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 WTF_EXPORT 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    friend class RefCounted<CStringBuffer>;
45    // CStringBuffers are allocated out of the WTF buffer partition.
46    void* operator new(size_t, void* ptr) { return ptr; };
47    void operator delete(void*);
48
49    static PassRefPtr<CStringBuffer> createUninitialized(size_t length);
50
51    CStringBuffer(size_t length) : m_length(length) { }
52    char* mutableData() { return reinterpret_cast<char*>(this + 1); }
53
54    const unsigned m_length;
55};
56
57// A container for a null-terminated char array supporting copy-on-write
58// assignment.  The contained char array may be null.
59class WTF_EXPORT CString {
60public:
61    CString() { }
62    CString(const char*);
63    CString(const char*, size_t length);
64    CString(CStringBuffer* buffer) : m_buffer(buffer) { }
65    static CString newUninitialized(size_t length, char*& characterBuffer);
66
67    const char* data() const
68    {
69        return m_buffer ? m_buffer->data() : 0;
70    }
71    char* mutableData();
72    size_t length() const
73    {
74        return m_buffer ? m_buffer->length() : 0;
75    }
76
77    bool isNull() const { return !m_buffer; }
78    bool isSafeToSendToAnotherThread() const;
79
80    CStringBuffer* buffer() const { return m_buffer.get(); }
81
82private:
83    void copyBufferIfNeeded();
84    void init(const char*, size_t length);
85    RefPtr<CStringBuffer> m_buffer;
86};
87
88WTF_EXPORT bool operator==(const CString& a, const CString& b);
89inline bool operator!=(const CString& a, const CString& b) { return !(a == b); }
90WTF_EXPORT bool operator==(const CString& a, const char* b);
91inline bool operator!=(const CString& a, const char* b) { return !(a == b); }
92
93} // namespace WTF
94
95using WTF::CString;
96
97#endif // CString_h
98