_fs_t *req) {
+    FileRequestBaton *ptr = (FileRequestBaton *)req->data;
+    assert(ptr->thread_id == uv_thread_self());
+
+    if (req->result < 0 || ptr->canceled || !ptr->request) {
+        // Stating failed or was canceled. We already have an open file handle
+        // though, which we'll have to close.
+        notify_error(req);
+
+        uv_fs_req_cleanup(req);
+        uv_fs_close(req->loop, req, ptr->fd, file_closed);
+    } else {
+        if (static_cast<const uv_stat_t *>(req->ptr)->st_size > std::numeric_limits<int>::max()) {
+            // File is too large for us to open this way because uv_buf's only support unsigned
+            // ints as maximum size.
+            if (ptr->request) {
+                ptr->request->response = std::unique_ptr<Response>(new Response);
+                ptr->request->response->code = UV_EFBIG;
+                ptr->request->response->message = uv_strerror(UV_EFBIG);
+                ptr->request->notify();
+            }
+
+            uv_fs_req_cleanup(req);
+            uv_fs_close(req->loop, req, ptr->fd, file_closed);
+        } else {
+            const unsigned int size =
+                (unsigned int)(static_cast<const uv_stat_t *>(req->ptr)->st_size);
+            ptr->body.resize(size);
+            ptr->buffer = uv_buf_init(const_cast<char *>(ptr->body.data()), size);
+            uv_fs_req_cleanup(req);
+            uv_fs_read(req->loop, req, ptr->fd, &ptr->buffer, 1, 0, file_read);
+        }
+    }
+}
+
+void FileRequestBaton::file_read(uv_fs_t *req) {
+    FileRequestBaton *ptr = (FileRequestBaton *)req->data;
+    assert(ptr->thread_id == uv_thread_self());
+
+    if (req->result < 0 || ptr->canceled || !ptr->request) {
+        // Stating failed or was canceled. We already have an open file handle
+        // though, which we'll have to close.
+        notify_error(req);
+    } else {
+        // File was successfully read.
+        if (ptr->request) {
+            ptr->request->response = std::unique_ptr<Response>(new Response);
+            ptr->request->response->code = 200;
+            ptr->request->response->data = std::move(ptr->body);
+            ptr->request->notify();
+        }
+    }
+
+    uv_fs_req_cleanup(req);
+    uv_fs_close(req->loop, req, ptr->fd, file_closed);
+}
+
+void FileRequestBaton::file_closed(uv_fs_t *req) {
+    FileRequestBaton *ptr = (FileRequestBaton *)req->data;
+    assert(ptr->thread_id == uv_thread_self());
+
+    if (req->result < 0) {
+        // Closing the file failed. But there isn't anything we can do.
+    }
+
+    cleanup(req);
+}
+
+void FileRequestBaton::cleanup(uv_fs_t *req) {
+    FileRequestBaton *ptr = (FileRequestBaton *)req->data;
+    assert(ptr->thread_id == uv_thread_self());
+
+    if (ptr->request) {
+        ptr->request->ptr = nullptr;
+    }
+
+    uv_fs_req_cleanup(req);
+    delete ptr;
+}
+
+}
diff --git a/src/storage/file_source.cpp b/src/storage/file_source.cpp
new file mode 100644
index 0000000000..12d924416c
--- /dev/null
+++ b/src/storage/file_source.cpp
@@ -0,0 +1,105 @@
+#include <mbgl/storage/file_source.hpp>
+#include <mbgl/storage/file_request.hpp>
+#include <mbgl/storage/http_request.hpp>
+#include <mbgl/storage/sqlite_store.hpp>
+#include <mbgl/util/uv-messenger.h>
+
+#include <uv.h>
+
+namespace mbgl {
+
+FileSource::FileSource(uv_loop_t *loop_, const std::string &path)
+    : thread_id(uv_thread_self()),
+      store(!path.empty() ? util::ptr<SQLiteStore>(new SQLiteStore(loop_, path)) : nullptr),
+      loop(loop_),
+      queue(new uv_messenger_t) {
+
+    uv_messenger_init(loop, queue, [](void *ptr) {
+        std::unique_ptr<std::function<void()>> fn { reinterpret_cast<std::function<void()> *>(ptr) };
+        (*fn)();
+    });
+    uv_unref((uv_handle_t *)&queue->async);
+}
+
+FileSource::~FileSource() {
+    assert(thread_id == uv_thread_self());
+    uv_messenger_stop(queue);
+    // NOTE: We don't need to delete the messenger since it will be deleted by the
+    // uv_messenger_stop() function.
+
+    util::ptr<BaseRequest> request;
+
+    // Send a cancel() message to all requests that we are still holding.
+    for (const std::pair<std::string, std::weak_ptr<BaseRequest>> &pair : pending) {
+        if ((request = pair.second.lock())) {
+            request->cancel();
+        }
+    }
+}
+
+void FileSource::setBase(const std::string &value) {
+    assert(thread_id == uv_thread_self());
+    base = value;
+}
+
+const std::string &FileSource::getBase() const {
+    assert(thread_id == uv_thread_self());
+    return base;
+}
+
+std::unique_ptr<Request> FileSource::request(ResourceType type, const std::string &url) {
+    assert(thread_id == uv_thread_self());
+
+    // Make URL absolute.
+    const std::string absoluteURL = [&]() -> std::string {
+        const size_t separator = url.find("://");
+        if (separator == std::string::npos) {
+            // Relative URL.
+            return base + url;
+        } else {
+            return url;
+        }
+    }();
+
+    util::ptr<BaseRequest> request;
+
+    // First, try to find an existing Request object.
+    auto it = pending.find(absoluteURL);
+    if (it != pending.end()) {
+        request = it->second.lock();
+    }
+
+    if (!request) {
+        if (absoluteURL.substr(0, 7) == "file://") {
+            request = std::make_shared<FileRequest>(absoluteURL.substr(7), loop);
+        } else {
+            request = std::make_shared<HTTPRequest>(type, absoluteURL, loop, store);
+        }
+
+        pending.emplace(absoluteURL, request);
+    }
+
+    return std::unique_ptr<Request>(new Request(request));
+}
+
+void FileSource::prepare(std::function<void()> fn) {
+    if (thread_id == uv_thread_self()) {
+        fn();
+    } else {
+        uv_messenger_send(queue, new std::function<void()>(std::move(fn)));
+    }
+}
+
+void FileSource::retryAllPending() {
+    assert(thread_id == uv_thread_self());
+
+    util::ptr<BaseRequest> request;
+    for (const std::pair<std::string, std::weak_ptr<BaseRequest>> &pair : pending) {
+        if ((request = pair.second.lock())) {
+            request->retryImmediately();
+        }
+    }
+
+}
+
+}
\ No newline at end of file
diff --git a/src/storage/http_request.cpp b/src/storage/http_request.cpp
new file mode 100644
index 0000000000..1b799d4895
--- /dev/null
+++ b/src/storage/http_request.cpp
@@ -0,0 +1,270 @@
+#include <mbgl/storage/http_request.hpp>
+#include <mbgl/storage/sqlite_store.hpp>
+#include <mbgl/storage/http_request_baton.hpp>
+
+#include <uv.h>
+
+#include <cassert>
+#include <chrono>
+
+namespace mbgl {
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdisabled-macro-expansion"
+#pragma clang diagnostic ignored "-Wexit-time-destructors"
+#pragma clang diagnostic ignored "-Wglobal-constructors"
+
+struct CacheRequestBaton {
+    HTTPRequest *request = nullptr;
+    std::string path;
+    util::ptr<SQLiteStore> store;
+};
+
+HTTPRequest::HTTPRequest(ResourceType type_, const std::string &path, uv_loop_t *loop_, util::ptr<SQLiteStore> store_)
+    : BaseRequest(path), thread_id(uv_thread_self()), loop(loop_), store(store_), type(type_) {
+    if (store) {
+        startCacheRequest();
+    } else {
+        startHTTPRequest(nullptr);
+    }
+}
+
+void HTTPRequest::startCacheRequest() {
+    assert(uv_thread_self() == thread_id);
+
+    cache_baton = new CacheRequestBaton;
+    cache_baton->request = this;
+    cache_baton->path = path;
+    cache_baton->store = store;
+    store->get(path, [](std::unique_ptr<Response> &&response, void *ptr) {
+        // Wrap in a unique_ptr, so it'll always get auto-destructed.
+        std::unique_ptr<CacheRequestBaton> baton((CacheRequestBaton *)ptr);
+        if (baton->request) {
+            baton->request->cache_baton = nullptr;
+            baton->request->handleCacheResponse(std::move(response));
+        }
+    }, cache_baton);
+}
+
+void HTTPRequest::handleCacheResponse(std::unique_ptr<Response> &&res) {
+    assert(uv_thread_self() == thread_id);
+
+    if (res) {
+        // This entry was stored in the cache. Now determine if we need to revalidate.
+        const int64_t now = std::chrono::duration_cast<std::chrono::seconds>(
+                                std::chrono::system_clock::now().time_since_epoch()).count();
+        if (res->expires > now) {
+            response = std::move(res);
+            notify();
+            // Note: after calling notify(), the request object may cease to exist.
+            // This HTTPRequest is completed.
+            return;
+        } else {
+            // TODO: notify with preliminary results.
+        }
+    }
+
+    startHTTPRequest(std::move(res));
+}
+
+void HTTPRequest::startHTTPRequest(std::unique_ptr<Response> &&res) {
+    assert(uv_thread_self() == thread_id);
+    assert(!http_baton);
+
+    http_baton = std::make_shared<HTTPRequestBaton>(path);
+    http_baton->request = this;
+    http_baton->async = new uv_async_t;
+    http_baton->response = std::move(res);
+    http_baton->async->data = new util::ptr<HTTPRequestBaton>(http_baton);
+
+    uv_async_init(loop, http_baton->async, [](uv_async_t *async) {
+        util::ptr<HTTPRequestBaton> &http_baton = *(util::ptr<HTTPRequestBaton> *)async->data;
+
+        if (http_baton->request) {
+            HTTPRequest *request = http_baton->request;
+            request->http_baton.reset();
+            http_baton->request = nullptr;
+            request->handleHTTPResponse(http_baton->type, std::move(http_baton->response));
+        }
+
+        delete (util::ptr<HTTPRequestBaton> *)async->data;
+        uv_close((uv_handle_t *)async, [](uv_handle_t *handle) {
+            uv_async_t *async = (uv_async_t *)handle;
+            delete async;
+        });
+    });
+    attempts++;
+    HTTPRequestBaton::start(http_baton);
+}
+
+
+
+void HTTPRequest::handleHTTPResponse(HTTPResponseType responseType, std::unique_ptr<Response> &&res) {
+    assert(uv_thread_self() == thread_id);
+    assert(!http_baton);
+    assert(!response);
+
+    switch (responseType) {
+        // This error was caused by a temporary error and it is likely that it will be resolved
+        // immediately. We are going to try again right away. This is like the TemporaryError,
+        // except that we will not perform exponential back-off.
+        case HTTPResponseType::SingularError:
+            if (attempts >= 4) {
+                // Report as error after 4 attempts.
+                response = std::move(res);
+                notify();
+            } else if (attempts >= 2) {
+                // Switch to the back-off algorithm after the second failure.
+                retryHTTPRequest(std::move(res), (1 << attempts) * 1000);
+                return;
+            } else {
+                startHTTPRequest(std::move(res));
+            }
+            break;
+
+        // This error might be resolved by waiting some time (e.g. server issues).
+        // We are going to do an exponential back-off and will try again in a few seconds.
+        case HTTPResponseType::TemporaryError:
+            if (attempts >= 4) {
+                // Report error back after it failed completely.
+                response = std::move(res);
+                notify();
+            } else {
+                retryHTTPRequest(std::move(res), (1 << attempts) * 1000);
+            }
+            break;
+
+        // This error might be resolved once the network reachability status changes.
+        // We are going to watch the network status for changes and will retry as soon as the
+        // operating system notifies us of a network status change.
+        case HTTPResponseType::ConnectionError:
+
+            if (attempts >= 4) {
+                // Report error back after it failed completely.
+                response = std::move(res);
+                notify();
+            } else {
+                // By default, we will retry every 60 seconds.
+                retryHTTPRequest(std::move(res), 60000);
+            }
+            break;
+
+        // The request was canceled programatically.
+        case HTTPResponseType::Canceled:
+            response.reset();
+            notify();
+            break;
+
+        // This error probably won't be resolved by retrying anytime soon. We are giving up.
+        case HTTPResponseType::PermanentError:
+            response = std::move(res);
+            notify();
+            break;
+
+        // The request returned data successfully. We retrieved and decoded the data successfully.
+        case HTTPResponseType::Successful:
+            if (store) {
+                store->put(path, type, *res);
+            }
+            response = std::move(res);
+            notify();
+            break;
+
+        // The request confirmed that the data wasn't changed. We already have the data.
+        case HTTPResponseType::NotModified:
+            if (store) {
+                store->updateExpiration(path, res->expires);
+            }
+            response = std::move(res);
+            notify();
+            break;
+
+        default:
+            assert(!"Response wasn't set");
+            break;
+    }
+}
+
+using RetryBaton = std::pair<HTTPRequest *, std::unique_ptr<Response>>;
+
+void HTTPRequest::retryHTTPRequest(std::unique_ptr<Response> &&res, uint64_t timeout) {
+    assert(uv_thread_self() == thread_id);
+    assert(!backoff_timer);
+    backoff_timer = new uv_timer_t();
+    uv_timer_init(loop, backoff_timer);
