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. 6 7 #ifndef NET_DISK_CACHE_BLOCK_FILES_H__ 8 #define NET_DISK_CACHE_BLOCK_FILES_H__ 9 10 #include <vector> 11 12 #include "base/file_path.h" 13 #include "net/disk_cache/addr.h" 14 #include "net/disk_cache/mapped_file.h" 15 #include "testing/gtest/include/gtest/gtest_prod.h" 16 17 namespace disk_cache { 18 19 class EntryImpl; 20 21 // This class handles the set of block-files open by the disk cache. 22 class BlockFiles { 23 public: BlockFiles(const FilePath & path)24 explicit BlockFiles(const FilePath& path) 25 : init_(false), zero_buffer_(NULL), path_(path) {} 26 ~BlockFiles(); 27 28 // Performs the object initialization. create_files indicates if the backing 29 // files should be created or just open. 30 bool Init(bool create_files); 31 32 // Returns the file that stores a given address. 33 MappedFile* GetFile(Addr address); 34 35 // Creates a new entry on a block file. block_type indicates the size of block 36 // to be used (as defined on cache_addr.h), block_count is the number of 37 // blocks to allocate, and block_address is the address of the new entry. 38 bool CreateBlock(FileType block_type, int block_count, Addr* block_address); 39 40 // Removes an entry from the block files. If deep is true, the storage is zero 41 // filled; otherwise the entry is removed but the data is not altered (must be 42 // already zeroed). 43 void DeleteBlock(Addr address, bool deep); 44 45 // Close all the files and set the internal state to be initializad again. The 46 // cache is being purged. 47 void CloseFiles(); 48 49 private: 50 // Set force to true to overwrite the file if it exists. 51 bool CreateBlockFile(int index, FileType file_type, bool force); 52 bool OpenBlockFile(int index); 53 54 // Attemp to grow this file. Fails if the file cannot be extended anymore. 55 bool GrowBlockFile(MappedFile* file, BlockFileHeader* header); 56 57 // Returns the appropriate file to use for a new block. 58 MappedFile* FileForNewBlock(FileType block_type, int block_count); 59 60 // Returns the next block file on this chain, creating new files if needed. 61 MappedFile* NextFile(const MappedFile* file); 62 63 // Creates an empty block file and returns its index. 64 int CreateNextBlockFile(FileType block_type); 65 66 // Removes a chained block file that is now empty. 67 void RemoveEmptyFile(FileType block_type); 68 69 // Restores the header of a potentially inconsistent file. 70 bool FixBlockFileHeader(MappedFile* file); 71 72 // Returns the filename for a given file index. 73 FilePath Name(int index); 74 75 bool init_; 76 char* zero_buffer_; // Buffer to speed-up cleaning deleted entries. 77 FilePath path_; // Path to the backing folder. 78 std::vector<MappedFile*> block_files_; // The actual files. 79 80 FRIEND_TEST(DiskCacheTest, BlockFiles_ZeroSizeFile); 81 FRIEND_TEST(DiskCacheTest, BlockFiles_InvalidFile); 82 83 DISALLOW_EVIL_CONSTRUCTORS(BlockFiles); 84 }; 85 86 } // namespace disk_cache 87 88 #endif // NET_DISK_CACHE_BLOCK_FILES_H__ 89