1// Copyright (c) 2010 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5// See net/disk_cache/disk_cache.h for the public interface.
6
7#ifndef NET_DISK_CACHE_MEM_RANKINGS_H__
8#define NET_DISK_CACHE_MEM_RANKINGS_H__
9#pragma once
10
11#include "base/basictypes.h"
12
13namespace disk_cache {
14
15class MemEntryImpl;
16
17// This class handles the ranking information for the memory-only cache.
18class MemRankings {
19 public:
20  MemRankings() : head_(NULL), tail_(NULL) {}
21  ~MemRankings();
22
23  // Inserts a given entry at the head of the queue.
24  void Insert(MemEntryImpl* node);
25
26  // Removes a given entry from the LRU list.
27  void Remove(MemEntryImpl* node);
28
29  // Moves a given entry to the head.
30  void UpdateRank(MemEntryImpl* node);
31
32  // Iterates through the list.
33  MemEntryImpl* GetNext(MemEntryImpl* node);
34  MemEntryImpl* GetPrev(MemEntryImpl* node);
35
36 private:
37  MemEntryImpl* head_;
38  MemEntryImpl* tail_;
39
40  DISALLOW_COPY_AND_ASSIGN(MemRankings);
41};
42
43}  // namespace disk_cache
44
45#endif  // NET_DISK_CACHE_MEM_RANKINGS_H__
46