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 #include "modules/rtp_rtcp/source/time_util.h"
11
12 #include <cstdint>
13 #include <limits>
14
15 #include "api/units/time_delta.h"
16 #include "test/gtest.h"
17
18 namespace webrtc {
19
TEST(TimeUtilTest,CompactNtp)20 TEST(TimeUtilTest, CompactNtp) {
21 const uint32_t kNtpSec = 0x12345678;
22 const uint32_t kNtpFrac = 0x23456789;
23 const NtpTime kNtp(kNtpSec, kNtpFrac);
24 const uint32_t kNtpMid = 0x56782345;
25 EXPECT_EQ(kNtpMid, CompactNtp(kNtp));
26 }
27
TEST(TimeUtilTest,CompactNtpRttToTimeDelta)28 TEST(TimeUtilTest, CompactNtpRttToTimeDelta) {
29 const NtpTime ntp1(0x12345, 0x23456);
30 const NtpTime ntp2(0x12654, 0x64335);
31 int64_t ms_diff = ntp2.ToMs() - ntp1.ToMs();
32 uint32_t ntp_diff = CompactNtp(ntp2) - CompactNtp(ntp1);
33
34 EXPECT_NEAR(CompactNtpRttToTimeDelta(ntp_diff).ms(), ms_diff, 1);
35 }
36
TEST(TimeUtilTest,CompactNtpRttToTimeDeltaWithWrap)37 TEST(TimeUtilTest, CompactNtpRttToTimeDeltaWithWrap) {
38 const NtpTime ntp1(0x1ffff, 0x23456);
39 const NtpTime ntp2(0x20000, 0x64335);
40 int64_t ms_diff = ntp2.ToMs() - ntp1.ToMs();
41
42 // While ntp2 > ntp1, there compact ntp presentation happen to be opposite.
43 // That shouldn't be a problem as long as unsigned arithmetic is used.
44 ASSERT_GT(ntp2.ToMs(), ntp1.ToMs());
45 ASSERT_LT(CompactNtp(ntp2), CompactNtp(ntp1));
46
47 uint32_t ntp_diff = CompactNtp(ntp2) - CompactNtp(ntp1);
48 EXPECT_NEAR(CompactNtpRttToTimeDelta(ntp_diff).ms(), ms_diff, 1);
49 }
50
TEST(TimeUtilTest,CompactNtpRttToTimeDeltaLarge)51 TEST(TimeUtilTest, CompactNtpRttToTimeDeltaLarge) {
52 const NtpTime ntp1(0x10000, 0x00006);
53 const NtpTime ntp2(0x17fff, 0xffff5);
54 int64_t ms_diff = ntp2.ToMs() - ntp1.ToMs();
55 // Ntp difference close to 2^15 seconds should convert correctly too.
56 ASSERT_NEAR(ms_diff, ((1 << 15) - 1) * 1000, 1);
57 uint32_t ntp_diff = CompactNtp(ntp2) - CompactNtp(ntp1);
58 EXPECT_NEAR(CompactNtpRttToTimeDelta(ntp_diff).ms(), ms_diff, 1);
59 }
60
TEST(TimeUtilTest,CompactNtpRttToTimeDeltaNegative)61 TEST(TimeUtilTest, CompactNtpRttToTimeDeltaNegative) {
62 const NtpTime ntp1(0x20000, 0x23456);
63 const NtpTime ntp2(0x1ffff, 0x64335);
64 int64_t ms_diff = ntp2.ToMs() - ntp1.ToMs();
65 ASSERT_GT(0, ms_diff);
66 // Ntp difference close to 2^16 seconds should be treated as negative.
67 uint32_t ntp_diff = CompactNtp(ntp2) - CompactNtp(ntp1);
68 EXPECT_EQ(CompactNtpRttToTimeDelta(ntp_diff), TimeDelta::Millis(1));
69 }
70
TEST(TimeUtilTest,SaturatedToCompactNtp)71 TEST(TimeUtilTest, SaturatedToCompactNtp) {
72 // Converts negative to zero.
