Instead of enqueueing SPDY frames, enqueue SPDY streams that are ready to produce data.

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 2975203f433dfe45c08b3f566108e069889b9df5..3d95101fcedd5cb5b66ec5ee6f83b1a5739708a0 100644
--- a/net/spdy/spdy_session.h
+++ b/net/spdy/spdy_session.h
@@ -19,6 +19,7 @@
 #include "net/base/load_states.h"
 #include "net/base/net_errors.h"
 #include "net/base/request_priority.h"
+#include "net/base/ssl_client_cert_type.h"
 #include "net/base/ssl_config_service.h"
 #include "net/base/upload_data_stream.h"
 #include "net/socket/client_socket_handle.h"
@@ -93,6 +94,32 @@ COMPILE_ASSERT(PROTOCOL_ERROR_UNEXPECTED_PING ==
 class NET_EXPORT SpdySession : public base::RefCounted<SpdySession>,
                                public BufferedSpdyFramerVisitorInterface {
  public:
+  // Defines an interface for producing SpdyIOBuffers.
+  class NET_EXPORT_PRIVATE SpdyIOBufferProducer {
+   public:
+    SpdyIOBufferProducer() {}
+
+    // Returns a newly created SpdyIOBuffer, owned by the caller, or NULL
+    // if not buffer is ready to be produced.
+    virtual SpdyIOBuffer* ProduceNextBuffer(SpdySession* session) = 0;
+
+    virtual RequestPriority GetPriority() const = 0;
+
+    virtual ~SpdyIOBufferProducer() {}
+
+   protected:
+    // Activates |spdy_stream| in |spdy_session|.
+    static void ActivateStream(SpdySession* spdy_session,
+                               SpdyStream* spdy_stream);
+
+    static SpdyIOBuffer* CreateIOBuffer(SpdyFrame* frame,
+                                        RequestPriority priority,
+                                        SpdyStream* spdy_stream);
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(SpdyIOBufferProducer);
+  };
+
   // Create a new SpdySession.
   // |host_port_proxy_pair| is the host/port that this session connects to, and
   // the proxy configuration settings that it's using.
@@ -157,9 +184,14 @@ class NET_EXPORT SpdySession : public base::RefCounted<SpdySession>,
   // authentication now.
   bool VerifyDomainAuthentication(const std::string& domain);
 
+  // Records that |stream| has a write available from |producer|.
+  // |producer| will be owned by this SpdySession.
+  void SetStreamHasWriteAvailable(SpdyStream* stream,
+                                  SpdyIOBufferProducer* producer);
+
   // Send the SYN frame for |stream_id|. This also sends PING message to check
   // the status of the connection.
-  int WriteSynStream(
+  SpdySynStreamControlFrame* CreateSynStream(
       SpdyStreamId stream_id,
       RequestPriority priority,
       uint8 credential_slot,
@@ -167,21 +199,24 @@ class NET_EXPORT SpdySession : public base::RefCounted<SpdySession>,
       const SpdyHeaderBlock& headers);
 
   // Write a CREDENTIAL frame to the session.
-  int WriteCredentialFrame(const std::string& origin,
-                           SSLClientCertType type,
-                           const std::string& key,
-                           const std::string& cert,
-                           RequestPriority priority);
+  SpdyCredentialControlFrame* CreateCredentialFrame(const std::string& origin,
+                                                    SSLClientCertType type,
+                                                    const std::string& key,
+                                                    const std::string& cert,
+                                                    RequestPriority priority);
 
   // Write a data frame to the stream.
   // Used to create and queue a data frame for the given stream.
-  int WriteStreamData(SpdyStreamId stream_id, net::IOBuffer* data,
-                      int len,
-                      SpdyDataFlags flags);
+  SpdyDataFrame* CreateDataFrame(SpdyStreamId stream_id,
+                                 net::IOBuffer* data, int len,
+                                 SpdyDataFlags flags);
 
   // Close a stream.
   void CloseStream(SpdyStreamId stream_id, int status);
 
