Source/WebCore/bindings/v8/V8Binding.h - WebKit - Git at Google

 /*
 * Copyright (C) 2009 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

 #ifndef V8Binding_h
 #define V8Binding_h

 #include "BindingSecurity.h"
 #include "MathExtras.h"
 #include "PlatformString.h"
 #include "V8DOMWrapper.h"
 #include <wtf/text/AtomicString.h>

 #include <v8.h>

 namespace WebCore {

     class EventListener;
     class EventTarget;

     // FIXME: Remove V8Binding.
     class V8Binding {
     };
     typedef BindingSecurity<V8Binding> V8BindingSecurity;

     enum ExternalMode {
         Externalize,
         DoNotExternalize
     };

     template <typename StringType>
     StringType v8StringToWebCoreString(v8::Handle<v8::String> v8String, ExternalMode external);

     // 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.
     inline String v8StringToWebCoreString(v8::Handle<v8::String> v8String)
     {
         return v8StringToWebCoreString<String>(v8String, Externalize);
     }
     String v8NonStringValueToWebCoreString(v8::Handle<v8::Value>);
     String v8ValueToWebCoreString(v8::Handle<v8::Value> value);

     // Convert v8 types to a WTF::AtomicString.
     inline AtomicString v8StringToAtomicWebCoreString(v8::Handle<v8::String> v8String)
     {
         return v8StringToWebCoreString<AtomicString>(v8String, Externalize);
     }
     AtomicString v8NonStringValueToAtomicWebCoreString(v8::Handle<v8::Value>);
     AtomicString v8ValueToAtomicWebCoreString(v8::Handle<v8::Value> value);

     // Note: RefPtr is a must as we cache by StringImpl* equality, not identity
     // hence lastStringImpl might be not a key of the cache (in sense of identity)
     // and hence it's not refed on addition.
     extern RefPtr<StringImpl> lastStringImpl;
     extern v8::Persistent<v8::String> lastV8String;
     v8::Local<v8::String> v8ExternalStringSlow(StringImpl* stringImpl);

     // 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)
     {
         StringImpl* stringImpl = string.impl();
         if (!stringImpl)
             return v8::String::Empty();

         if (lastStringImpl.get() == stringImpl) {
             ASSERT(!lastV8String.IsNearDeath());
             ASSERT(!lastV8String.IsEmpty());
             return v8::Local<v8::String>::New(lastV8String);
         }

         return v8ExternalStringSlow(stringImpl);
     }

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

     // Enables caching v8 wrappers created for WTF::StringImpl.  Currently this cache requires
     // all the calls (both to convert WTF::String to v8::String and to GC the handle)
     // to be performed on the main thread.
     void enableStringImplCache();

     // 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());
     }

     // FIXME: Drop this in favor of the type specific v8ValueToWebCoreString when we rework the code generation.
     inline String toWebCoreString(v8::Handle<v8::Value> object)
     {
         return v8ValueToWebCoreString(object);
     }

     String toWebCoreString(const v8::Arguments&, int index);

     // The string returned by this function is still owned by the argument
     // and will be deallocated when the argument is deallocated.
     inline const uint16_t* fromWebCoreString(const String& str)
     {
         return reinterpret_cast<const uint16_t*>(str.characters());
     }

     bool isUndefinedOrNull(v8::Handle<v8::Value> value);

     v8::Handle<v8::Boolean> v8Boolean(bool value);

     String toWebCoreStringWithNullCheck(v8::Handle<v8::Value> value);

     AtomicString toAtomicWebCoreStringWithNullCheck(v8::Handle<v8::Value> value);

     String toWebCoreStringWithNullOrUndefinedCheck(v8::Handle<v8::Value> value);

     v8::Handle<v8::String> v8UndetectableString(const String& str);

     v8::Handle<v8::Value> v8StringOrNull(const String& str);

     v8::Handle<v8::Value> v8StringOrUndefined(const String& str);

     v8::Handle<v8::Value> v8StringOrFalse(const String& str);

     double toWebCoreDate(v8::Handle<v8::Value> object);

     v8::Handle<v8::Value> v8DateOrNull(double value);

