85584d497e
In particular, we add a new FilterPolicy class. An instance of this class can be supplied in Options when opening a database. If supplied, the instance is used to generate summaries of keys (e.g., a bloom filter) which are placed in sstables. These summaries are consulted by DB::Get() so we can avoid reading sstable blocks that are guaranteed to not contain the key we are looking for. This change provides one implementation of FilterPolicy based on bloom filters. Other changes: - Updated version number to 1.4. - Some build tweaks. - C binding for CompactRange. - A few more benchmarks: deleteseq, deleterandom, readmissing, seekrandom. - Minor .gitignore update.
30 lines
764 B
C++
30 lines
764 B
C++
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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#include "leveldb/options.h"
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#include "leveldb/comparator.h"
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#include "leveldb/env.h"
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namespace leveldb {
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Options::Options()
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: comparator(BytewiseComparator()),
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create_if_missing(false),
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error_if_exists(false),
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paranoid_checks(false),
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env(Env::Default()),
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info_log(NULL),
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write_buffer_size(4<<20),
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max_open_files(1000),
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block_cache(NULL),
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block_size(4096),
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block_restart_interval(16),
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compression(kSnappyCompression),
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filter_policy(NULL) {
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}
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} // namespace leveldb
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