blob: 10ffecb311659c2deb3d4b579dd01e6dcda72136 [file] [log] [blame]
/*
* Copyright (c) 2022 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "rtc_base/numerics/sequence_number_unwrapper.h"
#include <cstdint>
#include <limits>
#include "test/gtest.h"
namespace webrtc {
TEST(SeqNumUnwrapper, PreserveStartValue) {
SeqNumUnwrapper<uint8_t> unwrapper;
EXPECT_EQ(123, unwrapper.Unwrap(123));
}
TEST(SeqNumUnwrapper, ForwardWrap) {
SeqNumUnwrapper<uint8_t> unwrapper;
EXPECT_EQ(255, unwrapper.Unwrap(255));
EXPECT_EQ(256, unwrapper.Unwrap(0));
}
TEST(SeqNumUnwrapper, ForwardWrapWithDivisor) {
SeqNumUnwrapper<uint8_t, 33> unwrapper;
EXPECT_EQ(30, unwrapper.Unwrap(30));
EXPECT_EQ(36, unwrapper.Unwrap(3));
}
TEST(SeqNumUnwrapper, BackWardWrap) {
SeqNumUnwrapper<uint8_t> unwrapper;
EXPECT_EQ(0, unwrapper.Unwrap(0));
EXPECT_EQ(-2, unwrapper.Unwrap(254));
}
TEST(SeqNumUnwrapper, BackWardWrapWithDivisor) {
SeqNumUnwrapper<uint8_t, 33> unwrapper;
EXPECT_EQ(0, unwrapper.Unwrap(0));
EXPECT_EQ(-2, unwrapper.Unwrap(31));
}
TEST(SeqNumUnwrapper, Unwrap) {
SeqNumUnwrapper<uint16_t> unwrapper;
const uint16_t kMax = std::numeric_limits<uint16_t>::max();
const uint16_t kMaxDist = kMax / 2 + 1;
EXPECT_EQ(0, unwrapper.Unwrap(0));
EXPECT_EQ(kMaxDist, unwrapper.Unwrap(kMaxDist));
EXPECT_EQ(0, unwrapper.Unwrap(0));
EXPECT_EQ(kMaxDist, unwrapper.Unwrap(kMaxDist));
EXPECT_EQ(kMax, unwrapper.Unwrap(kMax));
EXPECT_EQ(kMax + 1, unwrapper.Unwrap(0));
EXPECT_EQ(kMax, unwrapper.Unwrap(kMax));
EXPECT_EQ(kMaxDist, unwrapper.Unwrap(kMaxDist));
EXPECT_EQ(0, unwrapper.Unwrap(0));
}
TEST(SeqNumUnwrapper, UnwrapOddDivisor) {
SeqNumUnwrapper<uint8_t, 11> unwrapper;
EXPECT_EQ(10, unwrapper.Unwrap(10));
EXPECT_EQ(11, unwrapper.Unwrap(0));
EXPECT_EQ(16, unwrapper.Unwrap(5));
EXPECT_EQ(21, unwrapper.Unwrap(10));
EXPECT_EQ(22, unwrapper.Unwrap(0));
EXPECT_EQ(17, unwrapper.Unwrap(6));
EXPECT_EQ(12, unwrapper.Unwrap(1));
EXPECT_EQ(7, unwrapper.Unwrap(7));
EXPECT_EQ(2, unwrapper.Unwrap(2));
EXPECT_EQ(0, unwrapper.Unwrap(0));
}
TEST(SeqNumUnwrapper, ManyForwardWraps) {
const int kLargeNumber = 4711;
const int kMaxStep = kLargeNumber / 2;
const int kNumWraps = 100;
SeqNumUnwrapper<uint16_t, kLargeNumber> unwrapper;
uint16_t next_unwrap = 0;
int64_t expected = 0;
for (int i = 0; i < kNumWraps * 2 + 1; ++i) {
EXPECT_EQ(expected, unwrapper.Unwrap(next_unwrap));
expected += kMaxStep;
next_unwrap = (next_unwrap + kMaxStep) % kLargeNumber;
}
}
TEST(SeqNumUnwrapper, ManyBackwardWraps) {
const int kLargeNumber = 4711;
const int kMaxStep = kLargeNumber / 2;
const int kNumWraps = 100;
SeqNumUnwrapper<uint16_t, kLargeNumber> unwrapper;
uint16_t next_unwrap = 0;
int64_t expected = 0;
for (uint16_t i = 0; i < kNumWraps * 2 + 1; ++i) {
EXPECT_EQ(expected, unwrapper.Unwrap(next_unwrap));
expected -= kMaxStep;
next_unwrap = (next_unwrap + kMaxStep + 1) % kLargeNumber;
}
}
TEST(SeqNumUnwrapper, Reset) {
const uint16_t kMax = std::numeric_limits<uint16_t>::max();
const uint16_t kMaxStep = kMax / 2;
SeqNumUnwrapper<uint16_t> unwrapper;
EXPECT_EQ(10, unwrapper.Unwrap(10));
EXPECT_EQ(kMaxStep + 10, unwrapper.Unwrap(kMaxStep + 10));
EXPECT_EQ(kMax + 3, unwrapper.PeekUnwrap(2));
unwrapper.Reset();
// After Reset() the range is reset back to the start.
EXPECT_EQ(2, unwrapper.PeekUnwrap(2));
}
TEST(SeqNumUnwrapper, PeekUnwrap) {
const uint16_t kMax = std::numeric_limits<uint16_t>::max();
const uint16_t kMaxStep = kMax / 2;
const uint16_t kMaxDist = kMaxStep + 1;
SeqNumUnwrapper<uint16_t> unwrapper;
// No previous unwraps, so PeekUnwrap(x) == x.
EXPECT_EQ(10, unwrapper.PeekUnwrap(10));
EXPECT_EQ(kMaxDist + 10, unwrapper.PeekUnwrap(kMaxDist + 10));
EXPECT_EQ(10, unwrapper.Unwrap(10));
EXPECT_EQ(12, unwrapper.PeekUnwrap(12));
// State should not have updated, so kMaxDist + 12 should be negative.
EXPECT_EQ(-kMaxDist + 12, unwrapper.Unwrap(kMaxDist + 12));
// Test PeekUnwrap after around.
unwrapper.Reset();
EXPECT_EQ(kMaxStep, unwrapper.Unwrap(kMaxStep));
EXPECT_EQ(2 * kMaxStep, unwrapper.Unwrap(2 * kMaxStep));
EXPECT_EQ(kMax + 1, unwrapper.PeekUnwrap(0));
// Wrap back to last range.
EXPECT_EQ(kMax - 3, unwrapper.PeekUnwrap(kMax - 3));
}
} // namespace webrtc