mirror of https://github.com/facebook/rocksdb.git
108 lines
2.8 KiB
C++
108 lines
2.8 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root directory).
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//
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// Copyright (c) 2012 The LevelDB Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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#include "util/random.h"
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#include <cstring>
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#include <vector>
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#include "test_util/testharness.h"
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using ROCKSDB_NAMESPACE::Random;
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TEST(RandomTest, Uniform) {
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const int average = 20;
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for (uint32_t seed : {0, 1, 2, 37, 4096}) {
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Random r(seed);
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for (int range : {1, 2, 8, 12, 100}) {
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std::vector<int> counts(range, 0);
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for (int i = 0; i < range * average; ++i) {
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++counts.at(r.Uniform(range));
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}
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int max_variance = static_cast<int>(std::sqrt(range) * 2 + 4);
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for (int i = 0; i < range; ++i) {
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EXPECT_GE(counts[i], std::max(1, average - max_variance));
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EXPECT_LE(counts[i], average + max_variance + 1);
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}
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}
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}
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}
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TEST(RandomTest, OneIn) {
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Random r(42);
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for (int range : {1, 2, 8, 12, 100, 1234}) {
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const int average = 100;
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int count = 0;
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for (int i = 0; i < average * range; ++i) {
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if (r.OneIn(range)) {
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++count;
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}
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}
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if (range == 1) {
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EXPECT_EQ(count, average);
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} else {
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int max_variance = static_cast<int>(std::sqrt(average) * 1.5);
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EXPECT_GE(count, average - max_variance);
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EXPECT_LE(count, average + max_variance);
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}
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}
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}
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TEST(RandomTest, OneInOpt) {
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Random r(42);
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for (int range : {-12, 0, 1, 2, 8, 12, 100, 1234}) {
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const int average = 100;
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int count = 0;
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for (int i = 0; i < average * range; ++i) {
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if (r.OneInOpt(range)) {
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++count;
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}
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}
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if (range < 1) {
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EXPECT_EQ(count, 0);
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} else if (range == 1) {
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EXPECT_EQ(count, average);
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} else {
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int max_variance = static_cast<int>(std::sqrt(average) * 1.5);
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EXPECT_GE(count, average - max_variance);
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EXPECT_LE(count, average + max_variance);
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}
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}
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}
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TEST(RandomTest, PercentTrue) {
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Random r(42);
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for (int pct : {-12, 0, 1, 2, 10, 50, 90, 98, 99, 100, 1234}) {
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const int samples = 10000;
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int count = 0;
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for (int i = 0; i < samples; ++i) {
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if (r.PercentTrue(pct)) {
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++count;
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}
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}
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if (pct <= 0) {
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EXPECT_EQ(count, 0);
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} else if (pct >= 100) {
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EXPECT_EQ(count, samples);
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} else {
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int est = (count * 100 + (samples / 2)) / samples;
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EXPECT_EQ(est, pct);
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}
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}
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}
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int main(int argc, char** argv) {
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ROCKSDB_NAMESPACE::port::InstallStackTraceHandler();
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::testing::InitGoogleTest(&argc, argv);
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return RUN_ALL_TESTS();
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}
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