Reorganize net/disk_cache into backend specific directories.

net/disk_cache/block_files.h

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
-// 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_BLOCK_FILES_H_
-#define NET_DISK_CACHE_BLOCK_FILES_H_
-
-#include <vector>
-
-#include "base/files/file_path.h"
-#include "base/gtest_prod_util.h"
-#include "base/memory/scoped_ptr.h"
-#include "net/base/net_export.h"
-#include "net/disk_cache/addr.h"
-#include "net/disk_cache/disk_format_base.h"
-#include "net/disk_cache/mapped_file.h"
-
-namespace base {
-class ThreadChecker;
-}
-
-namespace disk_cache {
-
-// An instance of this class represents the header of a block file in memory.
-// Note that this class doesn't perform any file operation (as in it only deals
-// with entities in memory).
-// The header of a block file (and hence, this object) is all that is needed to
-// perform common operations like allocating or releasing space for storage;
-// actual access to that storage, however, is not performed through this class.
-class NET_EXPORT_PRIVATE BlockHeader {
- public:
-  BlockHeader();
-  explicit BlockHeader(BlockFileHeader* header);
-  explicit BlockHeader(MappedFile* file);
-  BlockHeader(const BlockHeader& other);
-  ~BlockHeader();
-
-  // Creates a new entry of |size| blocks on the allocation map, updating the
-  // apropriate counters.
-  bool CreateMapBlock(int size, int* index);
-
-  // Deletes the block pointed by |index|.
-  void DeleteMapBlock(int index, int block_size);
-
-  // Returns true if the specified block is used.
-  bool UsedMapBlock(int index, int size);
-
-  // Restores the "empty counters" and allocation hints.
-  void FixAllocationCounters();
-
-  // Returns true if the current block file should not be used as-is to store
-  // more records. |block_count| is the number of blocks to allocate.
-  bool NeedToGrowBlockFile(int block_count) const;
-
-  // Returns true if this block file can be used to store an extra record of
-  // size |block_count|.
-  bool CanAllocate(int block_count) const;
-
-  // Returns the number of empty blocks for this file.
-  int EmptyBlocks() const;
-
-  // Returns the minumum number of allocations that can be satisfied.
-  int MinimumAllocations() const;
-
-  // Returns the number of blocks that this file can store.
-  int Capacity() const;
-
-  // Returns true if the counters look OK.
-  bool ValidateCounters() const;
-
-  // Returns the identifiers of this and the next file (0 if there is none).
-  int FileId() const;
-  int NextFileId() const;
-
-  // Returns the size of the wrapped structure (BlockFileHeader).
-  int Size() const;
-
-  // Returns a pointer to the underlying BlockFileHeader.
-  // TODO(rvargas): This may be removed with the support for V2.
-  BlockFileHeader* Header();
-
- private:
-  BlockFileHeader* header_;
-};
-
-typedef std::vector<BlockHeader> BlockFilesBitmaps;
-
-// This class handles the set of block-files open by the disk cache.
-class NET_EXPORT_PRIVATE BlockFiles {
- public:
-  explicit BlockFiles(const base::FilePath& path);
-  ~BlockFiles();
-
-  // Performs the object initialization. create_files indicates if the backing
-  // files should be created or just open.
-  bool Init(bool create_files);
-
-  // Returns the file that stores a given address.
-  MappedFile* GetFile(Addr address);
-
-  // Creates a new entry on a block file. block_type indicates the size of block
-  // to be used (as defined on cache_addr.h), block_count is the number of
-  // blocks to allocate, and block_address is the address of the new entry.
-  bool CreateBlock(FileType block_type, int block_count, Addr* block_address);
-
-  // Removes an entry from the block files. If deep is true, the storage is zero
-  // filled; otherwise the entry is removed but the data is not altered (must be
-  // already zeroed).
-  void DeleteBlock(Addr address, bool deep);
-
-  // Close all the files and set the internal state to be initializad again. The
-  // cache is being purged.
-  void CloseFiles();
-
-  // Sends UMA stats.
-  void ReportStats();
-
-  // Returns true if the blocks pointed by a given address are currently used.
-  // This method is only intended for debugging.
-  bool IsValid(Addr address);
-
- private:
-  // Set force to true to overwrite the file if it exists.
-  bool CreateBlockFile(int index, FileType file_type, bool force);
-  bool OpenBlockFile(int index);
-
-  // Attemp to grow this file. Fails if the file cannot be extended anymore.
-  bool GrowBlockFile(MappedFile* file, BlockFileHeader* header);
-
-  // Returns the appropriate file to use for a new block.
-  MappedFile* FileForNewBlock(FileType block_type, int block_count);
-
-  // Returns the next block file on this chain, creating new files if needed.
-  MappedFile* NextFile(MappedFile* file);
-
-  // Creates an empty block file and returns its index.
-  int CreateNextBlockFile(FileType block_type);
-
-  // Removes a chained block file that is now empty.
-  bool RemoveEmptyFile(FileType block_type);
-
-  // Restores the header of a potentially inconsistent file.
-  bool FixBlockFileHeader(MappedFile* file);
-
-  // Retrieves stats for the given file index.
-  void GetFileStats(int index, int* used_count, int* load);
-
-  // Returns the filename for a given file index.
-  base::FilePath Name(int index);
-
-  bool init_;
-  char* zero_buffer_;  // Buffer to speed-up cleaning deleted entries.
-  base::FilePath path_;  // Path to the backing folder.
-  std::vector<MappedFile*> block_files_;  // The actual files.
-  scoped_ptr<base::ThreadChecker> thread_checker_;
-
-  FRIEND_TEST_ALL_PREFIXES(DiskCacheTest, BlockFiles_ZeroSizeFile);
-  FRIEND_TEST_ALL_PREFIXES(DiskCacheTest, BlockFiles_TruncatedFile);
-  FRIEND_TEST_ALL_PREFIXES(DiskCacheTest, BlockFiles_InvalidFile);
-  FRIEND_TEST_ALL_PREFIXES(DiskCacheTest, BlockFiles_Stats);
-
-  DISALLOW_COPY_AND_ASSIGN(BlockFiles);
-};
-
-}  // namespace disk_cache
-
-#endif  // NET_DISK_CACHE_BLOCK_FILES_H_