+    backoff_timer->data = new RetryBaton(this, std::move(res));
+    uv_timer_start(backoff_timer, [](uv_timer_t *timer) {
+        std::unique_ptr<RetryBaton> pair { static_cast<RetryBaton *>(timer->data) };
+        pair->first->startHTTPRequest(std::move(pair->second));
+        pair->first->backoff_timer = nullptr;
+        uv_timer_stop(timer);
+        uv_close((uv_handle_t *)timer, [](uv_handle_t *handle) { delete (uv_timer_t *)handle; });
+    }, timeout, 0);
+}
+
+void HTTPRequest::removeHTTPBaton() {
+    assert(uv_thread_self() == thread_id);
+    if (http_baton) {
+        http_baton->request = nullptr;
+        HTTPRequestBaton::stop(http_baton);
+        http_baton.reset();
+    }
+}
+
+void HTTPRequest::removeCacheBaton() {
+    assert(uv_thread_self() == thread_id);
+    if (cache_baton) {
+        // Make sre that this object doesn't accidentally get accessed when it is destructed before
+        // the callback returned. They are being run in the same thread, so just setting it to
+        // null is sufficient.
+        // Note: We don't manually delete the CacheRequestBaton since it'll be deleted by the
+        // callback.
+        cache_baton->request = nullptr;
+        cache_baton = nullptr;
+    }
+}
+
+void HTTPRequest::removeBackoffTimer() {
+    assert(uv_thread_self() == thread_id);
+    if (backoff_timer) {
+        delete static_cast<RetryBaton *>(backoff_timer->data);
+        uv_timer_stop(backoff_timer);
+        uv_close((uv_handle_t *)backoff_timer, [](uv_handle_t *handle) { delete (uv_timer_t *)handle; });
+        backoff_timer = nullptr;
+    }
+}
+
+void HTTPRequest::retryImmediately() {
+    assert(uv_thread_self() == thread_id);
+    if (!cache_baton && !http_baton) {
+        if (backoff_timer) {
+            // Retry immediately.
+            uv_timer_stop(backoff_timer);
+            std::unique_ptr<RetryBaton> pair { static_cast<RetryBaton *>(backoff_timer->data) };
+            assert(pair->first == this);
+            startHTTPRequest(std::move(pair->second));
+            uv_close((uv_handle_t *)backoff_timer, [](uv_handle_t *handle) { delete (uv_timer_t *)handle; });
+            backoff_timer = nullptr;
+        } else {
+            assert(!"We should always have a backoff_timer when there are no batons");
+        }
+    }
+}
+
+void HTTPRequest::cancel() {
+    assert(uv_thread_self() == thread_id);
+    removeCacheBaton();
+    removeHTTPBaton();
+    removeBackoffTimer();
+    notify();
+}
+
+
+HTTPRequest::~HTTPRequest() {
+    assert(uv_thread_self() == thread_id);
+    cancel();
+}
+
+#pragma clang diagnostic pop
+
+}
diff --git a/src/storage/http_request_baton.cpp b/src/storage/http_request_baton.cpp
new file mode 100644
index 0000000000..02edae748f
--- /dev/null
+++ b/src/storage/http_request_baton.cpp
@@ -0,0 +1,12 @@
+#include <mbgl/storage/http_request_baton.hpp>
+#include <uv.h>
+
+namespace mbgl {
+
+HTTPRequestBaton::HTTPRequestBaton(const std::string &path_) : thread_id(uv_thread_self()), path(path_) {
+}
+
+HTTPRequestBaton::~HTTPRequestBaton() {
+}
+
+}
diff --git a/src/storage/request.cpp b/src/storage/request.cpp
new file mode 100644
index 0000000000..42bf87a849
--- /dev/null
+++ b/src/storage/request.cpp
@@ -0,0 +1,49 @@
+#include <mbgl/storage/request.hpp>
+#include <mbgl/storage/base_request.hpp>
+
+#include <uv.h>
+
+#include <cassert>
+
+namespace mbgl {
+
+Request::Request(const util::ptr<BaseRequest> &base_)
+    : thread_id(uv_thread_self()), base(base_) {
+}
+
+Request::~Request() {
+    assert(thread_id == uv_thread_self());
+}
+
+void Request::onload(CompletedCallback cb) {
+    assert(thread_id == uv_thread_self());
+    if (base) {
+        Callback *callback = base->add(std::move(cb), base);
+        if (callback) {
+            callbacks.push_front(callback);
+        }
+    }
+}
+
+void Request::oncancel(AbortedCallback cb) {
+    assert(thread_id == uv_thread_self());
+    if (base) {
+        Callback *callback = base->add(std::move(cb), base);
+        if (callback) {
+            callbacks.push_front(callback);
+        }
+    }
+}
+
+void Request::cancel() {
+    assert(thread_id == uv_thread_self());
+    if (base) {
+        for (Callback *callback : callbacks) {
+            base->remove(callback);
+        }
+        base.reset();
+    }
+    callbacks.clear();
+}
+
+}
diff --git a/src/storage/response.cpp b/src/storage/response.cpp
new file mode 100644
index 0000000000..cdaf33e4e4
--- /dev/null
+++ b/src/storage/response.cpp
@@ -0,0 +1,22 @@
+#include <mbgl/storage/response.hpp>
+
+#include <chrono>
+
+namespace mbgl {
+
+int64_t Response::parseCacheControl(const char *value) {
+    if (value) {
+        uint64_t seconds = 0;
+        // TODO: cache-control may contain other information as well:
+        // http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9
+        if (std::sscanf(value, "max-age=%llu", &seconds) == 1) {
+            return std::chrono::duration_cast<std::chrono::seconds>(
+                       std::chrono::system_clock::now().time_since_epoch()).count() +
+                   seconds;
+        }
+    }
+
+    return -1;
+}
+
+}
diff --git a/src/storage/sqlite_store.cpp b/src/storage/sqlite_store.cpp
new file mode 100644
index 0000000000..763100f411
--- /dev/null
+++ b/src/storage/sqlite_store.cpp
@@ -0,0 +1,227 @@
+#include <mbgl/storage/sqlite_store.hpp>
+#include <mbgl/util/compression.hpp>
+#include <mbgl/util/sqlite3.hpp>
+
+#include <mbgl/util/uv-worker.h>
+
+#include <cassert>
+
+using namespace mapbox::sqlite;
+
+std::string removeAccessTokenFromURL(const std::string &url) {
+    const size_t token_start = url.find("access_token=");
+    // Ensure that token exists, isn't at the front and is preceded by either & or ?.
+    if (token_start == std::string::npos || token_start == 0 || !(url[token_start - 1] == '&' || url[token_start - 1] == '?')) {
+        return url;
+    }
+
+    const size_t token_end = url.find_first_of('&', token_start);
+    if (token_end == std::string::npos) {
+        // The token is the last query argument. We slice away the "&access_token=..." part
+        return url.substr(0, token_start - 1);
+    } else {
+        // We slice away the "access_token=...&" part.
+        return url.substr(0, token_start) + url.substr(token_end + 1);
+    }
+}
+
+std::string convertMapboxDomainsToProtocol(const std::string &url) {
+    const size_t protocol_separator = url.find("://");
+    if (protocol_separator == std::string::npos) {
+        return url;
+    }
+
+    const std::string protocol = url.substr(0, protocol_separator);
+    if (!(protocol == "http" || protocol == "https")) {
+        return url;
+    }
+
+    const size_t domain_begin = protocol_separator + 3;
+    const size_t path_separator = url.find("/", domain_begin);
+    if (path_separator == std::string::npos) {
+        return url;
+    }
+
+    const std::string domain = url.substr(domain_begin, path_separator - domain_begin);
+    if (domain.find(".tiles.mapbox.com") != std::string::npos) {
+        return "mapbox://" + url.substr(path_separator + 1);
+    } else {
+        return url;
+    }
+}
+
+std::string unifyMapboxURLs(const std::string &url) {
+    return removeAccessTokenFromURL(convertMapboxDomainsToProtocol(url));
+}
+
+namespace mbgl {
+
+SQLiteStore::SQLiteStore(uv_loop_t *loop, const std::string &path)
+    : thread_id(uv_thread_self()),
+      db(std::make_shared<Database>(path.c_str(), ReadWrite | Create)) {
+    createSchema();
+    worker = new uv_worker_t;
+    uv_worker_init(worker, loop, 1, "SQLite");
+}
+
+SQLiteStore::~SQLiteStore() {
+    // Nothing to do. This function needs to be here because we're forward-declaring
+    // Database, so we need the actual definition here to be able to properly destruct it.
+    if (worker) {
+        uv_worker_close(worker, [](uv_worker_t *worker) {
+            delete worker;
+        });
+    }
+}
+
+void SQLiteStore::createSchema() {
+    if (!db || !*db) {
+        return;
+    }
+
+    db->exec("CREATE TABLE IF NOT EXISTS `http_cache` ("
+             "    `url` TEXT PRIMARY KEY NOT NULL,"
+             "    `code` INTEGER NOT NULL,"
+             "    `type` INTEGER NOT NULL,"
+             "    `modified` INTEGER,"
+             "    `etag` TEXT,"
+             "    `expires` INTEGER,"
+             "    `data` BLOB,"
+             "    `compressed` INTEGER NOT NULL DEFAULT 0"
+             ");"
+             "CREATE INDEX IF NOT EXISTS `http_cache_type_idx` ON `http_cache` (`type`);");
+}
+
+struct GetBaton {
+    util::ptr<Database> db;
+    std::string path;
+    ResourceType type;
+    void *ptr = nullptr;
+    SQLiteStore::GetCallback callback = nullptr;
+    std::unique_ptr<Response> response;
+};
+
+void SQLiteStore::get(const std::string &path, GetCallback callback, void *ptr) {
+    assert(uv_thread_self() == thread_id);
+    if (!db || !*db) {
+        if (callback) {
+            callback(nullptr, ptr);
+        }
+        return;
+    }
+
+    GetBaton *get_baton = new GetBaton;
+    get_baton->db = db;
+    get_baton->path = path;
+    get_baton->ptr = ptr;
+    get_baton->callback = callback;
+
+    uv_worker_send(worker, get_baton, [](void *data) {
+        GetBaton *baton = (GetBaton *)data;
+        const std::string url = unifyMapboxURLs(baton->path);
+        //                                                    0       1         2
+        Statement stmt = baton->db->prepare("SELECT `code`, `type`, `modified`, "
+        //     3         4        5           6
+            "`etag`, `expires`, `data`, `compressed` FROM `http_cache` WHERE `url` = ?");
+
+        stmt.bind(1, url.c_str());
+        if (stmt.run()) {
+            // There is data.
+            baton->response = std::unique_ptr<Response>(new Response);
+
+            baton->response->code = stmt.get<int>(0);
+            baton->type = ResourceType(stmt.get<int>(1));
+            baton->response->modified = stmt.get<int64_t>(2);
+            baton->response->etag = stmt.get<std::string>(3);
+            baton->response->expires = stmt.get<int64_t>(4);
+            baton->response->data = stmt.get<std::string>(5);
+            if (stmt.get<int>(6)) { // == compressed
+                baton->response->data = util::decompress(baton->response->data);
+            }
+        } else {
+            // There is no data.
+            // This is a noop.
+        }
+    }, [](void *data) {
+        std::unique_ptr<GetBaton> baton { (GetBaton *)data };
+        if (baton->callback) {
+            baton->callback(std::move(baton->response), baton->ptr);
+        }
+    });
+}
+
+
+struct PutBaton {
+    util::ptr<Database> db;
+    std::string path;
+    ResourceType type;
+    Response response;
+};
+
+void SQLiteStore::put(const std::string &path, ResourceType type, const Response &response) {
+    assert(uv_thread_self() == thread_id);
+    if (!db) return;
+
+    PutBaton *put_baton = new PutBaton;
+    put_baton->db = db;
+    put_baton->path = path;
+    put_baton->type = type;
+    put_baton->response = response;
+
+    uv_worker_send(worker, put_baton, [](void *data) {
+        PutBaton *baton = (PutBaton *)data;
+        const std::string url = unifyMapboxURLs(baton->path);
+        Statement stmt = baton->db->prepare("REPLACE INTO `http_cache` ("
+        //     1      2       3         4         5         6        7          8
+            "`url`, `code`, `type`, `modified`, `etag`, `expires`, `data`, `compressed`"
+            ") VALUES(?, ?, ?, ?, ?, ?, ?, ?)");
+        stmt.bind(1, url.c_str());
+        stmt.bind(2, int(baton->response.code));
+        stmt.bind(3, int(baton->type));
+        stmt.bind(4, baton->response.modified);
+        stmt.bind(5, baton->response.etag.c_str());
+        stmt.bind(6, baton->response.expires);
+
+        if (baton->type == ResourceType::Image) {
+            stmt.bind(7, baton->response.data, false); // do not retain the string internally.
+            stmt.bind(8, false);
+        } else {
+            stmt.bind(7, util::compress(baton->response.data), true); // retain the string internally.
+            stmt.bind(8, true);
+        }
+
+        stmt.run();
+    }, [](void *data) {
+        delete (PutBaton *)data;
+    });
+}
+
+struct ExpirationBaton {
+    util::ptr<Database> db;
+    std::string path;
+    int64_t expires;
+};
+
+void SQLiteStore::updateExpiration(const std::string &path, int64_t expires) {
+    assert(uv_thread_self() == thread_id);
+    if (!db || !*db) return;
+
+    ExpirationBaton *expiration_baton = new ExpirationBaton;
+    expiration_baton->db = db;
+    expiration_baton->path = path;
+    expiration_baton->expires = expires;
+
+    uv_worker_send(worker, expiration_baton, [](void *data) {
+        ExpirationBaton *baton = (ExpirationBaton *)data;
+        const std::string url = unifyMapboxURLs(baton->path);
+        Statement stmt = //                                 1               2
+            baton->db->prepare("UPDATE `http_cache` SET `expires` = ? WHERE `url` = ?");
+        stmt.bind<int64_t>(1, baton->expires);
+        stmt.bind(2, url.c_str());
+        stmt.run();
+    }, [](void *data) {
+        delete (ExpirationBaton *)data;
+    });
+}
+
+}
diff --git a/src/style/style_layer_group.cpp b/src/style/style_layer_group.cpp
index c7e4360d21..a731aebdcb 100644
--- a/src/style/style_layer_group.cpp
+++ b/src/style/style_layer_group.cpp
@@ -5,7 +5,7 @@ namespace mbgl {
 