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

     struct BatchedAttribute;
     struct BatchedCallback;

     v8::Local<v8::Signature> configureTemplate(v8::Persistent<v8::FunctionTemplate>,
                                                const char* interfaceName,
                                                v8::Persistent<v8::FunctionTemplate> parentClass,
                                                int fieldCount,
                                                const BatchedAttribute*,
                                                size_t attributeCount,
                                                const BatchedCallback*,
                                                size_t callbackCount);

     v8::Handle<v8::Value> getElementStringAttr(const v8::AccessorInfo&,
                                                const QualifiedName&);
     void setElementStringAttr(const v8::AccessorInfo&,
                               const QualifiedName&,
                               v8::Local<v8::Value>);


     v8::Persistent<v8::String> getToStringName();
     v8::Persistent<v8::FunctionTemplate> getToStringTemplate();

     String int32ToWebCoreString(int value);

     class V8ParameterBase {
     public:
         operator String() { return toString<String>(); }
         operator AtomicString() { return toString<AtomicString>(); }

     protected:
         V8ParameterBase(v8::Local<v8::Value> object) : m_v8Object(object), m_mode(Externalize), m_string() { }

         bool prepareBase()
         {
             if (LIKELY(m_v8Object->IsString()))
                 return true;

             if (LIKELY(m_v8Object->IsInt32())) {
                 setString(int32ToWebCoreString(m_v8Object->Int32Value()));
                 return true;
             }

             m_mode = DoNotExternalize;
             v8::TryCatch block;
             m_v8Object = m_v8Object->ToString();
             // Handle the case where an exception is thrown as part of invoking toString on the object.
             if (block.HasCaught()) {
                 block.ReThrow();
                 return false;
             }

             return true;
         }

         v8::Local<v8::Value> object() { return m_v8Object; }

         void setString(String string)
         {
             m_string = string;
             m_v8Object.Clear(); // To signal that String is ready.
         }

      private:
         v8::Local<v8::Value> m_v8Object;
         ExternalMode m_mode;
         String m_string;

         template <class StringType>
         StringType toString()
         {
             if (LIKELY(!m_v8Object.IsEmpty()))
                 return v8StringToWebCoreString<StringType>(m_v8Object.As<v8::String>(), m_mode);

             return StringType(m_string);
         }
     };

     // V8Parameter is an adapter class that converts V8 values to Strings
     // or AtomicStrings as appropriate, using multiple typecast operators.
     enum V8ParameterMode {
         DefaultMode,
         WithNullCheck,
         WithUndefinedOrNullCheck
     };
     template <V8ParameterMode MODE = DefaultMode>
     class V8Parameter: public V8ParameterBase {
     public:
         V8Parameter(v8::Local<v8::Value> object) : V8ParameterBase(object) { }
         V8Parameter(v8::Local<v8::Value> object, bool) : V8ParameterBase(object) { prepare(); }

         bool prepare();
     };

     template<> inline bool V8Parameter<DefaultMode>::prepare()
     {
         return V8ParameterBase::prepareBase();
     }

     template<> inline bool V8Parameter<WithNullCheck>::prepare()
     {
         if (object()->IsNull()) {
             setString(String());
             return true;
         }

         return V8ParameterBase::prepareBase();
     }

     template<> inline bool V8Parameter<WithUndefinedOrNullCheck>::prepare()
     {
         if (object()->IsNull() || object()->IsUndefined()) {
             setString(String());
             return true;
         }

         return V8ParameterBase::prepareBase();
     }

 } // namespace WebCore

 #endif // V8Binding_h
	/*
	* Copyright (C) 2009 Google Inc. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are
	* met:
	*
	* * Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* * Redistributions in binary form must reproduce the above
	* copyright notice, this list of conditions and the following disclaimer
	* in the documentation and/or other materials provided with the
	* distribution.
	* * Neither the name of Google Inc. nor the names of its
	* contributors may be used to endorse or promote products derived from
	* this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#ifndef V8Binding_h
	#define V8Binding_h

