Source/JavaScriptCore/runtime/Lookup.h - WebKit - Git at Google

 /*
  *  Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
  *  Copyright (C) 2003, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
  *  License as published by the Free Software Foundation; either
  *  version 2 of the License, or (at your option) any later version.
  *
  *  This library is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  *  Lesser General Public License for more details.
  *
  *  You should have received a copy of the GNU Lesser General Public
  *  License along with this library; if not, write to the Free Software
  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  *
  */

 #ifndef Lookup_h
 #define Lookup_h

 #include "CallFrame.h"
 #include "Intrinsic.h"
 #include "Identifier.h"
 #include "JSGlobalObject.h"
 #include "PropertySlot.h"
 #include "PutPropertySlot.h"
 #include <wtf/Assertions.h>

 namespace JSC {
     // Hash table generated by the create_hash_table script.
     struct HashTableValue {
         const char* key; // property name
         unsigned char attributes; // JSObject attributes
         Intrinsic intrinsic;
         intptr_t value1;
         intptr_t value2;
     };

     // FIXME: There is no reason this get function can't be simpler.
     // ie. typedef JSValue (*GetFunction)(ExecState*, JSObject* baseObject)
     typedef PropertySlot::GetValueFunc GetFunction;
     typedef PutPropertySlot::PutValueFunc PutFunction;

     class HashEntry {
         WTF_MAKE_FAST_ALLOCATED;
     public:
         void initialize(StringImpl* key, unsigned char attributes, intptr_t v1, intptr_t v2, Intrinsic intrinsic)
         {
             m_key = key;
             m_attributes = attributes;
             m_u.store.value1 = v1;
             m_u.store.value2 = v2;
             m_intrinsic = intrinsic;
             m_next = 0;
         }

         void setKey(StringImpl* key) { m_key = key; }
         StringImpl* key() const { return m_key; }

         unsigned char attributes() const { return m_attributes; }

         Intrinsic intrinsic() const
         {
             ASSERT(m_attributes & Function);
             return m_intrinsic;
         }

         NativeFunction function() const { ASSERT(m_attributes & Function); return m_u.function.functionValue; }
         unsigned char functionLength() const { ASSERT(m_attributes & Function); return static_cast<unsigned char>(m_u.function.length); }

         GetFunction propertyGetter() const { ASSERT(!(m_attributes & Function)); return m_u.property.get; }
         PutFunction propertyPutter() const { ASSERT(!(m_attributes & Function)); return m_u.property.put; }

         intptr_t lexerValue() const { ASSERT(!m_attributes); return m_u.lexer.value; }

         void setNext(HashEntry *next) { m_next = next; }
         HashEntry* next() const { return m_next; }

     private:
         StringImpl* m_key;
         unsigned char m_attributes; // JSObject attributes
         Intrinsic m_intrinsic;

         union {
             struct {
                 intptr_t value1;
                 intptr_t value2;
             } store;
             struct {
                 NativeFunction functionValue;
                 intptr_t length; // number of arguments for function
             } function;
             struct {
                 GetFunction get;
                 PutFunction put;
             } property;
             struct {
                 intptr_t value;
                 intptr_t unused;
             } lexer;
         } m_u;

         HashEntry* m_next;
     };

     struct HashTable {

         int compactSize;
         int compactHashSizeMask;
         bool hasSetterOrReadonlyProperties;

         const HashTableValue* values; // Fixed values generated by script.
         mutable const HashEntry* table; // Table allocated at runtime.

