SPDY: Headers & Push-Promise now use Continuations

net/spdy/spdy_frame_builder.h

 // Copyright (c) 2012 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.
 
 #ifndef NET_SPDY_SPDY_FRAME_BUILDER_H_
 #define NET_SPDY_SPDY_FRAME_BUILDER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 10 matching lines @@
 // This class provides facilities for basic binary value packing
 // into Spdy frames.
 //
 // The SpdyFrameBuilder supports appending primitive values (int, string, etc)
 // to a frame instance.  The SpdyFrameBuilder grows its internal memory buffer
 // dynamically to hold the sequence of primitive values.   The internal memory
 // buffer is exposed as the "data" of the SpdyFrameBuilder.
 class NET_EXPORT_PRIVATE SpdyFrameBuilder {
  public:
   // Initializes a SpdyFrameBuilder with a buffer of given size
-  explicit SpdyFrameBuilder(size_t size);
+  SpdyFrameBuilder(size_t size, SpdyMajorVersion version);
 
   ~SpdyFrameBuilder();
 
-  // Returns the size of the SpdyFrameBuilder's data.
-  size_t length() const { return length_; }
+  // Returns the total size of the SpdyFrameBuilder's data, which may include
+  // multiple frames.
+  size_t length() const { return offset_ + length_; }
 
   // Returns a writeable buffer of given size in bytes, to be appended to the
   // currently written frame. Does bounds checking on length but does not
   // increment the underlying iterator. To do so, consumers should subsequently
   // call Seek().
   // In general, consumers should use Write*() calls instead of this.
   // Returns NULL on failure.
   char* GetWritableBuffer(size_t length);
 
   // Seeks forward by the given number of bytes. Useful in conjunction with
@@ skipping 11 matching lines @@
   // Populates this frame with a SPDY data frame header using version-specific
   // information from the |framer| and length information from capacity_.
   bool WriteDataFrameHeader(const SpdyFramer& framer,
                             SpdyStreamId stream_id,
                             uint8 flags);
 
   // Populates this frame with a SPDY4/HTTP2 frame prefix using
   // version-specific information from the |framer| and length information from
   // capacity_. The given type must be a control frame type.
   // Used only for SPDY versions >=4.
-  bool WriteFramePrefix(const SpdyFramer& framer,
-                        SpdyFrameType type,
-                        uint8 flags,
-                        SpdyStreamId stream_id);
+  bool BeginNewFrame(const SpdyFramer& framer,
+                     SpdyFrameType type,
+                     uint8 flags,
+                     SpdyStreamId stream_id);
 
   // Takes the buffer from the SpdyFrameBuilder.
   SpdyFrame* take() {
-    SpdyFrame* rv = new SpdyFrame(buffer_.release(), length_, true);
+    if (version_ > SPDY3) {
+      DLOG_IF(DFATAL, SpdyConstants::GetFrameMaximumSize(version_) < length_)
+          << "Frame length " << length_
+          << " is longer than the maximum allowed length.";
+    }
+    SpdyFrame* rv = new SpdyFrame(buffer_.release(), length(), true);
     capacity_ = 0;
     length_ = 0;
+    offset_ = 0;
     return rv;
   }

[Ryan Hamilton, 2014/04/22 03:31:53]

FWIW, this is a pretty complex method for a .h file. Consider landing an
internal change which moves this (and other non-trivial methods) to the .cc
file.

[Johnny, 2014/04/22 15:30:51]

Agreed, and noted.

On 2014/04/22 03:31:53, Ryan Hamilton wrote:

 
   // Methods for adding to the payload.  These values are appended to the end
   // of the SpdyFrameBuilder payload. Note - binary integers are converted from
   // host to network form.
   bool WriteUInt8(uint8 value) {
     return WriteBytes(&value, sizeof(value));
   }
   bool WriteUInt16(uint16 value) {
     value = htons(value);
     return WriteBytes(&value, sizeof(value));
@@ skipping 32 matching lines @@
   // Used only for SPDY versions >=4.
   bool OverwriteFlags(const SpdyFramer& framer, uint8 flags);
 
  private:
   // Checks to make sure that there is an appropriate amount of space for a
   // write of given size, in bytes.
   bool CanWrite(size_t length) const;
 
   scoped_ptr<char[]> buffer_;
   size_t capacity_;  // Allocation size of payload, set by constructor.
-  size_t length_;    // Current length of the buffer.
+  size_t length_;    // Length of the latest frame in the buffer.
+  size_t offset_;    // Position at which the latest frame begins.
+
+  const SpdyMajorVersion version_;
 };
 
 }  // namespace net
 
 #endif  // NET_SPDY_SPDY_FRAME_BUILDER_H_