Move webrtc/{base => rtc_base}

webrtc/base/random_unittest.cc

Index: webrtc/base/random_unittest.cc
diff --git a/webrtc/base/random_unittest.cc b/webrtc/base/random_unittest.cc
deleted file mode 100644
index 704e81fb2f5184f8a096eaa16c5d23ac6385ef01..0000000000000000000000000000000000000000
--- a/webrtc/base/random_unittest.cc
+++ /dev/null
@@ -1,309 +0,0 @@
-/*
- *  Copyright (c) 2015 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 <math.h>
-
-#include <limits>
-#include <vector>
-
-#include "webrtc/base/mathutils.h"  // unsigned difference
-#include "webrtc/base/random.h"
-#include "webrtc/test/gtest.h"
-
-namespace webrtc {
-
-namespace {
-// Computes the positive remainder of x/n.
-template <typename T>
-T fdiv_remainder(T x, T n) {
-  RTC_CHECK_GE(n, 0);
-  T remainder = x % n;
-  if (remainder < 0)
-    remainder += n;
-  return remainder;
-}
-}  // namespace
-
-// Sample a number of random integers of type T. Divide them into buckets
-// based on the remainder when dividing by bucket_count and check that each
-// bucket gets roughly the expected number of elements.
-template <typename T>
-void UniformBucketTest(T bucket_count, int samples, Random* prng) {
-  std::vector<int> buckets(bucket_count, 0);
-
-  uint64_t total_values = 1ull << (std::numeric_limits<T>::digits +
-                                   std::numeric_limits<T>::is_signed);
-  T upper_limit =
-      std::numeric_limits<T>::max() -
-      static_cast<T>(total_values % static_cast<uint64_t>(bucket_count));
-  ASSERT_GT(upper_limit, std::numeric_limits<T>::max() / 2);
-
-  for (int i = 0; i < samples; i++) {
-    T sample;
-    do {
-      // We exclude a few numbers from the range so that it is divisible by
-      // the number of buckets. If we are unlucky and hit one of the excluded
-      // numbers we just resample. Note that if the number of buckets is a
-      // power of 2, then we don't have to exclude anything.
-      sample = prng->Rand<T>();
-    } while (sample > upper_limit);
-    buckets[fdiv_remainder(sample, bucket_count)]++;
-  }
-
-  for (T i = 0; i < bucket_count; i++) {
-    // Expect the result to be within 3 standard deviations of the mean.
-    EXPECT_NEAR(buckets[i], samples / bucket_count,
-                3 * sqrt(samples / bucket_count));
-  }
-}
-
-TEST(RandomNumberGeneratorTest, BucketTestSignedChar) {
-  Random prng(7297352569824ull);
-  UniformBucketTest<signed char>(64, 640000, &prng);
-  UniformBucketTest<signed char>(11, 440000, &prng);
-  UniformBucketTest<signed char>(3, 270000, &prng);
-}
-
-TEST(RandomNumberGeneratorTest, BucketTestUnsignedChar) {
-  Random prng(7297352569824ull);
-  UniformBucketTest<unsigned char>(64, 640000, &prng);
-  UniformBucketTest<unsigned char>(11, 440000, &prng);
-  UniformBucketTest<unsigned char>(3, 270000, &prng);
-}
-
-TEST(RandomNumberGeneratorTest, BucketTestSignedShort) {
-  Random prng(7297352569824ull);
-  UniformBucketTest<int16_t>(64, 640000, &prng);
-  UniformBucketTest<int16_t>(11, 440000, &prng);
-  UniformBucketTest<int16_t>(3, 270000, &prng);
-}
-
-TEST(RandomNumberGeneratorTest, BucketTestUnsignedShort) {
-  Random prng(7297352569824ull);
-  UniformBucketTest<uint16_t>(64, 640000, &prng);
-  UniformBucketTest<uint16_t>(11, 440000, &prng);
-  UniformBucketTest<uint16_t>(3, 270000, &prng);
-}
-
-TEST(RandomNumberGeneratorTest, BucketTestSignedInt) {
-  Random prng(7297352569824ull);
-  UniformBucketTest<signed int>(64, 640000, &prng);
-  UniformBucketTest<signed int>(11, 440000, &prng);
-  UniformBucketTest<signed int>(3, 270000, &prng);
-}
-
-TEST(RandomNumberGeneratorTest, BucketTestUnsignedInt) {
-  Random prng(7297352569824ull);
-  UniformBucketTest<unsigned int>(64, 640000, &prng);
-  UniformBucketTest<unsigned int>(11, 440000, &prng);
-  UniformBucketTest<unsigned int>(3, 270000, &prng);
-}
-
-// The range of the random numbers is divided into bucket_count intervals
-// of consecutive numbers. Check that approximately equally many numbers
-// from each inteval are generated.
