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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 <string>
#include <stdint.h>
#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();
// 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 NULL 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 = NULL);
// 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:
Env* const env_;
const std::string dbname_;
const Options* options_;
Cache* cache_;
Status FindTable(uint64_t file_number, uint64_t file_size, Cache::Handle**);
};
} // namespace leveldb
#endif // STORAGE_LEVELDB_DB_TABLE_CACHE_H_