| // -*- c-basic-offset: 2 -*- |
| /* |
| * Copyright (C) 1999-2000 Harri Porten (porten@kde.org) |
| * Copyright (C) 2003, 2006, 2007 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 "function.h" |
| #include "identifier.h" |
| #include "JSGlobalObject.h" |
| #include "object.h" |
| #include <stdio.h> |
| #include <wtf/Assertions.h> |
| |
| namespace KJS { |
| |
| /** |
| * An entry in a hash table. |
| */ |
| struct HashEntry { |
| /** |
| * s is the key (e.g. a property name) |
| */ |
| const char* s; |
| |
| /** |
| * value is the result value (enum value for properties and a function pointer to a constructor factory for functions) |
| */ |
| union { |
| intptr_t intValue; |
| PrototypeFunction::JSMemberFunction functionValue; |
| } value; |
| |
| /** |
| * attr is a set for flags (e.g. the property flags, see object.h) |
| */ |
| unsigned char attr; |
| /** |
| * params is another number. For property hashtables, it is used to |
| * denote the number of argument of the function |
| */ |
| short int params; |
| /** |
| * next is the pointer to the next entry for the same hash value |
| */ |
| const HashEntry* next; |
| }; |
| |
| /** |
| * A hash table |
| * Usually the hashtable is generated by the create_hash_table script, from a .table file. |
| * |
| * The implementation uses an array of entries, "size" is the total size of that array. |
| * The entries between 0 and hashSize-1 are the entry points |
| * for each hash value, and the entries between hashSize and size-1 |
| * are the overflow entries for the hash values that need one. |
| * The "next" pointer of the entry links entry points to overflow entries, |
| * and links overflow entries between them. |
| */ |
| struct HashTable { |
| /** |
| * type is a version number. Currently always 2 |
| */ |
| int type; |
| /** |
| * size is the total number of entries in the hashtable, including the null entries, |
| * i.e. the size of the "entries" array. |
| * Used to iterate over all entries in the table |
| */ |
| int size; |
| /** |
| * pointer to the array of entries |
| * Mind that some entries in the array are null (0,0,0,0). |
| */ |
| const HashEntry* entries; |
| /** |
| * the maximum value for the hash minus 1. Always smaller than size. |
| */ |
| int hashSizeMask; |
| }; |
| |
| /** |
| * @short Fast keyword lookup. |
| */ |
| class Lookup { |
| public: |
| /** |
| * Find an entry in the table, and return its value (i.e. the value field of HashEntry) |
| */ |
| static int find(const struct HashTable*, const Identifier&); |
| static int find(const struct HashTable*, const UChar*, unsigned int len); |
| |
| /** |
| * Find an entry in the table, and return the entry |
| * This variant gives access to the other attributes of the entry, |
| * especially the attr field. |
| */ |
| static const HashEntry* findEntry(const struct HashTable*, const Identifier&); |
| |
| }; |
| |
| class ExecState; |
| class UString; |
| /** |
| * @internal |
| * Helper for getStaticFunctionSlot and getStaticPropertySlot |
| */ |
| inline JSValue* staticFunctionGetter(ExecState* exec, JSObject*, const Identifier& propertyName, const PropertySlot& slot) |
| { |
| // Look for cached value in dynamic map of properties (in JSObject) |
| JSObject* thisObj = slot.slotBase(); |
| JSValue* cachedVal = thisObj->getDirect(propertyName); |
| if (cachedVal) |
| return cachedVal; |
| |
| const HashEntry* entry = slot.staticEntry(); |
| JSValue* val = new PrototypeFunction(exec, entry->params, propertyName, entry->value.functionValue); |
| thisObj->putDirect(propertyName, val, entry->attr); |
| return val; |
| } |
| |
| /** |
| * @internal |
| * Helper for getStaticValueSlot and getStaticPropertySlot |
