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// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
//
// Thread-safe (provides internal synchronization)
#ifndef STORAGE_LEVELDB_DB_TABLE_CACHE_H_
#define STORAGE_LEVELDB_DB_TABLE_CACHE_H_
#include <cstdint>
#include <string>
#include "db/dbformat.h"
#include "leveldb/cache.h"
#include "leveldb/table.h"
#include "port/port.h"
namespace leveldb {
class Env;
class TableCache {
public:
TableCache(const std::string& dbname, const Options& options, int entries);
TableCache(const TableCache&) = delete;
TableCache& operator=(const TableCache&) = delete;
~TableCache();
// Return an iterator for the specified file number (the corresponding
// file length must be exactly "file_size" bytes). If "tableptr" is
// non-null, also sets "*tableptr" to point to the Table object
// underlying the returned iterator, or to nullptr if no Table object
// underlies the returned iterator. The returned "*tableptr" object is owned
// by the cache and should not be deleted, and is valid for as long as the
// returned iterator is live.
Iterator* NewIterator(const ReadOptions& options, uint64_t file_number,
uint64_t file_size, Table** tableptr = nullptr);
// If a seek to internal key "k" in specified file finds an entry,
// call (*handle_result)(arg, found_key, found_value).
Status Get(const ReadOptions& options, uint64_t file_number,
uint64_t file_size, const Slice& k, void* arg,
void (*handle_result)(void*, const Slice&, const Slice&));
// Evict any entry for the specified file number
void Evict(uint64_t file_number);
private:
Status FindTable(uint64_t file_number, uint64_t file_size, Cache::Handle**);
Env* const env_;
const std::string dbname_;
const Options& options_;
Cache* cache_;
};
} // namespace leveldb
#endif // STORAGE_LEVELDB_DB_TABLE_CACHE_H_
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