mirror of https://github.com/facebook/rocksdb.git
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_NAMESPACE {
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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, const ReadOptions& ro,
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FilePrefetchBuffer* prefetch_buffer, bool use_cache, bool prefetch,
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bool pin, 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_NAMESPACE
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