[ios, macos] Expose the url session configuration object. (#13886)

The `MGLNetworkConfiguration` class was make public, and added `sessionConfiguration` property to let developers customize the `NSURLSessionConfiguration` object that is used to make HTTP requests in the SDK.

12 files changed, 78 insertions, 28 deletions

diff --git a/platform/darwin/filesource-files.json b/platform/darwin/filesource-files.json
index f435c43877..3ee96f9b95 100644
--- a/platform/darwin/filesource-files.json
+++ b/platform/darwin/filesource-files.json
@@ -2,6 +2,7 @@
     "//": "This file can be edited manually and is the canonical source.",
     "sources": [
         "platform/darwin/src/MGLLoggingConfiguration.m",
+        "platform/darwin/src/MGLNetworkConfiguration.m",
         "platform/darwin/src/http_file_source.mm",
         "platform/default/src/mbgl/storage/sqlite3.cpp"
     ],
diff --git a/platform/darwin/src/MGLNetworkConfiguration.h b/platform/darwin/src/MGLNetworkConfiguration.h
index aaac5a330c..6c56050aae 100644
--- a/platform/darwin/src/MGLNetworkConfiguration.h
+++ b/platform/darwin/src/MGLNetworkConfiguration.h
@@ -1,18 +1,37 @@
 #import <Foundation/Foundation.h>
 
+#import "MGLFoundation.h"
+
 NS_ASSUME_NONNULL_BEGIN
 
 /**
- The MGLNetworkConfiguration object provides a global way to set a base API URL for
- retrieval of map data, styles, and other resources.
-
- Currently, MGLNetworkConfiguration is a private API.
+ The `MGLNetworkConfiguration` object provides a global way to set a base
+ `NSURLSessionConfiguration`, and other resources.
  */
+MGL_EXPORT
 @interface MGLNetworkConfiguration : NSObject
 
-/// Returns the shared instance of the `MGLNetworkConfiguration` class.
+/**
+ Returns the shared instance of the `MGLNetworkConfiguration` class.
+ */
 @property (class, nonatomic, readonly) MGLNetworkConfiguration *sharedManager;
 
+/**
+ The session configuration object that is used by the `NSURLSession` objects
+ in this SDK.
+ 
+ If this property is set to nil or if no session configuration is provided this property
+ is set to the default session configuration.
+ 
+ Assign this object before instantiating any `MGLMapView` object.
+ 
+ @note: `NSURLSession` objects store a copy of this configuration. Any further changes
+ to mutable properties on this configuration object passed to a session’s initializer
+ will not affect the behavior of that session.
+ 
+ */
+@property (atomic, strong, null_resettable) NSURLSessionConfiguration *sessionConfiguration;
+
 @end
 
 NS_ASSUME_NONNULL_END
diff --git a/platform/darwin/src/MGLNetworkConfiguration.m b/platform/darwin/src/MGLNetworkConfiguration.m
index 61422f7caa..8262e7eea1 100644
--- a/platform/darwin/src/MGLNetworkConfiguration.m
+++ b/platform/darwin/src/MGLNetworkConfiguration.m
@@ -1,23 +1,51 @@
 #import "MGLNetworkConfiguration.h"
 
+@interface MGLNetworkConfiguration ()
+
+@property (strong) NSURLSessionConfiguration *sessionConfig;
+
+@end
+
 @implementation MGLNetworkConfiguration
 
 + (instancetype)sharedManager {
     static dispatch_once_t onceToken;
     static MGLNetworkConfiguration *_sharedManager;
-    void (^setupBlock)(void) = ^{
-        dispatch_once(&onceToken, ^{
-            _sharedManager = [[self alloc] init];
-        });
-    };
-    if (![[NSThread currentThread] isMainThread]) {
-        dispatch_sync(dispatch_get_main_queue(), ^{
-            setupBlock();
-        });
-    } else {
-        setupBlock();
-    }
+    dispatch_once(&onceToken, ^{
+        _sharedManager = [[self alloc] init];
+        _sharedManager.sessionConfiguration = nil;
+    });
+
     return _sharedManager;
 }
 
