Source/WebCore/bindings/v8/V8Binding.h

/*
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#ifndef V8Binding_h
#define V8Binding_h

#include "BindingSecurity.h"
#include "Document.h"
#include "V8BindingMacros.h"
#include "V8DOMConfiguration.h"
#include "V8DOMWindowShell.h"
#include "V8DOMWrapper.h"
#include "V8HiddenPropertyName.h"
#include "V8ObjectConstructor.h"
#include "V8PerIsolateData.h"
#include "V8StringResource.h"
#include "V8ThrowException.h"
#include "V8ValueCache.h"
#include <wtf/Noncopyable.h>
#include <wtf/text/AtomicString.h>
#include <v8.h>

namespace WebCore {

    class DOMStringList;
    class ScriptExecutionContext;
    class WorldContextHandle;

    const int kMaxRecursionDepth = 22;

    // Schedule a DOM exception to be thrown, if the exception code is different
    // from zero.
    v8::Handle<v8::Value> setDOMException(int, v8::Isolate*);

    // Schedule a JavaScript error to be thrown.
    v8::Handle<v8::Value> throwError(ErrorType, const char*, v8::Isolate* = 0);

    // Schedule a JavaScript error to be thrown.
    v8::Handle<v8::Value> throwError(v8::Local<v8::Value>, v8::Isolate* = 0);

    // A helper for throwing JavaScript TypeError.
    v8::Handle<v8::Value> throwTypeError(const char* = 0, v8::Isolate* = 0);

    // A helper for throwing JavaScript TypeError for not enough arguments.
    v8::Handle<v8::Value> throwNotEnoughArgumentsError(v8::Isolate*);

    // Since v8::Null(isolate) crashes if we pass a null isolate,
    // we need to use v8NullWithCheck(isolate) if an isolate can be null.
    //
    // FIXME: Remove all null isolates from V8 bindings, and remove v8NullWithCheck(isolate).
    inline v8::Handle<v8::Value> v8NullWithCheck(v8::Isolate* isolate)
    {
        return isolate ? v8::Null(isolate) : v8::Null();
    }

    // Convert v8 types to a WTF::String. If the V8 string is not already
    // an external string then it is transformed into an external string at this
    // point to avoid repeated conversions.
    String toWebCoreString(v8::Handle<v8::Value>);

    // Convert a V8 value to a WTF::AtomicString.
    AtomicString toWebCoreAtomicString(v8::Handle<v8::Value>);

    // Return a V8 external string that shares the underlying buffer with the given
    // WebCore string. The reference counting mechanism is used to keep the
    // underlying buffer alive while the string is still live in the V8 engine.
    inline v8::Local<v8::String> v8ExternalString(const String& string, v8::Isolate* isolate = 0)
    {
        StringImpl* stringImpl = string.impl();
        if (!stringImpl)
            return isolate ? v8::String::Empty(isolate) : v8::String::Empty();
        if (UNLIKELY(!isolate))
            isolate = v8::Isolate::GetCurrent();
        return V8PerIsolateData::from(isolate)->stringCache()->v8ExternalString(stringImpl, isolate);
    }

    // Convert a string to a V8 string.
    inline v8::Handle<v8::String> v8String(const String& string, v8::Isolate* isolate = 0)
    {
        return v8ExternalString(string, isolate);
    }

    inline v8::Handle<v8::Integer> v8Integer(int value, v8::Isolate* isolate = 0)
    {
        if (UNLIKELY(!isolate))
            isolate = v8::Isolate::GetCurrent();
        return V8PerIsolateData::from(isolate)->integerCache()->v8Integer(value, isolate);
    }

    inline v8::Handle<v8::Integer> v8UnsignedInteger(unsigned value, v8::Isolate* isolate = 0)
    {
        if (UNLIKELY(!isolate))
            isolate = v8::Isolate::GetCurrent();
        return V8PerIsolateData::from(isolate)->integerCache()->v8UnsignedInteger(value, isolate);
    }

    inline v8::Handle<v8::Value> v8Undefined()
    {
        return v8::Handle<v8::Value>();
    }

    template <class T>
    struct V8ValueTraits {
        static inline v8::Handle<v8::Value> arrayV8Value(const T& value, v8::Isolate* isolate)
        {
            return toV8(WTF::getPtr(value), v8::Handle<v8::Object>(), isolate);
        }
    };

    template<>
    struct V8ValueTraits<String> {
        static inline v8::Handle<v8::Value> arrayV8Value(const String& value, v8::Isolate* isolate)
        {
            return v8String(value, isolate);
        }
    };