+  // Close a stream that has been created but is not yet active.
+  void CloseCreatedStream(SpdyStream* stream, int status);
+
   // Reset a stream by sending a RST_STREAM frame with given status code.
   // Also closes the stream.  Was not piggybacked to CloseStream since not
   // all of the calls to CloseStream necessitate sending a RST_STREAM.
@@ -268,7 +303,7 @@ class NET_EXPORT SpdySession : public base::RefCounted<SpdySession>,
 
   // Returns true if session is not currently active
   bool is_active() const {
-    return !active_streams_.empty();
+    return !active_streams_.empty() || !created_streams_.empty();
   }
 
   // Access to the number of active and pending streams.  These are primarily
@@ -277,6 +312,7 @@ class NET_EXPORT SpdySession : public base::RefCounted<SpdySession>,
   size_t num_unclaimed_pushed_streams() const {
       return unclaimed_pushed_streams_.size();
   }
+  size_t num_created_streams() const { return created_streams_.size(); }
 
   // Returns true if flow control is enabled for the session.
   bool is_flow_control_enabled() const {
@@ -356,6 +392,19 @@ class NET_EXPORT SpdySession : public base::RefCounted<SpdySession>,
       std::pair<scoped_refptr<SpdyStream>, base::TimeTicks> > PushedStreamMap;
   typedef std::priority_queue<SpdyIOBuffer> OutputQueue;
 
+  typedef std::set<scoped_refptr<SpdyStream> > CreatedStreamSet;
+  typedef std::map<SpdyIOBufferProducer*, SpdyStream*> StreamProducerMap;
+  class SpdyIOBufferProducerCompare {
+   public:
+    bool operator() (const SpdyIOBufferProducer* lhs,
+                     const SpdyIOBufferProducer* rhs) const {
+      return lhs->GetPriority() < rhs->GetPriority();
+    }
+  };
+  typedef std::priority_queue<SpdyIOBufferProducer*,
+                              std::vector<SpdyIOBufferProducer*>,
+                              SpdyIOBufferProducerCompare> WriteQueue;
+
   struct CallbackResultPair {
     CallbackResultPair(const CompletionCallback& callback_in, int result_in)
         : callback(callback_in), result(result_in) {}
@@ -434,9 +483,7 @@ class NET_EXPORT SpdySession : public base::RefCounted<SpdySession>,
   // Queue a frame for sending.
   // |frame| is the frame to send.
   // |priority| is the priority for insertion into the queue.
-  // |stream| is the stream which this IO is associated with (or NULL).
-  void QueueFrame(SpdyFrame* frame, RequestPriority priority,
-                  SpdyStream* stream);
+  void QueueFrame(SpdyFrame* frame, RequestPriority priority);
 
   // Track active streams in the active stream list.
   void ActivateStream(SpdyStream* stream);
@@ -462,6 +509,9 @@ class NET_EXPORT SpdySession : public base::RefCounted<SpdySession>,
   // Closes all streams.  Used as part of shutdown.
   void CloseAllStreams(net::Error status);
 
+  void LogAbandonedStream(const scoped_refptr<SpdyStream>& stream,
+                          net::Error status);
+
   // Invokes a user callback for stream creation.  We provide this method so it
   // can be deferred to the MessageLoop, so we avoid re-entrancy problems.
   void InvokeUserStreamCreationCallback(scoped_refptr<SpdyStream>* stream);
@@ -580,8 +630,16 @@ class NET_EXPORT SpdySession : public base::RefCounted<SpdySession>,
   // server, but do not have consumers yet.
   PushedStreamMap unclaimed_pushed_streams_;
 
-  // As we gather data to be sent, we put it into the output queue.
-  OutputQueue queue_;
+  // Set of all created streams but that have not yet sent any frames.
+  CreatedStreamSet created_streams_;
+
+  // As streams have data to be sent, we put them into the write queue.
+  WriteQueue write_queue_;
+
+  // Mapping from SpdyIOBufferProducers to their corresponding SpdyStream
+  // so that when a stream is destroyed, we can remove the corresponding
+  // producer from |write_queue_|.
+  StreamProducerMap stream_producers_;
 
   // The packet we are currently sending.
   bool write_pending_;            // Will be true when a write is in progress.