C++ (Cpp) Handle::ContainsOnlyOneByte示例

StringType v8StringToWebCoreString(v8::Handle<v8::String> v8String, ExternalMode external)
{
    {
        // This portion of this function is very hot in certain Dromeao benchmarks.
        v8::String::Encoding encoding;
        v8::String::ExternalStringResourceBase* resource = v8String->GetExternalStringResourceBase(&encoding);
        if (LIKELY(!!resource)) {
            WebCoreStringResourceBase* base;
            if (encoding == v8::String::ONE_BYTE_ENCODING)
                base = static_cast<WebCoreStringResource8*>(resource);
            else
                base = static_cast<WebCoreStringResource16*>(resource);
            return StringTraits<StringType>::fromStringResource(base);
        }
    }

    int length = v8String->Length();
    if (UNLIKELY(!length))
        return StringType("");

    bool oneByte = v8String->ContainsOnlyOneByte();
    StringType result(oneByte ? StringTraits<StringType>::template fromV8String<V8StringOneByteTrait>(v8String, length) : StringTraits<StringType>::template fromV8String<V8StringTwoBytesTrait>(v8String, length));

    if (external != Externalize || !v8String->CanMakeExternal())
        return result;

    if (result.is8Bit()) {
        WebCoreStringResource8* stringResource = new WebCoreStringResource8(result);
        if (UNLIKELY(!v8String->MakeExternal(stringResource)))
            delete stringResource;
    } else {
        WebCoreStringResource16* stringResource = new WebCoreStringResource16(result);
        if (UNLIKELY(!v8String->MakeExternal(stringResource)))
            delete stringResource;
    }
    return result;
}