    template<>
    struct V8ValueTraits<unsigned long> {
        static inline v8::Handle<v8::Value> arrayV8Value(const unsigned long& value, v8::Isolate* isolate)
        {
            return v8UnsignedInteger(value, isolate);
        }
    };

    template<>
    struct V8ValueTraits<float> {
        static inline v8::Handle<v8::Value> arrayV8Value(const float& value, v8::Isolate*)
        {
            return v8::Number::New(value);
        }
    };

    template<>
    struct V8ValueTraits<double> {
        static inline v8::Handle<v8::Value> arrayV8Value(const double& value, v8::Isolate*)
        {
            return v8::Number::New(value);
        }
    };

    template<typename T>
    v8::Handle<v8::Value> v8Array(const Vector<T>& iterator, v8::Isolate* isolate)
    {
        v8::Local<v8::Array> result = v8::Array::New(iterator.size());
        int index = 0;
        typename Vector<T>::const_iterator end = iterator.end();
        typedef V8ValueTraits<T> TraitsType;
        for (typename Vector<T>::const_iterator iter = iterator.begin(); iter != end; ++iter)
            result->Set(v8Integer(index++, isolate), TraitsType::arrayV8Value(*iter, isolate));
        return result;
    }

    v8::Handle<v8::Value> v8Array(PassRefPtr<DOMStringList>, v8::Isolate*);

    template<class T> struct NativeValueTraits;

    template<>
    struct NativeValueTraits<String> {
        static inline String nativeValue(const v8::Handle<v8::Value>& value)
        {
            return toWebCoreString(value);
        }
    };

    template<>
    struct NativeValueTraits<float> {
        static inline float nativeValue(const v8::Handle<v8::Value>& value)
        {
            return static_cast<float>(value->NumberValue());
        }
    };

    template<>
    struct NativeValueTraits<double> {
        static inline double nativeValue(const v8::Handle<v8::Value>& value)
        {
            return static_cast<double>(value->NumberValue());
        }
    };


    template <class T>
    Vector<T> toNativeArray(v8::Handle<v8::Value> value)
    {
        if (!value->IsArray())
            return Vector<T>();

        Vector<T> result;
        typedef NativeValueTraits<T> TraitsType;
        v8::Local<v8::Value> v8Value(v8::Local<v8::Value>::New(value));
        v8::Local<v8::Array> array = v8::Local<v8::Array>::Cast(v8Value);
        size_t length = array->Length();
        for (size_t i = 0; i < length; ++i)
            result.append(TraitsType::nativeValue(array->Get(i)));
        return result;
    }

    template <class T>
    Vector<T> toNativeArguments(const v8::Arguments& args, int startIndex)
    {
        ASSERT(startIndex <= args.Length());
        Vector<T> result;
        typedef NativeValueTraits<T> TraitsType;
        int length = args.Length();
        for (int i = startIndex; i < length; ++i)
            result.append(TraitsType::nativeValue(args[i]));
        return result;
    }


    // Validates that the passed object is a sequence type per WebIDL spec
    // http://www.w3.org/TR/2012/WD-WebIDL-20120207/#es-sequence
    inline v8::Handle<v8::Value> toV8Sequence(v8::Handle<v8::Value> value, uint32_t& length)
    {
        if (!value->IsObject()) {
            throwTypeError();
            return v8Undefined();
        }

        v8::Local<v8::Value> v8Value(v8::Local<v8::Value>::New(value));
        v8::Local<v8::Object> object = v8::Local<v8::Object>::Cast(v8Value);

        EXCEPTION_BLOCK(v8::Local<v8::Value>, lengthValue, object->Get(v8::String::New("length")));

        if (lengthValue->IsUndefined() || lengthValue->IsNull()) {
            throwTypeError();
            return v8Undefined();
        }

        EXCEPTION_BLOCK(uint32_t, sequenceLength, lengthValue->Int32Value());
        length = sequenceLength;

        return v8Value;
    }

    // Convert a value to a 32-bit integer.  The conversion fails if the
    // value cannot be converted to an integer or converts to nan or to an infinity.
    int toInt32(v8::Handle<v8::Value> value, bool& ok);

    // Convert a value to a 32-bit integer assuming the conversion cannot fail.
    inline int toInt32(v8::Handle<v8::Value> value)
    {
        bool ok;
        return toInt32(value, ok);
    }

    // Convert a value to a 32-bit unsigned integer.  The conversion fails if the
    // value cannot be converted to an unsigned integer or converts to nan or to an infinity.
    uint32_t toUInt32(v8::Handle<v8::Value> value, bool& ok);

