components/pairing/message_buffer.cc

   1 // Copyright 2014 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 "components/pairing/message_buffer.h"
   6
   7 #include "net/base/io_buffer.h"
   8
   9 namespace pairing_chromeos {
  10
  11 MessageBuffer::MessageBuffer()
  12     : buffer_offset_(0),
  13       total_buffer_size_(0) {
  14 }
  15
  16 MessageBuffer::~MessageBuffer() {}
  17
  18 int MessageBuffer::AvailableBytes() {
  19   return total_buffer_size_ - buffer_offset_;
  20 }
  21
  22 void MessageBuffer::ReadBytes(char* buffer, int size) {
  23   CHECK_LE(size, AvailableBytes());
  24
  25   int offset = 0;
  26   while (offset < size) {
  27     scoped_refptr<net::IOBuffer> io_buffer = pending_data_.front().first;
  28     int io_buffer_size = pending_data_.front().second;
  29
  30     CHECK_GT(io_buffer_size, buffer_offset_);
  31     int copy_size = std::min(size - offset, io_buffer_size - buffer_offset_);
  32     memcpy(&buffer[offset], &io_buffer->data()[buffer_offset_], copy_size);
  33
  34     offset += copy_size;
  35     buffer_offset_ += copy_size;
  36
  37     CHECK_LE(buffer_offset_, io_buffer_size);
  38     if (buffer_offset_ == io_buffer_size) {
  39       CHECK_GE(total_buffer_size_, io_buffer_size);
  40       total_buffer_size_ -= io_buffer_size;
  41       pending_data_.pop_front();
  42       buffer_offset_ = 0;
  43     }
  44   }
  45   CHECK_EQ(offset, size);
  46 }
  47
  48 void MessageBuffer::AddIOBuffer(scoped_refptr<net::IOBuffer> io_buffer,
  49                                 int size) {
  50   if (size == 0)
  51     return;
  52   pending_data_.push_back(std::make_pair(io_buffer, size));
  53   total_buffer_size_ += size;
  54 }
  55
  56 }  // namespace pairing_chromeos