--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/JavaScriptCore/runtime/Structure.h Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,296 @@
+/*
+ * Copyright (C) 2008, 2009 Apple 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:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``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 APPLE COMPUTER, INC. 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 Structure_h
+#define Structure_h
+
+#include "Identifier.h"
+#include "JSType.h"
+#include "JSValue.h"
+#include "PropertyMapHashTable.h"
+#include "PropertyNameArray.h"
+#include "Protect.h"
+#include "StructureChain.h"
+#include "StructureTransitionTable.h"
+#include "JSTypeInfo.h"
+#include "UString.h"
+#include "WeakGCPtr.h"
+#include <wtf/PassRefPtr.h>
+#include <wtf/RefCounted.h>
+
+#ifndef NDEBUG
+#define DUMP_PROPERTYMAP_STATS 0
+#else
+#define DUMP_PROPERTYMAP_STATS 0
+#endif
+
+namespace JSC {
+
+ class MarkStack;
+ class PropertyNameArray;
+ class PropertyNameArrayData;
+
+ enum EnumerationMode {
+ ExcludeDontEnumProperties,
+ IncludeDontEnumProperties
+ };
+
+ class Structure : public RefCounted<Structure> {
+ public:
+ friend class JIT;
+ friend class StructureTransitionTable;
+ static PassRefPtr<Structure> create(JSValue prototype, const TypeInfo& typeInfo, unsigned anonymousSlotCount)
+ {
+ return adoptRef(new Structure(prototype, typeInfo, anonymousSlotCount));
+ }
+
+ static void startIgnoringLeaks();
+ static void stopIgnoringLeaks();
+
+ static void dumpStatistics();
+
+ static PassRefPtr<Structure> addPropertyTransition(Structure*, const Identifier& propertyName, unsigned attributes, JSCell* specificValue, size_t& offset);
+ static PassRefPtr<Structure> addPropertyTransitionToExistingStructure(Structure*, const Identifier& propertyName, unsigned attributes, JSCell* specificValue, size_t& offset);
+ static PassRefPtr<Structure> removePropertyTransition(Structure*, const Identifier& propertyName, size_t& offset);
+ static PassRefPtr<Structure> changePrototypeTransition(Structure*, JSValue prototype);
+ static PassRefPtr<Structure> despecifyFunctionTransition(Structure*, const Identifier&);
+ static PassRefPtr<Structure> getterSetterTransition(Structure*);
+ static PassRefPtr<Structure> toCacheableDictionaryTransition(Structure*);
+ static PassRefPtr<Structure> toUncacheableDictionaryTransition(Structure*);
+
+ PassRefPtr<Structure> flattenDictionaryStructure(JSObject*);
+
+ ~Structure();
+
+ // These should be used with caution.
+ size_t addPropertyWithoutTransition(const Identifier& propertyName, unsigned attributes, JSCell* specificValue);
+ size_t removePropertyWithoutTransition(const Identifier& propertyName);
+ void setPrototypeWithoutTransition(JSValue prototype) { m_prototype = prototype; }
+
+ bool isDictionary() const { return m_dictionaryKind != NoneDictionaryKind; }
+ bool isUncacheableDictionary() const { return m_dictionaryKind == UncachedDictionaryKind; }
+
+ const TypeInfo& typeInfo() const { return m_typeInfo; }
+
+ JSValue storedPrototype() const { return m_prototype; }
+ JSValue prototypeForLookup(ExecState*) const;
+ StructureChain* prototypeChain(ExecState*) const;
+
+ Structure* previousID() const { return m_previous.get(); }
+
+ void growPropertyStorageCapacity();
