mirror of
https://github.com/facebook/rocksdb.git
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e7c434c364
Summary:
Summary:
Added a new option to ColumnFamllyOptions - optimize_filters_for_hits. This option can be used in the case where most
accesses to the store are key hits and we dont need to optimize performance for key misses.
This is useful when you have a very large database and most of your lookups succeed. The option allows the store to
not store and use filters in the last level (the largest level which contains data). These filters can take a large amount of
space for large databases (in memory and on-disk). For the last level, these filters are only useful for key misses and not
for key hits. If we are not optimizing for key misses, we can choose to not store these filters for that level.
This option is only provided for BlockBasedTable. We skip the filters when we are compacting
Test Plan:
1. Modified db_test toalso run tests with an additonal option (skip_filters_on_last_level)
2. Added another unit test to db_test which specifically tests that filters are being skipped
Reviewers: rven, igor, sdong
Reviewed By: sdong
Subscribers: lgalanis, yoshinorim, MarkCallaghan, rven, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D33717
101 lines
4 KiB
C++
101 lines
4 KiB
C++
// Copyright (c) 2013, Facebook, Inc. All rights reserved.
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// This source code is licensed under the BSD-style license found in the
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// LICENSE file in the root directory of this source tree. An additional grant
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// of patent rights can be found in the PATENTS file in the same directory.
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//
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// 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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#pragma once
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#include <stdint.h>
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#include <limits>
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#include "rocksdb/flush_block_policy.h"
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#include "rocksdb/options.h"
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#include "rocksdb/status.h"
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#include "table/table_builder.h"
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namespace rocksdb {
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class BlockBuilder;
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class BlockHandle;
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class WritableFile;
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struct BlockBasedTableOptions;
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class BlockBasedTableBuilder : public TableBuilder {
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public:
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// Create a builder that will store the contents of the table it is
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// building in *file. Does not close the file. It is up to the
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// caller to close the file after calling Finish().
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BlockBasedTableBuilder(const ImmutableCFOptions& ioptions,
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const BlockBasedTableOptions& table_options,
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const InternalKeyComparator& internal_comparator,
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WritableFile* file,
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const CompressionType compression_type,
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const CompressionOptions& compression_opts,
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const bool skip_filters);
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// REQUIRES: Either Finish() or Abandon() has been called.
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~BlockBasedTableBuilder();
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// Add key,value to the table being constructed.
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// REQUIRES: key is after any previously added key according to comparator.
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// REQUIRES: Finish(), Abandon() have not been called
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void Add(const Slice& key, const Slice& value) override;
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// Return non-ok iff some error has been detected.
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Status status() const override;
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// Finish building the table. Stops using the file passed to the
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// constructor after this function returns.
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// REQUIRES: Finish(), Abandon() have not been called
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Status Finish() override;
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// Indicate that the contents of this builder should be abandoned. Stops
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// using the file passed to the constructor after this function returns.
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// If the caller is not going to call Finish(), it must call Abandon()
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// before destroying this builder.
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// REQUIRES: Finish(), Abandon() have not been called
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void Abandon() override;
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// Number of calls to Add() so far.
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uint64_t NumEntries() const override;
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// Size of the file generated so far. If invoked after a successful
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// Finish() call, returns the size of the final generated file.
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uint64_t FileSize() const override;
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private:
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bool ok() const { return status().ok(); }
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// Call block's Finish() method and then write the finalize block contents to
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// file.
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void WriteBlock(BlockBuilder* block, BlockHandle* handle);
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// Directly write block content to the file.
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void WriteBlock(const Slice& block_contents, BlockHandle* handle);
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void WriteRawBlock(const Slice& data, CompressionType, BlockHandle* handle);
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Status InsertBlockInCache(const Slice& block_contents,
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const CompressionType type,
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const BlockHandle* handle);
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struct Rep;
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class BlockBasedTablePropertiesCollectorFactory;
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class BlockBasedTablePropertiesCollector;
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Rep* rep_;
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// Advanced operation: flush any buffered key/value pairs to file.
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// Can be used to ensure that two adjacent entries never live in
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// the same data block. Most clients should not need to use this method.
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// REQUIRES: Finish(), Abandon() have not been called
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void Flush();
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// Some compression libraries fail when the raw size is bigger than int. If
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// uncompressed size is bigger than kCompressionSizeLimit, don't compress it
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const uint64_t kCompressionSizeLimit = std::numeric_limits<int>::max();
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// No copying allowed
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BlockBasedTableBuilder(const BlockBasedTableBuilder&) = delete;
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void operator=(const BlockBasedTableBuilder&) = delete;
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};
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} // namespace rocksdb
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