 void StyleLayerGroup::setClasses(const std::vector<std::string> &class_names, timestamp now,
                                  const PropertyTransition &defaultTransition) {
-    for (const std::shared_ptr<StyleLayer> &layer : layers) {
+    for (const util::ptr<StyleLayer> &layer : layers) {
         if (layer) {
             layer->setClasses(class_names, now, defaultTransition);
         }
@@ -13,7 +13,7 @@ void StyleLayerGroup::setClasses(const std::vector<std::string> &class_names, ti
 }
 
 void StyleLayerGroup::updateProperties(float z, timestamp t) {
-    for (const std::shared_ptr<StyleLayer> &layer: layers) {
+    for (const util::ptr<StyleLayer> &layer: layers) {
         if (layer) {
             layer->updateProperties(z, t);
         }
@@ -21,7 +21,7 @@ void StyleLayerGroup::updateProperties(float z, timestamp t) {
 }
 
 bool StyleLayerGroup::hasTransitions() const {
-    for (const std::shared_ptr<const StyleLayer> &layer: layers) {
+    for (const util::ptr<const StyleLayer> &layer: layers) {
         if (layer) {
             if (layer->hasTransitions()) {
                 return true;
diff --git a/src/style/style_parser.cpp b/src/style/style_parser.cpp
index ad7694d9a9..2a64ab38f8 100644
--- a/src/style/style_parser.cpp
+++ b/src/style/style_parser.cpp
@@ -176,12 +176,12 @@ void StyleParser::parseSources(JSVal value) {
         rapidjson::Value::ConstMemberIterator itr = value.MemberBegin();
         for (; itr != value.MemberEnd(); ++itr) {
             std::string name { itr->name.GetString(), itr->name.GetStringLength() };
-            SourceInfo info;
+            util::ptr<SourceInfo> info = std::make_shared<SourceInfo>();
 
-            parseRenderProperty<SourceTypeClass>(itr->value, info.type, "type");
-            parseRenderProperty(itr->value, info.url, "url");
-            parseRenderProperty(itr->value, info.tile_size, "tileSize");
-            info.parseTileJSONProperties(itr->value);
+            parseRenderProperty<SourceTypeClass>(itr->value, info->type, "type");
+            parseRenderProperty(itr->value, info->url, "url");
+            parseRenderProperty(itr->value, info->tile_size, "tileSize");
+            info->parseTileJSONProperties(itr->value);
 
             sources.emplace(std::move(name), std::make_shared<StyleSource>(info));
         }
@@ -451,7 +451,7 @@ std::unique_ptr<StyleLayerGroup> StyleParser::createLayers(JSVal value) {
     if (value.IsArray()) {
         std::unique_ptr<StyleLayerGroup> group = std::make_unique<StyleLayerGroup>();
         for (rapidjson::SizeType i = 0; i < value.Size(); ++i) {
-            std::shared_ptr<StyleLayer> layer = createLayer(value[i]);
+            util::ptr<StyleLayer> layer = createLayer(value[i]);
             if (layer) {
                 group->layers.emplace_back(layer);
             }
@@ -463,7 +463,7 @@ std::unique_ptr<StyleLayerGroup> StyleParser::createLayers(JSVal value) {
     }
 }
 
-std::shared_ptr<StyleLayer> StyleParser::createLayer(JSVal value) {
+util::ptr<StyleLayer> StyleParser::createLayer(JSVal value) {
     if (value.IsObject()) {
         if (!value.HasMember("id")) {
             Log::Warning(Event::ParseStyle, "layer must have an id");
@@ -487,7 +487,7 @@ std::shared_ptr<StyleLayer> StyleParser::createLayer(JSVal value) {
         std::map<ClassID, ClassProperties> styles;
         parseStyles(value, styles);
 
-        std::shared_ptr<StyleLayer> layer = std::make_shared<StyleLayer>(
+        util::ptr<StyleLayer> layer = std::make_shared<StyleLayer>(
             layer_id, std::move(styles));
 
         if (value.HasMember("layers")) {
@@ -495,7 +495,7 @@ std::shared_ptr<StyleLayer> StyleParser::createLayer(JSVal value) {
         }
 
         // Store the layer ID so we can reference it later.
-        layers.emplace(layer_id, std::pair<JSVal, std::shared_ptr<StyleLayer>> { value, layer });
+        layers.emplace(layer_id, std::pair<JSVal, util::ptr<StyleLayer>> { value, layer });
 
         return layer;
     } else {
@@ -505,14 +505,14 @@ std::shared_ptr<StyleLayer> StyleParser::createLayer(JSVal value) {
 }
 
 void StyleParser::parseLayers() {
-    for (std::pair<const std::string, std::pair<JSVal, std::shared_ptr<StyleLayer>>> &pair : layers) {
+    for (std::pair<const std::string, std::pair<JSVal, util::ptr<StyleLayer>>> &pair : layers) {
         parseLayer(pair.second);
     }
 }
 
-void StyleParser::parseLayer(std::pair<JSVal, std::shared_ptr<StyleLayer>> &pair) {
+void StyleParser::parseLayer(std::pair<JSVal, util::ptr<StyleLayer>> &pair) {
     JSVal value = pair.first;
-    std::shared_ptr<StyleLayer> &layer = pair.second;
+    util::ptr<StyleLayer> &layer = pair.second;
 
     if (value.HasMember("type")) {
         JSVal type = value["type"];
@@ -642,7 +642,7 @@ void StyleParser::parseStyle(JSVal value, ClassProperties &klass) {
     parseOptionalProperty<Function<Color>>("background-color", Key::BackgroundColor, klass, value);
 }
 