| */ |
| template <class ThisImp> |
| inline JSValue* staticValueGetter(ExecState* exec, JSObject*, const Identifier&, const PropertySlot& slot) |
| { |
| ThisImp* thisObj = static_cast<ThisImp*>(slot.slotBase()); |
| const HashEntry* entry = slot.staticEntry(); |
| return thisObj->getValueProperty(exec, entry->value.intValue); |
| } |
| |
| /** |
| * Helper method for property lookups |
| * |
| * 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 arguments: |
| * @param FuncImp the class which implements this object's functions |
| * @param ThisImp the class of "this". It must implement the getValueProperty(exec,token) method, |
| * for non-function properties. |
| * @param ParentImp the class of the parent, to propagate the lookup. |
| * |
| * Method arguments: |
| * @param exec execution state, as usual |
| * @param propertyName the property we're looking for |
| * @param table the static hashtable for this class |
| * @param thisObj "this" |
| */ |
| template <class ThisImp, class ParentImp> |
| inline bool getStaticPropertySlot(ExecState* exec, const HashTable* table, |
| ThisImp* thisObj, const Identifier& propertyName, PropertySlot& slot) |
| { |
| const HashEntry* entry = Lookup::findEntry(table, propertyName); |
| |
| if (!entry) // not found, forward to parent |
| return thisObj->ParentImp::getOwnPropertySlot(exec, propertyName, slot); |
| |
| if (entry->attr & Function) |
| slot.setStaticEntry(thisObj, entry, staticFunctionGetter); |
| else |
| slot.setStaticEntry(thisObj, entry, staticValueGetter<ThisImp>); |
| |
| 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, const Identifier& propertyName, PropertySlot& slot) |
| { |
| const HashEntry* entry = Lookup::findEntry(table, propertyName); |
| |
| if (!entry) // not found, forward to parent |
| return static_cast<ParentImp*>(thisObj)->ParentImp::getOwnPropertySlot(exec, propertyName, slot); |
| |
| ASSERT(entry->attr & Function); |
| |
| slot.setStaticEntry(thisObj, entry, staticFunctionGetter); |
| 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 <class ThisImp, class ParentImp> |
| inline bool getStaticValueSlot(ExecState* exec, const HashTable* table, |
| ThisImp* thisObj, const Identifier& propertyName, PropertySlot& slot) |
| { |
| const HashEntry* entry = Lookup::findEntry(table, propertyName); |
| |
| if (!entry) // not found, forward to parent |
| return thisObj->ParentImp::getOwnPropertySlot(exec, propertyName, slot); |
| |
| ASSERT(!(entry->attr & Function)); |
| |
| slot.setStaticEntry(thisObj, entry, staticValueGetter<ThisImp>); |
| 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 <class ThisImp> |
| inline bool lookupPut(ExecState* exec, const Identifier& propertyName, |
| JSValue* value, int attr, |
| const HashTable* table, ThisImp* thisObj) |
| { |
| const HashEntry* entry = Lookup::findEntry(table, propertyName); |
| |
| if (!entry) |
| return false; |
| |
| if (entry->attr & Function) // function: put as override property |
| thisObj->JSObject::put(exec, propertyName, value, attr); |
| else if (!(entry->attr & ReadOnly)) |
| thisObj->putValueProperty(exec, entry->value.intValue, value, attr); |
| |
| return true; |
| } |
| |
| /** |
| * This one is for "put". |
| * It calls lookupPut<ThisImp>() 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 <class ThisImp, class ParentImp> |
| inline void lookupPut(ExecState* exec, const Identifier& propertyName, |
| JSValue* value, int attr, |
| const HashTable* table, ThisImp* thisObj) |
| { |
| if (!lookupPut<ThisImp>(exec, propertyName, value, attr, table, thisObj)) |
| thisObj->ParentImp::put(exec, propertyName, value, attr); // not found: forward to parent |
| } |
| |
| /** |
