73 lines
2.5 KiB
C++
73 lines
2.5 KiB
C++
// 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/env.h"
|
|
#include "leveldb/cache.h"
|
|
#include "port/port.h"
|
|
#include "table/table.h"
|
|
|
|
namespace leveldb {
|
|
|
|
class Env;
|
|
|
|
class TableCache {
|
|
public:
|
|
TableCache(const std::string& dbname, const Options* options,
|
|
const EnvOptions& storage_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-nullptr, also sets "*tableptr" to point to the Table object
|
|
// underlying the returned iterator, or 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,
|
|
const EnvOptions& toptions,
|
|
uint64_t file_number,
|
|
uint64_t file_size,
|
|
Table** tableptr = nullptr,
|
|
bool for_compaction = false);
|
|
|
|
// If a seek to internal key "k" in specified file finds an entry,
|
|
// call (*handle_result)(arg, found_key, found_value) repeatedly until
|
|
// it returns false.
|
|
Status Get(const ReadOptions& options,
|
|
uint64_t file_number,
|
|
uint64_t file_size,
|
|
const Slice& k,
|
|
void* arg,
|
|
bool (*handle_result)(void*, const Slice&, const Slice&, bool),
|
|
bool* table_io,
|
|
void (*mark_key_may_exist)(void*) = nullptr,
|
|
const bool no_io = false);
|
|
|
|
// 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_;
|
|
const EnvOptions& storage_options_;
|
|
std::shared_ptr<Cache> cache_;
|
|
|
|
Status FindTable(const EnvOptions& toptions, uint64_t file_number,
|
|
uint64_t file_size, Cache::Handle**, bool* table_io=nullptr,
|
|
const bool no_io = false);
|
|
};
|
|
|
|
} // namespace leveldb
|
|
|
|
#endif // STORAGE_LEVELDB_DB_TABLE_CACHE_H_
|