file_block.h revision a1401311d1ab56c4ed0a474bd38c108f75cb0cd9 
1// Copyright (c) 2006-2008 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 of the cache.
6
7#ifndef NET_DISK_CACHE_BLOCKFILE_FILE_BLOCK_H_
8#define NET_DISK_CACHE_BLOCKFILE_FILE_BLOCK_H_
9
10namespace disk_cache {
11
12// This interface exposes common functionality for a single block of data
13// stored on a file-block, regardless of the real type or size of the block.
14// Used to simplify loading / storing the block from disk.
15class FileBlock {
16 public:
17  virtual ~FileBlock() {}
18
19  // Returns a pointer to the actual data.
20  virtual void* buffer() const = 0;
21
22  // Returns the size of the block;
23  virtual size_t size() const = 0;
24
25  // Returns the file offset of this block.
26  virtual int offset() const = 0;
27};
28
29}  // namespace disk_cache
30
31#endif  // NET_DISK_CACHE_BLOCKFILE_FILE_BLOCK_H_
32