df8c307d63
Summary: PR https://github.com/facebook/rocksdb/issues/5584 decoupled the uncompression dictionary object from the underlying block data; however, this defeats the purpose of the digested ZSTD dictionary, since the whole point of the digest is to create it once and reuse it over and over again. This patch goes back to storing the uncompression dictionary itself in the cache (which should be now safe to do, since it no longer includes a Statistics pointer), while preserving the rest of the refactoring. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5645 Test Plan: make asan_check Differential Revision: D16551864 Pulled By: ltamasi fbshipit-source-id: 2a7e2d34bb16e70e3c816506d5afe1d842057800
60 lines
2.0 KiB
C++
60 lines
2.0 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root directory).
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//
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#pragma once
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#include <cassert>
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#include "table/block_based/cachable_entry.h"
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#include "table/format.h"
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namespace rocksdb {
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class BlockBasedTable;
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struct BlockCacheLookupContext;
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class FilePrefetchBuffer;
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class GetContext;
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struct ReadOptions;
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struct UncompressionDict;
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// Provides access to the uncompression dictionary regardless of whether
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// it is owned by the reader or stored in the cache, or whether it is pinned
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// in the cache or not.
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class UncompressionDictReader {
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public:
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static Status Create(
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const BlockBasedTable* table, FilePrefetchBuffer* prefetch_buffer,
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bool use_cache, bool prefetch, bool pin,
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BlockCacheLookupContext* lookup_context,
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std::unique_ptr<UncompressionDictReader>* uncompression_dict_reader);
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Status GetOrReadUncompressionDictionary(
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FilePrefetchBuffer* prefetch_buffer, bool no_io, GetContext* get_context,
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BlockCacheLookupContext* lookup_context,
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CachableEntry<UncompressionDict>* uncompression_dict) const;
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size_t ApproximateMemoryUsage() const;
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private:
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UncompressionDictReader(const BlockBasedTable* t,
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CachableEntry<UncompressionDict>&& uncompression_dict)
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: table_(t), uncompression_dict_(std::move(uncompression_dict)) {
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assert(table_);
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}
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bool cache_dictionary_blocks() const;
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static Status ReadUncompressionDictionary(
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const BlockBasedTable* table, FilePrefetchBuffer* prefetch_buffer,
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const ReadOptions& read_options, bool use_cache, GetContext* get_context,
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BlockCacheLookupContext* lookup_context,
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CachableEntry<UncompressionDict>* uncompression_dict);
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const BlockBasedTable* table_;
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CachableEntry<UncompressionDict> uncompression_dict_;
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};
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} // namespace rocksdb
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