xref: /aosp_15_r20/external/webrtc/rtc_base/buffer_queue.h (revision d9f758449e529ab9291ac668be2861e7a55c2422)
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 #ifndef RTC_BASE_BUFFER_QUEUE_H_
12 #define RTC_BASE_BUFFER_QUEUE_H_
13 
14 #include <stddef.h>
15 
16 #include <deque>
17 #include <vector>
18 
19 #include "api/sequence_checker.h"
20 #include "rtc_base/buffer.h"
21 #include "rtc_base/system/no_unique_address.h"
22 #include "rtc_base/thread_annotations.h"
23 
24 namespace rtc {
25 
26 class BufferQueue final {
27  public:
28   // Creates a buffer queue with a given capacity and default buffer size.
29   BufferQueue(size_t capacity, size_t default_size);
30   ~BufferQueue();
31 
32   BufferQueue(const BufferQueue&) = delete;
33   BufferQueue& operator=(const BufferQueue&) = delete;
34 
35   // Return number of queued buffers.
36   size_t size() const;
37 
38   // Clear the BufferQueue by moving all Buffers from `queue_` to `free_list_`.
39   void Clear();
40 
41   // ReadFront will only read one buffer at a time and will truncate buffers
42   // that don't fit in the passed memory.
43   // Returns true unless no data could be returned.
44   bool ReadFront(void* data, size_t bytes, size_t* bytes_read);
45 
46   // WriteBack always writes either the complete memory or nothing.
47   // Returns true unless no data could be written.
48   bool WriteBack(const void* data, size_t bytes, size_t* bytes_written);
49 
is_writable()50   bool is_writable() const {
51     RTC_DCHECK_RUN_ON(&sequence_checker_);
52     return queue_.size() < capacity_;
53   }
54 
is_readable()55   bool is_readable() const {
56     RTC_DCHECK_RUN_ON(&sequence_checker_);
57     return !queue_.empty();
58   }
59 
60  private:
61   RTC_NO_UNIQUE_ADDRESS webrtc::SequenceChecker sequence_checker_;
62   const size_t capacity_;
63   const size_t default_size_;
64   std::deque<Buffer*> queue_ RTC_GUARDED_BY(sequence_checker_);
65   std::vector<Buffer*> free_list_ RTC_GUARDED_BY(sequence_checker_);
66 };
67 
68 }  // namespace rtc
69 
70 #endif  // RTC_BASE_BUFFER_QUEUE_H_
71