1 : /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
2 : * vim: set ts=8 sw=4 et tw=99 ft=cpp:
3 : *
4 : * ***** BEGIN LICENSE BLOCK *****
5 : * Version: MPL 1.1/GPL 2.0/LGPL 2.1
6 : *
7 : * The contents of this file are subject to the Mozilla Public License Version
8 : * 1.1 (the "License"); you may not use this file except in compliance with
9 : * the License. You may obtain a copy of the License at:
10 : * http://www.mozilla.org/MPL/
11 : *
12 : * Software distributed under the License is distributed on an "AS IS" basis,
13 : * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
14 : * for the specific language governing rights and limitations under the
15 : * License.
16 : *
17 : * The Original Code is Mozilla Code.
18 : *
19 : * The Initial Developer of the Original Code is
20 : * The Mozilla Foundation
21 : * Portions created by the Initial Developer are Copyright (C) 2011
22 : * the Initial Developer. All Rights Reserved.
23 : *
24 : * Contributor(s):
25 : * Justin Lebar <justin.lebar@gmail.com>
26 : *
27 : * Alternatively, the contents of this file may be used under the terms of
28 : * either the GNU General Public License Version 2 or later (the "GPL"), or
29 : * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
30 : * in which case the provisions of the GPL or the LGPL are applicable instead
31 : * of those above. If you wish to allow use of your version of this file only
32 : * under the terms of either the GPL or the LGPL, and not to allow others to
33 : * use your version of this file under the terms of the MPL, indicate your
34 : * decision by deleting the provisions above and replace them with the notice
35 : * and other provisions required by the GPL or the LGPL. If you do not delete
36 : * the provisions above, a recipient may use your version of this file under
37 : * the terms of any one of the MPL, the GPL or the LGPL.
38 : *
39 : * ***** END LICENSE BLOCK ***** */
40 :
41 : /* Implementations of hash functions */
42 :
43 : #include "mozilla/HashFunctions.h"
44 : #include <string.h>
45 :
46 : namespace mozilla {
47 :
48 : MFBT_API(uint32_t)
49 8550955 : HashBytes(const void* bytes, size_t length)
50 : {
51 8550955 : uint32_t hash = 0;
52 8550955 : const char* b = reinterpret_cast<const char*>(bytes);
53 :
54 : /* Walk word by word. */
55 8550955 : size_t i = 0;
56 42754775 : for (; i < length - (length % sizeof(size_t)); i += sizeof(size_t)) {
57 : /* Do an explicitly unaligned load of the data. */
58 : size_t data;
59 34203820 : memcpy(&data, b + i, sizeof(size_t));
60 :
61 34203820 : hash = AddToHash(hash, data, sizeof(data));
62 : }
63 :
64 : /* Get the remaining bytes. */
65 8550955 : for (; i < length; i++) {
66 0 : hash = AddToHash(hash, b[i]);
67 : }
68 :
69 8550955 : return hash;
70 : }
71 :
72 : } /* namespace mozilla */
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