         ALWAYS_INLINE HashTable copy() const
         {
             // Don't copy dynamic table since it's thread specific.
             HashTable result = { compactSize, compactHashSizeMask, hasSetterOrReadonlyProperties, values, 0 };
             return result;
         }

         ALWAYS_INLINE void initializeIfNeeded(VM& vm) const
         {
             if (!table)
                 createTable(vm);
         }

         ALWAYS_INLINE void initializeIfNeeded(ExecState* exec) const
         {
             if (!table)
                 createTable(exec->vm());
         }

         JS_EXPORT_PRIVATE void deleteTable() const;

         // Find an entry in the table, and return the entry.
         ALWAYS_INLINE const HashEntry* entry(VM& vm, PropertyName identifier) const
         {
             initializeIfNeeded(vm);
             return entry(identifier);
         }

         ALWAYS_INLINE const HashEntry* entry(ExecState* exec, PropertyName identifier) const
         {
             initializeIfNeeded(exec);
             return entry(identifier);
         }

         class ConstIterator {
         public:
             ConstIterator(const HashTable* table, int position)
                 : m_table(table)
                 , m_position(position)
             {
                 skipInvalidKeys();
             }

             const HashEntry* operator->()
             {
                 return &m_table->table[m_position];
             }

             const HashEntry* operator*()
             {
                 return &m_table->table[m_position];
             }

             bool operator!=(const ConstIterator& other)
             {
                 ASSERT(m_table == other.m_table);
                 return m_position != other.m_position;
             }

             ConstIterator& operator++()
             {
                 ASSERT(m_position < m_table->compactSize);
                 ++m_position;
                 skipInvalidKeys();
                 return *this;
             }

         private:
             void skipInvalidKeys()
             {
                 ASSERT(m_position <= m_table->compactSize);
                 while (m_position < m_table->compactSize && !m_table->table[m_position].key())
                     ++m_position;
                 ASSERT(m_position <= m_table->compactSize);
             }

             const HashTable* m_table;
             int m_position;
         };

         ConstIterator begin(VM& vm) const
         {
             initializeIfNeeded(vm);
             return ConstIterator(this, 0);
         }
         ConstIterator end(VM& vm) const
         {
             initializeIfNeeded(vm);
             return ConstIterator(this, compactSize);
         }

     private:
         ALWAYS_INLINE const HashEntry* entry(PropertyName propertyName) const
         {
             StringImpl* impl = propertyName.publicName();
             if (!impl)
                 return 0;

             ASSERT(table);

             const HashEntry* entry = &table[impl->existingHash() & compactHashSizeMask];

             if (!entry->key())
                 return 0;

             do {
                 if (entry->key() == impl)
                     return entry;
                 entry = entry->next();
             } while (entry);

             return 0;
         }

         // Convert the hash table keys to identifiers.
         JS_EXPORT_PRIVATE void createTable(VM&) const;
     };

     JS_EXPORT_PRIVATE bool setUpStaticFunctionSlot(ExecState*, const HashEntry*, JSObject* thisObject, PropertyName, PropertySlot&);

     /**
      * This method does it all (looking in the hashtable, checking for function
      * overrides, creating the function or retrieving from cache, calling
      * getValueProperty in case of a non-function property, forwarding to parent if
      * unknown property).
      */
     template <class ThisImp, class ParentImp>
     inline bool getStaticPropertySlot(ExecState* exec, const HashTable& table, ThisImp* thisObj, PropertyName propertyName, PropertySlot& slot)
     {
         const HashEntry* entry = table.entry(exec, propertyName);

         if (!entry) // not found, forward to parent
             return ParentImp::getOwnPropertySlot(thisObj, exec, propertyName, slot);

         if (entry->attributes() & Function)
             return setUpStaticFunctionSlot(exec, entry, thisObj, propertyName, slot);

         slot.setCacheableCustom(thisObj, entry->attributes(), entry->propertyGetter());
         return true;
     }

