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
27#include "config.h"
28#include "CString.h"
29
30#include <string.h>
31#include <wtf/StringHasher.h>
32
33namespace WTF {
34
35PassRefPtr<CStringBuffer> CStringBuffer::createUninitialized(size_t length)
36{
37    RELEASE_ASSERT(length < (std::numeric_limits<unsigned>::max() - sizeof(CStringBuffer)));
38
39    // The +1 is for the terminating null character.
40    size_t size = sizeof(CStringBuffer) + length + 1;
41    CStringBuffer* stringBuffer = static_cast<CStringBuffer*>(fastMalloc(size));
42    return adoptRef(new (NotNull, stringBuffer) CStringBuffer(length));
43}
44
45CString::CString(const char* str)
46{
47    if (!str)
48        return;
49
50    init(str, strlen(str));
51}
52
53CString::CString(const char* str, size_t length)
54{
55    if (!str) {
56        ASSERT(!length);
57        return;
58    }
59
60    init(str, length);
61}
62
63void CString::init(const char* str, size_t length)
64{
65    ASSERT(str);
66
67    m_buffer = CStringBuffer::createUninitialized(length);
68    memcpy(m_buffer->mutableData(), str, length);
69    m_buffer->mutableData()[length] = '\0';
70}
71
72char* CString::mutableData()
73{
74    copyBufferIfNeeded();
75    if (!m_buffer)
76        return 0;
77    return m_buffer->mutableData();
78}
79
80CString CString::newUninitialized(size_t length, char*& characterBuffer)
81{
82    CString result;
83    result.m_buffer = CStringBuffer::createUninitialized(length);
84    char* bytes = result.m_buffer->mutableData();
85    bytes[length] = '\0';
86    characterBuffer = bytes;
87    return result;
88}
89
90void CString::copyBufferIfNeeded()
91{
92    if (!m_buffer || m_buffer->hasOneRef())
93        return;
94
95    RefPtr<CStringBuffer> buffer = m_buffer.release();
96    size_t length = buffer->length();
97    m_buffer = CStringBuffer::createUninitialized(length);
98    memcpy(m_buffer->mutableData(), buffer->data(), length + 1);
99}
100
101bool CString::isSafeToSendToAnotherThread() const
102{
103    return !m_buffer || m_buffer->hasOneRef();
104}
105
106bool operator==(const CString& a, const CString& b)
107{
108    if (a.isNull() != b.isNull())
109        return false;
110    if (a.length() != b.length())
111        return false;
112    return !memcmp(a.data(), b.data(), a.length());
113}
114
115bool operator==(const CString& a, const char* b)
116{
117    if (a.isNull() != !b)
118        return false;
119    if (!b)
120        return true;
121    return !strcmp(a.data(), b);
122}
123
124unsigned CString::hash() const
125{
126    if (isNull())
127        return 0;
128    StringHasher hasher;
129    for (const char* ptr = data(); *ptr; ++ptr)
130        hasher.addCharacter(*ptr);
131    return hasher.hash();
132}
133
134bool operator<(const CString& a, const CString& b)
135{
136    if (a.isNull())
137        return !b.isNull();
138    if (b.isNull())
139        return false;
140    return strcmp(a.data(), b.data()) < 0;
141}
142
143bool CStringHash::equal(const CString& a, const CString& b)
144{
145    if (a.isHashTableDeletedValue())
146        return b.isHashTableDeletedValue();
147    if (b.isHashTableDeletedValue())
148        return false;
149    return a == b;
150}
151
152} // namespace WTF
153