-void StyleParser::parseReference(JSVal value, std::shared_ptr<StyleLayer> &layer) {
+void StyleParser::parseReference(JSVal value, util::ptr<StyleLayer> &layer) {
     if (!value.IsString()) {
         Log::Warning(Event::ParseStyle, "layer ref of '%s' must be a string", layer->id.c_str());
         return;
@@ -661,7 +661,7 @@ void StyleParser::parseReference(JSVal value, std::shared_ptr<StyleLayer> &layer
     stack.pop_front();
 
 
-    std::shared_ptr<StyleLayer> reference = it->second.second;
+    util::ptr<StyleLayer> reference = it->second.second;
 
     layer->type = reference->type;
 
@@ -676,7 +676,7 @@ void StyleParser::parseReference(JSVal value, std::shared_ptr<StyleLayer> &layer
 
 #pragma mark - Parse Bucket
 
-void StyleParser::parseBucket(JSVal value, std::shared_ptr<StyleLayer> &layer) {
+void StyleParser::parseBucket(JSVal value, util::ptr<StyleLayer> &layer) {
     layer->bucket = std::make_shared<StyleBucket>(layer->type);
 
     // We name the buckets according to the layer that defined it.
@@ -822,7 +822,7 @@ std::vector<Value> StyleParser::parseValues(JSVal value) {
     return values;
 }
 
-void StyleParser::parseRender(JSVal value, std::shared_ptr<StyleLayer> &layer) {
+void StyleParser::parseRender(JSVal value, util::ptr<StyleLayer> &layer) {
     if (!value.IsObject()) {
         Log::Warning(Event::ParseStyle, "render property of layer '%s' must be an object", layer->id.c_str());
         return;
diff --git a/src/text/glyph.cpp b/src/text/glyph.cpp
index 7dea7246d7..f02c710db2 100644
--- a/src/text/glyph.cpp
+++ b/src/text/glyph.cpp
@@ -3,9 +3,6 @@
 namespace mbgl {
 
 // Note: this only works for the BMP
-// Note: we could use a binary lookup table to get averaged constant time lookups, however,
-// most of our lookups are going to be within the first 3 ranges listed here, so this is
-// likely faster.
 GlyphRange getGlyphRange(char32_t glyph) {
     unsigned start = (glyph/256) * 256;
     unsigned end = (start + 255);
diff --git a/src/text/glyph_store.cpp b/src/text/glyph_store.cpp
index 783710d929..1723bd3d94 100644
--- a/src/text/glyph_store.cpp
+++ b/src/text/glyph_store.cpp
@@ -8,7 +8,7 @@
 #include <mbgl/util/constants.hpp>
 #include <mbgl/util/token.hpp>
 #include <mbgl/util/math.hpp>
-#include <mbgl/util/filesource.hpp>
+#include <mbgl/storage/file_source.hpp>
 #include <mbgl/platform/platform.hpp>
 #include <mbgl/util/uv_detail.hpp>
 #include <algorithm>
@@ -137,7 +137,7 @@ void FontStack::lineWrap(Shaping &shaping, const float lineHeight, const float m
     align(shaping, justify, horizontalAlign, verticalAlign, maxLineLength, lineHeight, line);
 }
 
-GlyphPBF::GlyphPBF(const std::string &glyphURL, const std::string &fontStack, GlyphRange glyphRange, const std::shared_ptr<FileSource> &fileSource)
+GlyphPBF::GlyphPBF(const std::string &glyphURL, const std::string &fontStack, GlyphRange glyphRange, const util::ptr<FileSource> &fileSource)
     : future(promise.get_future().share())
 {
     // Load the glyph set URL
@@ -147,23 +147,26 @@ GlyphPBF::GlyphPBF(const std::string &glyphURL, const std::string &fontStack, Gl
         return "";
     });
 
-#if defined(DEBUG)
-    fprintf(stderr, "%s\n", url.c_str());
-#endif
-
-    fileSource->load(ResourceType::Glyphs, url, [&](platform::Response *res) {
-        if (res->code != 200) {
-            // Something went wrong with loading the glyph pbf. Pass on the error to the future listeners.
-            const std::string msg = util::sprintf<255>("[ERROR] failed to load glyphs (%d): %s\n", res->code, res->error_message.c_str());
-            promise.set_exception(std::make_exception_ptr(std::runtime_error(msg)));
-        } else {
-            // Transfer the data to the GlyphSet and signal its availability.
-            // Once it is available, the caller will need to call parse() to actually
-            // parse the data we received. We are not doing this here since this callback is being
-            // called from another (unknown) thread.
-            data.swap(res->body);
-            promise.set_value(*this);
-        }
+    // The prepare call jumps back to the main thread.
+    fileSource->prepare([&, url, fileSource] {
+        auto request = fileSource->request(ResourceType::Glyphs, url);
+        request->onload([&, url](const Response &res) {
+            if (res.code != 200) {
+                // Something went wrong with loading the glyph pbf. Pass on the error to the future listeners.
+                const std::string msg = util::sprintf<255>("[ERROR] failed to load glyphs (%d): %s\n", res.code, res.message.c_str());
+                promise.set_exception(std::make_exception_ptr(std::runtime_error(msg)));
+            } else {
+                // Transfer the data to the GlyphSet and signal its availability.
+                // Once it is available, the caller will need to call parse() to actually
+                // parse the data we received. We are not doing this here since this callback is being
+                // called from another (unknown) thread.
+                data = res.data;
+                promise.set_value(*this);
+            }
+        });
+        request->oncancel([&]() {
+            promise.set_exception(std::make_exception_ptr(std::runtime_error("Loading glyphs was canceled")));
+        });
     });
 }
 
@@ -225,7 +228,7 @@ void GlyphPBF::parse(FontStack &stack) {
     data.clear();
 }
 
-GlyphStore::GlyphStore(const std::shared_ptr<FileSource> &fileSource) : fileSource(fileSource) {}
+GlyphStore::GlyphStore(const util::ptr<FileSource> &fileSource) : fileSource(fileSource) {}
 
