Cronet for iOS with C API for GRPC support.

components/cronet/ios/cronet_engine.h

+// Copyright 2016 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 <Foundation/Foundation.h>
+
+#include "cronet_c_for_grpc.h"
+
+// Interface for installing CronetEngine.
+@interface CronetEngine : NSObject

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

Should we consider making all CronetEngine methods non-static? We can use the
singleton pattern if we do not want the client to create multiple instances of
CronetEngine. It may help with testing and moving to multi-engine support in the
future.

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

Yes. For the purpose of this CL I kept it close to original CrNet interface, but
we should definitely refactor this afterwards.

+
+// Sets whether HTTP/2 should be supported by CronetEngine. This method only has
+// any effect before |install| is called.
++ (void)setHttp2Enabled:(BOOL)http2Enabled;
+
+// Sets whether QUIC should be supported by CronetEngine. This method only has
+// any effect before |install| is called.
++ (void)setQuicEnabled:(BOOL)quicEnabled;
+
+// |userAgent| is expected to be of the form Product/Version.
+// Example: Foo/3.0.0.0
+//
+// This method only has any effect before |install| is called.
++ (void)setPartialUserAgent:(NSString*)userAgent;
+
+// Sets SSLKEYLogFileName to export SSL key for Wireshark decryption of packet
+// captures. This method only has any effect before |install| is called.
++ (void)setSslKeyLogFileName:(NSString*)sslKeyLogFileName;
+
+// Installs CronetEngine.
++ (void)install;

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

In CrNet we use install() method to install NSUrlConnection protocol handler, so
the name of the method corresponds to the action. In CronetEngine we don't
install the handler. Should we rename the method to something like start()?

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

Done.

+
+// Starts net-internals logging to a file named |fileName| in the application
+// temporary directory. |fileName| must not be empty. Log level is determined
+// by |logBytes| - if YES then LOG_ALL otherwise LOG_ALL_BUT_BYTES. If the file
+// exists it is truncated before starting. If actively logging the call is
+// ignored.
++ (void)startNetLogToFile:(NSString*)fileName logBytes:(BOOL)logBytes;
+
+// Stop net-internals logging and flush file to disk. If a logging session is
+// not in progress this call is ignored.
++ (void)stopNetLog;
+
+// Returns the full user-agent that the stack uses.
+// This is the exact string servers will see.
++ (NSString*)userAgent;

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

This can be an Objective C property. Otherwise, I would rename it to
getUserAgent().

@property (nonatomic, readonly) NSString *userAgent;

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

Done.

+
+// Get a pointer to global instance of cronet_engine for GRPC C API.
++ (cronet_engine*)getGlobalEngine;
+
+@end