mirror of
https://github.com/facebook/rocksdb.git
synced 2024-11-27 20:43:57 +00:00
33 lines
1.3 KiB
C
33 lines
1.3 KiB
C
|
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
|
||
|
|
// This source code is licensed under both the GPLv2 (found in the
|
||
|
|
// COPYING file in the root directory) and Apache 2.0 License
|
||
|
|
// (found in the LICENSE.Apache file in the root directory).
|
||
|
|
//
|
||
|
|
// 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.
|
||
|
|
#pragma once
|
||
|
|
#include "table/block_based/block_based_table_reader.h"
|
||
|
|
|
||
|
|
namespace ROCKSDB_NAMESPACE {
|
||
|
|
class BlockPrefetcher {
|
||
|
|
public:
|
||
|
|
explicit BlockPrefetcher(size_t compaction_readahead_size)
|
||
|
|
: compaction_readahead_size_(compaction_readahead_size) {}
|
||
|
|
void PrefetchIfNeeded(const BlockBasedTable::Rep* rep,
|
||
|
|
const BlockHandle& handle, size_t readahead_size,
|
||
|
|
bool is_for_compaction);
|
||
|
|
FilePrefetchBuffer* prefetch_buffer() { return prefetch_buffer_.get(); }
|
||
|
|
|
||
|
|
private:
|
||
|
|
// Readahead size used in compaction, its value is used only if
|
||
|
|
// lookup_context_.caller = kCompaction.
|
||
|
|
size_t compaction_readahead_size_;
|
||
|
|
|
||
|
|
size_t readahead_size_ = BlockBasedTable::kInitAutoReadaheadSize;
|
||
|
|
size_t readahead_limit_ = 0;
|
||
|
|
int64_t num_file_reads_ = 0;
|
||
|
|
std::unique_ptr<FilePrefetchBuffer> prefetch_buffer_;
|
||
|
|
};
|
||
|
|
} // namespace ROCKSDB_NAMESPACE
|