1/*
2 * Copyright (C) 2003, 2006, 2008, 2009, 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 * 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
27#include "config.h"
28#include "CString.h"
29
30using namespace std;
31
32namespace WTF {
33
34CString::CString(const char* str)
35{
36    if (!str)
37        return;
38
39    init(str, strlen(str));
40}
41
42CString::CString(const char* str, size_t length)
43{
44    init(str, length);
45}
46
47void CString::init(const char* str, size_t length)
48{
49    if (!str)
50        return;
51
52    // We need to be sure we can add 1 to length without overflowing.
53    // Since the passed-in length is the length of an actual existing
54    // string, and we know the string doesn't occupy the entire address
55    // space, we can assert here and there's no need for a runtime check.
56    ASSERT(length < numeric_limits<size_t>::max());
57
58    m_buffer = CStringBuffer::create(length + 1);
59    memcpy(m_buffer->mutableData(), str, length);
60    m_buffer->mutableData()[length] = '\0';
61}
62
63char* CString::mutableData()
64{
65    copyBufferIfNeeded();
66    if (!m_buffer)
67        return 0;
68    return m_buffer->mutableData();
69}
70
71CString CString::newUninitialized(size_t length, char*& characterBuffer)
72{
73    if (length >= numeric_limits<size_t>::max())
74        CRASH();
75
76    CString result;
77    result.m_buffer = CStringBuffer::create(length + 1);
78    char* bytes = result.m_buffer->mutableData();
79    bytes[length] = '\0';
80    characterBuffer = bytes;
81    return result;
82}
83
84void CString::copyBufferIfNeeded()
85{
86    if (!m_buffer || m_buffer->hasOneRef())
87        return;
88
89    RefPtr<CStringBuffer> buffer = m_buffer.release();
90    size_t length = buffer->length();
91    m_buffer = CStringBuffer::create(length);
92    memcpy(m_buffer->mutableData(), buffer->data(), length);
93}
94
95bool operator==(const CString& a, const CString& b)
96{
97    if (a.isNull() != b.isNull())
98        return false;
99    if (a.length() != b.length())
100        return false;
101    return !strncmp(a.data(), b.data(), min(a.length(), b.length()));
102}
103
104} // namespace WTF
105