| * This template method retrieves or create an object that is unique |
| * (for a given global object) The first time this is called (for a given |
| * property name), the Object will be constructed, and set as a property |
| * of the global object. Later calls will simply retrieve that cached object. |
| * Note that the object constructor must take 1 argument, exec. |
| */ |
| template <class ClassCtor> |
| inline JSObject* cacheGlobalObject(ExecState* exec, const Identifier& propertyName) |
| { |
| JSGlobalObject* globalObject = exec->lexicalGlobalObject(); |
| JSValue* obj = globalObject->getDirect(propertyName); |
| if (obj) { |
| ASSERT(obj->isObject()); |
| return static_cast<JSObject* >(obj); |
| } |
| JSObject* newObject = new ClassCtor(exec); |
| globalObject->putDirect(propertyName, newObject, Internal | DontEnum); |
| return newObject; |
| } |
| |
| } // namespace |
| |
| /** |
| * Helpers to define prototype objects (each of which simply implements |
| * the functions for a type of objects). |
| * Sorry for this not being very readable, but it actually saves much copy-n-paste. |
| * ParentPrototype is not our base class, it's the object we use as fallback. |
| * The reason for this is that there should only be ONE DOMNode.hasAttributes (e.g.), |
| * not one in each derived class. So we link the (unique) prototypes between them. |
| * |
| * Using those macros is very simple: define the hashtable (e.g. "DOMNodePrototypeTable"), then |
| * KJS_DEFINE_PROTOTYPE(DOMNodePrototype) |
| * KJS_IMPLEMENT_PROTOTYPE("DOMNode", DOMNodePrototype, DOMNodePrototypeFunction) |
| * and use DOMNodePrototype::self(exec) as prototype in the DOMNode constructor. |
| * If the prototype has a "parent prototype", e.g. DOMElementPrototype falls back on DOMNodePrototype, |
| * then the first line will use KJS_DEFINE_PROTOTYPE_WITH_PROTOTYPE, with DOMNodePrototype as the second argument. |
| */ |
| |
| // These macros assume that a prototype's only properties are functions |
| #define KJS_DEFINE_PROTOTYPE(ClassPrototype) \ |
| class ClassPrototype : public KJS::JSObject { \ |
| public: \ |
| static KJS::JSObject* self(KJS::ExecState* exec); \ |
| virtual const KJS::ClassInfo* classInfo() const { return &info; } \ |
| static const KJS::ClassInfo info; \ |
| bool getOwnPropertySlot(KJS::ExecState* , const KJS::Identifier&, KJS::PropertySlot&); \ |
| ClassPrototype(KJS::ExecState* exec) \ |
| : KJS::JSObject(exec->lexicalGlobalObject()->objectPrototype()) { } \ |
| \ |
| }; |
| |
| #define KJS_DEFINE_PROTOTYPE_WITH_PROTOTYPE(ClassPrototype, ClassPrototypePrototype) \ |
| class ClassPrototype : public KJS::JSObject { \ |
| public: \ |
| static KJS::JSObject* self(KJS::ExecState* exec); \ |
| virtual const KJS::ClassInfo* classInfo() const { return &info; } \ |
| static const KJS::ClassInfo info; \ |
| bool getOwnPropertySlot(KJS::ExecState*, const KJS::Identifier&, KJS::PropertySlot&); \ |
| ClassPrototype(KJS::ExecState* exec) \ |
| : KJS::JSObject(ClassPrototypePrototype::self(exec)) { } \ |
| \ |
| }; |
| |
| #define KJS_IMPLEMENT_PROTOTYPE(ClassName, ClassPrototype) \ |
| const ClassInfo ClassPrototype::info = { ClassName"Prototype", 0, &ClassPrototype##Table }; \ |
| JSObject* ClassPrototype::self(ExecState* exec) \ |
| { \ |
| static Identifier* prototypeIdentifier = new Identifier("[[" ClassName ".prototype]]"); \ |
| return KJS::cacheGlobalObject<ClassPrototype>(exec, *prototypeIdentifier); \ |
| } \ |
| bool ClassPrototype::getOwnPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot) \ |
| { \ |
| return getStaticFunctionSlot<JSObject>(exec, &ClassPrototype##Table, this, propertyName, slot); \ |
| } |
| |
| #endif // KJS_lookup_h |