chromium/third_party/leveldatabase/src/include/leveldb/cache.h

// 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.
//
// A Cache is an interface that maps keys to values.  It has internal
// synchronization and may be safely accessed concurrently from
// multiple threads.  It may automatically evict entries to make room
// for new entries.  Values have a specified charge against the cache
// capacity.  For example, a cache where the values are variable
// length strings, may use the length of the string as the charge for
// the string.
//
// A builtin cache implementation with a least-recently-used eviction
// policy is provided.  Clients may use their own implementations if
// they want something more sophisticated (like scan-resistance, a
// custom eviction policy, variable cache sizing, etc.)

#ifndef STORAGE_LEVELDB_INCLUDE_CACHE_H_
#define STORAGE_LEVELDB_INCLUDE_CACHE_H_

#include <cstdint>

#include "leveldb/export.h"
#include "leveldb/slice.h"

namespace leveldb {

class LEVELDB_EXPORT Cache;

// Create a new cache with a fixed size capacity.  This implementation
// of Cache uses a least-recently-used eviction policy.
LEVELDB_EXPORT Cache* NewLRUCache(size_t capacity);

class LEVELDB_EXPORT Cache { … };

}  // namespace leveldb

#endif  // STORAGE_LEVELDB_INCLUDE_CACHE_H_