+- (void)setSessionConfiguration:(NSURLSessionConfiguration *)sessionConfiguration {
+    @synchronized (self) {
+        if (sessionConfiguration == nil) {
+            _sessionConfig = [self defaultSessionConfiguration];
+        } else {
+            _sessionConfig = sessionConfiguration;
+        }
+    }
+}
+
+- (NSURLSessionConfiguration *)sessionConfiguration {
+    NSURLSessionConfiguration *sessionConfig = nil;
+    @synchronized (self) {
+        sessionConfig = _sessionConfig;
+    }
+    return sessionConfig;
+}
+
+- (NSURLSessionConfiguration *)defaultSessionConfiguration {
+    NSURLSessionConfiguration* sessionConfiguration = [NSURLSessionConfiguration defaultSessionConfiguration];
+    
+    sessionConfiguration.timeoutIntervalForResource = 30;
+    sessionConfiguration.HTTPMaximumConnectionsPerHost = 8;
+    sessionConfiguration.requestCachePolicy = NSURLRequestReloadIgnoringLocalCacheData;
+    sessionConfiguration.URLCache = nil;
+    
+    return sessionConfiguration;
+}
+
 @end
diff --git a/platform/darwin/src/http_file_source.mm b/platform/darwin/src/http_file_source.mm
index f11d44ea54..c3918ad62b 100644
--- a/platform/darwin/src/http_file_source.mm
+++ b/platform/darwin/src/http_file_source.mm
@@ -8,6 +8,7 @@
 
 #import <Foundation/Foundation.h>
 #import "MGLLoggingConfiguration_Private.h"
+#import "MGLNetworkConfiguration.h"
 
 #include <mutex>
 #include <chrono>
@@ -82,13 +83,10 @@ class HTTPFileSource::Impl {
 public:
     Impl() {
         @autoreleasepool {
-            NSURLSessionConfiguration* sessionConfig =
-                [NSURLSessionConfiguration defaultSessionConfiguration];
-            sessionConfig.timeoutIntervalForResource = 30;
-            sessionConfig.HTTPMaximumConnectionsPerHost = 8;
-            sessionConfig.requestCachePolicy = NSURLRequestReloadIgnoringLocalCacheData;
-            sessionConfig.URLCache = nil;
 
+            NSURLSessionConfiguration *sessionConfig =
+            [MGLNetworkConfiguration sharedManager].sessionConfiguration;
+            
             session = [NSURLSession sessionWithConfiguration:sessionConfig];
 
             userAgent = getUserAgent();
diff --git a/platform/ios/CHANGELOG.md b/platform/ios/CHANGELOG.md
index aa7ad42b9e..34977e2a03 100644
--- a/platform/ios/CHANGELOG.md
+++ b/platform/ios/CHANGELOG.md
@@ -7,6 +7,7 @@ Mapbox welcomes participation and contributions from everyone. Please read [CONT
 * Fixed a bug where setting `MGLMapView.userTrackingMode` to `MGLUserTrackingModeFollowWithHeading` or `MGLUserTrackingModeFollowWithCourse` would be ignored if the user’s location was not already available. ([#13849](https://github.com/mapbox/mapbox-gl-native/pull/13849))
 * Improved tilt gesture performance. ([#13902](https://github.com/mapbox/mapbox-gl-native/pull/13902))
 * Fixed a bug where `layoutSubviews` was always called on device rotation, regardless of the application's or top-most view controller's supported orientations. ([#13900](https://github.com/mapbox/mapbox-gl-native/pull/13900))
+* Added `MGLNetworkConfiguration` class to customize the SDK's `NSURLSessionConfiguration` object. ([#11447](https://github.com/mapbox/mapbox-gl-native/pull/13886))
 
