Reland "HashTable::Shrink() handlified and derived template parameter added to...

Reland "HashTable::Shrink() handlified and derived template parameter added to HashTable hierarchy."

R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/235643002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20724 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/objects-inl.h

@@ -2882,8 +2882,8 @@ DescriptorArray::WhitenessWitness::~WhitenessWitness() {
 }
 
 
-template<typename Shape, typename Key>
-int HashTable<Shape, Key>::ComputeCapacity(int at_least_space_for) {
+template<typename Derived, typename Shape, typename Key>
+int HashTable<Derived, Shape, Key>::ComputeCapacity(int at_least_space_for) {
   const int kMinCapacity = 32;
   int capacity = RoundUpToPowerOf2(at_least_space_for * 2);
   if (capacity < kMinCapacity) {
@@ -2893,17 +2893,17 @@ int HashTable<Shape, Key>::ComputeCapacity(int at_least_space_for) {
 }
 
 
-template<typename Shape, typename Key>
-int HashTable<Shape, Key>::FindEntry(Key key) {
+template<typename Derived, typename Shape, typename Key>
+int HashTable<Derived, Shape, Key>::FindEntry(Key key) {
   return FindEntry(GetIsolate(), key);
 }
 
 
 // Find entry for key otherwise return kNotFound.
-template<typename Shape, typename Key>
-int HashTable<Shape, Key>::FindEntry(Isolate* isolate, Key key) {
+template<typename Derived, typename Shape, typename Key>
+int HashTable<Derived, Shape, Key>::FindEntry(Isolate* isolate, Key key) {
   uint32_t capacity = Capacity();
-  uint32_t entry = FirstProbe(HashTable<Shape, Key>::Hash(key), capacity);
+  uint32_t entry = FirstProbe(HashTable::Hash(key), capacity);
   uint32_t count = 1;
   // EnsureCapacity will guarantee the hash table is never full.
   while (true) {
@@ -3028,8 +3028,9 @@ FixedTypedArray<Traits>* FixedTypedArray<Traits>::cast(Object* object) {
 #undef MAKE_STRUCT_CAST
 
 
-template <typename Shape, typename Key>
-HashTable<Shape, Key>* HashTable<Shape, Key>::cast(Object* obj) {
+template <typename Derived, typename Shape, typename Key>
+HashTable<Derived, Shape, Key>*
+HashTable<Derived, Shape, Key>::cast(Object* obj) {
   ASSERT(obj->IsHashTable());
   return reinterpret_cast<HashTable*>(obj);
 }
@@ -6671,23 +6672,23 @@ bool AccessorPair::prohibits_overwriting() {
 }
 
 
-template<typename Shape, typename Key>
-void Dictionary<Shape, Key>::SetEntry(int entry,
-                                      Object* key,
-                                      Object* value) {
+template<typename Derived, typename Shape, typename Key>
+void Dictionary<Derived, Shape, Key>::SetEntry(int entry,
+                                               Object* key,
+                                               Object* value) {
   SetEntry(entry, key, value, PropertyDetails(Smi::FromInt(0)));
 }
 
 
-template<typename Shape, typename Key>
-void Dictionary<Shape, Key>::SetEntry(int entry,
-                                      Object* key,
-                                      Object* value,
-                                      PropertyDetails details) {
+template<typename Derived, typename Shape, typename Key>
+void Dictionary<Derived, Shape, Key>::SetEntry(int entry,
+                                               Object* key,
+                                               Object* value,
+                                               PropertyDetails details) {
   ASSERT(!key->IsName() ||
          details.IsDeleted() ||
          details.dictionary_index() > 0);
-  int index = HashTable<Shape, Key>::EntryToIndex(entry);
+  int index = DerivedHashTable::EntryToIndex(entry);
   DisallowHeapAllocation no_gc;
   WriteBarrierMode mode = FixedArray::GetWriteBarrierMode(no_gc);
   FixedArray::set(index, key, mode);
@@ -6773,6 +6774,12 @@ MaybeObject* ObjectHashTableShape::AsObject(Heap* heap, Object* key) {
 }
 
