git / moonbite-core / src/leveldb/db/table_cache.h · raw

// 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 <stdint.h>#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();  // 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_