rocksdb/table/cuckoo_table_reader_test.cc

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// Copyright (c) 2014, 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.
#ifndef GFLAGS
#include <cstdio>
int main() {
fprintf(stderr, "Please install gflags to run this test\n");
return 1;
}
#else
#include <gflags/gflags.h>
#include <vector>
#include <string>
#include <map>
#include "table/meta_blocks.h"
#include "table/cuckoo_table_builder.h"
#include "table/cuckoo_table_reader.h"
#include "table/cuckoo_table_factory.h"
#include "util/random.h"
#include "util/testharness.h"
#include "util/testutil.h"
using GFLAGS::ParseCommandLineFlags;
using GFLAGS::SetUsageMessage;
DEFINE_string(file_dir, "", "Directory where the files will be created"
" for benchmark. Added for using tmpfs.");
DEFINE_bool(enable_perf, false, "Run Benchmark Tests too.");
namespace rocksdb {
extern const uint64_t kCuckooTableMagicNumber;
namespace {
const uint32_t kNumHashFunc = 10;
// Methods, variables related to Hash functions.
std::unordered_map<std::string, std::vector<uint64_t>> hash_map;
void AddHashLookups(const std::string& s, uint64_t bucket_id,
uint32_t num_hash_fun) {
std::vector<uint64_t> v;
for (uint32_t i = 0; i < num_hash_fun; i++) {
v.push_back(bucket_id + i);
}
hash_map[s] = v;
}
uint64_t GetSliceHash(const Slice& s, uint32_t index,
uint64_t max_num_buckets) {
return hash_map[s.ToString()][index];
}
// Methods, variables for checking key and values read.
struct ValuesToAssert {
ValuesToAssert(const std::string& key, const Slice& value)
: expected_user_key(key),
expected_value(value),
call_count(0) {}
std::string expected_user_key;
Slice expected_value;
int call_count;
};
bool AssertValues(void* assert_obj,
const ParsedInternalKey& k, const Slice& v) {
ValuesToAssert *ptr = reinterpret_cast<ValuesToAssert*>(assert_obj);
ASSERT_EQ(ptr->expected_value.ToString(), v.ToString());
ASSERT_EQ(ptr->expected_user_key, k.user_key.ToString());
++ptr->call_count;
return false;
}
} // namespace
class CuckooReaderTest {
public:
CuckooReaderTest() {
options.allow_mmap_reads = true;
env = options.env;
env_options = EnvOptions(options);
}
void SetUp(int num_items) {
this->num_items = num_items;
hash_map.clear();
keys.clear();
keys.resize(num_items);
user_keys.clear();
user_keys.resize(num_items);
values.clear();
values.resize(num_items);
}
void CreateCuckooFile(bool is_last_level) {
unique_ptr<WritableFile> writable_file;
ASSERT_OK(env->NewWritableFile(fname, &writable_file, env_options));
CuckooTableBuilder builder(
writable_file.get(), keys[0].size(), values[0].size(), 0.9,
10000, kNumHashFunc, 100, is_last_level, GetSliceHash);
ASSERT_OK(builder.status());
for (uint32_t key_idx = 0; key_idx < num_items; ++key_idx) {
builder.Add(Slice(keys[key_idx]), Slice(values[key_idx]));
ASSERT_EQ(builder.NumEntries(), key_idx + 1);
ASSERT_OK(builder.status());
}
ASSERT_OK(builder.Finish());
ASSERT_EQ(num_items, builder.NumEntries());
file_size = builder.FileSize();
ASSERT_OK(writable_file->Close());
}
void CheckReader() {
unique_ptr<RandomAccessFile> read_file;
ASSERT_OK(env->NewRandomAccessFile(fname, &read_file, env_options));
CuckooTableReader reader(
options,
std::move(read_file),
file_size,
GetSliceHash);
ASSERT_OK(reader.status());
for (uint32_t i = 0; i < num_items; ++i) {
ValuesToAssert v(user_keys[i], values[i]);
ASSERT_OK(reader.Get(
ReadOptions(), Slice(keys[i]), &v, AssertValues, nullptr));
ASSERT_EQ(1, v.call_count);
}
}
std::vector<std::string> keys;
std::vector<std::string> user_keys;
std::vector<std::string> values;
uint32_t num_items;
std::string fname;
uint64_t file_size;
Options options;
Env* env;
EnvOptions env_options;
};
TEST(CuckooReaderTest, WhenKeyExists) {
SetUp(10);
fname = test::TmpDir() + "/CuckooReader_WhenKeyExists";
for (uint32_t i = 0; i < num_items; i++) {
user_keys[i] = "keys" + std::to_string(i+100);
ParsedInternalKey ikey(user_keys[i], i + 1000, kTypeValue);
AppendInternalKey(&keys[i], ikey);
values[i] = "value" + std::to_string(i+100);
AddHashLookups(user_keys[i], i * kNumHashFunc, kNumHashFunc);
}
CreateCuckooFile(false);
CheckReader();
// Last level file.
