OLD | NEW |
| (Empty) |
1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | |
2 // Use of this source code is governed by a BSD-style license that can be | |
3 // found in the LICENSE file. | |
4 | |
5 #include "base/guid.h" | |
6 | |
7 #include <stdint.h> | |
8 | |
9 #include "base/rand_util.h" | |
10 #include "base/strings/stringprintf.h" | |
11 | |
12 namespace base { | |
13 | |
14 std::string GenerateGUID() { | |
15 uint64_t sixteen_bytes[2] = {base::RandUint64(), base::RandUint64()}; | |
16 | |
17 // Set the GUID to version 4 as described in RFC 4122, section 4.4. | |
18 // The format of GUID version 4 must be xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx, | |
19 // where y is one of [8, 9, A, B]. | |
20 | |
21 // Clear the version bits and set the version to 4: | |
22 sixteen_bytes[0] &= 0xffffffffffff0fffULL; | |
23 sixteen_bytes[0] |= 0x0000000000004000ULL; | |
24 | |
25 // Set the two most significant bits (bits 6 and 7) of the | |
26 // clock_seq_hi_and_reserved to zero and one, respectively: | |
27 sixteen_bytes[1] &= 0x3fffffffffffffffULL; | |
28 sixteen_bytes[1] |= 0x8000000000000000ULL; | |
29 | |
30 return RandomDataToGUIDString(sixteen_bytes); | |
31 } | |
32 | |
33 // TODO(cmasone): Once we're comfortable this works, migrate Windows code to | |
34 // use this as well. | |
35 std::string RandomDataToGUIDString(const uint64_t bytes[2]) { | |
36 return StringPrintf("%08X-%04X-%04X-%04X-%012llX", | |
37 static_cast<unsigned int>(bytes[0] >> 32), | |
38 static_cast<unsigned int>((bytes[0] >> 16) & 0x0000ffff), | |
39 static_cast<unsigned int>(bytes[0] & 0x0000ffff), | |
40 static_cast<unsigned int>(bytes[1] >> 48), | |
41 bytes[1] & 0x0000ffffffffffffULL); | |
42 } | |
43 | |
44 } // namespace base | |
OLD | NEW |