-void BucketTestSignedInterval(unsigned int bucket_count,
-                              unsigned int samples,
-                              int32_t low,
-                              int32_t high,
-                              int sigma_level,
-                              Random* prng) {
-  std::vector<unsigned int> buckets(bucket_count, 0);
-
-  ASSERT_GE(high, low);
-  ASSERT_GE(bucket_count, 2u);
-  uint32_t interval = unsigned_difference<int32_t>(high, low) + 1;
-  uint32_t numbers_per_bucket;
-  if (interval == 0) {
-    // The computation high - low + 1 should be 2^32 but overflowed
-    // Hence, bucket_count must be a power of 2
-    ASSERT_EQ(bucket_count & (bucket_count - 1), 0u);
-    numbers_per_bucket = (0x80000000u / bucket_count) * 2;
-  } else {
-    ASSERT_EQ(interval % bucket_count, 0u);
-    numbers_per_bucket = interval / bucket_count;
-  }
-
-  for (unsigned int i = 0; i < samples; i++) {
-    int32_t sample = prng->Rand(low, high);
-    EXPECT_LE(low, sample);
-    EXPECT_GE(high, sample);
-    buckets[unsigned_difference<int32_t>(sample, low) / numbers_per_bucket]++;
-  }
-
-  for (unsigned int i = 0; i < bucket_count; i++) {
-    // Expect the result to be within 3 standard deviations of the mean,
-    // or more generally, within sigma_level standard deviations of the mean.
-    double mean = static_cast<double>(samples) / bucket_count;
-    EXPECT_NEAR(buckets[i], mean, sigma_level * sqrt(mean));
-  }
-}
-
-// The range of the random numbers is divided into bucket_count intervals
-// of consecutive numbers. Check that approximately equally many numbers
-// from each inteval are generated.
-void BucketTestUnsignedInterval(unsigned int bucket_count,
-                                unsigned int samples,
-                                uint32_t low,
-                                uint32_t high,
-                                int sigma_level,
-                                Random* prng) {
-  std::vector<unsigned int> buckets(bucket_count, 0);
-
-  ASSERT_GE(high, low);
-  ASSERT_GE(bucket_count, 2u);
-  uint32_t interval = high - low + 1;
-  uint32_t numbers_per_bucket;
-  if (interval == 0) {
-    // The computation high - low + 1 should be 2^32 but overflowed
-    // Hence, bucket_count must be a power of 2
-    ASSERT_EQ(bucket_count & (bucket_count - 1), 0u);
-    numbers_per_bucket = (0x80000000u / bucket_count) * 2;
-  } else {
-    ASSERT_EQ(interval % bucket_count, 0u);
-    numbers_per_bucket = interval / bucket_count;
-  }
-
-  for (unsigned int i = 0; i < samples; i++) {
-    uint32_t sample = prng->Rand(low, high);
-    EXPECT_LE(low, sample);
-    EXPECT_GE(high, sample);
-    buckets[(sample - low) / numbers_per_bucket]++;
-  }
-
-  for (unsigned int i = 0; i < bucket_count; i++) {
-    // Expect the result to be within 3 standard deviations of the mean,
-    // or more generally, within sigma_level standard deviations of the mean.
-    double mean = static_cast<double>(samples) / bucket_count;
-    EXPECT_NEAR(buckets[i], mean, sigma_level * sqrt(mean));
-  }
-}
-
-TEST(RandomNumberGeneratorTest, UniformUnsignedInterval) {
-  Random prng(299792458ull);
-  BucketTestUnsignedInterval(2, 100000, 0, 1, 3, &prng);
-  BucketTestUnsignedInterval(7, 100000, 1, 14, 3, &prng);
-  BucketTestUnsignedInterval(11, 100000, 1000, 1010, 3, &prng);
-  BucketTestUnsignedInterval(100, 100000, 0, 99, 3, &prng);
-  BucketTestUnsignedInterval(2, 100000, 0, 4294967295, 3, &prng);
-  BucketTestUnsignedInterval(17, 100000, 455, 2147484110, 3, &prng);
-  // 99.7% of all samples will be within 3 standard deviations of the mean,
-  // but since we test 1000 buckets we allow an interval of 4 sigma.
-  BucketTestUnsignedInterval(1000, 1000000, 0, 2147483999, 4, &prng);
-}
-
-// Disabled for UBSan: https://bugs.chromium.org/p/webrtc/issues/detail?id=5491
-#ifdef UNDEFINED_SANITIZER
-#define MAYBE_UniformSignedInterval DISABLED_UniformSignedInterval
-#else
-#define MAYBE_UniformSignedInterval UniformSignedInterval
-#endif
-TEST(RandomNumberGeneratorTest, MAYBE_UniformSignedInterval) {
-  Random prng(66260695729ull);
-  BucketTestSignedInterval(2, 100000, 0, 1, 3, &prng);
-  BucketTestSignedInterval(7, 100000, -2, 4, 3, &prng);
-  BucketTestSignedInterval(11, 100000, 1000, 1010, 3, &prng);
-  BucketTestSignedInterval(100, 100000, 0, 99, 3, &prng);
-  BucketTestSignedInterval(2, 100000, std::numeric_limits<int32_t>::min(),
-                           std::numeric_limits<int32_t>::max(), 3, &prng);
-  BucketTestSignedInterval(17, 100000, -1073741826, 1073741829, 3, &prng);
-  // 99.7% of all samples will be within 3 standard deviations of the mean,
-  // but since we test 1000 buckets we allow an interval of 4 sigma.
