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_MAPPED_FILE_H_ 8 #define NET_DISK_CACHE_MAPPED_FILE_H_ 9 10 #include <string> 11 12 #include "net/disk_cache/disk_format.h" 13 #include "net/disk_cache/file.h" 14 #include "net/disk_cache/file_block.h" 15 16 class FilePath; 17 18 namespace disk_cache { 19 20 // This class implements a memory mapped file used to access block-files. The 21 // idea is that the header and bitmap will be memory mapped all the time, and 22 // the actual data for the blocks will be access asynchronously (most of the 23 // time). 24 class MappedFile : public File { 25 public: 26 MappedFile() : File(true), init_(false) {} 27 28 // Performs object initialization. name is the file to use, and size is the 29 // ammount of data to memory map from th efile. If size is 0, the whole file 30 // will be mapped in memory. 31 void* Init(const FilePath& name, size_t size); 32 33 void* buffer() const { 34 return buffer_; 35 } 36 37 // Loads or stores a given block from the backing file (synchronously). 38 bool Load(const FileBlock* block); 39 bool Store(const FileBlock* block); 40 41 private: 42 virtual ~MappedFile(); 43 44 bool init_; 45 #if defined(OS_WIN) 46 HANDLE section_; 47 #endif 48 void* buffer_; // Address of the memory mapped buffer. 49 size_t view_size_; // Size of the memory pointed by buffer_. 50 51 DISALLOW_COPY_AND_ASSIGN(MappedFile); 52 }; 53 54 } // namespace disk_cache 55 56 #endif // NET_DISK_CACHE_MAPPED_FILE_H_ 57
