1/*
2 * Copyright (C) 2009 Google 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. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "bindings/core/v8/V8ValueCache.h"
28
29#include "bindings/core/v8/V8Binding.h"
30#include "wtf/text/StringHash.h"
31
32namespace blink {
33
34StringCacheMapTraits::MapType* StringCacheMapTraits::MapFromWeakCallbackData(
35    const v8::WeakCallbackData<v8::String, WeakCallbackDataType>& data)
36{
37    return &(V8PerIsolateData::from(data.GetIsolate())->stringCache()->m_stringCache);
38}
39
40
41void StringCacheMapTraits::Dispose(
42    v8::Isolate* isolate, v8::UniquePersistent<v8::String> value, StringImpl* key)
43{
44    V8PerIsolateData::from(isolate)->stringCache()->InvalidateLastString();
45    key->deref();
46}
47
48
49StringCache::~StringCache()
50{
51    // The MapType::Dispose callback calls StringCache::InvalidateLastString,
52    // which will only work while the destructor has not yet finished. Thus,
53    // we need to clear the map before the destructor has completed.
54    m_stringCache.Clear();
55}
56
57static v8::Local<v8::String> makeExternalString(const String& string, v8::Isolate* isolate)
58{
59    if (string.is8Bit()) {
60        WebCoreStringResource8* stringResource = new WebCoreStringResource8(string);
61        v8::Local<v8::String> newString = v8::String::NewExternal(isolate, stringResource);
62        if (newString.IsEmpty())
63            delete stringResource;
64        return newString;
65    }
66
67    WebCoreStringResource16* stringResource = new WebCoreStringResource16(string);
68    v8::Local<v8::String> newString = v8::String::NewExternal(isolate, stringResource);
69    if (newString.IsEmpty())
70        delete stringResource;
71    return newString;
72}
73
74v8::Handle<v8::String> StringCache::v8ExternalStringSlow(StringImpl* stringImpl, v8::Isolate* isolate)
75{
76    if (!stringImpl->length())
77        return v8::String::Empty(isolate);
78
79    StringCacheMapTraits::MapType::PersistentValueReference cachedV8String = m_stringCache.GetReference(stringImpl);
80    if (!cachedV8String.IsEmpty()) {
81        m_lastStringImpl = stringImpl;
82        m_lastV8String = cachedV8String;
83        return m_lastV8String.NewLocal(isolate);
84    }
85
86    return createStringAndInsertIntoCache(stringImpl, isolate);
87}
88
89void StringCache::setReturnValueFromStringSlow(v8::ReturnValue<v8::Value> returnValue, StringImpl* stringImpl)
90{
91    if (!stringImpl->length()) {
92        returnValue.SetEmptyString();
93        return;
94    }
95
96    StringCacheMapTraits::MapType::PersistentValueReference cachedV8String = m_stringCache.GetReference(stringImpl);
97    if (!cachedV8String.IsEmpty()) {
98        m_lastStringImpl = stringImpl;
99        m_lastV8String = cachedV8String;
100        m_lastV8String.SetReturnValue(returnValue);
101        return;
102    }
103
104    returnValue.Set(createStringAndInsertIntoCache(stringImpl, returnValue.GetIsolate()));
105}
106
107v8::Local<v8::String> StringCache::createStringAndInsertIntoCache(StringImpl* stringImpl, v8::Isolate* isolate)
108{
109    ASSERT(!m_stringCache.Contains(stringImpl));
110    ASSERT(stringImpl->length());
111
112    v8::Local<v8::String> newString = makeExternalString(String(stringImpl), isolate);
113    if (newString.IsEmpty())
114        return newString;
115
116    v8::UniquePersistent<v8::String> wrapper(isolate, newString);
117
118    stringImpl->ref();
119    wrapper.MarkIndependent();
120    m_stringCache.Set(stringImpl, wrapper.Pass(), &m_lastV8String);
121    m_lastStringImpl = stringImpl;
122
123    return newString;
124}
125
126void StringCache::InvalidateLastString()
127{
128    m_lastStringImpl = nullptr;
129    m_lastV8String.Reset();
130}
131
132} // namespace blink
133