SPDY - Re-land greedy read support for SpdySession

net/spdy/spdy_session.h

Index: net/spdy/spdy_session.h
diff --git a/net/spdy/spdy_session.h b/net/spdy/spdy_session.h
index 88496839a2b495e845e8c8b80b7bf5765e7b8329..88cfee37b02bc3973244f0d9212b3c79a4ca0559 100644
--- a/net/spdy/spdy_session.h
+++ b/net/spdy/spdy_session.h
@@ -47,6 +47,10 @@ const int kMaxSpdyFrameChunkSize = (2 * kMss) - 8;
 // Specifies the maxiumum concurrent streams server could send (via push).
 const int kMaxConcurrentPushedStreams = 1000;
 
+// Specifies the number of bytes read synchronously (without yielding) if the
+// data is available.
+const int kMaxReadBytes = 32 * 1024;
+
 // The initial receive window size for both streams and sessions.
 const int32 kDefaultInitialRecvWindowSize = 10 * 1024 * 1024;  // 10MB
 
@@ -337,7 +341,7 @@ class NET_EXPORT SpdySession : public base::RefCounted<SpdySession>,
   void IncreaseRecvWindowSize(int32 delta_window_size);
 
   // If session is closed, no new streams/transactions should be created.
-  bool IsClosed() const { return state_ == CLOSED; }
+  bool IsClosed() const { return state_ == STATE_CLOSED; }
 
   // Closes this session.  This will close all active streams and mark
   // the session as permanently closed.
@@ -488,10 +492,11 @@ class NET_EXPORT SpdySession : public base::RefCounted<SpdySession>,
                               SpdyIOBufferProducerCompare> WriteQueue;
 
   enum State {
-    IDLE,
-    CONNECTING,
-    CONNECTED,
-    CLOSED
+    STATE_IDLE,
+    STATE_CONNECTING,
+    STATE_DO_READ,
+    STATE_DO_READ_COMPLETE,
+    STATE_CLOSED
   };
 
   virtual ~SpdySession();
@@ -519,6 +524,21 @@ class NET_EXPORT SpdySession : public base::RefCounted<SpdySession>,
   // possible.
   void ProcessPendingStreamRequests();
 
+  // Start the DoLoop to read data from socket.
+  void StartRead();
+
+  // Try to make progress by reading and processing data.
+  int DoLoop(int result);
+  // The implementations of STATE_DO_READ/STATE_DO_READ_COMPLETE state changes
+  // of the state machine.
+  int DoRead();
+  int DoReadComplete(int bytes_read);
+
+  // Check if session is connected or not.
+  bool IsConnected() const {
+    return state_ == STATE_DO_READ || state_ == STATE_DO_READ_COMPLETE;
+  }
+
   // IO Callbacks
   void OnReadComplete(int result);
   void OnWriteComplete(int result);
@@ -557,10 +577,6 @@ class NET_EXPORT SpdySession : public base::RefCounted<SpdySession>,
   // haven't received any data in |kHungInterval| time period.
   void CheckPingStatus(base::TimeTicks last_check_time);
 
-  // Start reading from the socket.
-  // Returns OK on success, or an error on failure.
-  net::Error ReadSocket();
-
   // Write current data to the socket.
   void WriteSocketLater();
   void WriteSocket();
@@ -724,7 +740,6 @@ class NET_EXPORT SpdySession : public base::RefCounted<SpdySession>,
 
   // The read buffer used to read data from the socket.
   scoped_refptr<IOBuffer> read_buffer_;
-  bool read_pending_;
 
   int stream_hi_water_mark_;  // The next stream id to use.
 
@@ -794,7 +809,15 @@ class NET_EXPORT SpdySession : public base::RefCounted<SpdySession>,
   int streams_pushed_count_;
   int streams_pushed_and_claimed_count_;
   int streams_abandoned_count_;
-  int bytes_received_;
+
+  // |total_bytes_received_| keeps track of all the bytes read by the
+  // SpdySession. It is used by the |Net.SpdySettingsCwnd...| histograms.
+  int total_bytes_received_;
+
+  // |bytes_read_| keeps track of number of bytes read continously in the
+  // DoLoop() without yielding.
+  int bytes_read_;
+
   bool sent_settings_;      // Did this session send settings when it started.
   bool received_settings_;  // Did this session receive at least one settings
                             // frame.