 ## 4.8.0 - January 30, 2019
 
diff --git a/platform/ios/ios.xcodeproj/project.pbxproj b/platform/ios/ios.xcodeproj/project.pbxproj
index 8d5a725848..0aa68018be 100644
--- a/platform/ios/ios.xcodeproj/project.pbxproj
+++ b/platform/ios/ios.xcodeproj/project.pbxproj
@@ -443,7 +443,7 @@
 		96E516F22000596D00A02306 /* NSException+MGLAdditions.h in Headers */ = {isa = PBXBuildFile; fileRef = DA8848141CBAFA6200AB86E3 /* NSException+MGLAdditions.h */; };
 		96E516F32000597100A02306 /* NSDictionary+MGLAdditions.h in Headers */ = {isa = PBXBuildFile; fileRef = 408AA8551DAEDA0800022900 /* NSDictionary+MGLAdditions.h */; };
 		96E516F42000597D00A02306 /* NSData+MGLAdditions.h in Headers */ = {isa = PBXBuildFile; fileRef = 35305D461D22AA450007D005 /* NSData+MGLAdditions.h */; };
-		96E516F5200059B100A02306 /* MGLNetworkConfiguration.h in Headers */ = {isa = PBXBuildFile; fileRef = DD0902A41DB18F1B00C5BDCE /* MGLNetworkConfiguration.h */; };
+		96E516F5200059B100A02306 /* MGLNetworkConfiguration.h in Headers */ = {isa = PBXBuildFile; fileRef = DD0902A41DB18F1B00C5BDCE /* MGLNetworkConfiguration.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		96E516F6200059EC00A02306 /* MGLRendererFrontend.h in Headers */ = {isa = PBXBuildFile; fileRef = 92F2C3EC1F0E3C3A00268EC0 /* MGLRendererFrontend.h */; };
 		96E516F720005A2700A02306 /* MGLAnnotationContainerView.h in Headers */ = {isa = PBXBuildFile; fileRef = 40EDA1BD1CFE0D4A00D9EA68 /* MGLAnnotationContainerView.h */; };
 		96E516F820005A3000A02306 /* MGLCompactCalloutView.h in Headers */ = {isa = PBXBuildFile; fileRef = DA8848441CBAFB9800AB86E3 /* MGLCompactCalloutView.h */; };
@@ -722,7 +722,7 @@
 		DAF25720201902BC00367EF5 /* MGLHillshadeStyleLayerTests.mm in Sources */ = {isa = PBXBuildFile; fileRef = DAF2571F201902BB00367EF5 /* MGLHillshadeStyleLayerTests.mm */; };
 		DD0902A91DB1929D00C5BDCE /* MGLNetworkConfiguration.m in Sources */ = {isa = PBXBuildFile; fileRef = DD0902A21DB18DE700C5BDCE /* MGLNetworkConfiguration.m */; };
 		DD0902AA1DB1929D00C5BDCE /* MGLNetworkConfiguration.m in Sources */ = {isa = PBXBuildFile; fileRef = DD0902A21DB18DE700C5BDCE /* MGLNetworkConfiguration.m */; };
-		DD0902AB1DB192A800C5BDCE /* MGLNetworkConfiguration.h in Headers */ = {isa = PBXBuildFile; fileRef = DD0902A41DB18F1B00C5BDCE /* MGLNetworkConfiguration.h */; };
+		DD0902AB1DB192A800C5BDCE /* MGLNetworkConfiguration.h in Headers */ = {isa = PBXBuildFile; fileRef = DD0902A41DB18F1B00C5BDCE /* MGLNetworkConfiguration.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		DD4823751D94AE6C00EB71B7 /* fill_filter_style.json in Resources */ = {isa = PBXBuildFile; fileRef = DD4823721D94AE6C00EB71B7 /* fill_filter_style.json */; };
 		DD4823761D94AE6C00EB71B7 /* line_filter_style.json in Resources */ = {isa = PBXBuildFile; fileRef = DD4823731D94AE6C00EB71B7 /* line_filter_style.json */; };
 		DD4823771D94AE6C00EB71B7 /* numeric_filter_style.json in Resources */ = {isa = PBXBuildFile; fileRef = DD4823741D94AE6C00EB71B7 /* numeric_filter_style.json */; };