CreateCuckooFile(true);
CheckReader();
// Test with collision. Make all hash values collide.
hash_map.clear();
for (uint32_t i = 0; i < num_items; i++) {
AddHashLookups(user_keys[i], 0, kNumHashFunc);
}
CreateCuckooFile(false);
CheckReader();
// Last level file.
CreateCuckooFile(true);
CheckReader();
}
TEST(CuckooReaderTest, WhenKeyNotFound) {
// Add keys with colliding hash values.
SetUp(kNumHashFunc / 2);
fname = test::TmpDir() + "/CuckooReader_WhenKeyNotFound";
for (uint32_t i = 0; i < num_items; i++) {
user_keys[i] = "keys" + std::to_string(i+100);
ParsedInternalKey ikey(user_keys[i], i + 1000, kTypeValue);
AppendInternalKey(&keys[i], ikey);
values[i] = "value" + std::to_string(i+100);
// Make all hash values collide.
AddHashLookups(user_keys[i], 0, kNumHashFunc);
}
CreateCuckooFile(false);
CheckReader();
unique_ptr<RandomAccessFile> read_file;
ASSERT_OK(env->NewRandomAccessFile(fname, &read_file, env_options));
CuckooTableReader reader(
options,
std::move(read_file),
file_size,
GetSliceHash);
ASSERT_OK(reader.status());
// Search for a key with colliding hash values.
std::string not_found_user_key = "keys" + std::to_string(num_items + 100);
std::string not_found_key;
AddHashLookups(not_found_user_key, 0, kNumHashFunc);
ParsedInternalKey ikey(not_found_user_key, 1000, kTypeValue);
AppendInternalKey(&not_found_key, ikey);
ValuesToAssert v("", "");
ASSERT_OK(reader.Get(
ReadOptions(), Slice(not_found_key), &v, AssertValues, nullptr));
ASSERT_EQ(0, v.call_count);
ASSERT_OK(reader.status());
// Search for a key with an independent hash value.
std::string not_found_user_key2 = "keys" + std::to_string(num_items + 101);
std::string not_found_key2;
AddHashLookups(not_found_user_key2, kNumHashFunc, kNumHashFunc);
ParsedInternalKey ikey2(not_found_user_key2, 1000, kTypeValue);
AppendInternalKey(&not_found_key2, ikey2);
ASSERT_OK(reader.Get(
ReadOptions(), Slice(not_found_key2), &v, AssertValues, nullptr));
ASSERT_EQ(0, v.call_count);
ASSERT_OK(reader.status());
// Test read with corrupted key.
not_found_key2.pop_back();
ASSERT_TRUE(!ParseInternalKey(not_found_key2, &ikey));
ASSERT_TRUE(reader.Get(
ReadOptions(), Slice(not_found_key2), &v,
AssertValues, nullptr).IsCorruption());
ASSERT_EQ(0, v.call_count);
ASSERT_OK(reader.status());
// Test read when key is unused key.
std::string unused_user_key = "keys10:";
// Add hash values that map to empty buckets.
AddHashLookups(unused_user_key, kNumHashFunc, kNumHashFunc);
std::string unused_key;
ParsedInternalKey ikey3(unused_user_key, 1000, kTypeValue);
AppendInternalKey(&unused_key, ikey3);
ASSERT_OK(reader.Get(
ReadOptions(), Slice(unused_key), &v, AssertValues, nullptr));
ASSERT_EQ(0, v.call_count);
ASSERT_OK(reader.status());
}
// Performance tests
namespace {
void GenerateKeys(uint64_t num, std::vector<std::string>* keys,
uint32_t user_key_length) {
for (uint64_t i = 0; i < num; ++i) {
std::string new_key(reinterpret_cast<char*>(&i), sizeof(i));
new_key = std::string(user_key_length - new_key.size(), 'k') + new_key;
ParsedInternalKey ikey(new_key, num, kTypeValue);
std::string full_key;
AppendInternalKey(&full_key, ikey);
keys->push_back(full_key);
}
}
bool DoNothing(void* arg, const ParsedInternalKey& k, const Slice& v) {
// Deliberately empty.
