[Cronet] Integrate CrNet functionality into Cronet on iOS.

components/cronet/ios/Cronet.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"
 
+// A block, that takes a request, and returns YES if the request should
+// be handled.
+typedef BOOL (^RequestFilterBlock)(NSURLRequest* request);
+
 // Interface for installing Cronet.
 CRONET_EXPORT
 @interface Cronet : NSObject
 
 // Sets whether HTTP/2 should be supported by CronetEngine. This method only has
 // any effect before |start| is called.
 + (void)setHttp2Enabled:(BOOL)http2Enabled;
 
 // Sets whether QUIC should be supported by CronetEngine. This method only has
 // any effect before |start| is called.
 + (void)setQuicEnabled:(BOOL)quicEnabled;
 
 // Adds hint that host supports QUIC on altPort. This method only has any effect
 // before |start| is called.
 + (void)addQuicHint:(NSString*)host port:(int)port altPort:(int)altPort;
 
 // |userAgent| is expected to be of the form Product/Version.
 // Example: Foo/3.0.0.0
 //
 // This method only has any effect before |start| is called.
 + (void)setPartialUserAgent:(NSString*)userAgent;
 
+// This method only has any effect before |start| is called.
++ (void)setHostResolverRulesForTesting:(NSString*)hostResolverRulesForTesting;

[kapishnikov, 2016/08/10 17:47:40]

I wonder if we can somehow hide "...ForTesting" methods. Maybe we can move them
to the subclass?

[mef, 2016/08/11 21:22:15]

Great idea! I've extracted them into Cronet(TestSupport)..

+
+// Sets a native MockCertVerifier for testing.
+// This method only has any effect before |start| is called.
++ (void)setMockCertVerifierForTesting:(void*)mockCertVerifierForTesting;
+
 // Sets SSLKEYLogFileName to export SSL key for Wireshark decryption of packet
 // captures. This method only has any effect before |start| is called.
 + (void)setSslKeyLogFileName:(NSString*)sslKeyLogFileName;
 
+// Set the block used to determine whether or not Cronet should handle the
+// request. If this is not set, Cronet will handle all requests.
+// This method only has any effect before |start| is called.
++ (void)setRequestFilterBlock:(RequestFilterBlock)block;
+
 // Starts CronetEngine. It is recommended to call this method on the application
 // main thread. If the method is called on any thread other than the main one,
 // the method will internally try to execute synchronously using the main GCD
 // queue. Please make sure that the main thread is not blocked by a job
 // that calls this method; otherwise, a deadlock can occur.
 + (void)start;
 
+// Registers Cronet as HttpProtocol Handler. Once registered, Cronet intercepts
+// and handles all NSURLConnection and NSURLRequests issued by the app,
+// including
+// requests done through shared NSURLSession.

[kapishnikov, 2016/08/10 17:47:40]

This can fit in the previous line.

[mef, 2016/08/11 21:22:15]

Done.

+// This method must be called after |start|.
++ (void)registerHttpProtocolHandler;
+
+// Unregister Cronet as HttpProtocol Handler. This means that Cronet will stop
+// intercepting requests, however, it won't tear down the Cronet environment.
+// This method must be called after |start|.
++ (void)unregisterHttpProtocolHandler;
+
+// Installs Croet into an NSURLSession, passed in by the caller. Note that this

[kapishnikov, 2016/08/10 17:47:40]

Croer=>Cronet

[mef, 2016/08/11 21:22:15]

Done.

+// NSURLSession will share settings with the sharedSession, which the

[kapishnikov, 2016/08/10 17:47:40]

The shared session has its own internal configuration. It is not clear, how this
method impacts it. Also, a single NSURLSessionConfiguration can be used for
multiple sessions. Should we say that this method enables Cronet in
NSURLSessionConfiguration so that all sessions created with this configuration
will use the Cronet stack?

[mef, 2016/08/11 21:22:15]

Done.

+// |registerHttpProtocolHandler| method installs Cronet into.
+// This method must be called after |start|.
++ (void)installIntoSessionConfiguration:(NSURLSessionConfiguration*)config;
+
 // 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*)getUserAgent;
 
 // Get a pointer to global instance of cronet_engine for GRPC C API.
 + (cronet_engine*)getGlobalEngine;
 
+// Returns differences in metrics collected by Cronet since the last call to
+// getGlobalMetricsDeltas.
+// Cronet starts collecting these metrics after the first call to
+// getGlobalMetricsDeltras, so the first call returns no
+// useful data as no metrics have yet been collected.
++ (NSData*)getGlobalMetricsDeltas;

[kapishnikov, 2016/08/10 17:47:40]

What is the structure of NSData? What should the user do with it?

[mef, 2016/08/11 21:22:15]

Done.

+
 @end