Cronet for iOS with C API for GRPC support.

components/cronet/ios/cronet_engine.mm

Index: components/cronet/ios/cronet_engine.mm
diff --git a/components/cronet/ios/cronet_engine.mm b/components/cronet/ios/cronet_engine.mm
new file mode 100644
index 0000000000000000000000000000000000000000..a1c572ec0b54e0b2f30168938f1db61c7891715e
--- /dev/null
+++ b/components/cronet/ios/cronet_engine.mm
@@ -0,0 +1,87 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "components/cronet/ios/cronet_engine.h"
+
+#include "base/logging.h"
+#include "base/strings/sys_string_conversions.h"
+#import "components/cronet/ios/cronet_environment.h"
+
+static cronet::CronetEnvironment* g_chrome_net = NULL;
+
+static BOOL g_http2_enabled = YES;

[kapishnikov, 2016/04/06 17:33:25]

The convention is to use mixed case to delimit words in the variable names. It
would be great to convert them to instance variables and start the names with
underscore.
https://engdoc.corp.google.com/eng/doc/objcguide.xml?cl=head#Variable_Names

[mef, 2016/04/08 15:13:01]

Done. I'd do instance variables in another CL.

+static BOOL g_quic_enabled = NO;
+static NSString* g_user_agent = nil;
+static NSString* g_ssl_key_log_file_name = nil;
+
+@implementation CronetEngine
+
++ (void)setHttp2Enabled:(BOOL)http2Enabled {

[kapishnikov, 2016/04/06 17:33:25]

We could add the verification that the method is not called after the engine was
installed/started. It least we should log an error message. Same for all
setters.

[mef, 2016/04/08 15:13:01]

Done.

+  g_http2_enabled = http2Enabled;
+}
+
++ (void)setQuicEnabled:(BOOL)quicEnabled {
+  g_quic_enabled = quicEnabled;
+}
+
++ (void)setPartialUserAgent:(NSString*)userAgent {
+  g_user_agent = userAgent;
+}
+
++ (void)setSslKeyLogFileName:(NSString*)sslKeyLogFileName {
+  g_ssl_key_log_file_name = sslKeyLogFileName;
+}
+
++ (void)installInternal {
+  cronet::CronetEnvironment::Initialize();
+  std::string partial_user_agent = base::SysNSStringToUTF8(g_user_agent);
+  g_chrome_net = new cronet::CronetEnvironment(partial_user_agent);
+
+  g_chrome_net->set_http2_enabled(g_http2_enabled);
+  g_chrome_net->set_quic_enabled(g_quic_enabled);
+  g_chrome_net->set_ssl_key_log_file_name(
+      base::SysNSStringToUTF8(g_ssl_key_log_file_name));
+  g_chrome_net->Install();
+}
+
++ (void)install {
+  static dispatch_once_t onceToken;
+  dispatch_once(&onceToken, ^{
+    [self installInternal];
+  });
+}
+
++ (void)startNetLogToFile:(NSString*)fileName logBytes:(BOOL)logBytes {
+  if (g_chrome_net && [fileName length]) {

[kapishnikov, 2016/04/06 17:33:25]

It would be great to log full path to the netlog file, so it can be easily
found. Also, if somebody calls startNetLogToFile but it cannot be started, we
should at least log an error.

[mef, 2016/04/08 15:13:01]

Full path is logged in CronetEnvironment::StartNetLogInternal. I'll add error
logs there as well.

+    g_chrome_net->StartNetLog([fileName UTF8String], logBytes);
+  }
+}
+
++ (void)stopNetLog {
+  if (g_chrome_net) {
+    return g_chrome_net->StopNetLog();

[kapishnikov, 2016/04/06 17:33:25]

The method return type is void. Does this line generate a warning?

[mef, 2016/04/08 15:13:01]

Done.

+  }
+}
+
++ (NSString*)userAgent {
+  if (!g_chrome_net) {
+    return nil;
+  }
+
+  std::string user_agent = g_chrome_net->user_agent();
+  return [NSString stringWithCString:user_agent.c_str()
+                            encoding:[NSString defaultCStringEncoding]];
+}
+
++ (cronet_engine*)getGlobalEngine {
+  DCHECK(g_chrome_net);
+  if (g_chrome_net) {
+    static cronet_engine engine;
+    engine.obj = g_chrome_net;
+    return &engine;
+  }
+  return nil;
+}
+
+@end