    // Convert a value to a 32-bit unsigned integer assuming the conversion cannot fail.
    inline uint32_t toUInt32(v8::Handle<v8::Value> value)
    {
        bool ok;
        return toUInt32(value, ok);
    }

    inline float toFloat(v8::Local<v8::Value> value)
    {
        return static_cast<float>(value->NumberValue());
    }

    inline long long toInt64(v8::Local<v8::Value> value)
    {
        return static_cast<long long>(value->IntegerValue());
    }

    inline bool isUndefinedOrNull(v8::Handle<v8::Value> value)
    {
        return value->IsNull() || value->IsUndefined();
    }

    // Returns true if the provided object is to be considered a 'host object', as used in the
    // HTML5 structured clone algorithm.
    inline bool isHostObject(v8::Handle<v8::Object> object)
    {
        // If the object has any internal fields, then we won't be able to serialize or deserialize
        // them; conveniently, this is also a quick way to detect DOM wrapper objects, because
        // the mechanism for these relies on data stored in these fields. We should
        // catch external array data as a special case.
        return object->InternalFieldCount() || object->HasIndexedPropertiesInExternalArrayData();
    }

    inline v8::Handle<v8::Boolean> v8Boolean(bool value)
    {
        return value ? v8::True() : v8::False();
    }

    inline v8::Handle<v8::Boolean> v8Boolean(bool value, v8::Isolate* isolate)
    {
        return value ? v8::True(isolate) : v8::False(isolate);
    }

    // Since v8Boolean(value, isolate) crashes if we pass a null isolate,
    // we need to use v8BooleanWithCheck(value, isolate) if an isolate can be null.
    //
    // FIXME: Remove all null isolates from V8 bindings, and remove v8BooleanWithCheck(value, isolate).
    inline v8::Handle<v8::Boolean> v8BooleanWithCheck(bool value, v8::Isolate* isolate)
    {
        return isolate ? v8Boolean(value, isolate) : v8Boolean(value);
    }

    inline String toWebCoreStringWithNullCheck(v8::Handle<v8::Value> value)
    {
        return value->IsNull() ? String() : toWebCoreString(value);
    }

    inline String toWebCoreStringWithNullOrUndefinedCheck(v8::Handle<v8::Value> value)
    {
        return (value->IsNull() || value->IsUndefined()) ? String() : toWebCoreString(value);
    }

    inline AtomicString toWebCoreAtomicStringWithNullCheck(v8::Handle<v8::Value> value)
    {
        return value->IsNull() ? AtomicString() : toWebCoreAtomicString(value);
    }

    inline v8::Handle<v8::Value> v8StringOrNull(const String& str, v8::Isolate* isolate = 0)
    {
        return str.isNull() ? v8::Handle<v8::Value>(v8::Null()) : v8::Handle<v8::Value>(v8String(str, isolate));
    }

    inline v8::Handle<v8::Value> v8StringOrUndefined(const String& str, v8::Isolate* isolate = 0)
    {
        return str.isNull() ? v8::Handle<v8::Value>(v8::Undefined()) : v8::Handle<v8::Value>(v8String(str, isolate));
    }

    inline double toWebCoreDate(v8::Handle<v8::Value> object)
    {
        return (object->IsDate() || object->IsNumber()) ? object->NumberValue() : std::numeric_limits<double>::quiet_NaN();
    }

    inline v8::Handle<v8::Value> v8DateOrNull(double value, v8::Isolate* isolate = 0)
    {
        return isfinite(value) ? v8::Date::New(value) : v8NullWithCheck(isolate);
    }

    v8::Persistent<v8::FunctionTemplate> createRawTemplate();

    PassRefPtr<DOMStringList> toDOMStringList(v8::Handle<v8::Value>);
    PassRefPtr<XPathNSResolver> toXPathNSResolver(v8::Handle<v8::Value>);

    v8::Handle<v8::Object> toInnerGlobalObject(v8::Handle<v8::Context>);
    DOMWindow* toDOMWindow(v8::Handle<v8::Context>);
    ScriptExecutionContext* toScriptExecutionContext(v8::Handle<v8::Context>);

    // Returns the context associated with a ScriptExecutionContext.
    v8::Local<v8::Context> toV8Context(ScriptExecutionContext*, const WorldContextHandle&);

    // Returns the frame object of the window object associated with
    // a context, if the window is currently being displayed in the Frame.
    Frame* toFrameIfNotDetached(v8::Handle<v8::Context>);

    // Returns the PerContextData associated with a frame for the current isolated world.
    V8PerContextData* perContextDataForCurrentWorld(Frame*);

    // If the current context causes out of memory, JavaScript setting
    // is disabled and it returns true.
    bool handleOutOfMemory();
    v8::Local<v8::Value> handleMaxRecursionDepthExceeded();

    void crashIfV8IsDead();

} // namespace WebCore

#endif // V8Binding_h