 
+Handle<ObjectHashTable> ObjectHashTable::Shrink(
+    Handle<ObjectHashTable> table, Handle<Object> key) {
+  return HashTable_::Shrink(table, *key);
+}
+
+
 template <int entrysize>
 bool WeakHashTableShape<entrysize>::IsMatch(Object* key, Object* other) {
   return key->SameValue(other);

src/objects.h

@@ -3656,7 +3656,7 @@ class BaseShape {
   }
 };
 
-template<typename Shape, typename Key>
+template<typename Derived, typename Shape, typename Key>
 class HashTable: public FixedArray {
  public:
   // Wrapper methods
@@ -3709,12 +3709,20 @@ class HashTable: public FixedArray {
   }
 
   // Returns a new HashTable object. Might return Failure.
+  // TODO(ishell): this will be eventually replaced by New().
   MUST_USE_RESULT static MaybeObject* Allocate(
       Heap* heap,
       int at_least_space_for,
       MinimumCapacity capacity_option = USE_DEFAULT_MINIMUM_CAPACITY,
       PretenureFlag pretenure = NOT_TENURED);
 
+  // Returns a new HashTable object.
+  static Handle<Derived> New(
+      Isolate* isolate,
+      int at_least_space_for,
+      MinimumCapacity capacity_option = USE_DEFAULT_MINIMUM_CAPACITY,
+      PretenureFlag pretenure = NOT_TENURED);
+
   // Computes the required capacity for a table holding the given
   // number of elements. May be more than HashTable::kMaxCapacity.
   static int ComputeCapacity(int at_least_space_for);
@@ -3824,10 +3832,10 @@ class HashTable: public FixedArray {
   void Swap(uint32_t entry1, uint32_t entry2, WriteBarrierMode mode);
 
   // Rehashes this hash-table into the new table.
-  MUST_USE_RESULT MaybeObject* Rehash(HashTable* new_table, Key key);
+  void Rehash(Derived* new_table, Key key);
 
   // Attempt to shrink hash table after removal of key.
-  MUST_USE_RESULT MaybeObject* Shrink(Key key);
+  static Handle<Derived> Shrink(Handle<Derived> table, Key key);
 
   // Ensure enough space for n additional elements.
   MUST_USE_RESULT MaybeObject* EnsureCapacity(
@@ -3880,7 +3888,9 @@ class SeqOneByteString;
 //
 // No special elements in the prefix and the element size is 1
 // because only the string itself (the key) needs to be stored.
-class StringTable: public HashTable<StringTableShape, HashTableKey*> {
+class StringTable: public HashTable<StringTable,
+                                    StringTableShape,
+                                    HashTableKey*> {
  public:
   // Find string in the string table.  If it is not there yet, it is
   // added.  The return value is the string table which might have
@@ -3932,7 +3942,7 @@ class MapCacheShape : public BaseShape<HashTableKey*> {
 //
 // Maps keys that are a fixed array of unique names to a map.
 // Used for canonicalize maps for object literals.
-class MapCache: public HashTable<MapCacheShape, HashTableKey*> {
+class MapCache: public HashTable<MapCache, MapCacheShape, HashTableKey*> {
  public:
   // Find cached value for a name key, otherwise return null.
   Object* Lookup(FixedArray* key);
@@ -3944,33 +3954,36 @@ class MapCache: public HashTable<MapCacheShape, HashTableKey*> {
 };
 
 
-template <typename Shape, typename Key>
-class Dictionary: public HashTable<Shape, Key> {
+template <typename Derived, typename Shape, typename Key>
+class Dictionary: public HashTable<Derived, Shape, Key> {
+ protected:
+  typedef HashTable<Derived, Shape, Key> DerivedHashTable;
+
  public:
-  static inline Dictionary<Shape, Key>* cast(Object* obj) {
-    return reinterpret_cast<Dictionary<Shape, Key>*>(obj);
+  static inline Dictionary* cast(Object* obj) {
+    return reinterpret_cast<Dictionary*>(obj);
   }
 
