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 COMPUTER, 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 COMPUTER, 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/RefCounted.h"
30#include "wtf/RefPtr.h"
31#include "wtf/WTFExport.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 PassRefPtr<CStringBuffer> createUninitialized(size_t length);
46
47    CStringBuffer(size_t length) : m_length(length) { }
48    char* mutableData() { return reinterpret_cast<char*>(this + 1); }
49
50    const unsigned 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 WTF_EXPORT CString {
56public:
57    CString() { }
58    CString(const char*);
59    CString(const char*, size_t length);
60    CString(CStringBuffer* buffer) : m_buffer(buffer) { }
61    static CString newUninitialized(size_t length, char*& characterBuffer);
62
63    const char* data() const
64    {
65        return m_buffer ? m_buffer->data() : 0;
66    }
67    char* mutableData();
68    size_t length() const
69    {
70        return m_buffer ? m_buffer->length() : 0;
71    }
72
73    bool isNull() const { return !m_buffer; }
74    bool isSafeToSendToAnotherThread() const;
75
76    CStringBuffer* buffer() const { return m_buffer.get(); }
77
78private:
79    void copyBufferIfNeeded();
80    void init(const char*, size_t length);
81    RefPtr<CStringBuffer> m_buffer;
82};
83
84WTF_EXPORT bool operator==(const CString& a, const CString& b);
85inline bool operator!=(const CString& a, const CString& b) { return !(a == b); }
86WTF_EXPORT bool operator==(const CString& a, const char* b);
87inline bool operator!=(const CString& a, const char* b) { return !(a == b); }
88
89} // namespace WTF
90
91using WTF::CString;
92
93#endif // CString_h
94