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27 #include "bindings/v8/V8StringResource.h"
29 #include "bindings/v8/V8Binding.h"
30 #include "core/inspector/BindingVisitors.h"
31 #include "wtf/MainThread.h"
35 template<class StringClass> struct StringTraits {
36 static const StringClass& fromStringResource(WebCoreStringResourceBase*);
37 template <typename V8StringTrait>
38 static StringClass fromV8String(v8::Handle<v8::String>, int);
42 struct StringTraits<String> {
43 static const String& fromStringResource(WebCoreStringResourceBase* resource)
45 return resource->webcoreString();
47 template <typename V8StringTrait>
48 static String fromV8String(v8::Handle<v8::String>, int);
52 struct StringTraits<AtomicString> {
53 static const AtomicString& fromStringResource(WebCoreStringResourceBase* resource)
55 return resource->atomicString();
57 template <typename V8StringTrait>
58 static AtomicString fromV8String(v8::Handle<v8::String>, int);
61 struct V8StringTwoBytesTrait {
62 typedef UChar CharType;
63 ALWAYS_INLINE static void write(v8::Handle<v8::String> v8String, CharType* buffer, int length)
65 v8String->Write(reinterpret_cast<uint16_t*>(buffer), 0, length);
69 struct V8StringOneByteTrait {
70 typedef LChar CharType;
71 ALWAYS_INLINE static void write(v8::Handle<v8::String> v8String, CharType* buffer, int length)
73 v8String->WriteOneByte(buffer, 0, length);
77 template <typename V8StringTrait>
78 String StringTraits<String>::fromV8String(v8::Handle<v8::String> v8String, int length)
80 ASSERT(v8String->Length() == length);
81 typename V8StringTrait::CharType* buffer;
82 String result = String::createUninitialized(length, buffer);
83 V8StringTrait::write(v8String, buffer, length);
87 template <typename V8StringTrait>
88 AtomicString StringTraits<AtomicString>::fromV8String(v8::Handle<v8::String> v8String, int length)
90 ASSERT(v8String->Length() == length);
91 static const int inlineBufferSize = 32 / sizeof(typename V8StringTrait::CharType);
92 if (length <= inlineBufferSize) {
93 typename V8StringTrait::CharType inlineBuffer[inlineBufferSize];
94 V8StringTrait::write(v8String, inlineBuffer, length);
95 return AtomicString(inlineBuffer, length);
97 typename V8StringTrait::CharType* buffer;
98 String string = String::createUninitialized(length, buffer);
99 V8StringTrait::write(v8String, buffer, length);
100 return AtomicString(string);
103 template<typename StringType>
104 StringType v8StringToWebCoreString(v8::Handle<v8::String> v8String, ExternalMode external)
107 // This portion of this function is very hot in certain Dromeao benchmarks.
108 v8::String::Encoding encoding;
109 v8::String::ExternalStringResourceBase* resource = v8String->GetExternalStringResourceBase(&encoding);
110 if (LIKELY(!!resource)) {
111 WebCoreStringResourceBase* base;
112 if (encoding == v8::String::ONE_BYTE_ENCODING)
113 base = static_cast<WebCoreStringResource8*>(resource);
115 base = static_cast<WebCoreStringResource16*>(resource);
116 return StringTraits<StringType>::fromStringResource(base);
120 int length = v8String->Length();
121 if (UNLIKELY(!length))
122 return StringType("");
124 bool oneByte = v8String->ContainsOnlyOneByte();
125 StringType result(oneByte ? StringTraits<StringType>::template fromV8String<V8StringOneByteTrait>(v8String, length) : StringTraits<StringType>::template fromV8String<V8StringTwoBytesTrait>(v8String, length));
127 if (external != Externalize || !v8String->CanMakeExternal())
130 if (result.is8Bit()) {
131 WebCoreStringResource8* stringResource = new WebCoreStringResource8(result);
132 if (UNLIKELY(!v8String->MakeExternal(stringResource)))
133 delete stringResource;
135 WebCoreStringResource16* stringResource = new WebCoreStringResource16(result);
136 if (UNLIKELY(!v8String->MakeExternal(stringResource)))
137 delete stringResource;
142 // Explicitly instantiate the above template with the expected parameterizations,
143 // to ensure the compiler generates the code; otherwise link errors can result in GCC 4.4.
144 template String v8StringToWebCoreString<String>(v8::Handle<v8::String>, ExternalMode);
145 template AtomicString v8StringToWebCoreString<AtomicString>(v8::Handle<v8::String>, ExternalMode);
147 // Fast but non thread-safe version.
148 String int32ToWebCoreStringFast(int value)
150 // Caching of small strings below is not thread safe: newly constructed AtomicString
151 // are not safely published.
152 ASSERT(isMainThread());
154 // Most numbers used are <= 100. Even if they aren't used there's very little cost in using the space.
155 const int kLowNumbers = 100;
156 DEFINE_STATIC_LOCAL(Vector<AtomicString>, lowNumbers, (kLowNumbers + 1));
157 String webCoreString;
158 if (0 <= value && value <= kLowNumbers) {
159 webCoreString = lowNumbers[value];
160 if (!webCoreString) {
161 AtomicString valueString = AtomicString::number(value);
162 lowNumbers[value] = valueString;
163 webCoreString = valueString;
166 webCoreString = String::number(value);
167 return webCoreString;
170 String int32ToWebCoreString(int value)
172 // If we are on the main thread (this should always true for non-workers), call the faster one.
174 return int32ToWebCoreStringFast(value);
175 return String::number(value);
178 } // namespace WebCore