-  BucketTestSignedInterval(1000, 1000000, -352, 2147483647, 4, &prng);
-}
-
-// The range of the random numbers is divided into bucket_count intervals
-// of consecutive numbers. Check that approximately equally many numbers
-// from each inteval are generated.
-void BucketTestFloat(unsigned int bucket_count,
-                     unsigned int samples,
-                     int sigma_level,
-                     Random* prng) {
-  ASSERT_GE(bucket_count, 2u);
-  std::vector<unsigned int> buckets(bucket_count, 0);
-
-  for (unsigned int i = 0; i < samples; i++) {
-    uint32_t sample = bucket_count * prng->Rand<float>();
-    EXPECT_LE(0u, sample);
-    EXPECT_GE(bucket_count - 1, sample);
-    buckets[sample]++;
-  }
-
-  for (unsigned int i = 0; i < bucket_count; i++) {
-    // Expect the result to be within 3 standard deviations of the mean,
-    // or more generally, within sigma_level standard deviations of the mean.
-    double mean = static_cast<double>(samples) / bucket_count;
-    EXPECT_NEAR(buckets[i], mean, sigma_level * sqrt(mean));
-  }
-}
-
-TEST(RandomNumberGeneratorTest, UniformFloatInterval) {
-  Random prng(1380648813ull);
-  BucketTestFloat(100, 100000, 3, &prng);
-  // 99.7% of all samples will be within 3 standard deviations of the mean,
-  // but since we test 1000 buckets we allow an interval of 4 sigma.
-  // BucketTestSignedInterval(1000, 1000000, -352, 2147483647, 4, &prng);
-}
-
-TEST(RandomNumberGeneratorTest, SignedHasSameBitPattern) {
-  Random prng_signed(66738480ull), prng_unsigned(66738480ull);
-
-  for (int i = 0; i < 1000; i++) {
-    signed int s = prng_signed.Rand<signed int>();
-    unsigned int u = prng_unsigned.Rand<unsigned int>();
-    EXPECT_EQ(u, static_cast<unsigned int>(s));
-  }
-
-  for (int i = 0; i < 1000; i++) {
-    int16_t s = prng_signed.Rand<int16_t>();
-    uint16_t u = prng_unsigned.Rand<uint16_t>();
-    EXPECT_EQ(u, static_cast<uint16_t>(s));
-  }
-
-  for (int i = 0; i < 1000; i++) {
-    signed char s = prng_signed.Rand<signed char>();
-    unsigned char u = prng_unsigned.Rand<unsigned char>();
-    EXPECT_EQ(u, static_cast<unsigned char>(s));
-  }
-}
-
-TEST(RandomNumberGeneratorTest, Gaussian) {
-  const int kN = 100000;
-  const int kBuckets = 100;
-  const double kMean = 49;
-  const double kStddev = 10;
-
-  Random prng(1256637061);
-
-  std::vector<unsigned int> buckets(kBuckets, 0);
-  for (int i = 0; i < kN; i++) {
-    int index = prng.Gaussian(kMean, kStddev) + 0.5;
-    if (index >= 0 && index < kBuckets) {
-      buckets[index]++;
-    }
-  }
-
-  const double kPi = 3.14159265358979323846;
-  const double kScale = 1 / (kStddev * sqrt(2.0 * kPi));
-  const double kDiv = -2.0 * kStddev * kStddev;
-  for (int n = 0; n < kBuckets; ++n) {
-    // Use Simpsons rule to estimate the probability that a random gaussian
-    // sample is in the interval [n-0.5, n+0.5].
-    double f_left = kScale * exp((n - kMean - 0.5) * (n - kMean - 0.5) / kDiv);
-    double f_mid = kScale * exp((n - kMean) * (n - kMean) / kDiv);
-    double f_right = kScale * exp((n - kMean + 0.5) * (n - kMean + 0.5) / kDiv);
-    double normal_dist = (f_left + 4 * f_mid + f_right) / 6;
-    // Expect the number of samples to be within 3 standard deviations
-    // (rounded up) of the expected number of samples in the bucket.
-    EXPECT_NEAR(buckets[n], kN * normal_dist, 3 * sqrt(kN * normal_dist) + 1);
-  }
-}
-
-}  // namespace webrtc