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// Copyright (c) 2006-2008 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.
#ifndef BASE_PLATFORM_FILE_H_
#define BASE_PLATFORM_FILE_H_
#pragma once
#include "build/build_config.h"
#if defined(OS_WIN)
#include <windows.h>
#endif
#include <string>
class FilePath;
namespace base {
#if defined(OS_WIN)
typedef HANDLE PlatformFile;
const PlatformFile kInvalidPlatformFileValue = INVALID_HANDLE_VALUE;
#elif defined(OS_POSIX)
typedef int PlatformFile;
const PlatformFile kInvalidPlatformFileValue = -1;
#endif
enum PlatformFileFlags {
PLATFORM_FILE_OPEN = 1,
PLATFORM_FILE_CREATE = 2,
PLATFORM_FILE_OPEN_ALWAYS = 4, // May create a new file.
PLATFORM_FILE_CREATE_ALWAYS = 8, // May overwrite an old file.
PLATFORM_FILE_READ = 16,
PLATFORM_FILE_WRITE = 32,
PLATFORM_FILE_EXCLUSIVE_READ = 64, // EXCLUSIVE is opposite of Windows SHARE
PLATFORM_FILE_EXCLUSIVE_WRITE = 128,
PLATFORM_FILE_ASYNC = 256,
PLATFORM_FILE_TEMPORARY = 512, // Used on Windows only
PLATFORM_FILE_HIDDEN = 1024, // Used on Windows only
PLATFORM_FILE_DELETE_ON_CLOSE = 2048
};
// Creates or opens the given file. If PLATFORM_FILE_OPEN_ALWAYS is used, and
// |created| is provided, |created| will be set to true if the file was created
// or to false in case the file was just opened.
PlatformFile CreatePlatformFile(const FilePath& name,
int flags,
bool* created);
// Deprecated.
PlatformFile CreatePlatformFile(const std::wstring& name,
int flags,
bool* created);
// Closes a file handle
bool ClosePlatformFile(PlatformFile file);
// Use this class to pass ownership of a PlatformFile to a receiver that may or
// may not want to accept it. This class does not own the storage for the
// PlatformFile.
//
// EXAMPLE:
//
// void MaybeProcessFile(PassPlatformFile pass_file) {
// if (...) {
// PlatformFile file = pass_file.ReleaseValue();
// // Now, we are responsible for closing |file|.
// }
// }
//
// void OpenAndMaybeProcessFile(const FilePath& path) {
// PlatformFile file = CreatePlatformFile(path, ...);
// MaybeProcessFile(PassPlatformFile(&file));
// if (file != kInvalidPlatformFileValue)
// ClosePlatformFile(file);
// }
//
class PassPlatformFile {
public:
explicit PassPlatformFile(PlatformFile* value) : value_(value) {
}
// Called to retrieve the PlatformFile stored in this object. The caller
// gains ownership of the PlatformFile and is now responsible for closing it.
// Any subsequent calls to this method will return an invalid PlatformFile.
PlatformFile ReleaseValue() {
PlatformFile temp = *value_;
*value_ = kInvalidPlatformFileValue;
return temp;
}
private:
PlatformFile* value_;
};
} // namespace base
#endif // BASE_PLATFORM_FILE_H_
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