   // Returns the value at entry.
   Object* ValueAt(int entry) {
-    return this->get(HashTable<Shape, Key>::EntryToIndex(entry) + 1);
+    return this->get(DerivedHashTable::EntryToIndex(entry) + 1);
   }
 
   // Set the value for entry.
   void ValueAtPut(int entry, Object* value) {
-    this->set(HashTable<Shape, Key>::EntryToIndex(entry) + 1, value);
+    this->set(DerivedHashTable::EntryToIndex(entry) + 1, value);
   }
 
   // Returns the property details for the property at entry.
   PropertyDetails DetailsAt(int entry) {
     ASSERT(entry >= 0);  // Not found is -1, which is not caught by get().
     return PropertyDetails(
-        Smi::cast(this->get(HashTable<Shape, Key>::EntryToIndex(entry) + 2)));
+        Smi::cast(this->get(DerivedHashTable::EntryToIndex(entry) + 2)));
   }
 
   // Set the details for entry.
   void DetailsAtPut(int entry, PropertyDetails value) {
-    this->set(HashTable<Shape, Key>::EntryToIndex(entry) + 2, value.AsSmi());
+    this->set(DerivedHashTable::EntryToIndex(entry) + 2, value.AsSmi());
   }
 
   // Sorting support
@@ -3980,16 +3993,14 @@ class Dictionary: public HashTable<Shape, Key> {
   Object* DeleteProperty(int entry, JSObject::DeleteMode mode);
   // TODO(ishell): Temporary wrapper until handlified.
   static Handle<Object> DeleteProperty(
-      Handle<Dictionary<Shape, Key> > dictionary,
+      Handle<Dictionary> dictionary,
       int entry,
       JSObject::DeleteMode mode);
 
   // Attempt to shrink the dictionary after deletion of key.
-  MUST_USE_RESULT MaybeObject* Shrink(Key key);
-  // TODO(ishell): Temporary wrapper until handlified.
-  MUST_USE_RESULT static Handle<FixedArray> Shrink(
-      Handle<Dictionary<Shape, Key> > dictionary,
-      Key key);
+  static inline Handle<Derived> Shrink(Handle<Derived> dictionary, Key key) {
+    return DerivedHashTable::Shrink(dictionary, key);
+  }
 
   // Returns the number of elements in the dictionary filtering out properties
   // with the specified attributes.
@@ -4059,8 +4070,7 @@ class Dictionary: public HashTable<Shape, Key> {
 
   // Generate new enumeration indices to avoid enumeration index overflow.
   MUST_USE_RESULT MaybeObject* GenerateNewEnumerationIndices();
-  static const int kMaxNumberKeyIndex =
-      HashTable<Shape, Key>::kPrefixStartIndex;
+  static const int kMaxNumberKeyIndex = DerivedHashTable::kPrefixStartIndex;
   static const int kNextEnumerationIndexIndex = kMaxNumberKeyIndex + 1;
 };
 
@@ -4078,7 +4088,9 @@ class NameDictionaryShape : public BaseShape<Name*> {
 };
 