73 EXPECT_EQ(SaturatedToCompactNtp(TimeDelta::Micros(-1)), 0u);
74 EXPECT_EQ(SaturatedToCompactNtp(TimeDelta::Zero()), 0u);
75 // Converts values just above and just below max uint32_t.
76 EXPECT_EQ(SaturatedToCompactNtp(TimeDelta::Micros(65536000000)), 0xffffffff);
77 EXPECT_EQ(SaturatedToCompactNtp(TimeDelta::Micros(65535999985)), 0xffffffff);
78 EXPECT_EQ(SaturatedToCompactNtp(TimeDelta::Micros(65535999970)), 0xfffffffe);
79 // Converts half-seconds.
80 EXPECT_EQ(SaturatedToCompactNtp(TimeDelta::Millis(500)), 0x8000u);
81 EXPECT_EQ(SaturatedToCompactNtp(TimeDelta::Seconds(1)), 0x10000u);
82 EXPECT_EQ(SaturatedToCompactNtp(TimeDelta::Millis(1'500)), 0x18000u);
83 // Convert us -> compact_ntp -> TimeDelta. Compact ntp precision is ~15us.
84 EXPECT_NEAR(
85 CompactNtpRttToTimeDelta(SaturatedToCompactNtp(TimeDelta::Micros(1'516)))
86 .us(),
87 1'516, 16);
88 EXPECT_NEAR(
89 CompactNtpRttToTimeDelta(SaturatedToCompactNtp(TimeDelta::Millis(15)))
90 .us(),
91 15'000, 16);
92 EXPECT_NEAR(
93 CompactNtpRttToTimeDelta(SaturatedToCompactNtp(TimeDelta::Micros(5'485)))
94 .us(),
95 5'485, 16);
96 EXPECT_NEAR(
97 CompactNtpRttToTimeDelta(SaturatedToCompactNtp(TimeDelta::Micros(5'515)))
98 .us(),
99 5'515, 16);
100 }
101
TEST(TimeUtilTest,ToNtpUnits)102 TEST(TimeUtilTest, ToNtpUnits) {
103 EXPECT_EQ(ToNtpUnits(TimeDelta::Zero()), 0);
104 EXPECT_EQ(ToNtpUnits(TimeDelta::Seconds(1)), int64_t{1} << 32);
105 EXPECT_EQ(ToNtpUnits(TimeDelta::Seconds(-1)), -(int64_t{1} << 32));
106
107 EXPECT_EQ(ToNtpUnits(TimeDelta::Millis(500)), int64_t{1} << 31);
108 EXPECT_EQ(ToNtpUnits(TimeDelta::Millis(-1'500)), -(int64_t{3} << 31));
109
110 // Smallest TimeDelta that can be converted without precision loss.
111 EXPECT_EQ(ToNtpUnits(TimeDelta::Micros(15'625)), int64_t{1} << 26);
112
113 // 1 us ~= 4'294.97 NTP units. ToNtpUnits makes no rounding promises.
114 EXPECT_GE(ToNtpUnits(TimeDelta::Micros(1)), 4'294);
115 EXPECT_LE(ToNtpUnits(TimeDelta::Micros(1)), 4'295);
116
117 // Test near maximum and minimum supported values.
118 static constexpr int64_t k35MinutesInNtpUnits = int64_t{35 * 60} << 32;
119 EXPECT_EQ(ToNtpUnits(TimeDelta::Seconds(35 * 60)), k35MinutesInNtpUnits);
120 EXPECT_EQ(ToNtpUnits(TimeDelta::Seconds(-35 * 60)), -k35MinutesInNtpUnits);
121
122 // The result for too large or too small values is unspecified, but
123 // shouldn't cause integer overflow or other undefined behavior.
124 ToNtpUnits(TimeDelta::Micros(std::numeric_limits<int64_t>::max() - 1));
125 ToNtpUnits(TimeDelta::Micros(std::numeric_limits<int64_t>::min() + 1));
126 }
127
128 } // namespace webrtc
129