1 /*
2 * Copyright (c) 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 <assert.h>
12
13 #include "webrtc/modules/remote_bitrate_estimator/include/send_time_history.h"
14
15 namespace webrtc {
16
SendTimeHistory(Clock * clock,int64_t packet_age_limit)17 SendTimeHistory::SendTimeHistory(Clock* clock, int64_t packet_age_limit)
18 : clock_(clock),
19 packet_age_limit_(packet_age_limit),
20 oldest_sequence_number_(0) {}
21
~SendTimeHistory()22 SendTimeHistory::~SendTimeHistory() {
23 }
24
Clear()25 void SendTimeHistory::Clear() {
26 history_.clear();
27 }
28
AddAndRemoveOld(uint16_t sequence_number,size_t length,bool was_paced)29 void SendTimeHistory::AddAndRemoveOld(uint16_t sequence_number,
30 size_t length,
31 bool was_paced) {
32 EraseOld();
33
34 if (history_.empty())
35 oldest_sequence_number_ = sequence_number;
36
37 history_.insert(std::pair<uint16_t, PacketInfo>(
38 sequence_number, PacketInfo(clock_->TimeInMilliseconds(), 0, -1,
39 sequence_number, length, was_paced)));
40 }
41
OnSentPacket(uint16_t sequence_number,int64_t send_time_ms)42 bool SendTimeHistory::OnSentPacket(uint16_t sequence_number,
43 int64_t send_time_ms) {
44 auto it = history_.find(sequence_number);
45 if (it == history_.end())
46 return false;
47 it->second.send_time_ms = send_time_ms;
48 return true;
49 }
50
EraseOld()51 void SendTimeHistory::EraseOld() {
52 while (!history_.empty()) {
53 auto it = history_.find(oldest_sequence_number_);
54 assert(it != history_.end());
55
56 if (clock_->TimeInMilliseconds() - it->second.creation_time_ms <=
57 packet_age_limit_) {
58 return; // Oldest packet within age limit, return.
59 }
60
61 // TODO(sprang): Warn if erasing (too many) old items?
62 history_.erase(it);
63 UpdateOldestSequenceNumber();
64 }
65 }
66
UpdateOldestSequenceNumber()67 void SendTimeHistory::UpdateOldestSequenceNumber() {
68 // After removing an element from the map, update oldest_sequence_number_ to
69 // the element with the lowest sequence number higher than the previous
70 // value (there might be gaps).
71 if (history_.empty())
72 return;
73 auto it = history_.upper_bound(oldest_sequence_number_);
74 if (it == history_.end()) {
75 // No element with higher sequence number than oldest_sequence_number_
76 // found, check wrap around. Note that history_.upper_bound(0) will not
77 // find 0 even if it is there, need to explicitly check for 0.
78 it = history_.find(0);
79 if (it == history_.end())
80 it = history_.upper_bound(0);
81 }
82 assert(it != history_.end());
83 oldest_sequence_number_ = it->first;
84 }
85
GetInfo(PacketInfo * packet,bool remove)86 bool SendTimeHistory::GetInfo(PacketInfo* packet, bool remove) {
87 auto it = history_.find(packet->sequence_number);
88 if (it == history_.end())
89 return false;
90 int64_t receive_time = packet->arrival_time_ms;
91 *packet = it->second;
92 packet->arrival_time_ms = receive_time;
93 if (remove) {
94 history_.erase(it);
95 if (packet->sequence_number == oldest_sequence_number_)
96 UpdateOldestSequenceNumber();
97 }
98 return true;
99 }
100
101 } // namespace webrtc
102