C++程序  |  55行  |  2.73 KB

/*
* Copyright (C) 2010 Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
*     * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef UUID_h
#define UUID_h

#include "PlatformString.h"

namespace WebCore {

// Creates a UUID that consists of 32 hexadecimal digits and returns its canonical form.
// The canonical form is displayed in 5 groups separated by hyphens, in the form 8-4-4-4-12 for a total of 36 characters.
// The hexadecimal values "a" through "f" are output as lower case characters.
//
// Note: for security reason, we should always generate version 4 UUID that use a scheme relying only on random numbers.
// This algorithm sets the version number as well as two reserved bits. All other bits are set using a random or pseudorandom
// data source. Version 4 UUIDs have the form xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx with hexadecimal digits for x and one of 8,
// 9, A, or B for y.
//
// On Windows, version 4 UUIDs are used since Windows 2000 (http://msdn.microsoft.com/en-us/library/aa446557.aspx).
// On MacOSX, version 4 UUIDs are used since Tiger (http://developer.apple.com/mac/library/technotes/tn/tn1103.html#TNTAG8).
// On Linux, the kernel offers the procfs pseudo-file /proc/sys/kernel/random/uuid that yields version 4 UUIDs (http://hbfs.wordpress.com/2008/09/30/ueid-unique-enough-ids/).
String createCanonicalUUIDString();

}

#endif