 void GlyphStore::setURL(const std::string &url) {
     glyphURL = url;
diff --git a/src/util/compression.cpp b/src/util/compression.cpp
new file mode 100644
index 0000000000..de4e09764c
--- /dev/null
+++ b/src/util/compression.cpp
@@ -0,0 +1,81 @@
+#include <mbgl/util/compression.hpp>
+
+#include <zlib.h>
+
+#include <cstring>
+#include <stdexcept>
+
+namespace mbgl {
+namespace util {
+
+std::string compress(const std::string &raw) {
+    z_stream deflate_stream;
+    memset(&deflate_stream, 0, sizeof(deflate_stream));
+
+    // TODO: reuse z_streams
+    if (deflateInit(&deflate_stream, Z_DEFAULT_COMPRESSION) != Z_OK) {
+        throw std::runtime_error("failed to initialize deflate");
+    }
+
+    deflate_stream.next_in = (Bytef *)raw.data();
+    deflate_stream.avail_in = raw.size();
+
+    std::string result;
+    char out[16384];
+
+    int code;
+    do {
+        deflate_stream.next_out = reinterpret_cast<Bytef *>(out);
+        deflate_stream.avail_out = sizeof(out);
+        code = deflate(&deflate_stream, Z_FINISH);
+        if (result.size() < deflate_stream.total_out) {
+            // append the block to the output string
+            result.append(out, deflate_stream.total_out - result.size());
+        }
+    } while (code == Z_OK);
+
+    deflateEnd(&deflate_stream);
+
+    if (code != Z_STREAM_END) {
+        throw std::runtime_error(deflate_stream.msg);
+    }
+
+    return result;
+}
+
+std::string decompress(const std::string &raw) {
+    z_stream inflate_stream;
+    memset(&inflate_stream, 0, sizeof(inflate_stream));
+
+    // TODO: reuse z_streams
+    if (inflateInit(&inflate_stream) != Z_OK) {
+        throw std::runtime_error("failed to initialize inflate");
+    }
+
+    inflate_stream.next_in = (Bytef *)raw.data();
+    inflate_stream.avail_in = raw.size();
+
+    std::string result;
+    char out[15384];
+
+    int code;
+    do {
+        inflate_stream.next_out = reinterpret_cast<Bytef *>(out);
+        inflate_stream.avail_out = sizeof(out);
+        code = inflate(&inflate_stream, 0);
+        // result.append(out, sizeof(out) - inflate_stream.avail_out);
+        if (result.size() < inflate_stream.total_out) {
+            result.append(out, inflate_stream.total_out - result.size());
+        }
+    } while (code == Z_OK);
+
+    inflateEnd(&inflate_stream);
+
+    if (code != Z_STREAM_END) {
+        throw std::runtime_error(inflate_stream.msg);
+    }
+
+    return result;
+}
+}
+}
diff --git a/src/util/filesource.cpp b/src/util/filesource.cpp
deleted file mode 100644
index 503d4dfb1d..0000000000
--- a/src/util/filesource.cpp
+++ /dev/null
@@ -1,58 +0,0 @@
-#include <mbgl/util/filesource.hpp>
-#include <mbgl/platform/platform.hpp>
-
-#include <fstream>
-#include <sstream>
-
-namespace mbgl {
-
-FileSource::FileSource() {}
-
-
-void FileSource::setBase(const std::string &value) {
-    base = value;
-}
-
-const std::string &FileSource::getBase() const {
-    return base;
-}
-
-void FileSource::load(ResourceType /*type*/, const std::string &url, std::function<void(platform::Response *)> callback, const std::shared_ptr<uv::loop> loop) {
-    // convert relative URLs to absolute URLs
-
-    const std::string absoluteURL = [&]() -> std::string {
-        const size_t separator = url.find("://");
-        if (separator == std::string::npos) {
-            // Relative URL.
-            return base + url;
-        } else {
-            return url;
-        }
-    }();
-
-    const size_t separator = absoluteURL.find("://");
-    const std::string protocol = separator != std::string::npos ? absoluteURL.substr(0, separator) : "";
-
-    if (protocol == "file") {
-        // load from disk
-        const std::string path = absoluteURL.substr(separator + 3);
-        std::ifstream file(path);
-
-        platform::Response response(callback);
-        if (!file.good()) {
-            response.error_message = "file not found (" + path + ")";
-        } else {
-            std::stringstream data;
-            data << file.rdbuf();
-            response.code = 200;
-            response.body = data.str();
-        }
-
-        callback(&response);
-    } else {
-        // load from the internet
-        platform::request_http(absoluteURL, callback, loop);
-    }
-}
-
-}
\ No newline at end of file
diff --git a/src/util/parsedate.c b/src/util/parsedate.c
new file mode 100644
index 0000000000..123c5c4e5f
--- /dev/null
+++ b/src/util/parsedate.c
@@ -0,0 +1,689 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2014, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+/*
+  A brief summary of the date string formats this parser groks:
+
+  RFC 2616 3.3.1
+
+  Sun, 06 Nov 1994 08:49:37 GMT  ; RFC 822, updated by RFC 1123
+  Sunday, 06-Nov-94 08:49:37 GMT ; RFC 850, obsoleted by RFC 1036
+  Sun Nov  6 08:49:37 1994       ; ANSI C's asctime() format
+
+  we support dates without week day name:
+
+  06 Nov 1994 08:49:37 GMT
+  06-Nov-94 08:49:37 GMT
+  Nov  6 08:49:37 1994
+
+  without the time zone:
+
+  06 Nov 1994 08:49:37
+  06-Nov-94 08:49:37
+
+  weird order:
+
+  1994 Nov 6 08:49:37  (GNU date fails)
+  GMT 08:49:37 06-Nov-94 Sunday
+  94 6 Nov 08:49:37    (GNU date fails)
+
+  time left out:
+
+  1994 Nov 6
+  06-Nov-94
+  Sun Nov 6 94
+
+  unusual separators:
+
+  1994.Nov.6
+  Sun/Nov/6/94/GMT
+
+  commonly used time zone names:
+
+  Sun, 06 Nov 1994 08:49:37 CET
+  06 Nov 1994 08:49:37 EST
+
+  time zones specified using RFC822 style:
+
+  Sun, 12 Sep 2004 15:05:58 -0700
+  Sat, 11 Sep 2004 21:32:11 +0200
+
+  compact numerical date strings:
+
+  20040912 15:05:58 -0700
+  20040911 +0200
+
+*/
+
+#include <mbgl/util/parsedate.h>
+
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <limits.h>
+#include <stdbool.h>
+#include <errno.h>
+#include <string.h>
+#include <ctype.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+
+#define ERRNO         (errno)
+#define SET_ERRNO(x)  (errno = (x))
+
+
+/* Portable, consistent toupper (remember EBCDIC). Do not use toupper() because
+   its behavior is altered by the current locale. */
+char raw_toupper(char in)
+{
+  switch (in) {
+  case 'a':
+    return 'A';
+  case 'b':
+    return 'B';
+  case 'c':
+    return 'C';
+  case 'd':
+    return 'D';
+  case 'e':
+    return 'E';
+  case 'f':
+    return 'F';
+  case 'g':
+    return 'G';
+  case 'h':
+    return 'H';
+  case 'i':
+    return 'I';
+  case 'j':
+    return 'J';
+  case 'k':
+    return 'K';
+  case 'l':
+    return 'L';
+  case 'm':
+    return 'M';
+  case 'n':
+    return 'N';
+  case 'o':
+    return 'O';
+  case 'p':
+    return 'P';
+  case 'q':
+    return 'Q';
+  case 'r':
+    return 'R';
+  case 's':
+    return 'S';
+  case 't':
+    return 'T';
+  case 'u':
+    return 'U';
+  case 'v':
+    return 'V';
+  case 'w':
+    return 'W';
+  case 'x':
+    return 'X';
+  case 'y':
+    return 'Y';
+  case 'z':
+    return 'Z';
+  }
+  return in;
+}
+
+/*
+ * raw_equal() is for doing "raw" case insensitive strings. This is meant
+ * to be locale independent and only compare strings we know are safe for
+ * this.  See http://daniel.haxx.se/blog/2008/10/15/strcasecmp-in-turkish/ for
+ * some further explanation to why this function is necessary.
+ *
+ * The function is capable of comparing a-z case insensitively even for
+ * non-ascii.
+ */
+
+int raw_equal(const char *first, const char *second)
+{
+  while(*first && *second) {
+    if(raw_toupper(*first) != raw_toupper(*second))
+      /* get out of the loop as soon as they don't match */
+      break;
+    first++;
+    second++;
+  }
+  /* we do the comparison here (possibly again), just to make sure that if the
+     loop above is skipped because one of the strings reached zero, we must not
+     return this as a successful match */
+  return (raw_toupper(*first) == raw_toupper(*second));
+}
+
+#define ISSPACE(x)  (isspace((int)  ((unsigned char)x)))
+#define ISDIGIT(x)  (isdigit((int)  ((unsigned char)x)))
+#define ISALNUM(x)  (isalnum((int)  ((unsigned char)x)))
+#define ISALPHA(x)  (isalpha((int)  ((unsigned char)x)))
+
+
+/*
+ * Redefine TRUE and FALSE too, to catch current use. With this
+ * change, 'bool found = 1' will give a warning on MIPSPro, but
+ * 'bool found = TRUE' will not. Change tested on IRIX/MIPSPro,
+ * AIX 5.1/Xlc, Tru64 5.1/cc, w/make test too.
+ */
+
+#ifndef TRUE
+#define TRUE true
+#endif
+#ifndef FALSE
+#define FALSE false
+#endif
+
+
+
+/*
+** signed long to signed int
+*/
+
+int clamp_to_int(long slnum)
+{
+  return slnum > INT_MAX ? INT_MAX : slnum < INT_MIN ? INT_MIN : slnum;
+}
+
+
+const char * const wkday[] =
+{"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"};
+static const char * const weekday[] =
+{ "Monday", "Tuesday", "Wednesday", "Thursday",
+  "Friday", "Saturday", "Sunday" };
+const char * const month[]=
+{ "Jan", "Feb", "Mar", "Apr", "May", "Jun",
+  "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
+
+struct tzinfo {
+  char name[5];
+  int offset; /* +/- in minutes */
+};
+
+/*
+ * parsedate()
+ *
+ * Returns:
+ *
+ * PARSEDATE_OK     - a fine conversion
+ * PARSEDATE_FAIL   - failed to convert
+ * PARSEDATE_LATER  - time overflow at the far end of time_t
+ * PARSEDATE_SOONER - time underflow at the low end of time_t
+ */
+
+static int parsedate(const char *date, time_t *output);
+
+#define PARSEDATE_OK     0
+#define PARSEDATE_FAIL   -1
+#define PARSEDATE_LATER  1
+#define PARSEDATE_SOONER 2
+
+/* Here's a bunch of frequently used time zone names. These were supported
+   by the old getdate parser. */
+#define tDAYZONE -60       /* offset for daylight savings time */
+static const struct tzinfo tz[]= {
+  {"GMT", 0},              /* Greenwich Mean */
+  {"UTC", 0},              /* Universal (Coordinated) */
+  {"WET", 0},              /* Western European */
+  {"BST", 0 tDAYZONE},     /* British Summer */
+  {"WAT", 60},             /* West Africa */
+  {"AST", 240},            /* Atlantic Standard */
+  {"ADT", 240 tDAYZONE},   /* Atlantic Daylight */
+  {"EST", 300},            /* Eastern Standard */
+  {"EDT", 300 tDAYZONE},   /* Eastern Daylight */
+  {"CST", 360},            /* Central Standard */
+  {"CDT", 360 tDAYZONE},   /* Central Daylight */
+  {"MST", 420},            /* Mountain Standard */
+  {"MDT", 420 tDAYZONE},   /* Mountain Daylight */
+  {"PST", 480},            /* Pacific Standard */
+  {"PDT", 480 tDAYZONE},   /* Pacific Daylight */
+  {"YST", 540},            /* Yukon Standard */
+  {"YDT", 540 tDAYZONE},   /* Yukon Daylight */
+  {"HST", 600},            /* Hawaii Standard */
+  {"HDT", 600 tDAYZONE},   /* Hawaii Daylight */
+  {"CAT", 600},            /* Central Alaska */
+  {"AHST", 600},           /* Alaska-Hawaii Standard */
+  {"NT",  660},            /* Nome */
+  {"IDLW", 720},           /* International Date Line West */
+  {"CET", -60},            /* Central European */
+  {"MET", -60},            /* Middle European */
+  {"MEWT", -60},           /* Middle European Winter */
+  {"MEST", -60 tDAYZONE},  /* Middle European Summer */
+  {"CEST", -60 tDAYZONE},  /* Central European Summer */
+  {"MESZ", -60 tDAYZONE},  /* Middle European Summer */
+  {"FWT", -60},            /* French Winter */
+  {"FST", -60 tDAYZONE},   /* French Summer */
+  {"EET", -120},           /* Eastern Europe, USSR Zone 1 */
+  {"WAST", -420},          /* West Australian Standard */
+  {"WADT", -420 tDAYZONE}, /* West Australian Daylight */
+  {"CCT", -480},           /* China Coast, USSR Zone 7 */
+  {"JST", -540},           /* Japan Standard, USSR Zone 8 */