	#include "BindingSecurity.h"
	#include "MathExtras.h"
	#include "PlatformString.h"
	#include "V8DOMWrapper.h"
	#include <wtf/text/AtomicString.h>

	#include <v8.h>

	namespace WebCore {

	class EventListener;
	class EventTarget;

	// FIXME: Remove V8Binding.
	class V8Binding {
	};
	typedef BindingSecurity<V8Binding> V8BindingSecurity;

	enum ExternalMode {
	Externalize,
	DoNotExternalize
	};

	template <typename StringType>
	StringType v8StringToWebCoreString(v8::Handle<v8::String> v8String, ExternalMode external);

	// 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.
	inline String v8StringToWebCoreString(v8::Handle<v8::String> v8String)
	{
	return v8StringToWebCoreString<String>(v8String, Externalize);
	}
	String v8NonStringValueToWebCoreString(v8::Handle<v8::Value>);
	String v8ValueToWebCoreString(v8::Handle<v8::Value> value);

	// Convert v8 types to a WTF::AtomicString.
	inline AtomicString v8StringToAtomicWebCoreString(v8::Handle<v8::String> v8String)
	{
	return v8StringToWebCoreString<AtomicString>(v8String, Externalize);
	}
	AtomicString v8NonStringValueToAtomicWebCoreString(v8::Handle<v8::Value>);
	AtomicString v8ValueToAtomicWebCoreString(v8::Handle<v8::Value> value);

	// Note: RefPtr is a must as we cache by StringImpl* equality, not identity
	// hence lastStringImpl might be not a key of the cache (in sense of identity)
	// and hence it's not refed on addition.
	extern RefPtr<StringImpl> lastStringImpl;
	extern v8::Persistent<v8::String> lastV8String;
	v8::Local<v8::String> v8ExternalStringSlow(StringImpl* stringImpl);

	// 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)
	{
	StringImpl* stringImpl = string.impl();
	if (!stringImpl)
	return v8::String::Empty();

	if (lastStringImpl.get() == stringImpl) {
	ASSERT(!lastV8String.IsNearDeath());
	ASSERT(!lastV8String.IsEmpty());
	return v8::Local<v8::String>::New(lastV8String);
	}

	return v8ExternalStringSlow(stringImpl);
	}

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

	// Enables caching v8 wrappers created for WTF::StringImpl. Currently this cache requires
	// all the calls (both to convert WTF::String to v8::String and to GC the handle)
	// to be performed on the main thread.
	void enableStringImplCache();

	// 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());
	}

	// FIXME: Drop this in favor of the type specific v8ValueToWebCoreString when we rework the code generation.
	inline String toWebCoreString(v8::Handle<v8::Value> object)
	{
	return v8ValueToWebCoreString(object);
	}

	String toWebCoreString(const v8::Arguments&, int index);

	// The string returned by this function is still owned by the argument
	// and will be deallocated when the argument is deallocated.
	inline const uint16_t* fromWebCoreString(const String& str)
	{
	return reinterpret_cast<const uint16_t*>(str.characters());
	}

	bool isUndefinedOrNull(v8::Handle<v8::Value> value);

	v8::Handle<v8::Boolean> v8Boolean(bool value);

	String toWebCoreStringWithNullCheck(v8::Handle<v8::Value> value);

	AtomicString toAtomicWebCoreStringWithNullCheck(v8::Handle<v8::Value> value);

