1 /*
2  *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #include "webrtc/base/bufferqueue.h"
12 
13 namespace rtc {
14 
BufferQueue(size_t capacity,size_t default_size)15 BufferQueue::BufferQueue(size_t capacity, size_t default_size)
16     : capacity_(capacity), default_size_(default_size) {
17 }
18 
~BufferQueue()19 BufferQueue::~BufferQueue() {
20   CritScope cs(&crit_);
21 
22   for (Buffer* buffer : queue_) {
23     delete buffer;
24   }
25   for (Buffer* buffer : free_list_) {
26     delete buffer;
27   }
28 }
29 
size() const30 size_t BufferQueue::size() const {
31   CritScope cs(&crit_);
32   return queue_.size();
33 }
34 
ReadFront(void * buffer,size_t bytes,size_t * bytes_read)35 bool BufferQueue::ReadFront(void* buffer, size_t bytes, size_t* bytes_read) {
36   CritScope cs(&crit_);
37   if (queue_.empty()) {
38     return false;
39   }
40 
41   bool was_writable = queue_.size() < capacity_;
42   Buffer* packet = queue_.front();
43   queue_.pop_front();
44 
45   bytes = std::min(bytes, packet->size());
46   memcpy(buffer, packet->data(), bytes);
47   if (bytes_read) {
48     *bytes_read = bytes;
49   }
50   free_list_.push_back(packet);
51   if (!was_writable) {
52     NotifyWritableForTest();
53   }
54   return true;
55 }
56 
WriteBack(const void * buffer,size_t bytes,size_t * bytes_written)57 bool BufferQueue::WriteBack(const void* buffer, size_t bytes,
58                             size_t* bytes_written) {
59   CritScope cs(&crit_);
60   if (queue_.size() == capacity_) {
61     return false;
62   }
63 
64   bool was_readable = !queue_.empty();
65   Buffer* packet;
66   if (!free_list_.empty()) {
67     packet = free_list_.back();
68     free_list_.pop_back();
69   } else {
70     packet = new Buffer(bytes, default_size_);
71   }
72 
73   packet->SetData(static_cast<const uint8_t*>(buffer), bytes);
74   if (bytes_written) {
75     *bytes_written = bytes;
76   }
77   queue_.push_back(packet);
78   if (!was_readable) {
79     NotifyReadableForTest();
80   }
81   return true;
82 }
83 
84 }  // namespace rtc
85