1/*
2 * Copyright (C) 2003-2017 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. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#pragma once
27
28#include <wtf/HashFunctions.h>
29#include <wtf/HashTraits.h>
30#include <wtf/Ref.h>
31#include <wtf/RefCounted.h>
32
33namespace WTF {
34
35// CStringBuffer is the ref-counted storage class for the characters in a CString.
36// The data is implicitly allocated 1 character longer than length(), as it is zero-terminated.
37class CStringBuffer : public RefCounted<CStringBuffer> {
38public:
39 const char* data() { return mutableData(); }
40 size_t length() const { return m_length; }
41
42private:
43 friend class CString;
44
45 static Ref<CStringBuffer> createUninitialized(size_t length);
46
47 CStringBuffer(size_t length) : m_length(length) { }
48 char* mutableData() { return reinterpret_cast_ptr<char*>(this + 1); }
49
50 const size_t m_length;
51};
52
53// A container for a null-terminated char array supporting copy-on-write
54// assignment. The contained char array may be null.
55class CString {
56public:
57 CString() { }
58 WTF_EXPORT_PRIVATE CString(const char*);
59 WTF_EXPORT_PRIVATE CString(const char*, size_t length);
60 CString(CStringBuffer* buffer) : m_buffer(buffer) { }
61 WTF_EXPORT_PRIVATE static CString newUninitialized(size_t length, char*& characterBuffer);
62 CString(HashTableDeletedValueType) : m_buffer(HashTableDeletedValue) { }
63
64 const char* data() const
65 {
66 return m_buffer ? m_buffer->data() : 0;
67 }
68 WTF_EXPORT_PRIVATE char* mutableData();
69 size_t length() const
70 {
71 return m_buffer ? m_buffer->length() : 0;
72 }
73
74 bool isNull() const { return !m_buffer; }
75 bool isSafeToSendToAnotherThread() const;
76
77 CStringBuffer* buffer() const { return m_buffer.get(); }
78
79 bool isHashTableDeletedValue() const { return m_buffer.isHashTableDeletedValue(); }
80
81 WTF_EXPORT_PRIVATE unsigned hash() const;
82
83private:
84 void copyBufferIfNeeded();
85 void init(const char*, size_t length);
86 RefPtr<CStringBuffer> m_buffer;
87};
88
89WTF_EXPORT_PRIVATE bool operator==(const CString& a, const CString& b);
90inline bool operator!=(const CString& a, const CString& b) { return !(a == b); }
91WTF_EXPORT_PRIVATE bool operator==(const CString& a, const char* b);
92inline bool operator!=(const CString& a, const char* b) { return !(a == b); }
93WTF_EXPORT_PRIVATE bool operator<(const CString& a, const CString& b);
94
95struct CStringHash {
96 static unsigned hash(const CString& string) { return string.hash(); }
97 WTF_EXPORT_PRIVATE static bool equal(const CString& a, const CString& b);
98 static const bool safeToCompareToEmptyOrDeleted = true;
99};
100
101template<typename T> struct DefaultHash;
102template<> struct DefaultHash<CString> {
103 typedef CStringHash Hash;
104};
105
106template<typename T> struct HashTraits;
107template<> struct HashTraits<CString> : SimpleClassHashTraits<CString> { };
108
109} // namespace WTF
110
111using WTF::CString;
112