rocksdb/util/dynamic_bloom_test.cc

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// Copyright (c) 2013, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
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#define __STDC_FORMAT_MACROS
#include <inttypes.h>
#include <algorithm>
#include <gflags/gflags.h>
#include "dynamic_bloom.h"
#include "port/port.h"
#include "util/logging.h"
#include "util/testharness.h"
#include "util/testutil.h"
#include "util/stop_watch.h"
DEFINE_int32(bits_per_key, 10, "");
DEFINE_int32(num_probes, 6, "");
DEFINE_bool(enable_perf, false, "");
namespace rocksdb {
static Slice Key(uint64_t i, char* buffer) {
memcpy(buffer, &i, sizeof(i));
return Slice(buffer, sizeof(i));
}
class DynamicBloomTest {
};
TEST(DynamicBloomTest, EmptyFilter) {
DynamicBloom bloom1(100, 0, 2);
ASSERT_TRUE(!bloom1.MayContain("hello"));
ASSERT_TRUE(!bloom1.MayContain("world"));
DynamicBloom bloom2(CACHE_LINE_SIZE * 8 * 2 - 1, 1, 2);
ASSERT_TRUE(!bloom2.MayContain("hello"));
ASSERT_TRUE(!bloom2.MayContain("world"));
}
TEST(DynamicBloomTest, Small) {
DynamicBloom bloom1(100, 0, 2);
bloom1.Add("hello");
bloom1.Add("world");
ASSERT_TRUE(bloom1.MayContain("hello"));
ASSERT_TRUE(bloom1.MayContain("world"));
ASSERT_TRUE(!bloom1.MayContain("x"));
ASSERT_TRUE(!bloom1.MayContain("foo"));
DynamicBloom bloom2(CACHE_LINE_SIZE * 8 * 2 - 1, 1, 2);
bloom2.Add("hello");
bloom2.Add("world");
ASSERT_TRUE(bloom2.MayContain("hello"));
ASSERT_TRUE(bloom2.MayContain("world"));
ASSERT_TRUE(!bloom2.MayContain("x"));
ASSERT_TRUE(!bloom2.MayContain("foo"));
}
static uint32_t NextNum(uint32_t num) {
if (num < 10) {
num += 1;
} else if (num < 100) {
num += 10;
} else if (num < 1000) {
num += 100;
} else {
num += 1000;
}
return num;
}
TEST(DynamicBloomTest, VaryingLengths) {
char buffer[sizeof(uint64_t)];
// Count number of filters that significantly exceed the false positive rate
int mediocre_filters = 0;
int good_filters = 0;
uint32_t num_probes = static_cast<uint32_t>(FLAGS_num_probes);
fprintf(stderr, "bits_per_key: %d num_probes: %d\n",
FLAGS_bits_per_key, num_probes);
for (uint32_t cl_per_block = 0; cl_per_block < num_probes;
++cl_per_block) {
for (uint32_t num = 1; num <= 10000; num = NextNum(num)) {
uint32_t bloom_bits = 0;
if (cl_per_block == 0) {
bloom_bits = std::max(num * FLAGS_bits_per_key, 64U);
} else {
bloom_bits = std::max(num * FLAGS_bits_per_key,
cl_per_block * CACHE_LINE_SIZE * 8);
}
DynamicBloom bloom(bloom_bits, cl_per_block, num_probes);
for (uint64_t i = 0; i < num; i++) {
bloom.Add(Key(i, buffer));
ASSERT_TRUE(bloom.MayContain(Key(i, buffer)));
}
// All added keys must match
for (uint64_t i = 0; i < num; i++) {
ASSERT_TRUE(bloom.MayContain(Key(i, buffer)))
<< "Num " << num << "; key " << i;
}
// Check false positive rate
int result = 0;
for (uint64_t i = 0; i < 10000; i++) {
if (bloom.MayContain(Key(i + 1000000000, buffer))) {
result++;
}
}
double rate = result / 10000.0;
fprintf(stderr, "False positives: %5.2f%% @ num = %6u, bloom_bits = %6u, "
"cl per block = %u\n", rate*100.0, num, bloom_bits, cl_per_block);
if (rate > 0.0125)
mediocre_filters++; // Allowed, but not too often
else
good_filters++;
}
fprintf(stderr, "Filters: %d good, %d mediocre\n",
good_filters, mediocre_filters);
ASSERT_LE(mediocre_filters, good_filters/5);
}
}
TEST(DynamicBloomTest, perf) {
StopWatchNano timer(Env::Default());
uint32_t num_probes = static_cast<uint32_t>(FLAGS_num_probes);
if (!FLAGS_enable_perf) {
return;
}
for (uint64_t m = 1; m <= 8; ++m) {
const uint64_t num_keys = m * 8 * 1024 * 1024;
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fprintf(stderr, "testing %" PRIu64 "M keys\n", m * 8);
DynamicBloom std_bloom(num_keys * 10, 0, num_probes);
timer.Start();
for (uint64_t i = 1; i <= num_keys; ++i) {
std_bloom.Add(Slice(reinterpret_cast<const char*>(&i), 8));
}
uint64_t elapsed = timer.ElapsedNanos();
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fprintf(stderr, "standard bloom, avg add latency %" PRIu64 "\n",
elapsed / num_keys);
uint64_t count = 0;
timer.Start();
for (uint64_t i = 1; i <= num_keys; ++i) {
if (std_bloom.MayContain(Slice(reinterpret_cast<const char*>(&i), 8))) {
++count;
}
}
elapsed = timer.ElapsedNanos();
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fprintf(stderr, "standard bloom, avg query latency %" PRIu64 "\n",
elapsed / count);
ASSERT_TRUE(count == num_keys);
for (uint32_t cl_per_block = 1; cl_per_block <= num_probes;
++cl_per_block) {
DynamicBloom blocked_bloom(num_keys * 10, cl_per_block, num_probes);
timer.Start();
for (uint64_t i = 1; i <= num_keys; ++i) {
blocked_bloom.Add(Slice(reinterpret_cast<const char*>(&i), 8));
}
uint64_t elapsed = timer.ElapsedNanos();
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fprintf(stderr, "blocked bloom(%d), avg add latency %" PRIu64 "\n",
cl_per_block, elapsed / num_keys);
uint64_t count = 0;
timer.Start();
for (uint64_t i = 1; i <= num_keys; ++i) {
if (blocked_bloom.MayContain(
Slice(reinterpret_cast<const char*>(&i), 8))) {
++count;
}
}
elapsed = timer.ElapsedNanos();
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fprintf(stderr, "blocked bloom(%d), avg query latency %" PRIu64 "\n",
cl_per_block, elapsed / count);
ASSERT_TRUE(count == num_keys);
}
}
}
} // namespace rocksdb
int main(int argc, char** argv) {
google::ParseCommandLineFlags(&argc, &argv, true);
return rocksdb::test::RunAllTests();
}