Reorganize net/disk_cache into backend specific directories.

net/disk_cache/mapped_file_avoid_mmap_posix.cc

-// 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.
-
-#include "net/disk_cache/mapped_file.h"
-
-#include <stdlib.h>
-
-#include "base/files/file_path.h"
-#include "base/logging.h"
-
-namespace disk_cache {
-
-void* MappedFile::Init(const base::FilePath& name, size_t size) {
-  DCHECK(!init_);
-  if (init_ || !File::Init(name))
-    return NULL;
-
-  if (!size)
-    size = GetLength();
-
-  buffer_ = malloc(size);
-  snapshot_ = malloc(size);
-  if (buffer_ && snapshot_ && Read(buffer_, size, 0)) {
-    memcpy(snapshot_, buffer_, size);
-  } else {
-    free(buffer_);
-    free(snapshot_);
-    buffer_ = snapshot_ = 0;
-  }
-
-  init_ = true;
-  view_size_ = size;
-  return buffer_;
-}
-
-void MappedFile::Flush() {
-  DCHECK(buffer_);
-  DCHECK(snapshot_);
-  const char* buffer_ptr = static_cast<const char*>(buffer_);
-  char* snapshot_ptr = static_cast<char*>(snapshot_);
-  const size_t block_size = 4096;
-  for (size_t offset = 0; offset < view_size_; offset += block_size) {
-    size_t size = std::min(view_size_ - offset, block_size);
-    if (memcmp(snapshot_ptr + offset, buffer_ptr + offset, size)) {
-      memcpy(snapshot_ptr + offset, buffer_ptr + offset, size);
-      Write(snapshot_ptr + offset, size, offset);
-    }
-  }
-}
-
-MappedFile::~MappedFile() {
-  if (!init_)
-    return;
-
-  if (buffer_ && snapshot_) {
-    Flush();
-  }
-  free(buffer_);
-  free(snapshot_);
-}
-
-}  // namespace disk_cache