     /**
      * Simplified version of getStaticPropertySlot in case there are only functions.
      * Using this instead of getStaticPropertySlot allows 'this' to avoid implementing
      * a dummy getValueProperty.
      */
     template <class ParentImp>
     inline bool getStaticFunctionSlot(ExecState* exec, const HashTable& table, JSObject* thisObj, PropertyName propertyName, PropertySlot& slot)
     {
         if (ParentImp::getOwnPropertySlot(thisObj, exec, propertyName, slot))
             return true;

         const HashEntry* entry = table.entry(exec, propertyName);
         if (!entry)
             return false;

         return setUpStaticFunctionSlot(exec, entry, thisObj, propertyName, slot);
     }

     /**
      * Simplified version of getStaticPropertySlot in case there are no functions, only "values".
      * Using this instead of getStaticPropertySlot removes the need for a FuncImp class.
      */
     template <class ThisImp, class ParentImp>
     inline bool getStaticValueSlot(ExecState* exec, const HashTable& table, ThisImp* thisObj, PropertyName propertyName, PropertySlot& slot)
     {
         const HashEntry* entry = table.entry(exec, propertyName);

         if (!entry) // not found, forward to parent
             return ParentImp::getOwnPropertySlot(thisObj, exec, propertyName, slot);

         ASSERT(!(entry->attributes() & Function));

         slot.setCacheableCustom(thisObj, entry->attributes(), entry->propertyGetter());
         return true;
     }

     inline void putEntry(ExecState* exec, const HashEntry* entry, JSObject* base, PropertyName propertyName, JSValue value, PutPropertySlot& slot)
     {
         // If this is a function put it as an override property.
         if (entry->attributes() & Function) {
             if (JSObject* thisObject = jsDynamicCast<JSObject*>(slot.thisValue()))
                 thisObject->putDirect(exec->vm(), propertyName, value);
         } else if (!(entry->attributes() & ReadOnly)) {
             entry->propertyPutter()(exec, base, JSValue::encode(slot.thisValue()), JSValue::encode(value));
             slot.setCustomProperty(base, entry->propertyPutter());
         } else if (slot.isStrictMode())
             throwTypeError(exec, StrictModeReadonlyPropertyWriteError);
     }

     /**
      * This one is for "put".
      * It looks up a hash entry for the property to be set.  If an entry
      * is found it sets the value and returns true, else it returns false.
      */
     inline bool lookupPut(ExecState* exec, PropertyName propertyName, JSObject* base, JSValue value, const HashTable& table, PutPropertySlot& slot)
     {
         const HashEntry* entry = table.entry(exec, propertyName);

         if (!entry)
             return false;

         putEntry(exec, entry, base, propertyName, value, slot);
         return true;
     }
 } // namespace JSC

 #endif // Lookup_h
	/*
	* Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
	* Copyright (C) 2003, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2 of the License, or (at your option) any later version.
	*
	* This library is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser General Public
	* License along with this library; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	*
	*/

	#ifndef Lookup_h
	#define Lookup_h

	#include "CallFrame.h"
	#include "Intrinsic.h"
	#include "Identifier.h"
	#include "JSGlobalObject.h"
	#include "PropertySlot.h"
	#include "PutPropertySlot.h"
	#include <wtf/Assertions.h>

	namespace JSC {
	// Hash table generated by the create_hash_table script.
	struct HashTableValue {
	const char* key; // property name
	unsigned char attributes; // JSObject attributes
	Intrinsic intrinsic;
	intptr_t value1;
	intptr_t value2;
	};

	// FIXME: There is no reason this get function can't be simpler.
	// ie. typedef JSValue (GetFunction)(ExecState, JSObject* baseObject)
	typedef PropertySlot::GetValueFunc GetFunction;
	typedef PutPropertySlot::PutValueFunc PutFunction;

	class HashEntry {
	WTF_MAKE_FAST_ALLOCATED;
	public:
	void initialize(StringImpl* key, unsigned char attributes, intptr_t v1, intptr_t v2, Intrinsic intrinsic)
	{
	m_key = key;
	m_attributes = attributes;
	m_u.store.value1 = v1;
	m_u.store.value2 = v2;
	m_intrinsic = intrinsic;
	m_next = 0;
	}

	void setKey(StringImpl* key) { m_key = key; }
	StringImpl* key() const { return m_key; }

	unsigned char attributes() const { return m_attributes; }

	Intrinsic intrinsic() const
	{
	ASSERT(m_attributes & Function);
	return m_intrinsic;
	}

