ad96563b79
Summary: This patch allows an application to specify whether to use bufferedio, reads-via-mmaps and writes-via-mmaps per database. Earlier, there was a global static variable that was used to configure this functionality. The default setting remains the same (and is backward compatible): 1. use bufferedio 2. do not use mmaps for reads 3. use mmap for writes 4. use readaheads for reads needed for compaction I also added a parameter to db_bench to be able to explicitly specify whether to do readaheads for compactions or not. Test Plan: make check Reviewers: sheki, heyongqiang, MarkCallaghan Reviewed By: sheki CC: leveldb Differential Revision: https://reviews.facebook.net/D9429
38 lines
1.3 KiB
C++
38 lines
1.3 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_TABLE_TWO_LEVEL_ITERATOR_H_
|
|
#define STORAGE_LEVELDB_TABLE_TWO_LEVEL_ITERATOR_H_
|
|
|
|
#include "leveldb/iterator.h"
|
|
#include "leveldb/env.h"
|
|
|
|
namespace leveldb {
|
|
|
|
struct ReadOptions;
|
|
|
|
// Return a new two level iterator. A two-level iterator contains an
|
|
// index iterator whose values point to a sequence of blocks where
|
|
// each block is itself a sequence of key,value pairs. The returned
|
|
// two-level iterator yields the concatenation of all key/value pairs
|
|
// in the sequence of blocks. Takes ownership of "index_iter" and
|
|
// will delete it when no longer needed.
|
|
//
|
|
// Uses a supplied function to convert an index_iter value into
|
|
// an iterator over the contents of the corresponding block.
|
|
extern Iterator* NewTwoLevelIterator(
|
|
Iterator* index_iter,
|
|
Iterator* (*block_function)(
|
|
void* arg,
|
|
const ReadOptions& options,
|
|
const EnvOptions& soptions,
|
|
const Slice& index_value),
|
|
void* arg,
|
|
const ReadOptions& options,
|
|
const EnvOptions& soptions);
|
|
|
|
} // namespace leveldb
|
|
|
|
#endif // STORAGE_LEVELDB_TABLE_TWO_LEVEL_ITERATOR_H_
|