+  {"EAST", -600},          /* Eastern Australian Standard */
+  {"EADT", -600 tDAYZONE}, /* Eastern Australian Daylight */
+  {"GST", -600},           /* Guam Standard, USSR Zone 9 */
+  {"NZT", -720},           /* New Zealand */
+  {"NZST", -720},          /* New Zealand Standard */
+  {"NZDT", -720 tDAYZONE}, /* New Zealand Daylight */
+  {"IDLE", -720},          /* International Date Line East */
+  /* Next up: Military timezone names. RFC822 allowed these, but (as noted in
+     RFC 1123) had their signs wrong. Here we use the correct signs to match
+     actual military usage.
+   */
+  {"A",  +1 * 60},         /* Alpha */
+  {"B",  +2 * 60},         /* Bravo */
+  {"C",  +3 * 60},         /* Charlie */
+  {"D",  +4 * 60},         /* Delta */
+  {"E",  +5 * 60},         /* Echo */
+  {"F",  +6 * 60},         /* Foxtrot */
+  {"G",  +7 * 60},         /* Golf */
+  {"H",  +8 * 60},         /* Hotel */
+  {"I",  +9 * 60},         /* India */
+  /* "J", Juliet is not used as a timezone, to indicate the observer's local
+     time */
+  {"K", +10 * 60},         /* Kilo */
+  {"L", +11 * 60},         /* Lima */
+  {"M", +12 * 60},         /* Mike */
+  {"N",  -1 * 60},         /* November */
+  {"O",  -2 * 60},         /* Oscar */
+  {"P",  -3 * 60},         /* Papa */
+  {"Q",  -4 * 60},         /* Quebec */
+  {"R",  -5 * 60},         /* Romeo */
+  {"S",  -6 * 60},         /* Sierra */
+  {"T",  -7 * 60},         /* Tango */
+  {"U",  -8 * 60},         /* Uniform */
+  {"V",  -9 * 60},         /* Victor */
+  {"W", -10 * 60},         /* Whiskey */
+  {"X", -11 * 60},         /* X-ray */
+  {"Y", -12 * 60},         /* Yankee */
+  {"Z", 0},                /* Zulu, zero meridian, a.k.a. UTC */
+};
+
+/* returns:
+   -1 no day
+   0 monday - 6 sunday
+*/
+
+static int checkday(const char *check, size_t len)
+{
+  int i;
+  const char * const *what;
+  bool found= FALSE;
+  if(len > 3)
+    what = &weekday[0];
+  else
+    what = &wkday[0];
+  for(i=0; i<7; i++) {
+    if(raw_equal(check, what[0])) {
+      found=TRUE;
+      break;
+    }
+    what++;
+  }
+  return found?i:-1;
+}
+
+static int checkmonth(const char *check)
+{
+  int i;
+  const char * const *what;
+  bool found= FALSE;
+
+  what = &month[0];
+  for(i=0; i<12; i++) {
+    if(raw_equal(check, what[0])) {
+      found=TRUE;
+      break;
+    }
+    what++;
+  }
+  return found?i:-1; /* return the offset or -1, no real offset is -1 */
+}
+
+/* return the time zone offset between GMT and the input one, in number
+   of seconds or -1 if the timezone wasn't found/legal */
+
+static int checktz(const char *check)
+{
+  unsigned int i;
+  const struct tzinfo *what;
+  bool found= FALSE;
+
+  what = tz;
+  for(i=0; i< sizeof(tz)/sizeof(tz[0]); i++) {
+    if(raw_equal(check, what->name)) {
+      found=TRUE;
+      break;
+    }
+    what++;
+  }
+  return found?what->offset*60:-1;
+}
+
+static void skip(const char **date)
+{
+  /* skip everything that aren't letters or digits */
+  while(**date && !ISALNUM(**date))
+    (*date)++;
+}
+
+enum assume {
+  DATE_MDAY,
+  DATE_YEAR,
+  DATE_TIME
+};
+
+/* this is a clone of 'struct tm' but with all fields we don't need or use
+   cut out */
+struct my_tm {
+  int tm_sec;
+  int tm_min;
+  int tm_hour;
+  int tm_mday;
+  int tm_mon;
+  int tm_year;
+};
+
+/* struct tm to time since epoch in GMT time zone.
+ * This is similar to the standard mktime function but for GMT only, and
+ * doesn't suffer from the various bugs and portability problems that
+ * some systems' implementations have.
+ */
+static time_t my_timegm(struct my_tm *tm)
+{
+  static const int month_days_cumulative [12] =
+    { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
+  int month, year, leap_days;
+
+  if(tm->tm_year < 70)
+    /* we don't support years before 1970 as they will cause this function
+       to return a negative value */
+    return -1;
+
+  year = tm->tm_year + 1900;
+  month = tm->tm_mon;
+  if(month < 0) {
+    year += (11 - month) / 12;
+    month = 11 - (11 - month) % 12;
+  }
+  else if(month >= 12) {
+    year -= month / 12;
+    month = month % 12;
+  }
+
+  leap_days = year - (tm->tm_mon <= 1);
+  leap_days = ((leap_days / 4) - (leap_days / 100) + (leap_days / 400)
+               - (1969 / 4) + (1969 / 100) - (1969 / 400));
+
+  return ((((time_t) (year - 1970) * 365
+            + leap_days + month_days_cumulative [month] + tm->tm_mday - 1) * 24
+           + tm->tm_hour) * 60 + tm->tm_min) * 60 + tm->tm_sec;
+}
+
+/*
+ * parsedate()
+ *
+ * Returns:
+ *
+ * PARSEDATE_OK     - a fine conversion
+ * PARSEDATE_FAIL   - failed to convert
+ * PARSEDATE_LATER  - time overflow at the far end of time_t
+ * PARSEDATE_SOONER - time underflow at the low end of time_t
+ */
+
+static int parsedate(const char *date, time_t *output)
+{
+  time_t t = 0;
+  int wdaynum=-1;  /* day of the week number, 0-6 (mon-sun) */
+  int monnum=-1;   /* month of the year number, 0-11 */
+  int mdaynum=-1; /* day of month, 1 - 31 */
+  int hournum=-1;
+  int minnum=-1;
+  int secnum=-1;
+  int yearnum=-1;
+  int tzoff=-1;
+  struct my_tm tm;
+  enum assume dignext = DATE_MDAY;
+  const char *indate = date; /* save the original pointer */
+  int part = 0; /* max 6 parts */
+
+  while(*date && (part < 6)) {
+    bool found=FALSE;
+
+    skip(&date);
+
+    if(ISALPHA(*date)) {
+      /* a name coming up */
+      char buf[32]="";
+      size_t len;
+      if(sscanf(date, "%31[ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+                          "abcdefghijklmnopqrstuvwxyz]", buf))
+        len = strlen(buf);
+      else
+        len = 0;
+
+      if(wdaynum == -1) {
+        wdaynum = checkday(buf, len);
+        if(wdaynum != -1)
+          found = TRUE;
+      }
+      if(!found && (monnum == -1)) {
+        monnum = checkmonth(buf);
+        if(monnum != -1)
+          found = TRUE;
+      }
+
+      if(!found && (tzoff == -1)) {
+        /* this just must be a time zone string */
+        tzoff = checktz(buf);
+        if(tzoff != -1)
+          found = TRUE;
+      }
+
+      if(!found)
+        return PARSEDATE_FAIL; /* bad string */
+
+      date += len;
+    }
+    else if(ISDIGIT(*date)) {
+      /* a digit */
+      int val;
+      char *end;
+      if((secnum == -1) &&
+         (3 == sscanf(date, "%02d:%02d:%02d", &hournum, &minnum, &secnum))) {
+        /* time stamp! */
+        date += 8;
+      }
+      else if((secnum == -1) &&
+              (2 == sscanf(date, "%02d:%02d", &hournum, &minnum))) {
+        /* time stamp without seconds */
+        date += 5;
+        secnum = 0;
+      }
+      else {
+        long lval;
+        int error;
+        int old_errno;
+
+        old_errno = ERRNO;
+        SET_ERRNO(0);
+        lval = strtol(date, &end, 10);
+        error = ERRNO;
+        if(error != old_errno)
+          SET_ERRNO(old_errno);
+
+        if(error)
+          return PARSEDATE_FAIL;
+
+#if LONG_MAX != INT_MAX
+        if((lval > (long)INT_MAX) || (lval < (long)INT_MIN))
+          return PARSEDATE_FAIL;
+#endif
+
+        val = clamp_to_int(lval);
+
+        if((tzoff == -1) &&
+           ((end - date) == 4) &&
+           (val <= 1400) &&
+           (indate< date) &&
+           ((date[-1] == '+' || date[-1] == '-'))) {
+          /* four digits and a value less than or equal to 1400 (to take into
+             account all sorts of funny time zone diffs) and it is preceded
+             with a plus or minus. This is a time zone indication.  1400 is
+             picked since +1300 is frequently used and +1400 is mentioned as
+             an edge number in the document "ISO C 200X Proposal: Timezone
+             Functions" at http://david.tribble.com/text/c0xtimezone.html If
+             anyone has a more authoritative source for the exact maximum time
+             zone offsets, please speak up! */
+          found = TRUE;
+          tzoff = (val/100 * 60 + val%100)*60;
+
+          /* the + and - prefix indicates the local time compared to GMT,
+             this we need ther reversed math to get what we want */
+          tzoff = date[-1]=='+'?-tzoff:tzoff;
+        }
+
+        if(((end - date) == 8) &&
+           (yearnum == -1) &&
+           (monnum == -1) &&
+           (mdaynum == -1)) {
+          /* 8 digits, no year, month or day yet. This is YYYYMMDD */
+          found = TRUE;
+          yearnum = val/10000;
+          monnum = (val%10000)/100-1; /* month is 0 - 11 */
+          mdaynum = val%100;
+        }
+
+        if(!found && (dignext == DATE_MDAY) && (mdaynum == -1)) {
+          if((val > 0) && (val<32)) {
+            mdaynum = val;
+            found = TRUE;
+          }
+          dignext = DATE_YEAR;
+        }
+
+        if(!found && (dignext == DATE_YEAR) && (yearnum == -1)) {
+          yearnum = val;
+          found = TRUE;
+          if(yearnum < 1900) {
+            if(yearnum > 70)
+              yearnum += 1900;
+            else
+              yearnum += 2000;
+          }
+          if(mdaynum == -1)
+            dignext = DATE_MDAY;
+        }
+
+        if(!found)
+          return PARSEDATE_FAIL;
+
+        date = end;
+      }
+    }
+
+    part++;
+  }
+
+  if(-1 == secnum)
+    secnum = minnum = hournum = 0; /* no time, make it zero */
+
+  if((-1 == mdaynum) ||
+     (-1 == monnum) ||
+     (-1 == yearnum))
+    /* lacks vital info, fail */
+    return PARSEDATE_FAIL;
+
+#if SIZEOF_TIME_T < 5
+  /* 32 bit time_t can only hold dates to the beginning of 2038 */
+  if(yearnum > 2037) {
+    *output = 0x7fffffff;
+    return PARSEDATE_LATER;
+  }
+#endif
+
+  if(yearnum < 1970) {
+    *output = 0;
+    return PARSEDATE_SOONER;
+  }
+
+  if((mdaynum > 31) || (monnum > 11) ||
+     (hournum > 23) || (minnum > 59) || (secnum > 60))
+    return PARSEDATE_FAIL; /* clearly an illegal date */
+
+  tm.tm_sec = secnum;
+  tm.tm_min = minnum;
+  tm.tm_hour = hournum;
+  tm.tm_mday = mdaynum;
+  tm.tm_mon = monnum;
+  tm.tm_year = yearnum - 1900;
+
+  /* my_timegm() returns a time_t. time_t is often 32 bits, even on many
+     architectures that feature 64 bit 'long'.
+
+     Some systems have 64 bit time_t and deal with years beyond 2038. However,
+     even on some of the systems with 64 bit time_t mktime() returns -1 for
+     dates beyond 03:14:07 UTC, January 19, 2038. (Such as AIX 5100-06)
+  */
+  t = my_timegm(&tm);
+
+  /* time zone adjust (cast t to int to compare to negative one) */
+  if(-1 != (int)t) {
+
+    /* Add the time zone diff between local time zone and GMT. */
+    long delta = (long)(tzoff!=-1?tzoff:0);
+
+    if((delta>0) && (t > LONG_MAX  - delta))
+      return -1; /* time_t overflow */
+
+    t += delta;
+  }
+
+  *output = t;
+
+  return PARSEDATE_OK;
+}
+
+time_t parse_date(const char *p)
+{
+  time_t parsed;
+  int rc = parsedate(p, &parsed);
+
+  switch(rc) {
+  case PARSEDATE_OK:
+  case PARSEDATE_LATER:
+  case PARSEDATE_SOONER:
+    return parsed;
+  }
+  /* everything else is fail */
+  return -1;
+}
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/src/util/raster.cpp b/src/util/raster.cpp
index 9a71573d01..7b52c51037 100644
--- a/src/util/raster.cpp
+++ b/src/util/raster.cpp
@@ -1,20 +1,19 @@
-#include <mbgl/util/raster.hpp>
-
-#include <memory>
-#include <cassert>
-#include <cstring>
-
 #include <mbgl/platform/platform.hpp>
 #include <mbgl/platform/gl.hpp>
+
+#include <mbgl/util/raster.hpp>
 #include <mbgl/util/time.hpp>
 #include <mbgl/util/uv_detail.hpp>
 #include <mbgl/util/std.hpp>
 