diff --git a/platform/ios/sdk-files.json b/platform/ios/sdk-files.json
index 0bf09e48fa..2267f3ce42 100644
--- a/platform/ios/sdk-files.json
+++ b/platform/ios/sdk-files.json
@@ -158,6 +158,7 @@
         "MGLAccountManager.h": "platform/darwin/src/MGLAccountManager.h",
         "NSValue+MGLAdditions.h": "platform/darwin/src/NSValue+MGLAdditions.h",
         "MGLVectorStyleLayer.h": "platform/darwin/src/MGLVectorStyleLayer.h",
+        "MGLNetworkConfiguration.h": "platform/darwin/src/MGLNetworkConfiguration.h",
         "MGLComputedShapeSource.h": "platform/darwin/src/MGLComputedShapeSource.h",
         "MGLLoggingConfiguration.h": "platform/darwin/src/MGLLoggingConfiguration.h",
         "MGLLocationManager.h": "platform/darwin/src/MGLLocationManager.h",
@@ -236,7 +237,6 @@
         "MGLLoggingConfiguration_Private.h": "platform/darwin/src/MGLLoggingConfiguration_Private.h",
         "NSComparisonPredicate+MGLAdditions.h": "platform/darwin/src/NSComparisonPredicate+MGLAdditions.h",
         "MGLMapAccessibilityElement.h": "platform/ios/src/MGLMapAccessibilityElement.h",
-        "MGLNetworkConfiguration.h": "platform/darwin/src/MGLNetworkConfiguration.h",
         "MGLScaleBar.h": "platform/ios/src/MGLScaleBar.h",
         "NSString+MGLAdditions.h": "platform/darwin/src/NSString+MGLAdditions.h",
         "UIDevice+MGLAdditions.h": "platform/ios/src/UIDevice+MGLAdditions.h",
diff --git a/platform/ios/src/Mapbox.h b/platform/ios/src/Mapbox.h
index 829583be6a..43300b6aa5 100644
--- a/platform/ios/src/Mapbox.h
+++ b/platform/ios/src/Mapbox.h
@@ -71,3 +71,4 @@ FOUNDATION_EXPORT MGL_EXPORT const unsigned char MapboxVersionString[];
 #import "NSPredicate+MGLAdditions.h"
 #import "MGLLocationManager.h"
 #import "MGLLoggingConfiguration.h"
+#import "MGLNetworkConfiguration.h"
diff --git a/platform/macos/CHANGELOG.md b/platform/macos/CHANGELOG.md
index 4754ae8ddb..7e9c844059 100644
--- a/platform/macos/CHANGELOG.md
+++ b/platform/macos/CHANGELOG.md
@@ -7,6 +7,7 @@
 * Added an `MGLStyle.performsPlacementTransitions` property to control how long it takes for colliding labels to fade out. ([#13565](https://github.com/mapbox/mapbox-gl-native/pull/13565))
 * Fixed a crash when casting large numbers in `NSExpression`. ([#13580](https://github.com/mapbox/mapbox-gl-native/pull/13580))
 * Added the `-[MGLShapeSource leavesOfCluster:offset:limit:]`, `-[MGLShapeSource childrenOfCluster:]`, `-[MGLShapeSource zoomLevelForExpandingCluster:]` methods for inspecting a cluster in an `MGLShapeSource`s created with the `MGLShapeSourceOptionClustered` option. Feature querying now returns clusters represented by `MGLPointFeatureCluster` objects (that conform to the `MGLCluster` protocol). ([#12952](https://github.com/mapbox/mapbox-gl-native/pull/12952)
+* Added `MGLNetworkConfiguration` class to customize the SDK's `NSURLSessionConfiguration` object. ([#11447](https://github.com/mapbox/mapbox-gl-native/pull/13886))
 