	String toWebCoreStringWithNullOrUndefinedCheck(v8::Handle<v8::Value> value);

	v8::Handle<v8::String> v8UndetectableString(const String& str);

	v8::Handle<v8::Value> v8StringOrNull(const String& str);

	v8::Handle<v8::Value> v8StringOrUndefined(const String& str);

	v8::Handle<v8::Value> v8StringOrFalse(const String& str);

	double toWebCoreDate(v8::Handle<v8::Value> object);

	v8::Handle<v8::Value> v8DateOrNull(double value);

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

	struct BatchedAttribute;
	struct BatchedCallback;

	v8::Local<v8::Signature> configureTemplate(v8::Persistent<v8::FunctionTemplate>,
	const char* interfaceName,
	v8::Persistent<v8::FunctionTemplate> parentClass,
	int fieldCount,
	const BatchedAttribute*,
	size_t attributeCount,
	const BatchedCallback*,
	size_t callbackCount);

	v8::Handle<v8::Value> getElementStringAttr(const v8::AccessorInfo&,
	const QualifiedName&);
	void setElementStringAttr(const v8::AccessorInfo&,
	const QualifiedName&,
	v8::Local<v8::Value>);


	v8::Persistent<v8::String> getToStringName();
	v8::Persistent<v8::FunctionTemplate> getToStringTemplate();

	String int32ToWebCoreString(int value);

	class V8ParameterBase {
	public:
	operator String() { return toString<String>(); }
	operator AtomicString() { return toString<AtomicString>(); }

	protected:
	V8ParameterBase(v8::Local<v8::Value> object) : m_v8Object(object), m_mode(Externalize), m_string() { }

	bool prepareBase()
	{
	if (LIKELY(m_v8Object->IsString()))
	return true;

	if (LIKELY(m_v8Object->IsInt32())) {
	setString(int32ToWebCoreString(m_v8Object->Int32Value()));
	return true;
	}

	m_mode = DoNotExternalize;
	v8::TryCatch block;
	m_v8Object = m_v8Object->ToString();
	// Handle the case where an exception is thrown as part of invoking toString on the object.
	if (block.HasCaught()) {
	block.ReThrow();
	return false;
	}

	return true;
	}

	v8::Local<v8::Value> object() { return m_v8Object; }

	void setString(String string)
	{
	m_string = string;
	m_v8Object.Clear(); // To signal that String is ready.
	}

	private:
	v8::Local<v8::Value> m_v8Object;
	ExternalMode m_mode;
	String m_string;

	template <class StringType>
	StringType toString()
	{
	if (LIKELY(!m_v8Object.IsEmpty()))
	return v8StringToWebCoreString<StringType>(m_v8Object.As<v8::String>(), m_mode);

	return StringType(m_string);
	}
	};

	// V8Parameter is an adapter class that converts V8 values to Strings
	// or AtomicStrings as appropriate, using multiple typecast operators.
	enum V8ParameterMode {
	DefaultMode,
	WithNullCheck,
	WithUndefinedOrNullCheck
	};
	template <V8ParameterMode MODE = DefaultMode>
	class V8Parameter: public V8ParameterBase {
	public:
	V8Parameter(v8::Local<v8::Value> object) : V8ParameterBase(object) { }
	V8Parameter(v8::Local<v8::Value> object, bool) : V8ParameterBase(object) { prepare(); }

	bool prepare();
	};

	template<> inline bool V8Parameter<DefaultMode>::prepare()
	{
	return V8ParameterBase::prepareBase();
	}

	template<> inline bool V8Parameter<WithNullCheck>::prepare()
	{
	if (object()->IsNull()) {
	setString(String());
	return true;
	}

	return V8ParameterBase::prepareBase();
	}

	template<> inline bool V8Parameter<WithUndefinedOrNullCheck>::prepare()
	{
	if (object()->IsNull() \|\| object()->IsUndefined()) {
	setString(String());
	return true;
	}

	return V8ParameterBase::prepareBase();
	}

	} // namespace WebCore

	#endif // V8Binding_h