+ unsigned propertyStorageCapacity() const { return m_propertyStorageCapacity; }
+ unsigned propertyStorageSize() const { return m_anonymousSlotCount + (m_propertyTable ? m_propertyTable->keyCount + (m_propertyTable->deletedOffsets ? m_propertyTable->deletedOffsets->size() : 0) : static_cast<unsigned>(m_offset + 1)); }
+ bool isUsingInlineStorage() const;
+
+ size_t get(const Identifier& propertyName);
+ size_t get(const UString::Rep* rep, unsigned& attributes, JSCell*& specificValue);
+ size_t get(const Identifier& propertyName, unsigned& attributes, JSCell*& specificValue)
+ {
+ ASSERT(!propertyName.isNull());
+ return get(propertyName.ustring().rep(), attributes, specificValue);
+ }
+ bool transitionedFor(const JSCell* specificValue)
+ {
+ return m_specificValueInPrevious == specificValue;
+ }
+ bool hasTransition(UString::Rep*, unsigned attributes);
+ bool hasTransition(const Identifier& propertyName, unsigned attributes)
+ {
+ return hasTransition(propertyName._ustring.rep(), attributes);
+ }
+
+ bool hasGetterSetterProperties() const { return m_hasGetterSetterProperties; }
+ void setHasGetterSetterProperties(bool hasGetterSetterProperties) { m_hasGetterSetterProperties = hasGetterSetterProperties; }
+
+ bool hasNonEnumerableProperties() const { return m_hasNonEnumerableProperties; }
+
+ bool hasAnonymousSlots() const { return !!m_anonymousSlotCount; }
+ unsigned anonymousSlotCount() const { return m_anonymousSlotCount; }
+
+ bool isEmpty() const { return m_propertyTable ? !m_propertyTable->keyCount : m_offset == noOffset; }
+
+ void despecifyDictionaryFunction(const Identifier& propertyName);
+ void disableSpecificFunctionTracking() { m_specificFunctionThrashCount = maxSpecificFunctionThrashCount; }
+
+ void setEnumerationCache(JSPropertyNameIterator* enumerationCache); // Defined in JSPropertyNameIterator.h.
+ void clearEnumerationCache(JSPropertyNameIterator* enumerationCache); // Defined in JSPropertyNameIterator.h.
+ JSPropertyNameIterator* enumerationCache(); // Defined in JSPropertyNameIterator.h.
+ void getPropertyNames(PropertyNameArray&, EnumerationMode mode);
+
+ private:
+
+ Structure(JSValue prototype, const TypeInfo&, unsigned anonymousSlotCount);
+
+ typedef enum {
+ NoneDictionaryKind = 0,
+ CachedDictionaryKind = 1,
+ UncachedDictionaryKind = 2
+ } DictionaryKind;
+ static PassRefPtr<Structure> toDictionaryTransition(Structure*, DictionaryKind);
+
+ size_t put(const Identifier& propertyName, unsigned attributes, JSCell* specificValue);
+ size_t remove(const Identifier& propertyName);
+
+ void expandPropertyMapHashTable();
+ void rehashPropertyMapHashTable();
+ void rehashPropertyMapHashTable(unsigned newTableSize);
+ void createPropertyMapHashTable();
+ void createPropertyMapHashTable(unsigned newTableSize);
+ void insertIntoPropertyMapHashTable(const PropertyMapEntry&);
+ void checkConsistency();
+
+ bool despecifyFunction(const Identifier&);
+ void despecifyAllFunctions();
+
+ PropertyMapHashTable* copyPropertyTable();
+ void materializePropertyMap();
+ void materializePropertyMapIfNecessary()
+ {
+ if (m_propertyTable || !m_previous)
+ return;
+ materializePropertyMap();
+ }
+
+ signed char transitionCount() const
+ {
+ // Since the number of transitions is always the same as m_offset, we keep the size of Structure down by not storing both.