 
-class NameDictionary: public Dictionary<NameDictionaryShape, Name*> {
+class NameDictionary: public Dictionary<NameDictionary,
+                                        NameDictionaryShape,
+                                        Name*> {
  public:
   static inline NameDictionary* cast(Object* obj) {
     ASSERT(obj->IsDictionary());
@@ -4128,7 +4140,9 @@ class UnseededNumberDictionaryShape : public NumberDictionaryShape {
 
 
 class SeededNumberDictionary
-    : public Dictionary<SeededNumberDictionaryShape, uint32_t> {
+    : public Dictionary<SeededNumberDictionary,
+                        SeededNumberDictionaryShape,
+                        uint32_t> {
  public:
   static SeededNumberDictionary* cast(Object* obj) {
     ASSERT(obj->IsDictionary());
@@ -4181,7 +4195,9 @@ class SeededNumberDictionary
 
 
 class UnseededNumberDictionary
-    : public Dictionary<UnseededNumberDictionaryShape, uint32_t> {
+    : public Dictionary<UnseededNumberDictionary,
+                        UnseededNumberDictionaryShape,
+                        uint32_t> {
  public:
   static UnseededNumberDictionary* cast(Object* obj) {
     ASSERT(obj->IsDictionary());
@@ -4217,7 +4233,10 @@ class ObjectHashTableShape : public BaseShape<Object*> {
 
 // ObjectHashTable maps keys that are arbitrary objects to object values by
 // using the identity hash of the key for hashing purposes.
-class ObjectHashTable: public HashTable<ObjectHashTableShape, Object*> {
+class ObjectHashTable: public HashTable<ObjectHashTable,
+                                        ObjectHashTableShape,
+                                        Object*> {
+  typedef HashTable<ObjectHashTable, ObjectHashTableShape, Object*> HashTable_;
  public:
   static inline ObjectHashTable* cast(Object* obj) {
     ASSERT(obj->IsHashTable());
@@ -4231,8 +4250,8 @@ class ObjectHashTable: public HashTable<ObjectHashTableShape, Object*> {
       PretenureFlag pretenure = NOT_TENURED);
 
   // Attempt to shrink hash table after removal of key.
-  static Handle<ObjectHashTable> Shrink(Handle<ObjectHashTable> table,
-                                        Handle<Object> key);
+  static inline Handle<ObjectHashTable> Shrink(Handle<ObjectHashTable> table,
+                                               Handle<Object> key);
 
   // Looks up the value associated with the given key. The hole value is
   // returned in case the key is not present.
@@ -4430,7 +4449,9 @@ class WeakHashTableShape : public BaseShape<Object*> {
 // WeakHashTable maps keys that are arbitrary objects to object values.
 // It is used for the global weak hash table that maps objects
 // embedded in optimized code to dependent code lists.
-class WeakHashTable: public HashTable<WeakHashTableShape<2>, Object*> {
+class WeakHashTable: public HashTable<WeakHashTable,
+                                      WeakHashTableShape<2>,
+                                      Object*> {
  public:
   static inline WeakHashTable* cast(Object* obj) {
     ASSERT(obj->IsHashTable());
@@ -8200,7 +8221,8 @@ class CompilationCacheShape : public BaseShape<HashTableKey*> {
 };
 
 
-class CompilationCacheTable: public HashTable<CompilationCacheShape,
+class CompilationCacheTable: public HashTable<CompilationCacheTable,
+                                              CompilationCacheShape,
                                               HashTableKey*> {
  public:
   // Find cached value for a string key, otherwise return null.
@@ -8301,7 +8323,8 @@ class CodeCacheHashTableShape : public BaseShape<HashTableKey*> {
 };
 
 
-class CodeCacheHashTable: public HashTable<CodeCacheHashTableShape,
+class CodeCacheHashTable: public HashTable<CodeCacheHashTable,
+                                           CodeCacheHashTableShape,
                                            HashTableKey*> {
  public:
   Object* Lookup(Name* name, Code::Flags flags);
@@ -8351,7 +8374,9 @@ class PolymorphicCodeCache: public Struct {
 
 
 class PolymorphicCodeCacheHashTable
-    : public HashTable<CodeCacheHashTableShape, HashTableKey*> {
+    : public HashTable<PolymorphicCodeCacheHashTable,
+                       CodeCacheHashTableShape,
+                       HashTableKey*> {
  public:
   Object* Lookup(MapHandleList* maps, int code_kind);