Reorganize net/disk_cache into backend specific directories.

net/disk_cache/mapped_file.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 of the cache.
-
-#ifndef NET_DISK_CACHE_MAPPED_FILE_H_
-#define NET_DISK_CACHE_MAPPED_FILE_H_
-
-#include "net/base/net_export.h"
-#include "net/disk_cache/file.h"
-#include "net/disk_cache/file_block.h"
-
-namespace base {
-class FilePath;
-}
-
-namespace disk_cache {
-
-// This class implements a memory mapped file used to access block-files. The
-// idea is that the header and bitmap will be memory mapped all the time, and
-// the actual data for the blocks will be access asynchronously (most of the
-// time).
-class NET_EXPORT_PRIVATE MappedFile : public File {
- public:
-  MappedFile() : File(true), init_(false) {}
-
-  // Performs object initialization. name is the file to use, and size is the
-  // amount of data to memory map from the file. If size is 0, the whole file
-  // will be mapped in memory.
-  void* Init(const base::FilePath& name, size_t size);
-
-  void* buffer() const {
-    return buffer_;
-  }
-
-  // Loads or stores a given block from the backing file (synchronously).
-  bool Load(const FileBlock* block);
-  bool Store(const FileBlock* block);
-
-  // Asynchronous versions of Load/Store, following the semantics of File::Read
-  // and File::Write.
-  bool Load(const FileBlock* block, FileIOCallback* callback, bool* completed);
-  bool Store(const FileBlock* block, FileIOCallback* callback, bool* completed);
-
-  // Flush the memory-mapped section to disk (synchronously).
-  void Flush();
-
- private:
-  virtual ~MappedFile();
-
-  bool init_;
-#if defined(OS_WIN)
-  HANDLE section_;
-#endif
-  void* buffer_;  // Address of the memory mapped buffer.
-  size_t view_size_;  // Size of the memory pointed by buffer_.
-#if defined(POSIX_AVOID_MMAP)
-  void* snapshot_;  // Copy of the buffer taken when it was last flushed.
-#endif
-
-  DISALLOW_COPY_AND_ASSIGN(MappedFile);
-};
-
-// Helper class for calling Flush() on exit from the current scope.
-class ScopedFlush {
- public:
-  explicit ScopedFlush(MappedFile* file) : file_(file) {}
-  ~ScopedFlush() {
-    file_->Flush();
-  }
- private:
-  MappedFile* file_;
-};
-
-}  // namespace disk_cache
-
-#endif  // NET_DISK_CACHE_MAPPED_FILE_H_