Move Preload() code to MappedFile

net/disk_cache/blockfile/mapped_file.cc

 // Copyright 2013 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/blockfile/mapped_file.h"
 
+#include <algorithm>
+
+#include "base/memory/scoped_ptr.h"
+
 namespace disk_cache {
 
 // Note: Most of this class is implemented in platform-specific files.
 
 bool MappedFile::Load(const FileBlock* block) {
   size_t offset = block->offset() + view_size_;
   return Read(block->buffer(), block->size(), offset);
 }
 
 bool MappedFile::Store(const FileBlock* block) {
   size_t offset = block->offset() + view_size_;
   return Write(block->buffer(), block->size(), offset);
 }
 
 bool MappedFile::Load(const FileBlock* block,
                       FileIOCallback* callback,
                       bool* completed) {
   size_t offset = block->offset() + view_size_;
   return Read(block->buffer(), block->size(), offset, callback, completed);
 }
 
 bool MappedFile::Store(const FileBlock* block,
                        FileIOCallback* callback,
                        bool* completed) {
   size_t offset = block->offset() + view_size_;
   return Write(block->buffer(), block->size(), offset, callback, completed);
 }
 
+bool MappedFile::Preload() {
+  size_t file_len = GetLength();
+  scoped_ptr<char[]> buf(new char[file_len]);
+  if (!Read(buf.get(), file_len, 0))
+    return false;
+  return true;
+}
 }  // namespace disk_cache