1/*
2 * Copyright (C) 2012 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 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#ifndef StringReference_h
27#define StringReference_h
28
29#include <string.h>
30#include <wtf/Forward.h>
31#include <wtf/HashTraits.h>
32
33namespace IPC {
34
35class Encoder;
36class Decoder;
37
38class StringReference {
39public:
40 StringReference()
41 : m_data(0)
42 , m_size(0)
43 {
44 }
45
46 StringReference(const char* data, size_t size)
47 : m_data(data)
48 , m_size(size)
49 {
50 }
51
52 template<size_t length>
53 StringReference(const char (&string)[length])
54 : m_data(string)
55 , m_size(length - 1)
56 {
57 }
58
59 bool isEmpty() const { return !m_size; }
60
61 size_t size() const { return m_size; }
62 const char* data() const { return m_data; }
63
64 CString toString() const;
65
66 friend bool operator==(const StringReference& a, const StringReference& b)
67 {
68 return a.m_size == b.m_size && !memcmp(a.m_data, b.m_data, a.m_size);
69 }
70
71 void encode(Encoder&) const;
72 static bool decode(Decoder&, StringReference&);
73
74 struct Hash {
75 static unsigned hash(const StringReference& a);
76 static bool equal(const StringReference& a, const StringReference& b) { return a == b; }
77 static const bool safeToCompareToEmptyOrDeleted = true;
78 };
79
80private:
81 const char* m_data;
82 size_t m_size;
83};
84
85} // namespace IPC
86
87namespace WTF {
88template<typename T> struct DefaultHash;
89
90template<> struct DefaultHash<IPC::StringReference> {
91 typedef IPC::StringReference::Hash Hash;
92};
93
94template<> struct HashTraits<IPC::StringReference> : GenericHashTraits<IPC::StringReference> {
95 static const bool emptyValueIsZero = 0;
96 static void constructDeletedValue(IPC::StringReference& stringReference) { stringReference = IPC::StringReference(0, std::numeric_limits<size_t>::max()); }
97 static bool isDeletedValue(const IPC::StringReference& stringReference) { return stringReference.size() == std::numeric_limits<size_t>::max(); }
98};
99
100} // namespace WTF
101
102#endif // StringReference_h
103