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 * 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 "SmallStrings.h"
28
29#include "JSGlobalObject.h"
30#include "JSString.h"
31#include "JSCInlines.h"
32#include <wtf/Noncopyable.h>
33#include <wtf/text/StringImpl.h>
34
35namespace JSC {
36
37SmallStrings::SmallStrings()
38{
39 COMPILE_ASSERT(singleCharacterStringCount == sizeof(m_singleCharacterStrings) / sizeof(m_singleCharacterStrings[0]), IsNumCharactersConstInSyncWithClassUsage);
40
41 for (unsigned i = 0; i < singleCharacterStringCount; ++i)
42 m_singleCharacterStrings[i] = nullptr;
43}
44
45void SmallStrings::initializeCommonStrings(VM& vm)
46{
47 ASSERT(!m_emptyString);
48 m_emptyString = JSString::createEmptyString(vm);
49 ASSERT(m_needsToBeVisited);
50
51 for (unsigned i = 0; i < singleCharacterStringCount; ++i) {
52 ASSERT(!m_singleCharacterStrings[i]);
53 const LChar string[] = { static_cast<LChar>(i) };
54 m_singleCharacterStrings[i] = JSString::createHasOtherOwner(vm, AtomicStringImpl::add(string, 1).releaseNonNull());
55 ASSERT(m_needsToBeVisited);
56 }
57
58#define JSC_COMMON_STRINGS_ATTRIBUTE_INITIALIZE(name) initialize(&vm, m_##name, #name);
59 JSC_COMMON_STRINGS_EACH_NAME(JSC_COMMON_STRINGS_ATTRIBUTE_INITIALIZE)
60#undef JSC_COMMON_STRINGS_ATTRIBUTE_INITIALIZE
61 initialize(&vm, m_objectStringStart, "[object ");
62 initialize(&vm, m_nullObjectString, "[object Null]");
63 initialize(&vm, m_undefinedObjectString, "[object Undefined]");
64
65 setIsInitialized(true);
66}
67
68void SmallStrings::visitStrongReferences(SlotVisitor& visitor)
69{
70 m_needsToBeVisited = false;
71 visitor.appendUnbarriered(m_emptyString);
72 for (unsigned i = 0; i <= maxSingleCharacterString; ++i)
73 visitor.appendUnbarriered(m_singleCharacterStrings[i]);
74#define JSC_COMMON_STRINGS_ATTRIBUTE_VISIT(name) visitor.appendUnbarriered(m_##name);
75 JSC_COMMON_STRINGS_EACH_NAME(JSC_COMMON_STRINGS_ATTRIBUTE_VISIT)
76#undef JSC_COMMON_STRINGS_ATTRIBUTE_VISIT
77 visitor.appendUnbarriered(m_objectStringStart);
78 visitor.appendUnbarriered(m_nullObjectString);
79 visitor.appendUnbarriered(m_undefinedObjectString);
80}
81
82SmallStrings::~SmallStrings()
83{
84}
85
86Ref<StringImpl> SmallStrings::singleCharacterStringRep(unsigned char character)
87{
88 if (LIKELY(m_isInitialized))
89 return *const_cast<StringImpl*>(m_singleCharacterStrings[character]->tryGetValueImpl());
90 const LChar string[] = { static_cast<LChar>(character) };
91 return AtomicStringImpl::add(string, 1).releaseNonNull();
92}
93
94void SmallStrings::initialize(VM* vm, JSString*& string, const char* value)
95{
96 string = JSString::create(*vm, AtomicStringImpl::add(value).releaseNonNull());
97 ASSERT(m_needsToBeVisited);
98}
99
100} // namespace JSC
101