1/*
2 *  Copyright (c) 2011 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 <assert.h>
12#include <stdlib.h>
13
14#include "webrtc/modules/include/module_common_types.h"
15#include "webrtc/modules/video_coding/timestamp_map.h"
16
17namespace webrtc {
18
19VCMTimestampMap::VCMTimestampMap(size_t capacity)
20    : ring_buffer_(new TimestampDataTuple[capacity]),
21      capacity_(capacity),
22      next_add_idx_(0),
23      next_pop_idx_(0) {}
24
25VCMTimestampMap::~VCMTimestampMap() {}
26
27void VCMTimestampMap::Add(uint32_t timestamp, VCMFrameInformation* data) {
28  ring_buffer_[next_add_idx_].timestamp = timestamp;
29  ring_buffer_[next_add_idx_].data = data;
30  next_add_idx_ = (next_add_idx_ + 1) % capacity_;
31
32  if (next_add_idx_ == next_pop_idx_) {
33    // Circular list full; forget oldest entry.
34    next_pop_idx_ = (next_pop_idx_ + 1) % capacity_;
35  }
36}
37
38VCMFrameInformation* VCMTimestampMap::Pop(uint32_t timestamp) {
39  while (!IsEmpty()) {
40    if (ring_buffer_[next_pop_idx_].timestamp == timestamp) {
41      // Found start time for this timestamp.
42      VCMFrameInformation* data = ring_buffer_[next_pop_idx_].data;
43      ring_buffer_[next_pop_idx_].data = nullptr;
44      next_pop_idx_ = (next_pop_idx_ + 1) % capacity_;
45      return data;
46    } else if (IsNewerTimestamp(ring_buffer_[next_pop_idx_].timestamp,
47                                timestamp)) {
48      // The timestamp we are looking for is not in the list.
49      return nullptr;
50    }
51
52    // Not in this position, check next (and forget this position).
53    next_pop_idx_ = (next_pop_idx_ + 1) % capacity_;
54  }
55
56  // Could not find matching timestamp in list.
57  return nullptr;
58}
59
60bool VCMTimestampMap::IsEmpty() const {
61  return (next_add_idx_ == next_pop_idx_);
62}
63}  // namespace webrtc
64