7fdd5f5b33
Summary: Use non mmapd files for Write-Ahead log. Earlier use of MMaped files. made the log iterator read ahead and miss records. Now the reader and writer will point to the same physical location. There is no perf regression : ./db_bench --benchmarks=fillseq --db=/dev/shm/mmap_test --num=$(million 20) --use_existing_db=0 --threads=2 with This diff : fillseq : 10.756 micros/op 185281 ops/sec; 20.5 MB/s without this dif : fillseq : 11.085 micros/op 179676 ops/sec; 19.9 MB/s Test Plan: unit test included Reviewers: dhruba, heyongqiang Reviewed By: heyongqiang CC: leveldb Differential Revision: https://reviews.facebook.net/D9741
68 lines
2.0 KiB
C++
68 lines
2.0 KiB
C++
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style license that can be
|
|
// found in the LICENSE file. See the AUTHORS file for names of contributors.
|
|
//
|
|
#ifndef STORAGE_LEVELDB_UTIL_STORAGE_OPTIONS_H_
|
|
#define STORAGE_LEVELDB_UTIL_STORAGE_OPTIONS_H_
|
|
|
|
#include <string>
|
|
#include <stdint.h>
|
|
#include "leveldb/env.h"
|
|
#include "leveldb/options.h"
|
|
|
|
namespace leveldb {
|
|
|
|
// Environment Options that are used to read files from storage
|
|
class StorageOptions : public EnvOptions {
|
|
public:
|
|
/* implicit */ StorageOptions(const Options& opt) :
|
|
data_in_os_(opt.allow_os_buffer),
|
|
fs_readahead_(opt.allow_readahead),
|
|
readahead_compactions_(opt.allow_readahead_compactions),
|
|
use_mmap_reads_(opt.allow_mmap_reads),
|
|
use_mmap_writes_(opt.allow_mmap_writes) {
|
|
}
|
|
|
|
// copy constructor with readaheads set to readahead_compactions_
|
|
StorageOptions(const StorageOptions& opt) {
|
|
data_in_os_ = opt.UseOsBuffer();
|
|
fs_readahead_ = opt.UseReadaheadCompactions();
|
|
readahead_compactions_ = opt.UseReadaheadCompactions();
|
|
use_mmap_reads_ = opt.UseMmapReads();
|
|
use_mmap_writes_ = opt.UseMmapWrites();
|
|
}
|
|
|
|
// constructor with default options
|
|
StorageOptions() {
|
|
Options opt;
|
|
data_in_os_ = opt.allow_os_buffer;
|
|
fs_readahead_ = opt.allow_readahead;
|
|
readahead_compactions_ = fs_readahead_;
|
|
use_mmap_reads_ = opt.allow_mmap_reads;
|
|
use_mmap_writes_ = opt.allow_mmap_writes;
|
|
}
|
|
|
|
virtual ~StorageOptions() {}
|
|
|
|
bool UseOsBuffer() const { return data_in_os_; };
|
|
bool UseReadahead() const { return fs_readahead_; };
|
|
bool UseMmapReads() const { return use_mmap_reads_; }
|
|
bool UseMmapWrites() const { return use_mmap_writes_; }
|
|
bool UseReadaheadCompactions() const { return readahead_compactions_;}
|
|
|
|
void DisableMmapWrites() {
|
|
use_mmap_writes_ = false;
|
|
}
|
|
|
|
private:
|
|
bool data_in_os_;
|
|
bool fs_readahead_;
|
|
bool readahead_compactions_;
|
|
bool use_mmap_reads_;
|
|
bool use_mmap_writes_;
|
|
};
|
|
|
|
} // namespace leveldb
|
|
|
|
#endif // STORAGE_LEVELDB_UTIL_STORAGE_OPTIONS_H_
|