chromium/net/disk_cache/blockfile/storage_block.h

// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// See net/disk_cache/disk_cache.h for the public interface.

#ifndef NET_DISK_CACHE_BLOCKFILE_STORAGE_BLOCK_H_
#define NET_DISK_CACHE_BLOCKFILE_STORAGE_BLOCK_H_

#include <stddef.h>
#include <stdint.h>

#include "base/memory/raw_ptr.h"
#include "net/disk_cache/blockfile/addr.h"
#include "net/disk_cache/blockfile/mapped_file.h"

namespace disk_cache {

// This class encapsulates common behavior of a single "block" of data that is
// stored on a block-file. It implements the FileBlock interface, so it can be
// serialized directly to the backing file.
// This object provides a memory buffer for the related data, and it can be used
// to actually share that memory with another instance of the class.
//
// The following example shows how to share storage with another object:
//    StorageBlock<TypeA> a(file, address);
//    StorageBlock<TypeB> b(file, address);
//    a.Load();
//    DoSomething(a.Data());
//    b.SetData(a.Data());
//    ModifySomething(b.Data());
//    // Data modified on the previous call will be saved by b's destructor.
//    b.set_modified();
template<typename T>
class StorageBlock : public FileBlock { … };

}  // namespace disk_cache

#endif  // NET_DISK_CACHE_BLOCKFILE_STORAGE_BLOCK_H_