Home | History | Annotate | Download | only in spdy 
      1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #include "net/spdy/spdy_buffer.h"
      6 
      7 #include <cstring>
      8 
      9 #include "base/callback.h"
     10 #include "base/logging.h"
     11 #include "net/base/io_buffer.h"
     12 #include "net/spdy/spdy_protocol.h"
     13 
     14 namespace net {
     15 
     16 namespace {
     17 
     18 // Makes a SpdyFrame with |size| bytes of data copied from
     19 // |data|. |data| must be non-NULL and |size| must be positive.
     20 scoped_ptr<SpdyFrame> MakeSpdyFrame(const char* data, size_t size) {
     21   DCHECK(data);
     22   DCHECK_GT(size, 0u);
     23   scoped_ptr<char[]> frame_data(new char[size]);
     24   std::memcpy(frame_data.get(), data, size);
     25   scoped_ptr<SpdyFrame> frame(
     26       new SpdyFrame(frame_data.release(), size, true /* owns_buffer */));
     27   return frame.Pass();
     28 }
     29 
     30 }  // namespace
     31 
     32 // This class is an IOBuffer implementation that simply holds a
     33 // reference to a SharedFrame object and a fixed offset. Used by
     34 // SpdyBuffer::GetIOBufferForRemainingData().
     35 class SpdyBuffer::SharedFrameIOBuffer : public IOBuffer {
     36  public:
     37   SharedFrameIOBuffer(const scoped_refptr<SharedFrame>& shared_frame,
     38                       size_t offset)
     39       : IOBuffer(shared_frame->data->data() + offset),
     40         shared_frame_(shared_frame),
     41         offset_(offset) {}
     42 
     43  private:
     44   virtual ~SharedFrameIOBuffer() {
     45     // Prevent ~IOBuffer() from trying to delete |data_|.
     46     data_ = NULL;
     47   }
     48 
     49   const scoped_refptr<SharedFrame> shared_frame_;
     50   const size_t offset_;
     51 
     52   DISALLOW_COPY_AND_ASSIGN(SharedFrameIOBuffer);
     53 };
     54 
     55 SpdyBuffer::SpdyBuffer(scoped_ptr<SpdyFrame> frame)
     56     : shared_frame_(new SharedFrame()),
     57       offset_(0) {
     58   shared_frame_->data = frame.Pass();
     59 }
     60 
     61 // The given data may not be strictly a SPDY frame; we (ab)use
     62 // |frame_| just as a container.
     63 SpdyBuffer::SpdyBuffer(const char* data, size_t size) :
     64     shared_frame_(new SharedFrame()),
     65     offset_(0) {
     66   shared_frame_->data = MakeSpdyFrame(data, size);
     67 }
     68 
     69 SpdyBuffer::~SpdyBuffer() {
     70   if (GetRemainingSize() > 0)
     71     ConsumeHelper(GetRemainingSize(), DISCARD);
     72 }
     73 
     74 const char* SpdyBuffer::GetRemainingData() const {
     75   return shared_frame_->data->data() + offset_;
     76 }
     77 
     78 size_t SpdyBuffer::GetRemainingSize() const {
     79   return shared_frame_->data->size() - offset_;
     80 }
     81 
     82 void SpdyBuffer::AddConsumeCallback(const ConsumeCallback& consume_callback) {
     83   consume_callbacks_.push_back(consume_callback);
     84 }
     85 
     86 void SpdyBuffer::Consume(size_t consume_size) {
     87   ConsumeHelper(consume_size, CONSUME);
     88 };
     89 
     90 IOBuffer* SpdyBuffer::GetIOBufferForRemainingData() {
     91   return new SharedFrameIOBuffer(shared_frame_, offset_);
     92 }
     93 
     94 void SpdyBuffer::ConsumeHelper(size_t consume_size,
     95                                ConsumeSource consume_source) {
     96   DCHECK_GE(consume_size, 1u);
     97   DCHECK_LE(consume_size, GetRemainingSize());
     98   offset_ += consume_size;
     99   for (std::vector<ConsumeCallback>::const_iterator it =
    100            consume_callbacks_.begin(); it != consume_callbacks_.end(); ++it) {
    101     it->Run(consume_size, consume_source);
    102   }
    103 };
    104 
    105 }  // namespace net
    106