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
14namespace net {
15
16namespace {
17
18// Bound on largest frame any SPDY version has allowed.
19const 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.
23scoped_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().
39class 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  virtual ~SharedFrameIOBuffer() {
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
59SpdyBuffer::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.
67SpdyBuffer::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
75SpdyBuffer::~SpdyBuffer() {
76  if (GetRemainingSize() > 0)
77    ConsumeHelper(GetRemainingSize(), DISCARD);
78}
79
80const char* SpdyBuffer::GetRemainingData() const {
81  return shared_frame_->data->data() + offset_;
82}
83
84size_t SpdyBuffer::GetRemainingSize() const {
85  return shared_frame_->data->size() - offset_;
86}
87
88void SpdyBuffer::AddConsumeCallback(const ConsumeCallback& consume_callback) {
89  consume_callbacks_.push_back(consume_callback);
90}
91
92void SpdyBuffer::Consume(size_t consume_size) {
93  ConsumeHelper(consume_size, CONSUME);
94};
95
96IOBuffer* SpdyBuffer::GetIOBufferForRemainingData() {
97  return new SharedFrameIOBuffer(shared_frame_, offset_);
98}
99
100void 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
112