blob: c62c8c0dfd916021074222208bc704c00fc34bf1 [file] [log] [blame]
// 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 "chrome/app/file_pre_reader_win.h"
#include <windows.h>
#include "base/files/file.h"
void PreReadFile(const base::FilePath& file_path) {
base::File file(file_path, base::File::FLAG_OPEN | base::File::FLAG_READ |
if (!file.IsValid())
// This could be replaced with ::PrefetchVirtualMemory once we drop support
// for Win7. The performance of ::PrefetchVirtualMemory is roughly equivalent
// to these buffered reads.
const DWORD kStepSize = 1024 * 1024;
char* buffer = reinterpret_cast<char*>(
::VirtualAlloc(nullptr, kStepSize, MEM_COMMIT, PAGE_READWRITE));
if (!buffer)
while (file.ReadAtCurrentPos(buffer, kStepSize) > 0) {}
::VirtualFree(buffer, 0, MEM_RELEASE);