Add useful idioms to Random API (OneInOpt, PercentTrue) (#6154)
Summary: And clean up related code, especially in stress test. (More clean up of db_stress_test_base.cc coming after this.) Pull Request resolved: https://github.com/facebook/rocksdb/pull/6154 Test Plan: make check, make blackbox_crash_test for a bit Differential Revision: D18938180 Pulled By: pdillinger fbshipit-source-id: 524d27621b8dbb25f6dff40f1081e7c00630357emain
Peter Dillinger
5 years ago
committed by
Facebook Github Bot
parent
6d54eb3dc2
commit
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// 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 <cstring> |
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#include <vector> |
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#include "test_util/testharness.h" |
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#include "util/random.h" |
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using rocksdb::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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::testing::InitGoogleTest(&argc, argv); |
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return RUN_ALL_TESTS(); |
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} |
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