rocksdb/util/dynamic_bloom.cc
Kai Liu cd535c2280 Optimize MayContainHash()
Summary:
In latest leaf's, MayContainHash() consistently consumes 5%~7% CPU usage.

I checked the code and did an experiment with/without inlining this method.

In release mode, with `1024 * 1024 * 256` bits and `1024 * 512` entries, both call 2^30 MayContainHash() with distinctive parameters.

As the result showed, this patch reduced the running time from 9.127 sec to 7.891 sec.

Test Plan: make check

Reviewers: sdong, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15177
2014-01-14 22:03:57 -08:00

37 lines
1 KiB
C++

// 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.
#include "dynamic_bloom.h"
#include "rocksdb/slice.h"
#include "util/hash.h"
namespace rocksdb {
namespace {
static uint32_t BloomHash(const Slice& key) {
return Hash(key.data(), key.size(), 0xbc9f1d34);
}
}
DynamicBloom::DynamicBloom(uint32_t total_bits,
uint32_t (*hash_func)(const Slice& key),
uint32_t num_probes)
: hash_func_(hash_func),
kTotalBits((total_bits + 7) / 8 * 8),
kNumProbes(num_probes) {
assert(hash_func_);
assert(kNumProbes > 0);
assert(kTotalBits > 0);
data_.reset(new unsigned char[kTotalBits / 8]());
}
DynamicBloom::DynamicBloom(uint32_t total_bits,
uint32_t num_probes)
: DynamicBloom(total_bits, &BloomHash, num_probes) {
}
} // rocksdb