Log the Environment ID and the Thread name

To make it easier to debug, add the Environment ID and the Thread name
to the log messages. For instance log messages from the TileParser will look like:

[WARNING] {0}{TileWorker_15/18653/9486}[ParseTile]: some relevant warning message
   |       |             |                  |
   |       |             |                  +-> Component
   |       |             +--------------------> Thread name
   |       +----------------------------------> Environment ID
   +------------------------------------------> Severity level

Log messages that are not inside an Environment::Scope will work
normally and will look like:

[WARNING] [JNI]: some relevant warning message

Fixes #882.

5 files changed, 32 insertions, 13 deletions

diff --git a/include/mbgl/platform/log.hpp b/include/mbgl/platform/log.hpp
index de7f131714..5d287eb572 100644
--- a/include/mbgl/platform/log.hpp
+++ b/include/mbgl/platform/log.hpp
@@ -68,7 +68,7 @@ private:
     // This method is the data sink that must be implemented by each platform we
     // support. It should ideally output the error message in a human readable
     // format to the developer.
-    static void platformRecord(EventSeverity severity, Event event, int64_t code, const std::string &msg);
+    static void platformRecord(EventSeverity severity, const std::string &msg);
 };
 
 }
diff --git a/platform/android/log_android.cpp b/platform/android/log_android.cpp
index 9de8232bac..e5c8cfd812 100644
--- a/platform/android/log_android.cpp
+++ b/platform/android/log_android.cpp
@@ -1,8 +1,5 @@
 #include <mbgl/platform/log.hpp>
 
-#define __STDC_FORMAT_MACROS // NDK bug workaround: https://code.google.com/p/android/issues/detail?id=72349
-#include <cinttypes>
-
 #include <android/log.h>
 
 namespace mbgl {
@@ -30,8 +27,8 @@ int severityToPriority(EventSeverity severity) {
 
 } // namespace
 
-void Log::platformRecord(EventSeverity severity, Event event, int64_t code, const std::string &msg) {
-    __android_log_print(severityToPriority(severity), EventClass(event).c_str(), "(%" PRId64 ") %s", code, msg.c_str());
+void Log::platformRecord(EventSeverity severity, const std::string &msg) {
+    __android_log_print(severityToPriority(severity), "mbgl", "%s", msg.c_str());
 }
 
 }
diff --git a/platform/darwin/log_nslog.mm b/platform/darwin/log_nslog.mm
index 5d53ed812f..a2e31968ab 100644
--- a/platform/darwin/log_nslog.mm
+++ b/platform/darwin/log_nslog.mm
@@ -4,12 +4,10 @@
 
 namespace mbgl {
 
-void Log::platformRecord(EventSeverity severity, Event event, int64_t code,
-                         const std::string &msg) {
+void Log::platformRecord(EventSeverity severity, const std::string &msg) {
     NSString *message =
         [[NSString alloc] initWithBytes:msg.data() length:msg.size() encoding:NSUTF8StringEncoding];
-    NSLog(@"[%s] %s: (%lld) %@", EventSeverityClass(severity).c_str(), EventClass(event).c_str(),
-          code, message);
+    NSLog(@"[%s] %@", EventSeverityClass(severity).c_str(), message);
 }
 
 }
diff --git a/platform/default/log_stderr.cpp b/platform/default/log_stderr.cpp
index 3305176d96..f7ef341845 100644
--- a/platform/default/log_stderr.cpp
+++ b/platform/default/log_stderr.cpp
@@ -4,8 +4,8 @@
 
 namespace mbgl {
 
-void Log::platformRecord(EventSeverity severity, Event event, int64_t code, const std::string &msg) {
-    std::cerr << "[" << severity << "] " << event << ": (" << code << ") " << msg << std::endl;
+void Log::platformRecord(EventSeverity severity, const std::string &msg) {
+    std::cerr << "[" << severity << "] " << msg << std::endl;
 }
 
 }
diff --git a/src/mbgl/platform/log.cpp b/src/mbgl/platform/log.cpp
index e9712f727c..d6cbc4fd11 100644
--- a/src/mbgl/platform/log.cpp
+++ b/src/mbgl/platform/log.cpp
@@ -1,6 +1,9 @@
 #include <mbgl/platform/log.hpp>
 
+#include <mbgl/map/environment.hpp>
+
 #include <cstdarg>
+#include <sstream>
 
 namespace mbgl {
 
@@ -37,7 +40,28 @@ void Log::record(EventSeverity severity, Event event, int64_t code, const std::s
         return;
     }
 
-    platformRecord(severity, event, code, msg);
+    std::stringstream logStream;
+
+    if (Environment::inScope()) {
+        logStream << "{" << Environment::Get().getID() << "}";
+    }
+
+    const std::string threadName = Environment::threadName();
+    if (!threadName.empty()) {
+        logStream << "{" << threadName << "}";
+    }
+
+    logStream << "[" << event << "]";
+
+    if (code >= 0) {
+        logStream << "(" << code << ")";
+    }
+
+    if (!msg.empty()) {
+        logStream << ": " << msg;
+    }
+
+    platformRecord(severity, logStream.str());
 }
 
 }