 ### Annotations
 
diff --git a/platform/macos/macos.xcodeproj/project.pbxproj b/platform/macos/macos.xcodeproj/project.pbxproj
index a618b85a7a..ad93c317ed 100644
--- a/platform/macos/macos.xcodeproj/project.pbxproj
+++ b/platform/macos/macos.xcodeproj/project.pbxproj
@@ -283,7 +283,7 @@
 		DAF25716201901C200367EF5 /* MGLHillshadeStyleLayer.h in Headers */ = {isa = PBXBuildFile; fileRef = DAF25714201901C200367EF5 /* MGLHillshadeStyleLayer.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		DAF25721201902C100367EF5 /* MGLHillshadeStyleLayerTests.mm in Sources */ = {isa = PBXBuildFile; fileRef = DAF2571D201902A500367EF5 /* MGLHillshadeStyleLayerTests.mm */; };
 		DD0902B21DB1AC6400C5BDCE /* MGLNetworkConfiguration.m in Sources */ = {isa = PBXBuildFile; fileRef = DD0902AF1DB1AC6400C5BDCE /* MGLNetworkConfiguration.m */; };
-		DD0902B31DB1AC6400C5BDCE /* MGLNetworkConfiguration.h in Headers */ = {isa = PBXBuildFile; fileRef = DD0902B01DB1AC6400C5BDCE /* MGLNetworkConfiguration.h */; };
+		DD0902B31DB1AC6400C5BDCE /* MGLNetworkConfiguration.h in Headers */ = {isa = PBXBuildFile; fileRef = DD0902B01DB1AC6400C5BDCE /* MGLNetworkConfiguration.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		DD58A4C91D822C6700E1F038 /* MGLExpressionTests.mm in Sources */ = {isa = PBXBuildFile; fileRef = DD58A4C71D822C6200E1F038 /* MGLExpressionTests.mm */; };
 /* End PBXBuildFile section */
 
diff --git a/platform/macos/sdk-files.json b/platform/macos/sdk-files.json
index f7d2fd3426..3c728ad37d 100644
--- a/platform/macos/sdk-files.json
+++ b/platform/macos/sdk-files.json
@@ -109,6 +109,7 @@
         "MGLFillStyleLayer.h": "platform/darwin/src/MGLFillStyleLayer.h",
         "MGLCoordinateFormatter.h": "platform/darwin/src/MGLCoordinateFormatter.h",
         "MGLShapeOfflineRegion.h": "platform/darwin/src/MGLShapeOfflineRegion.h",
+        "MGLNetworkConfiguration.h": "platform/darwin/src/MGLNetworkConfiguration.h",
         "MGLOverlay.h": "platform/darwin/src/MGLOverlay.h",
         "MGLPolyline.h": "platform/darwin/src/MGLPolyline.h",
         "MGLLineStyleLayer.h": "platform/darwin/src/MGLLineStyleLayer.h",
@@ -170,7 +171,6 @@
         "NSExpression+MGLPrivateAdditions.h": "platform/darwin/src/NSExpression+MGLPrivateAdditions.h",
         "NSCompoundPredicate+MGLAdditions.h": "platform/darwin/src/NSCompoundPredicate+MGLAdditions.h",
         "MGLSymbolStyleLayer_Private.h": "platform/darwin/src/MGLSymbolStyleLayer_Private.h",
-        "MGLNetworkConfiguration.h": "platform/darwin/src/MGLNetworkConfiguration.h",
         "NSProcessInfo+MGLAdditions.h": "platform/darwin/src/NSProcessInfo+MGLAdditions.h",
         "MGLRendererFrontend.h": "platform/darwin/src/MGLRendererFrontend.h",
         "NSValue+MGLStyleAttributeAdditions.h": "platform/darwin/src/NSValue+MGLStyleAttributeAdditions.h",
diff --git a/platform/macos/src/Mapbox.h b/platform/macos/src/Mapbox.h
index 0fd81a4df7..4d54c753df 100644
--- a/platform/macos/src/Mapbox.h
+++ b/platform/macos/src/Mapbox.h
@@ -66,3 +66,4 @@ FOUNDATION_EXPORT MGL_EXPORT const unsigned char MapboxVersionString[];
 #import "NSExpression+MGLAdditions.h"
 #import "NSPredicate+MGLAdditions.h"
 #import "MGLLoggingConfiguration.h"
+#import "MGLNetworkConfiguration.h"