b4ad5e89ae
Summary: Rocksdb can now support a uncompressed block cache, or a compressed block cache or both. Lookups first look for a block in the uncompressed cache, if it is not found only then it is looked up in the compressed cache. If it is found in the compressed cache, then it is uncompressed and inserted into the uncompressed cache. It is possible that the same block resides in the compressed cache as well as the uncompressed cache at the same time. Both caches have their own individual LRU policy. Test Plan: Unit test case attached. Reviewers: kailiu, sdong, haobo, leveldb Reviewed By: haobo CC: xjin, haobo Differential Revision: https://reviews.facebook.net/D12675
52 lines
1.4 KiB
C++
52 lines
1.4 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 <stddef.h>
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#include <stdint.h>
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#include "rocksdb/iterator.h"
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#include "rocksdb/options.h"
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namespace rocksdb {
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struct BlockContents;
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class Comparator;
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class Block {
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public:
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// Initialize the block with the specified contents.
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explicit Block(const BlockContents& contents);
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~Block();
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size_t size() const { return size_; }
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bool isCachable() const { return cachable_; }
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CompressionType compressionType() const { return compression_type_; }
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Iterator* NewIterator(const Comparator* comparator);
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const char* data() { return data_; }
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private:
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uint32_t NumRestarts() const;
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const char* data_;
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size_t size_;
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uint32_t restart_offset_; // Offset in data_ of restart array
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bool owned_; // Block owns data_[]
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bool cachable_;
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CompressionType compression_type_;
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// No copying allowed
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Block(const Block&);
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void operator=(const Block&);
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class Iter;
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};
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} // namespace rocksdb
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