1/*
2 * Copyright (C) 2003, 2006, 2008, 2009, 2010, 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. ``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#ifndef CString_h
27#define CString_h
28
29#include <wtf/HashFunctions.h>
30#include <wtf/HashTraits.h>
31#include <wtf/PassRefPtr.h>
32#include <wtf/RefCounted.h>
33
34namespace WTF {
35
36// CStringBuffer is the ref-counted storage class for the characters in a CString.
37// The data is implicitly allocated 1 character longer than length(), as it is zero-terminated.
38class CStringBuffer : public RefCounted<CStringBuffer> {
39public:
40 const char* data() { return mutableData(); }
41 size_t length() const { return m_length; }
42
43private:
44 friend class CString;
45
46 static PassRefPtr<CStringBuffer> createUninitialized(size_t length);
47
48 CStringBuffer(size_t length) : m_length(length) { }
49 char* mutableData() { return reinterpret_cast_ptr<char*>(this + 1); }
50
51 const size_t m_length;
52};
53
54// A container for a null-terminated char array supporting copy-on-write
55// assignment. The contained char array may be null.
56class CString {
57public:
58 CString() { }
59 WTF_EXPORT_PRIVATE CString(const char*);
60 WTF_EXPORT_PRIVATE CString(const char*, size_t length);
61 CString(CStringBuffer* buffer) : m_buffer(buffer) { }
62 WTF_EXPORT_PRIVATE static CString newUninitialized(size_t length, char*& characterBuffer);
63 CString(HashTableDeletedValueType) : m_buffer(HashTableDeletedValue) { }
64
65 const char* data() const
66 {
67 return m_buffer ? m_buffer->data() : 0;
68 }
69 WTF_EXPORT_PRIVATE char* mutableData();
70 size_t length() const
71 {
72 return m_buffer ? m_buffer->length() : 0;
73 }
74
75 bool isNull() const { return !m_buffer; }
76 bool isSafeToSendToAnotherThread() const;
77
78 CStringBuffer* buffer() const { return m_buffer.get(); }
79
80 bool isHashTableDeletedValue() const { return m_buffer.isHashTableDeletedValue(); }
81
82 WTF_EXPORT_PRIVATE unsigned hash() const;
83
84private:
85 void copyBufferIfNeeded();
86 void init(const char*, size_t length);
87 RefPtr<CStringBuffer> m_buffer;
88};
89
90WTF_EXPORT_PRIVATE bool operator==(const CString& a, const CString& b);
91inline bool operator!=(const CString& a, const CString& b) { return !(a == b); }
92WTF_EXPORT_PRIVATE bool operator==(const CString& a, const char* b);
93inline bool operator!=(const CString& a, const char* b) { return !(a == b); }
94WTF_EXPORT_PRIVATE bool operator<(const CString& a, const CString& b);
95
96struct CStringHash {
97 static unsigned hash(const CString& string) { return string.hash(); }
98 WTF_EXPORT_PRIVATE static bool equal(const CString& a, const CString& b);
99 static const bool safeToCompareToEmptyOrDeleted = true;
100};
101
102template<typename T> struct DefaultHash;
103template<> struct DefaultHash<CString> {
104 typedef CStringHash Hash;
105};
106
107template<typename T> struct HashTraits;
108template<> struct HashTraits<CString> : SimpleClassHashTraits<CString> { };
109
110} // namespace WTF
111
112using WTF::CString;
113
114#endif // CString_h
115