 #include <png.h>
 
+#include <cassert>
+#include <cstring>
+
 using namespace mbgl;
 
-Raster::Raster(const std::shared_ptr<Texturepool> &texturepool)
+Raster::Raster(const util::ptr<Texturepool> &texturepool)
     : texturepool(texturepool)
 {}
 
diff --git a/src/util/sqlite3.cpp b/src/util/sqlite3.cpp
new file mode 100644
index 0000000000..19e0ce9c79
--- /dev/null
+++ b/src/util/sqlite3.cpp
@@ -0,0 +1,166 @@
+#include <mbgl/util/sqlite3.hpp>
+#include <sqlite3.h>
+
+#include <cassert>
+
+namespace mapbox {
+namespace sqlite {
+
+Database::Database(const std::string &filename, int flags) {
+    const int err = sqlite3_open_v2(filename.c_str(), &db, flags, nullptr);
+    if (err != SQLITE_OK) {
+        Exception ex { err, sqlite3_errmsg(db) };
+        db = nullptr;
+        throw ex;
+    }
+}
+
+Database::Database(Database &&other) {
+    *this = std::move(other);
+}
+
+Database &Database::operator=(Database &&other) {
+    std::swap(db, other.db);
+    return *this;
+}
+
+Database::~Database() {
+    if (db) {
+        const int err = sqlite3_close(db);
+        if (err != SQLITE_OK) {
+            throw Exception { err, sqlite3_errmsg(db) };
+        }
+    }
+}
+
+Database::operator bool() const {
+    return db != nullptr;
+}
+
+void Database::exec(const std::string &sql) {
+    assert(db);
+    char *msg = nullptr;
+    const int err = sqlite3_exec(db, sql.c_str(), nullptr, nullptr, &msg);
+    if (msg) {
+        Exception ex { err, msg };
+        sqlite3_free(msg);
+        throw ex;
+    } else if (err != SQLITE_OK) {
+        throw Exception { err, sqlite3_errmsg(db) };
+    }
+}
+
+Statement Database::prepare(const char *query) {
+    assert(db);
+    return std::move(Statement(db, query));
+}
+
+Statement::Statement(sqlite3 *db, const char *sql) {
+    const int err = sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr);
+    if (err != SQLITE_OK) {
+        stmt = nullptr;
+        throw Exception { err, sqlite3_errmsg(db) };
+    }
+}
+
+#define CHECK_SQLITE_OK(err) \
+    if (err != SQLITE_OK) { \
+        throw Exception { err, sqlite3_errmsg(sqlite3_db_handle(stmt)) }; \
+    }
+
+Statement::Statement(Statement &&other) {
+    *this = std::move(other);
+}
+
+Statement &Statement::operator=(Statement &&other) {
+    std::swap(stmt, other.stmt);
+    return *this;
+}
+
+Statement::~Statement() {
+    if (stmt) {
+        const int err = sqlite3_finalize(stmt);
+        CHECK_SQLITE_OK(err)
+    }
+}
+
+Statement::operator bool() const {
+    return stmt != nullptr;
+}
+
+#define BIND_3(type, value) \
+    assert(stmt); \
+    const int err = sqlite3_bind_##type(stmt, offset, value); \
+    CHECK_SQLITE_OK(err)
+
+#define BIND_5(type, value, length, param) \
+    assert(stmt); \
+    const int err = sqlite3_bind_##type(stmt, offset, value, length, param); \
+    CHECK_SQLITE_OK(err)
+
+template <> void Statement::bind(int offset, int value) {
+    BIND_3(int, value)
+}
+
+template <> void Statement::bind(int offset, int64_t value) {
+    BIND_3(int64, value)
+}
+
+template <> void Statement::bind(int offset, double value) {
+    BIND_3(double, value)
+}
+
+template <> void Statement::bind(int offset, bool value) {
+    BIND_3(int, value)
+}
+
+template <> void Statement::bind(int offset, const char *value) {
+    BIND_5(text, value, -1, nullptr)
+}
+
+void Statement::bind(int offset, const std::string &value, bool retain) {
+    BIND_5(blob, value.data(), int(value.size()), retain ? SQLITE_TRANSIENT : SQLITE_STATIC)
+}
+
+bool Statement::run() {
+    assert(stmt);
+    const int err = sqlite3_step(stmt);
+    if (err == SQLITE_DONE) {
+        return false;
+    } else if (err == SQLITE_ROW) {
+        return true;
+    } else {
+        throw std::runtime_error("failed to run statement");
+    }
+}
+
+template <> int Statement::get(int offset) {
+    assert(stmt);
+    return sqlite3_column_int(stmt, offset);
+}
+
+template <> int64_t Statement::get(int offset) {
+    assert(stmt);
+    return sqlite3_column_int64(stmt, offset);
+}
+
+template <> double Statement::get(int offset) {
+    assert(stmt);
+    return sqlite3_column_double(stmt, offset);
+}
+
+template <> std::string Statement::get(int offset) {
+    assert(stmt);
+    return {
+        reinterpret_cast<const char *>(sqlite3_column_blob(stmt, offset)),
+        size_t(sqlite3_column_bytes(stmt, offset))
+    };
+}
+
+void Statement::reset() {
+    assert(stmt);
+    sqlite3_reset(stmt);
+}
+
+}
+}
diff --git a/src/util/uv-channel.c b/src/util/uv-channel.c
new file mode 100644
index 0000000000..4e3b9fa5ff
--- /dev/null
+++ b/src/util/uv-channel.c
@@ -0,0 +1,69 @@
+#include <mbgl/util/uv-channel.h>
+#include <mbgl/util/queue.h>
+
+#include <stdlib.h>
+
+// Taken from http://navaneeth.github.io/blog/2013/08/02/channels-in-libuv/
+
+typedef struct {
+    void *data;
+    void *active_queue[2];
+} uv__chan_item_t;
+
+int uv_chan_init(uv_chan_t *chan) {
+    int r = uv_mutex_init(&chan->mutex);
+    if (r == -1)
+        return r;
+
+    QUEUE_INIT(&chan->q);
+
+    return uv_cond_init(&chan->cond);
+}
+
+void uv_chan_send(uv_chan_t *chan, void *data) {
+    uv__chan_item_t *item = (uv__chan_item_t *)malloc(sizeof(uv__chan_item_t));
+    item->data = data;
+
+    uv_mutex_lock(&chan->mutex);
+    QUEUE_INSERT_TAIL(&chan->q, &item->active_queue);
+    uv_cond_signal(&chan->cond);
+    uv_mutex_unlock(&chan->mutex);
+}
+
+void *uv_chan_receive(uv_chan_t *chan) {
+    uv__chan_item_t *item;
+    QUEUE *head;
+    void *data = NULL;
+
+    uv_mutex_lock(&chan->mutex);
+    while (QUEUE_EMPTY(&chan->q)) {
+        uv_cond_wait(&chan->cond, &chan->mutex);
+    }
+
+    head = QUEUE_HEAD(&chan->q);
+    item = QUEUE_DATA(head, uv__chan_item_t, active_queue);
+    data = item->data;
+    QUEUE_REMOVE(head);
+    free(item);
+    uv_mutex_unlock(&chan->mutex);
+    return data;
+}
+
+void uv_chan_clear(uv_chan_t *chan) {
+    uv_mutex_lock(&chan->mutex);
+    uv__chan_item_t *item = NULL;
+    QUEUE *head = NULL;
+    while (!QUEUE_EMPTY(&chan->q)) {
+        head = QUEUE_HEAD(&chan->q);
+        item = QUEUE_DATA(head, uv__chan_item_t, active_queue);
+        QUEUE_REMOVE(head);
+        free(item);
+    }
+    uv_mutex_unlock(&chan->mutex);
+}
+
+void uv_chan_destroy(uv_chan_t *chan) {
+    uv_chan_clear(chan);
+    uv_cond_destroy(&chan->cond);
+    uv_mutex_destroy(&chan->mutex);
+}
diff --git a/src/util/uv-messenger.c b/src/util/uv-messenger.c
new file mode 100644
index 0000000000..a25c84dc59
--- /dev/null
+++ b/src/util/uv-messenger.c
@@ -0,0 +1,74 @@
+#include <mbgl/util/uv-messenger.h>
+#include <mbgl/util/queue.h>
+
+#include <stdlib.h>
+
+typedef struct {
+    void *data;
+    void *queue[2];
+} uv__messenger_item_t;
+
+void uv__messenger_callback(uv_async_t *async) {
+    uv_messenger_t *msgr = (uv_messenger_t *)async->data;
+
+    uv__messenger_item_t *item;
+    QUEUE *head;
+
+    while (1) {
+        uv_mutex_lock(&msgr->mutex);
+        if (QUEUE_EMPTY(&msgr->queue)) {
+            uv_mutex_unlock(&msgr->mutex);
+            break;
+        }
+
+        head = QUEUE_HEAD(&msgr->queue);
+        item = QUEUE_DATA(head, uv__messenger_item_t, queue);
+        QUEUE_REMOVE(head);
+        uv_mutex_unlock(&msgr->mutex);
+
+        msgr->callback(item->data);
+
+        free(item);
+    }
+}
+
+int uv_messenger_init(uv_loop_t *loop, uv_messenger_t *msgr, uv_messenger_cb callback) {
+    int ret = uv_mutex_init(&msgr->mutex);
+    if (ret < 0) {
+        return ret;
+    }
+
+    msgr->callback = callback;
+
+    QUEUE_INIT(&msgr->queue);
+
+    msgr->async.data = msgr;
+    return uv_async_init(loop, &msgr->async, uv__messenger_callback);
+}
+
+void uv_messenger_send(uv_messenger_t *msgr, void *data) {
+    uv__messenger_item_t *item = (uv__messenger_item_t *)malloc(sizeof(uv__messenger_item_t));
+    item->data = data;
+
+    uv_mutex_lock(&msgr->mutex);
+    QUEUE_INSERT_TAIL(&msgr->queue, &item->queue);
+    uv_mutex_unlock(&msgr->mutex);
+
+    uv_async_send(&msgr->async);
+}
+
+void uv_messenger_ref(uv_messenger_t *msgr) {
+    uv_ref((uv_handle_t *)&msgr->async);
+}
+
+void uv_messenger_unref(uv_messenger_t *msgr) {
+    uv_unref((uv_handle_t *)&msgr->async);
+}
+
+void uv__messenger_stop_callback(uv_handle_t *handle) {
+    free((uv_messenger_t *)handle->data);
+}
+
+void uv_messenger_stop(uv_messenger_t *msgr) {
+    uv_close((uv_handle_t *)&msgr->async, uv__messenger_stop_callback);
+}
diff --git a/src/util/uv-worker.c b/src/util/uv-worker.c
new file mode 100644
index 0000000000..8b0cc6dda7
--- /dev/null
+++ b/src/util/uv-worker.c
@@ -0,0 +1,166 @@
+#include <mbgl/util/uv-worker.h>
+#include <mbgl/util/uv-messenger.h>
+
+#include <stdio.h>
+#include <assert.h>
+
+typedef struct uv__worker_item_s uv__worker_item_t;
+struct uv__worker_item_s {
+    uv_worker_t *worker;
+    void *data;
+    uv_worker_cb work_cb;
+    uv_worker_after_cb after_work_cb;
+};
+
+typedef struct uv__worker_thread_s uv__worker_thread_t;
+struct uv__worker_thread_s {
+    uv_worker_t *worker;
+    uv_thread_t thread;
+};
+
+void uv__worker_thread_finished(uv__worker_thread_t *worker_thread) {
+    uv_worker_t *worker = worker_thread->worker;
+
+#ifndef NDEBUG
+    assert(uv_thread_self() == worker->thread_id);
+#endif
+
+    // This should at most block very briefly. We are sending the termination
+    // notification as the last thing in the worker thread, so by now the thread
+    // has probably terminated already. If not, the waiting time should be
+    // extremely short.
+    uv_thread_join(&worker_thread->thread);
+
+    assert(worker->count > 0);
+    worker->count--;
+    if (worker->count == 0) {
+        uv_chan_destroy(&worker->chan);
+        uv_messenger_stop(worker->msgr);
+        if (worker->close_cb) {
+            worker->close_cb(worker);
+        }
+    }
+}
+
+void uv__worker_after(void *ptr) {
+    uv__worker_item_t *item = (uv__worker_item_t *)ptr;
+
+    if (item->work_cb) {
+        // We are finishing a regular work request.
+        if (item->after_work_cb) {
+            assert(item->after_work_cb);
+            item->after_work_cb(item->data);
+        }
+        uv_worker_t *worker = item->worker;
+        assert(worker->active_items > 0);
+        if (--worker->active_items == 0) {
+            uv_messenger_unref(worker->msgr);
+        }
+    } else {
+        // This is a worker thread termination.
+        uv__worker_thread_t *worker_thread = (uv__worker_thread_t *)item->data;
+        uv__worker_thread_finished(worker_thread);
+        free(worker_thread);
+    }
+
+    free(item);
+}
+
+void uv__worker_thread_loop(void *ptr) {
+    uv__worker_thread_t *worker_thread = (uv__worker_thread_t *)ptr;
+    uv_worker_t *worker = worker_thread->worker;
+
+#ifdef __APPLE__
+    if (worker->name) {
+        pthread_setname_np(worker->name);
+    }
+#endif
+
+    uv__worker_item_t *item = NULL;
+    while ((item = (uv__worker_item_t *)uv_chan_receive(&worker->chan)) != NULL) {
+        assert(item->work_cb);
+        item->work_cb(item->data);
+
+        // Trigger the after callback in the main thread.
+        uv_messenger_send(worker->msgr, item);
+    }
+
+    // Make sure to close all other workers too.
+    uv_chan_send(&worker->chan, NULL);
+
+    // Create a new worker item that acts as a terminate flag for this thread.
+    item = (uv__worker_item_t *)malloc(sizeof(uv__worker_item_t));
+    item->data = worker_thread;
+    item->work_cb = NULL;
+    item->after_work_cb = NULL;
+    uv_messenger_send(worker->msgr, item);
+}
+
+int uv_worker_init(uv_worker_t *worker, uv_loop_t *loop, int count, const char *name) {
+#ifndef NDEBUG
+    worker->thread_id = uv_thread_self();
+#endif
+    worker->loop = loop;
+    worker->name = name;
+    worker->count = 0;
+    worker->close_cb = NULL;
+    worker->active_items = 0;
+    worker->msgr = (uv_messenger_t *)malloc(sizeof(uv_messenger_t));
+    int ret = uv_messenger_init(loop, worker->msgr, uv__worker_after);
+    if (ret < 0) {
+        free(worker->msgr);
+        return ret;
+    }
+    uv_messenger_unref(worker->msgr);
+    ret = uv_chan_init(&worker->chan);
+    if (ret < 0) return ret;
+
+    // Initialize all worker threads.
+    int i;
+    for (i = 0; i < count; i++) {
+        uv__worker_thread_t *worker_thread = (uv__worker_thread_t *)malloc(sizeof(uv__worker_thread_t));
+        worker_thread->worker = worker;
+        ret = uv_thread_create(&worker_thread->thread, uv__worker_thread_loop, worker_thread);
+        if (ret < 0) return ret;
+        worker->count++;
+    }
+
+    return 0;
+}
+
+void uv_worker_send(uv_worker_t *worker, void *data, uv_worker_cb work_cb,
+                    uv_worker_after_cb after_work_cb) {
+#ifndef NDEBUG
+    assert(uv_thread_self() == worker->thread_id);
+#endif
+
+    // It doesn't make sense to not provide a work callback. On the other hand, the after_work_cb
+    // may be NULL. In that case, there will be no callback called in the current thread and the
+    // worker item will instead be freed in the worker thread.
+    assert(work_cb);
+
+    uv__worker_item_t *item = (uv__worker_item_t *)malloc(sizeof(uv__worker_item_t));
+    item->worker = worker;
+    item->work_cb = work_cb;
+    item->after_work_cb = after_work_cb;
+    item->data = data;
+    uv_chan_send(&worker->chan, item);
+    if (worker->active_items++ == 0) {
+        uv_messenger_ref(worker->msgr);
+    }
+}
+
+void uv_worker_close(uv_worker_t *worker, uv_worker_close_cb close_cb) {
+#ifndef NDEBUG
+    assert(uv_thread_self() == worker->thread_id);
+#endif
+
+    // Prevent double calling.
+    assert(worker->close_cb == NULL);
+
+    worker->close_cb = close_cb;
+    uv_chan_send(&worker->chan, NULL);
+    if (worker->active_items++ == 0) {
+        uv_messenger_ref(worker->msgr);
+    }
+}
diff --git a/src/util/uv.cpp b/src/util/uv.cpp
index 94f074bfa1..6e15ac4537 100644
--- a/src/util/uv.cpp
+++ b/src/util/uv.cpp
@@ -16,4 +16,16 @@ std::string cwd() {
     return dir;
 }
 