	NativeFunction function() const { ASSERT(m_attributes & Function); return m_u.function.functionValue; }
	unsigned char functionLength() const { ASSERT(m_attributes & Function); return static_cast<unsigned char>(m_u.function.length); }

	GetFunction propertyGetter() const { ASSERT(!(m_attributes & Function)); return m_u.property.get; }
	PutFunction propertyPutter() const { ASSERT(!(m_attributes & Function)); return m_u.property.put; }

	intptr_t lexerValue() const { ASSERT(!m_attributes); return m_u.lexer.value; }

	void setNext(HashEntry *next) { m_next = next; }
	HashEntry* next() const { return m_next; }

	private:
	StringImpl* m_key;
	unsigned char m_attributes; // JSObject attributes
	Intrinsic m_intrinsic;

	union {
	struct {
	intptr_t value1;
	intptr_t value2;
	} store;
	struct {
	NativeFunction functionValue;
	intptr_t length; // number of arguments for function
	} function;
	struct {
	GetFunction get;
	PutFunction put;
	} property;
	struct {
	intptr_t value;
	intptr_t unused;
	} lexer;
	} m_u;

	HashEntry* m_next;
	};

	struct HashTable {

	int compactSize;
	int compactHashSizeMask;
	bool hasSetterOrReadonlyProperties;

	const HashTableValue* values; // Fixed values generated by script.
	mutable const HashEntry* table; // Table allocated at runtime.

	ALWAYS_INLINE HashTable copy() const
	{
	// Don't copy dynamic table since it's thread specific.
	HashTable result = { compactSize, compactHashSizeMask, hasSetterOrReadonlyProperties, values, 0 };
	return result;
	}

	ALWAYS_INLINE void initializeIfNeeded(VM& vm) const
	{
	if (!table)
	createTable(vm);
	}

	ALWAYS_INLINE void initializeIfNeeded(ExecState* exec) const
	{
	if (!table)
	createTable(exec->vm());
	}

	JS_EXPORT_PRIVATE void deleteTable() const;

	// Find an entry in the table, and return the entry.
	ALWAYS_INLINE const HashEntry* entry(VM& vm, PropertyName identifier) const
	{
	initializeIfNeeded(vm);
	return entry(identifier);
	}

	ALWAYS_INLINE const HashEntry* entry(ExecState* exec, PropertyName identifier) const
	{
	initializeIfNeeded(exec);
	return entry(identifier);
	}

	class ConstIterator {
	public:
	ConstIterator(const HashTable* table, int position)
	: m_table(table)
	, m_position(position)
	{
	skipInvalidKeys();
	}

	const HashEntry* operator->()
	{
	return &m_table->table[m_position];
	}

	const HashEntry* operator*()
	{
	return &m_table->table[m_position];
	}

	bool operator!=(const ConstIterator& other)
	{
	ASSERT(m_table == other.m_table);
	return m_position != other.m_position;
	}

	ConstIterator& operator++()
	{
	ASSERT(m_position < m_table->compactSize);
	++m_position;
	skipInvalidKeys();
	return *this;
	}

	private:
	void skipInvalidKeys()
	{
	ASSERT(m_position <= m_table->compactSize);
	while (m_position < m_table->compactSize && !m_table->table[m_position].key())
	++m_position;
	ASSERT(m_position <= m_table->compactSize);
	}

	const HashTable* m_table;
	int m_position;
	};

	ConstIterator begin(VM& vm) const
	{
	initializeIfNeeded(vm);
	return ConstIterator(this, 0);
	}
	ConstIterator end(VM& vm) const
	{
	initializeIfNeeded(vm);
	return ConstIterator(this, compactSize);
	}

	private:
	ALWAYS_INLINE const HashEntry* entry(PropertyName propertyName) const
	{
	StringImpl* impl = propertyName.publicName();
	if (!impl)
	return 0;

	ASSERT(table);

	const HashEntry* entry = &table[impl->existingHash() & compactHashSizeMask];

	if (!entry->key())
	return 0;

	do {
	if (entry->key() == impl)
	return entry;
	entry = entry->next();
	} while (entry);

	return 0;
	}

	// Convert the hash table keys to identifiers.
	JS_EXPORT_PRIVATE void createTable(VM&) const;
	};

