1/*
2 * Copyright (C) 2008 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of Apple Inc. ("Apple") nor the names of
14 * its contributors may be used to endorse or promote products derived
15 * from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#pragma once
30
31#include <wtf/text/AtomString.h>
32#include <wtf/HashTraits.h>
33
34namespace WTF {
35
36 struct AtomStringHash {
37 static unsigned hash(const AtomString& key)
38 {
39 return key.impl()->existingHash();
40 }
41
42 static bool equal(const AtomString& a, const AtomString& b)
43 {
44 return a == b;
45 }
46
47 static const bool safeToCompareToEmptyOrDeleted = false;
48 };
49
50 template<> struct HashTraits<WTF::AtomString> : SimpleClassHashTraits<WTF::AtomString> {
51 static const bool hasIsEmptyValueFunction = true;
52 static bool isEmptyValue(const AtomString& value)
53 {
54 return value.isNull();
55 }
56
57 static void customDeleteBucket(AtomString& value)
58 {
59 // See unique_ptr's customDeleteBucket() for an explanation.
60 ASSERT(!isDeletedValue(value));
61 AtomString valueToBeDestroyed = WTFMove(value);
62 constructDeletedValue(value);
63 }
64 };
65
66}
67
68using WTF::AtomStringHash;
69