+void deleter::operator()(uv_async_t *async) {
+    uv_close((uv_handle_t *)async, [](uv_handle_t *handle) {
+        delete (uv_async_t *)handle;
+    });
+}
+
+void deleter::operator()(uv_timer_t *timer) {
+    uv_close((uv_handle_t *)timer, [](uv_handle_t *handle) {
+        delete (uv_timer_t *)handle;
+    });
+}
+
 }
diff --git a/test/fixtures/fixture_request.cpp b/test/fixtures/fixture_request.cpp
index 417958a33d..b37cd92bee 100644
--- a/test/fixtures/fixture_request.cpp
+++ b/test/fixtures/fixture_request.cpp
@@ -1,10 +1,16 @@
-#include <mbgl/platform/platform.hpp>
-#include <mbgl/platform/request.hpp>
-#include <mbgl/util/uv_detail.hpp>
+#include <mbgl/storage/http_request_baton.hpp>
+#include <mbgl/storage/file_request_baton.hpp>
+#include <mbgl/storage/response.hpp>
 #include <mbgl/util/url.hpp>
+#include <mbgl/util/std.hpp>
 #include <mbgl/platform/log.hpp>
 #include <iostream>
 
+#include <uv.h>
+
+#include <cassert>
+
+
 const std::string base_directory = []{
     std::string fn = __FILE__;
     fn.erase(fn.find_last_of("/"));
@@ -13,110 +19,48 @@ const std::string base_directory = []{
     return fn + "/node_modules/mapbox-gl-test-suite/";
 }();
 
-
 namespace mbgl {
 
-std::shared_ptr<platform::Request>
-platform::request_http(const std::string &url,
-                       std::function<void(Response *)> callback,
-                       std::shared_ptr<uv::loop> loop) {
-    uv_loop_t *l = nullptr;
-    if (loop) {
-        l = **loop;
-    } else {
-        l = uv_default_loop();
-    }
+void HTTPRequestBaton::start(const util::ptr<HTTPRequestBaton> &baton) {
+    assert(uv_thread_self() == baton->thread_id);
 
-    std::string clean_url = util::percentDecode(url);
+    std::string clean_url = util::percentDecode(baton->path);
     if (clean_url.find("local://") == 0) {
         clean_url = base_directory + clean_url.substr(8);
     }
 
-    std::shared_ptr<Request> req = std::make_shared<Request>(url, callback, loop);
-
-    int err;
-
-    std::string body;
-    FILE *file = std::fopen(clean_url.c_str(),"rb");
-
-    if (file != NULL)
-    {
-        std::fseek(file, 0, SEEK_END);
-        std::size_t file_size = std::ftell(file);
-        std::fseek(file, 0, SEEK_SET);
-        body.resize(file_size);
-        std::fread(&body[0], file_size, 1, file);
-        std::fclose(file);
-    }
-
-    /*
-    uv_fs_t open_req;
-    err = uv_fs_open(l, &open_req, clean_url.c_str(), O_RDONLY, S_IRUSR, nullptr);
-    uv_fs_req_cleanup(&open_req);
-    if (err < 0) {
-        req->res->code = err;
-        req->res->error_message = uv_strerror(uv_last_error(l));
-        Log::Warning(Event::HttpRequest, err, url + ": " + uv_strerror(uv_last_error(l)));
-        req->complete();
-        return req;
-    }
-    uv_file fd = err;
-
-    uv_fs_t stat_req;
-    uv_fs_fstat(l, &stat_req, fd, nullptr);
-    uv_fs_req_cleanup(&stat_req);
-    err = uv_fs_fstat(l, &stat_req, fd, nullptr);
-    if (err < 0) {
-        req->res->code = err;
-        req->res->error_message = uv_strerror(uv_last_error(l));
-        Log::Warning(Event::HttpRequest, err, url + ": " + uv_strerror(uv_last_error(l)));
-        req->complete();
-        return req;
-    }
-
-    const uint64_t size = static_cast<const uv_statbuf_t*>(stat_req.ptr)->st_size;
-
-
-    std::string body;
-    body.resize(size);
-    uv_buf_t uvbuf = uv_buf_init(const_cast<char *>(body.data()), body.size());
-
-    uv_fs_t read_req;
-    err = uv_fs_read(l, &read_req, fd, &uvbuf, 1, 0, nullptr);
-    uv_fs_req_cleanup(&read_req);
-    if (err < 0) {
-        req->res->code = err;
-        req->res->error_message = uv_strerror(uv_last_error(l));
-        Log::Warning(Event::HttpRequest, err, url + ": " + uv_strerror(uv_last_error(l)));
-        req->complete();
-        return req;
+    baton->response = std::make_unique<Response>();
+    FILE *file = fopen(clean_url.c_str(),"rb");
+    if (file != NULL) {
+        fseek(file, 0, SEEK_END);
+        const size_t size = ftell(file);
+        fseek(file, 0, SEEK_SET);
+        baton->response->data.resize(size);
+        fread(&baton->response->data[0], size, 1, file);
+        fclose(file);
+
+        baton->response->code = 200;
+        baton->type = HTTPResponseType::Successful;
+    } else {
+        baton->type = HTTPResponseType::PermanentError;
+        baton->response->code = 404;
     }
 
+    uv_async_send(baton->async);
+}
 
-    uv_fs_t close_req;
-    err = uv_fs_close(l, &close_req, fd, nullptr);
-    uv_fs_req_cleanup(&close_req);
-    if (err < 0) {
-        req->res->code = err;
-        req->res->error_message = uv_strerror(uv_last_error(l));
-        Log::Warning(Event::HttpRequest, err, url + ": " + uv_strerror(uv_last_error(l)));
-        req->complete();
-        return req;
-    }
-    */
+void HTTPRequestBaton::stop(const util::ptr<HTTPRequestBaton> &baton) {
+    fprintf(stderr, "HTTP request cannot be canceled because it is answered immediately");
+    abort();
+}
 
-    req->res->body.swap(body);
-    req->res->code = 200;
-    Log::Info(Event::HttpRequest, 200, url);
-    req->complete();
+namespace platform {
 
-    return req;
+std::string defaultCacheDatabase() {
+    // Disables the cache.
+    return "";
 }
 
-void platform::cancel_request_http(const std::shared_ptr<Request> &req) {
-    if (req) {
-        req->cancelled = true;
-    }
 }
 
 }