/* * Copyright (C) 1999-2000 Harri Porten (porten@kde.org) * Copyright (C) 2003, 2006, 2007, 2008 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 KJS_lookup_h #define KJS_lookup_h #include "ExecState.h" #include "JSFunction.h" #include "JSGlobalObject.h" #include "JSObject.h" #include "PropertySlot.h" #include "identifier.h" #include #include namespace JSC { // Hash table generated by the create_hash_table script. struct HashTableValue { const char* key; // property name unsigned char attributes; // JSObject attributes 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 void (*PutFunction)(ExecState*, JSObject* baseObject, JSValue* value); class HashEntry { public: void initialize(UString::Rep* key, unsigned char attributes, intptr_t v1, intptr_t v2) { m_key = key; m_attributes = attributes; m_u.store.value1 = v1; m_u.store.value2 = v2; } void setKey(UString::Rep* key) { m_key = key; } UString::Rep* key() const { return m_key; } unsigned char attributes() const { return m_attributes; } NativeFunction function() const { ASSERT(m_attributes & Function); return m_u.function.functionValue; } unsigned char functionLength() const { ASSERT(m_attributes & Function); return static_cast(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; } private: UString::Rep* m_key; unsigned char m_attributes; // JSObject attributes 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; }; struct HashTable { int hashSizeMask; // Precomputed size for the hash table (minus 1). const HashTableValue* values; // Fixed values generated by script. mutable const HashEntry* table; // Table allocated at runtime. ALWAYS_INLINE void initializeIfNeeded(JSGlobalData* globalData) const { if (!table) createTable(globalData); } ALWAYS_INLINE void initializeIfNeeded(ExecState* exec) const { if (!table) createTable(&exec->globalData()); } void deleteTable() const; // Find an entry in the table, and return the entry. ALWAYS_INLINE const HashEntry* entry(JSGlobalData* globalData, const Identifier& identifier) const { initializeIfNeeded(globalData); return entry(identifier); } ALWAYS_INLINE const HashEntry* entry(ExecState* exec, const Identifier& identifier) const { initializeIfNeeded(exec); return entry(identifier); } private: ALWAYS_INLINE const HashEntry* entry(const Identifier& identifier) const { ASSERT(table); const HashEntry* entry = &table[identifier.ustring().rep()->computedHash() & hashSizeMask]; if (entry->key() != identifier.ustring().rep()) return 0; return entry; } // Convert the hash table keys to identifiers. void createTable(JSGlobalData*) const; }; void setUpStaticFunctionSlot(ExecState*, const HashEntry*, JSObject* thisObject, const Identifier& 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 inline bool getStaticPropertySlot(ExecState* exec, const HashTable* table, ThisImp* thisObj, const Identifier& propertyName, PropertySlot& slot) { const HashEntry* entry = table->entry(exec, propertyName); if (!entry) // not found, forward to parent return thisObj->ParentImp::getOwnPropertySlot(exec, propertyName, slot); if (entry->attributes() & Function) setUpStaticFunctionSlot(exec, entry, thisObj, propertyName, slot); else slot.setCustom(thisObj, 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 inline bool getStaticFunctionSlot(ExecState* exec, const HashTable* table, JSObject* thisObj, const Identifier& propertyName, PropertySlot& slot) { if (static_cast(thisObj)->ParentImp::getOwnPropertySlot(exec, propertyName, slot)) return true; const HashEntry* entry = table->entry(exec, propertyName); if (!entry) return false; setUpStaticFunctionSlot(exec, entry, thisObj, propertyName, slot); return true; } /** * 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 inline bool getStaticValueSlot(ExecState* exec, const HashTable* table, ThisImp* thisObj, const Identifier& propertyName, PropertySlot& slot) { const HashEntry* entry = table->entry(exec, propertyName); if (!entry) // not found, forward to parent return thisObj->ParentImp::getOwnPropertySlot(exec, propertyName, slot); ASSERT(!(entry->attributes() & Function)); slot.setCustom(thisObj, entry->propertyGetter()); return true; } /** * 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. */ template inline bool lookupPut(ExecState* exec, const Identifier& propertyName, JSValue* value, const HashTable* table, ThisImp* thisObj) { const HashEntry* entry = table->entry(exec, propertyName); if (!entry) return false; if (entry->attributes() & Function) // function: put as override property thisObj->putDirect(propertyName, value); else if (!(entry->attributes() & ReadOnly)) entry->propertyPutter()(exec, thisObj, value); return true; } /** * This one is for "put". * It calls lookupPut() to set the value. If that call * returns false (meaning no entry in the hash table was found), * then it calls put() on the ParentImp class. */ template inline void lookupPut(ExecState* exec, const Identifier& propertyName, JSValue* value, const HashTable* table, ThisImp* thisObj, PutPropertySlot& slot) { if (!lookupPut(exec, propertyName, value, table, thisObj)) thisObj->ParentImp::put(exec, propertyName, value, slot); // not found: forward to parent } } // namespace JSC #endif // KJS_lookup_h