1/*
2 * Copyright (C) 2019 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "DownloadMonitor.h"
28
29#include "Download.h"
30#include "Logging.h"
31
32#undef RELEASE_LOG_IF_ALLOWED
33#define RELEASE_LOG_IF_ALLOWED(fmt, ...) RELEASE_LOG_IF(m_download.isAlwaysOnLoggingAllowed(), Network, "%p - DownloadMonitor::" fmt, this, ##__VA_ARGS__)
34
35namespace WebKit {
36
37constexpr uint64_t operator"" _kbps(unsigned long long kilobytesPerSecond)
38{
39 return kilobytesPerSecond * 1024;
40}
41
42struct ThroughputInterval {
43 Seconds time;
44 uint64_t bytesPerSecond;
45};
46
47static const ThroughputInterval throughputIntervals[] = {
48 { 1_min, 1_kbps },
49 { 5_min, 2_kbps },
50 { 10_min, 4_kbps },
51 { 15_min, 8_kbps },
52 { 20_min, 16_kbps },
53 { 25_min, 32_kbps },
54 { 30_min, 64_kbps },
55 { 45_min, 96_kbps },
56 { 60_min, 128_kbps }
57};
58
59static Seconds timeUntilNextInterval(size_t currentInterval)
60{
61 RELEASE_ASSERT(currentInterval + 1 < WTF_ARRAY_LENGTH(throughputIntervals));
62 return throughputIntervals[currentInterval + 1].time - throughputIntervals[currentInterval].time;
63}
64
65DownloadMonitor::DownloadMonitor(Download& download)
66 : m_download(download)
67{
68}
69
70double DownloadMonitor::measuredThroughputRate() const
71{
72 uint64_t bytes { 0 };
73 for (const auto& timestamp : m_timestamps)
74 bytes += timestamp.bytesReceived;
75 if (!bytes)
76 return 0;
77 ASSERT(!m_timestamps.isEmpty());
78 Seconds timeDifference = m_timestamps.last().time.secondsSinceEpoch() - m_timestamps.first().time.secondsSinceEpoch();
79 double seconds = timeDifference.seconds();
80 if (!seconds)
81 return std::numeric_limits<double>::max();
82 return bytes / seconds;
83}
84
85void DownloadMonitor::downloadReceivedBytes(uint64_t bytesReceived)
86{
87 if (m_timestamps.size() > timestampCapacity - 1) {
88 ASSERT(m_timestamps.size() == timestampCapacity);
89 m_timestamps.removeFirst();
90 }
91 m_timestamps.append({ MonotonicTime::now(), bytesReceived });
92}
93
94void DownloadMonitor::applicationWillEnterForeground()
95{
96 RELEASE_LOG_IF_ALLOWED("applicationWillEnterForeground (id = %" PRIu64 ")", m_download.downloadID().downloadID());
97 m_timer.stop();
98 m_interval = 0;
99}
100
101void DownloadMonitor::applicationDidEnterBackground()
102{
103 RELEASE_LOG_IF_ALLOWED("applicationDidEnterBackground (id = %" PRIu64 ")", m_download.downloadID().downloadID());
104 ASSERT(!m_timer.isActive());
105 ASSERT(!m_interval);
106 m_timer.startOneShot(throughputIntervals[0].time / speedMultiplier());
107}
108
109uint32_t DownloadMonitor::speedMultiplier() const
110{
111 return m_download.manager().client().downloadMonitorSpeedMultiplier();
112}
113
114void DownloadMonitor::timerFired()
115{
116 RELEASE_ASSERT(m_interval < WTF_ARRAY_LENGTH(throughputIntervals));
117 if (measuredThroughputRate() < throughputIntervals[m_interval].bytesPerSecond) {
118 RELEASE_LOG_IF_ALLOWED("timerFired: cancelling download (id = %" PRIu64 ")", m_download.downloadID().downloadID());
119 m_download.cancel();
120 } else if (m_interval + 1 < WTF_ARRAY_LENGTH(throughputIntervals)) {
121 RELEASE_LOG_IF_ALLOWED("timerFired: sufficient throughput rate (id = %" PRIu64 ")", m_download.downloadID().downloadID());
122 m_timer.startOneShot(timeUntilNextInterval(m_interval++) / speedMultiplier());
123 } else
124 RELEASE_LOG_IF_ALLOWED("timerFired: Download reached threshold to not be terminated (id = %" PRIu64 ")", m_download.downloadID().downloadID());
125}
126
127} // namespace WebKit
128