ab8d2f6ab2
Summary: Current posix advice implementation ties up the access pattern hint with the creation of a file. It is not possible to apply different advice for different access (random get vs compaction read), without keeping two open files for the same table. This patch extended the RandomeAccessFile interface to accept new access hint at anytime. Particularly, we are able to set different access hint on the same table file based on when/how the file is used. Two options are added to set the access hint, after the file is first opened and after the file is being compacted. Test Plan: make check; db_stress; db_bench Reviewers: dhruba Reviewed By: dhruba CC: MarkCallaghan, leveldb Differential Revision: https://reviews.facebook.net/D10905
72 lines
2.4 KiB
C++
72 lines
2.4 KiB
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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//
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// Thread-safe (provides internal synchronization)
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#ifndef STORAGE_LEVELDB_DB_TABLE_CACHE_H_
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#define STORAGE_LEVELDB_DB_TABLE_CACHE_H_
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#include <string>
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#include <stdint.h>
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#include "db/dbformat.h"
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#include "leveldb/env.h"
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#include "leveldb/cache.h"
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#include "port/port.h"
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#include "table/table.h"
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#include "util/storage_options.h"
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namespace leveldb {
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class Env;
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class TableCache {
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public:
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TableCache(const std::string& dbname, const Options* options,
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const StorageOptions& storage_options, int entries);
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~TableCache();
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// Return an iterator for the specified file number (the corresponding
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// file length must be exactly "file_size" bytes). If "tableptr" is
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// non-nullptr, also sets "*tableptr" to point to the Table object
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// underlying the returned iterator, or nullptr if no Table object underlies
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// the returned iterator. The returned "*tableptr" object is owned by
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// the cache and should not be deleted, and is valid for as long as the
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// returned iterator is live.
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Iterator* NewIterator(const ReadOptions& options,
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const EnvOptions& toptions,
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uint64_t file_number,
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uint64_t file_size,
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Table** tableptr = nullptr,
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bool for_compaction = false);
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// If a seek to internal key "k" in specified file finds an entry,
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// call (*handle_result)(arg, found_key, found_value) repeatedly until
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// it returns false.
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Status Get(const ReadOptions& options,
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uint64_t file_number,
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uint64_t file_size,
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const Slice& k,
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void* arg,
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bool (*handle_result)(void*, const Slice&, const Slice&, bool),
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bool* tableIO);
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// Evict any entry for the specified file number
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void Evict(uint64_t file_number);
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private:
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Env* const env_;
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const std::string dbname_;
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const Options* options_;
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const StorageOptions& storage_options_;
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std::shared_ptr<Cache> cache_;
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Status FindTable(const EnvOptions& toptions,
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uint64_t file_number, uint64_t file_size, Cache::Handle**,
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bool* tableIO = nullptr);
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};
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} // namespace leveldb
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#endif // STORAGE_LEVELDB_DB_TABLE_CACHE_H_
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