1/*
2 * Copyright (C) 2008, 2010 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 *
8 * 1.  Redistributions of source code must retain the above copyright
9 *     notice, this list of conditions and the following disclaimer.
10 * 2.  Redistributions in binary form must reproduce the above copyright
11 *     notice, this list of conditions and the following disclaimer in the
12 *     documentation and/or other materials provided with the distribution.
13 * 3.  Neither the name of Apple Inc. ("Apple") nor the names of its
14 *     contributors may be used to endorse or promote products derived
15 *     from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#ifndef StringBuffer_h
30#define StringBuffer_h
31
32#include "wtf/Assertions.h"
33#include "wtf/text/StringImpl.h"
34#include "wtf/unicode/Unicode.h"
35
36namespace WTF {
37
38template <typename CharType>
39class StringBuffer {
40    WTF_MAKE_NONCOPYABLE(StringBuffer);
41public:
42    StringBuffer() { }
43
44    explicit StringBuffer(unsigned length)
45    {
46        CharType* characters;
47        m_data = StringImpl::createUninitialized(length, characters);
48    }
49
50    ~StringBuffer()
51    {
52    }
53
54    void shrink(unsigned newLength);
55
56    unsigned length() const { return m_data ? m_data->length() : 0; }
57    CharType* characters() { return length() ? const_cast<CharType*>(m_data->getCharacters<CharType>()) : 0; }
58
59    CharType& operator[](unsigned i) { ASSERT_WITH_SECURITY_IMPLICATION(i < length()); return characters()[i]; }
60
61    PassRefPtr<StringImpl> release() { return m_data.release(); }
62
63private:
64    RefPtr<StringImpl> m_data;
65};
66
67template <typename CharType>
68void StringBuffer<CharType>::shrink(unsigned newLength)
69{
70    ASSERT(m_data);
71    if (m_data->length() == newLength)
72        return;
73    m_data->truncateAssumingIsolated(newLength);
74}
75
76} // namespace WTF
77
78using WTF::StringBuffer;
79
80#endif // StringBuffer_h
81