return false;
}
bool CheckValue(void* cnt_ptr, const ParsedInternalKey& k, const Slice& v) {
++*reinterpret_cast<int*>(cnt_ptr);
std::string expected_value;
AppendInternalKey(&expected_value, k);
ASSERT_EQ(0, v.compare(Slice(&expected_value[0], v.size())));
return false;
}
// Create last level file as we are interested in measuring performance of
// last level file only.
void BM_CuckooRead(uint64_t num, uint32_t key_length,
uint32_t value_length, uint64_t num_reads, double hash_ratio) {
assert(value_length <= key_length);
std::vector<std::string> keys;
Options options;
options.allow_mmap_reads = true;
Env* env = options.env;
EnvOptions env_options = EnvOptions(options);
uint64_t file_size;
if (FLAGS_file_dir.empty()) {
FLAGS_file_dir = test::TmpDir();
}
std::string fname = FLAGS_file_dir + "/cuckoo_read_benchmark";
GenerateKeys(num, &keys, key_length);
uint64_t predicted_file_size =
num * (key_length + value_length) / hash_ratio + 1024;
unique_ptr<WritableFile> writable_file;
ASSERT_OK(env->NewWritableFile(fname, &writable_file, env_options));
CuckooTableBuilder builder(
writable_file.get(), keys[0].size(), value_length, hash_ratio,
predicted_file_size, kMaxNumHashTable, 1000, true, GetSliceMurmurHash);
ASSERT_OK(builder.status());
for (uint32_t key_idx = 0; key_idx < num; ++key_idx) {
// Value is just a part of key.
builder.Add(Slice(keys[key_idx]), Slice(&keys[key_idx][0], value_length));
ASSERT_EQ(builder.NumEntries(), key_idx + 1);
ASSERT_OK(builder.status());
}
ASSERT_OK(builder.Finish());
ASSERT_EQ(num, builder.NumEntries());
file_size = builder.FileSize();
ASSERT_OK(writable_file->Close());
unique_ptr<RandomAccessFile> read_file;
ASSERT_OK(env->NewRandomAccessFile(fname, &read_file, env_options));
CuckooTableReader reader(
options,
std::move(read_file),
file_size,
GetSliceMurmurHash);
ASSERT_OK(reader.status());
const UserCollectedProperties user_props =
reader.GetTableProperties()->user_collected_properties;
const uint32_t num_hash_fun = *reinterpret_cast<const uint32_t*>(
user_props.at(CuckooTablePropertyNames::kNumHashTable).data());
fprintf(stderr, "With %lu items and hash table ratio %f, number of hash"
" functions used: %u.\n", num, hash_ratio, num_hash_fun);
ReadOptions r_options;
for (auto& key : keys) {
int cnt = 0;
ASSERT_OK(reader.Get(r_options, Slice(key), &cnt, CheckValue, nullptr));
ASSERT_EQ(1, cnt);
}
// Shuffle Keys.
std::random_shuffle(keys.begin(), keys.end());
uint64_t time_now = env->NowMicros();
for (uint64_t i = 0; i < num_reads; ++i) {
reader.Get(r_options, Slice(keys[i % num]), nullptr, DoNothing, nullptr);
}
fprintf(stderr, "Time taken per op is %.3fus\n",
(env->NowMicros() - time_now)*1.0/num_reads);
}
} // namespace.
TEST(CuckooReaderTest, Performance) {
// In all these tests, num_reads = 10*num_items.
if (!FLAGS_enable_perf) {
return;
}
BM_CuckooRead(100000, 8, 4, 1000000, 0.9);
BM_CuckooRead(1000000, 8, 4, 10000000, 0.9);
BM_CuckooRead(1000000, 8, 4, 10000000, 0.7);
BM_CuckooRead(10000000, 8, 4, 100000000, 0.9);
BM_CuckooRead(10000000, 8, 4, 100000000, 0.7);
}
} // namespace rocksdb
int main(int argc, char** argv) {
ParseCommandLineFlags(&argc, &argv, true);
rocksdb::test::RunAllTests();
return 0;
}
#endif // GFLAGS.