net/spdy/spdy_buffer.cc

   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 // Bound on largest frame any SPDY version has allowed.
  19 const size_t kMaxSpdyFrameSize = 0x00ffffff;
  20
  21 // Makes a SpdyFrame with |size| bytes of data copied from
  22 // |data|. |data| must be non-NULL and |size| must be positive.
  23 scoped_ptr<SpdyFrame> MakeSpdyFrame(const char* data, size_t size) {
  24   DCHECK(data);
  25   CHECK_GT(size, 0u);
  26   CHECK_LE(size, kMaxSpdyFrameSize);
  27   scoped_ptr<char[]> frame_data(new char[size]);
  28   std::memcpy(frame_data.get(), data, size);
  29   scoped_ptr<SpdyFrame> frame(
  30       new SpdyFrame(frame_data.release(), size, true /* owns_buffer */));
  31   return frame.Pass();
  32 }
  33
  34 }  // namespace
  35
  36 // This class is an IOBuffer implementation that simply holds a
  37 // reference to a SharedFrame object and a fixed offset. Used by
  38 // SpdyBuffer::GetIOBufferForRemainingData().
  39 class SpdyBuffer::SharedFrameIOBuffer : public IOBuffer {
  40  public:
  41   SharedFrameIOBuffer(const scoped_refptr<SharedFrame>& shared_frame,
  42                       size_t offset)
  43       : IOBuffer(shared_frame->data->data() + offset),
  44         shared_frame_(shared_frame) {}
  45
  46  private:
  47   ~SharedFrameIOBuffer() override {
  48     // Prevent ~IOBuffer() from trying to delete |data_|.
  49     data_ = NULL;
  50   }
  51
  52   const scoped_refptr<SharedFrame> shared_frame_;
  53
  54   DISALLOW_COPY_AND_ASSIGN(SharedFrameIOBuffer);
  55 };
  56
  57 SpdyBuffer::SpdyBuffer(scoped_ptr<SpdyFrame> frame)
  58     : shared_frame_(new SharedFrame()),
  59       offset_(0) {
  60   shared_frame_->data = frame.Pass();
  61 }
  62
  63 // The given data may not be strictly a SPDY frame; we (ab)use
  64 // |frame_| just as a container.
  65 SpdyBuffer::SpdyBuffer(const char* data, size_t size) :
  66     shared_frame_(new SharedFrame()),
  67     offset_(0) {
  68   CHECK_GT(size, 0u);
  69   CHECK_LE(size, kMaxSpdyFrameSize);
  70   shared_frame_->data = MakeSpdyFrame(data, size);
  71 }
  72
  73 SpdyBuffer::~SpdyBuffer() {
  74   if (GetRemainingSize() > 0)
  75     ConsumeHelper(GetRemainingSize(), DISCARD);
  76 }
  77
  78 const char* SpdyBuffer::GetRemainingData() const {
  79   return shared_frame_->data->data() + offset_;
  80 }
  81
  82 size_t SpdyBuffer::GetRemainingSize() const {
  83   return shared_frame_->data->size() - offset_;
  84 }
  85
  86 void SpdyBuffer::AddConsumeCallback(const ConsumeCallback& consume_callback) {
  87   consume_callbacks_.push_back(consume_callback);
  88 }
  89
  90 void SpdyBuffer::Consume(size_t consume_size) {
  91   ConsumeHelper(consume_size, CONSUME);
  92 };
  93
  94 IOBuffer* SpdyBuffer::GetIOBufferForRemainingData() {
  95   return new SharedFrameIOBuffer(shared_frame_, offset_);
  96 }
  97
  98 void SpdyBuffer::ConsumeHelper(size_t consume_size,
  99                                ConsumeSource consume_source) {
 100   DCHECK_GE(consume_size, 1u);
 101   DCHECK_LE(consume_size, GetRemainingSize());
 102   offset_ += consume_size;
 103   for (std::vector<ConsumeCallback>::const_iterator it =
 104            consume_callbacks_.begin(); it != consume_callbacks_.end(); ++it) {
 105     it->Run(consume_size, consume_source);
 106   }
 107 };
 108
 109 }  // namespace net