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Unified Diff: webrtc/base/random.cc

Issue 2877023002: Move webrtc/{base => rtc_base} (Closed)
Patch Set: update presubmit.py and DEPS include rules Created 3 years, 6 months ago
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Index: webrtc/base/random.cc
diff --git a/webrtc/base/random.cc b/webrtc/base/random.cc
deleted file mode 100644
index 14a9faf5b37c9144ade7a88af53392ad1d592378..0000000000000000000000000000000000000000
--- a/webrtc/base/random.cc
+++ /dev/null
@@ -1,86 +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 "webrtc/base/random.h"
-
-#include <math.h>
-
-#include "webrtc/base/checks.h"
-
-namespace webrtc {
-
-Random::Random(uint64_t seed) {
- RTC_DCHECK(seed != 0x0ull);
- state_ = seed;
-}
-
-uint32_t Random::Rand(uint32_t t) {
- // Casting the output to 32 bits will give an almost uniform number.
- // Pr[x=0] = (2^32-1) / (2^64-1)
- // Pr[x=k] = 2^32 / (2^64-1) for k!=0
- // Uniform would be Pr[x=k] = 2^32 / 2^64 for all 32-bit integers k.
- uint32_t x = NextOutput();
- // If x / 2^32 is uniform on [0,1), then x / 2^32 * (t+1) is uniform on
- // the interval [0,t+1), so the integer part is uniform on [0,t].
- uint64_t result = x * (static_cast<uint64_t>(t) + 1);
- result >>= 32;
- return result;
-}
-
-uint32_t Random::Rand(uint32_t low, uint32_t high) {
- RTC_DCHECK(low <= high);
- return Rand(high - low) + low;
-}
-
-int32_t Random::Rand(int32_t low, int32_t high) {
- RTC_DCHECK(low <= high);
- // We rely on subtraction (and addition) to be the same for signed and
- // unsigned numbers in two-complement representation. Thus, although
- // high - low might be negative as an int, it is the correct difference
- // when interpreted as an unsigned.
- return Rand(high - low) + low;
-}
-
-template <>
-float Random::Rand<float>() {
- double result = NextOutput() - 1;
- result = result / 0xFFFFFFFFFFFFFFFEull;
- return static_cast<float>(result);
-}
-
-template <>
-double Random::Rand<double>() {
- double result = NextOutput() - 1;
- result = result / 0xFFFFFFFFFFFFFFFEull;
- return result;
-}
-
-template <>
-bool Random::Rand<bool>() {
- return Rand(0, 1) == 1;
-}
-
-double Random::Gaussian(double mean, double standard_deviation) {
- // Creating a Normal distribution variable from two independent uniform
- // variables based on the Box-Muller transform, which is defined on the
- // interval (0, 1]. Note that we rely on NextOutput to generate integers
- // in the range [1, 2^64-1]. Normally this behavior is a bit frustrating,
- // but here it is exactly what we need.
- const double kPi = 3.14159265358979323846;
- double u1 = static_cast<double>(NextOutput()) / 0xFFFFFFFFFFFFFFFFull;
- double u2 = static_cast<double>(NextOutput()) / 0xFFFFFFFFFFFFFFFFull;
- return mean + standard_deviation * sqrt(-2 * log(u1)) * cos(2 * kPi * u2);
-}
-
-double Random::Exponential(double lambda) {
- double uniform = Rand<double>();
- return -log(uniform) / lambda;
-}
-
-} // namespace webrtc
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