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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 
30 using namespace std;
31 
32 namespace WTF {
33 
CString(const char * str)34 CString::CString(const char* str)
35 {
36     if (!str)
37         return;
38 
39     init(str, strlen(str));
40 }
41 
CString(const char * str,size_t length)42 CString::CString(const char* str, size_t length)
43 {
44     init(str, length);
45 }
46 
init(const char * str,size_t length)47 void 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 
mutableData()63 char* CString::mutableData()
64 {
65     copyBufferIfNeeded();
66     if (!m_buffer)
67         return 0;
68     return m_buffer->mutableData();
69 }
70 
newUninitialized(size_t length,char * & characterBuffer)71 CString 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 
copyBufferIfNeeded()84 void 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 
operator ==(const CString & a,const CString & b)95 bool 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