+ return m_offset == noOffset ? 0 : m_offset + 1;
+ }
+
+ typedef std::pair<Structure*, Structure*> Transition;
+ typedef HashMap<StructureTransitionTableHash::Key, Transition, StructureTransitionTableHash, StructureTransitionTableHashTraits> TransitionTable;
+
+ inline bool transitionTableContains(const StructureTransitionTableHash::Key& key, JSCell* specificValue);
+ inline void transitionTableRemove(const StructureTransitionTableHash::Key& key, JSCell* specificValue);
+ inline void transitionTableAdd(const StructureTransitionTableHash::Key& key, Structure* structure, JSCell* specificValue);
+ inline bool transitionTableHasTransition(const StructureTransitionTableHash::Key& key) const;
+ inline Structure* transitionTableGet(const StructureTransitionTableHash::Key& key, JSCell* specificValue) const;
+
+ TransitionTable* transitionTable() const { ASSERT(!m_isUsingSingleSlot); return m_transitions.m_table; }
+ inline void setTransitionTable(TransitionTable* table);
+ Structure* singleTransition() const { ASSERT(m_isUsingSingleSlot); return m_transitions.m_singleTransition; }
+ void setSingleTransition(Structure* structure) { ASSERT(m_isUsingSingleSlot); m_transitions.m_singleTransition = structure; }
+
+ bool isValid(ExecState*, StructureChain* cachedPrototypeChain) const;
+
+ static const unsigned emptyEntryIndex = 0;
+
+ static const signed char s_maxTransitionLength = 64;
+
+ static const signed char noOffset = -1;
+
+ static const unsigned maxSpecificFunctionThrashCount = 3;
+
+ TypeInfo m_typeInfo;
+
+ JSValue m_prototype;
+ mutable RefPtr<StructureChain> m_cachedPrototypeChain;
+
+ RefPtr<Structure> m_previous;
+ RefPtr<UString::Rep> m_nameInPrevious;
+ JSCell* m_specificValueInPrevious;
+
+ // 'm_isUsingSingleSlot' indicates whether we are using the single transition optimisation.
+ union {
+ TransitionTable* m_table;
+ Structure* m_singleTransition;
+ } m_transitions;
+
+ WeakGCPtr<JSPropertyNameIterator> m_enumerationCache;
+
+ PropertyMapHashTable* m_propertyTable;
+
+ uint32_t m_propertyStorageCapacity;
+
+ // m_offset does not account for anonymous slots
+ signed char m_offset;
+
+ unsigned m_dictionaryKind : 2;
+ bool m_isPinnedPropertyTable : 1;
+ bool m_hasGetterSetterProperties : 1;
+ bool m_hasNonEnumerableProperties : 1;
+#if COMPILER(WINSCW)
+ // Workaround for Symbian WINSCW compiler that cannot resolve unsigned type of the declared
+ // bitfield, when used as argument in make_pair() function calls in structure.ccp.
+ // This bitfield optimization is insignificant for the Symbian emulator target.
+ unsigned m_attributesInPrevious;
+#else
+ unsigned m_attributesInPrevious : 7;
+#endif
+ unsigned m_specificFunctionThrashCount : 2;
+ unsigned m_anonymousSlotCount : 5;
+ unsigned m_isUsingSingleSlot : 1;
+ // 4 free bits
+ };
+
+ inline size_t Structure::get(const Identifier& propertyName)
+ {
+ ASSERT(!propertyName.isNull());
+
+ materializePropertyMapIfNecessary();
+ if (!m_propertyTable)
+ return WTF::notFound;
+
+ UString::Rep* rep = propertyName._ustring.rep();
+
+ unsigned i = rep->existingHash();
+
+#if DUMP_PROPERTYMAP_STATS
+ ++numProbes;
+#endif
+
+ unsigned entryIndex = m_propertyTable->entryIndices[i & m_propertyTable->sizeMask];
+ if (entryIndex == emptyEntryIndex)
+ return WTF::notFound;
+
+ if (rep == m_propertyTable->entries()[entryIndex - 1].key)
+ return m_propertyTable->entries()[entryIndex - 1].offset;
+
+#if DUMP_PROPERTYMAP_STATS
+ ++numCollisions;
+#endif
+
+ unsigned k = 1 | WTF::doubleHash(rep->existingHash());
+
+ while (1) {
+ i += k;
+
+#if DUMP_PROPERTYMAP_STATS
+ ++numRehashes;
+#endif
+
+ entryIndex = m_propertyTable->entryIndices[i & m_propertyTable->sizeMask];
+ if (entryIndex == emptyEntryIndex)
+ return WTF::notFound;
+
+ if (rep == m_propertyTable->entries()[entryIndex - 1].key)
+ return m_propertyTable->entries()[entryIndex - 1].offset;
+ }
+ }
+
+} // namespace JSC
+
+#endif // Structure_h