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         offset_(offset) {}
  46
  47  private:
  48   ~SharedFrameIOBuffer() override {
  49     // Prevent ~IOBuffer() from trying to delete |data_|.
  50     data_ = NULL;
  51   }
  52
  53   const scoped_refptr<SharedFrame> shared_frame_;
  54   const size_t offset_;
  55
  56   DISALLOW_COPY_AND_ASSIGN(SharedFrameIOBuffer);
  57 };
  58
  59 SpdyBuffer::SpdyBuffer(scoped_ptr<SpdyFrame> frame)
  60     : shared_frame_(new SharedFrame()),
  61       offset_(0) {
  62   shared_frame_->data = frame.Pass();
  63 }
  64
  65 // The given data may not be strictly a SPDY frame; we (ab)use
  66 // |frame_| just as a container.
  67 SpdyBuffer::SpdyBuffer(const char* data, size_t size) :
  68     shared_frame_(new SharedFrame()),
  69     offset_(0) {
  70   CHECK_GT(size, 0u);
  71   CHECK_LE(size, kMaxSpdyFrameSize);
  72   shared_frame_->data = MakeSpdyFrame(data, size);
  73 }
  74
  75 SpdyBuffer::~SpdyBuffer() {
  76   if (GetRemainingSize() > 0)
  77     ConsumeHelper(GetRemainingSize(), DISCARD);
  78 }
  79
  80 const char* SpdyBuffer::GetRemainingData() const {
  81   return shared_frame_->data->data() + offset_;
  82 }
  83
  84 size_t SpdyBuffer::GetRemainingSize() const {
  85   return shared_frame_->data->size() - offset_;
  86 }
  87
  88 void SpdyBuffer::AddConsumeCallback(const ConsumeCallback& consume_callback) {
  89   consume_callbacks_.push_back(consume_callback);
  90 }
  91
  92 void SpdyBuffer::Consume(size_t consume_size) {
  93   ConsumeHelper(consume_size, CONSUME);
  94 };
  95
  96 IOBuffer* SpdyBuffer::GetIOBufferForRemainingData() {
  97   return new SharedFrameIOBuffer(shared_frame_, offset_);
  98 }
  99
 100 void SpdyBuffer::ConsumeHelper(size_t consume_size,
 101                                ConsumeSource consume_source) {
 102   DCHECK_GE(consume_size, 1u);
 103   DCHECK_LE(consume_size, GetRemainingSize());
 104   offset_ += consume_size;
 105   for (std::vector<ConsumeCallback>::const_iterator it =
 106            consume_callbacks_.begin(); it != consume_callbacks_.end(); ++it) {
 107     it->Run(consume_size, consume_source);
 108   }
 109 };
 110
 111 }  // namespace net