1/*
2 * Copyright (C) 2012-2016 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#include "config.h"
27#include "JSStringJoiner.h"
28
29#include "JSCInlines.h"
30
31namespace JSC {
32
33JSStringJoiner::~JSStringJoiner()
34{
35}
36
37template<typename CharacterType>
38static inline void appendStringToData(CharacterType*& data, StringView string)
39{
40 string.getCharactersWithUpconvert(data);
41 data += string.length();
42}
43
44template<typename CharacterType>
45static inline String joinStrings(const Vector<StringViewWithUnderlyingString>& strings, StringView separator, unsigned joinedLength)
46{
47 ASSERT(joinedLength);
48
49 CharacterType* data;
50 String result = StringImpl::tryCreateUninitialized(joinedLength, data);
51 if (UNLIKELY(result.isNull()))
52 return result;
53
54 appendStringToData(data, strings[0].view);
55
56 unsigned size = strings.size();
57
58 switch (separator.length()) {
59 case 0:
60 for (unsigned i = 1; i < size; ++i)
61 appendStringToData(data, strings[i].view);
62 break;
63 case 1: {
64 CharacterType separatorCharacter = separator[0];
65 for (unsigned i = 1; i < size; ++i) {
66 *data++ = separatorCharacter;
67 appendStringToData(data, strings[i].view);
68 }
69 break;
70 }
71 default:
72 for (unsigned i = 1; i < size; ++i) {
73 appendStringToData(data, separator);
74 appendStringToData(data, strings[i].view);
75 }
76 }
77 ASSERT(data == result.characters<CharacterType>() + joinedLength);
78
79 return result;
80}
81
82inline unsigned JSStringJoiner::joinedLength(ExecState& state) const
83{
84 VM& vm = state.vm();
85 auto scope = DECLARE_THROW_SCOPE(vm);
86
87 unsigned numberOfStrings = m_strings.size();
88 if (!numberOfStrings)
89 return 0;
90
91 Checked<int32_t, RecordOverflow> separatorLength = m_separator.length();
92 Checked<int32_t, RecordOverflow> totalSeparatorsLength = separatorLength * (numberOfStrings - 1);
93 Checked<int32_t, RecordOverflow> totalLength = totalSeparatorsLength + m_accumulatedStringsLength;
94
95 int32_t result;
96 if (totalLength.safeGet(result) == CheckedState::DidOverflow) {
97 throwOutOfMemoryError(&state, scope);
98 return 0;
99 }
100 return result;
101}
102
103JSValue JSStringJoiner::join(ExecState& state)
104{
105 VM& vm = state.vm();
106 auto scope = DECLARE_THROW_SCOPE(vm);
107
108 ASSERT(m_strings.size() <= m_strings.capacity());
109
110 unsigned length = joinedLength(state);
111 RETURN_IF_EXCEPTION(scope, JSValue());
112
113 if (!length)
114 return jsEmptyString(&state);
115
116 String result;
117 if (m_isAll8Bit)
118 result = joinStrings<LChar>(m_strings, m_separator, length);
119 else
120 result = joinStrings<UChar>(m_strings, m_separator, length);
121
122 if (result.isNull())
123 return throwOutOfMemoryError(&state, scope);
124
125 return jsString(&state, WTFMove(result));
126}
127
128}
129