	JS_EXPORT_PRIVATE bool setUpStaticFunctionSlot(ExecState, const HashEntry, JSObject* thisObject, PropertyName, PropertySlot&);

	/**
	* This method does it all (looking in the hashtable, checking for function
	* overrides, creating the function or retrieving from cache, calling
	* getValueProperty in case of a non-function property, forwarding to parent if
	* unknown property).
	*/
	template <class ThisImp, class ParentImp>
	inline bool getStaticPropertySlot(ExecState* exec, const HashTable& table, ThisImp* thisObj, PropertyName propertyName, PropertySlot& slot)
	{
	const HashEntry* entry = table.entry(exec, propertyName);

	if (!entry) // not found, forward to parent
	return ParentImp::getOwnPropertySlot(thisObj, exec, propertyName, slot);

	if (entry->attributes() & Function)
	return setUpStaticFunctionSlot(exec, entry, thisObj, propertyName, slot);

	slot.setCacheableCustom(thisObj, entry->attributes(), entry->propertyGetter());
	return true;
	}

	/**
	* Simplified version of getStaticPropertySlot in case there are only functions.
	* Using this instead of getStaticPropertySlot allows 'this' to avoid implementing
	* a dummy getValueProperty.
	*/
	template <class ParentImp>
	inline bool getStaticFunctionSlot(ExecState* exec, const HashTable& table, JSObject* thisObj, PropertyName propertyName, PropertySlot& slot)
	{
	if (ParentImp::getOwnPropertySlot(thisObj, exec, propertyName, slot))
	return true;

	const HashEntry* entry = table.entry(exec, propertyName);
	if (!entry)
	return false;

	return setUpStaticFunctionSlot(exec, entry, thisObj, propertyName, slot);
	}

	/**
	* Simplified version of getStaticPropertySlot in case there are no functions, only "values".
	* Using this instead of getStaticPropertySlot removes the need for a FuncImp class.
	*/
	template <class ThisImp, class ParentImp>
	inline bool getStaticValueSlot(ExecState* exec, const HashTable& table, ThisImp* thisObj, PropertyName propertyName, PropertySlot& slot)
	{
	const HashEntry* entry = table.entry(exec, propertyName);

	if (!entry) // not found, forward to parent
	return ParentImp::getOwnPropertySlot(thisObj, exec, propertyName, slot);

	ASSERT(!(entry->attributes() & Function));

	slot.setCacheableCustom(thisObj, entry->attributes(), entry->propertyGetter());
	return true;
	}

	inline void putEntry(ExecState* exec, const HashEntry* entry, JSObject* base, PropertyName propertyName, JSValue value, PutPropertySlot& slot)
	{
	// If this is a function put it as an override property.
	if (entry->attributes() & Function) {
	if (JSObject* thisObject = jsDynamicCast<JSObject*>(slot.thisValue()))
	thisObject->putDirect(exec->vm(), propertyName, value);
	} else if (!(entry->attributes() & ReadOnly)) {
	entry->propertyPutter()(exec, base, JSValue::encode(slot.thisValue()), JSValue::encode(value));
	slot.setCustomProperty(base, entry->propertyPutter());
	} else if (slot.isStrictMode())
	throwTypeError(exec, StrictModeReadonlyPropertyWriteError);
	}

	/**
	* This one is for "put".
	* It looks up a hash entry for the property to be set. If an entry
	* is found it sets the value and returns true, else it returns false.
	*/
	inline bool lookupPut(ExecState* exec, PropertyName propertyName, JSObject* base, JSValue value, const HashTable& table, PutPropertySlot& slot)
	{
	const HashEntry* entry = table.entry(exec, propertyName);

	if (!entry)
	return false;

	putEntry(exec, entry, base, propertyName, value, slot);
	return true;
	}
	} // namespace JSC

	#endif // Lookup_h