Split Put into Put and Remove

src/objects.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include "allocation.h"
 #include "assert-scope.h"
 #include "builtins.h"
@@ skipping 4116 matching lines @@
 
   // Attempt to shrink hash table after removal of key.
   MUST_USE_RESULT 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.
   Object* Lookup(Handle<Object> key);
 
-  // Adds (or overwrites) the value associated with the given key. Mapping a
-  // key to the hole value causes removal of the whole entry.
+  // Adds (or overwrites) the value associated with the given key.
   static Handle<ObjectHashTable> Put(Handle<ObjectHashTable> table,
                                      Handle<Object> key,
                                      Handle<Object> value);
 
+  // Returns an ObjectHashTable (possibly |table|) where |key| has been removed.
+  static Handle<ObjectHashTable> Remove(Handle<ObjectHashTable> table,

[arv (Not doing code reviews), 2014/05/30 18:47:08]

I wasn't sure if I should add a `bool* was_present` version here as well. It is
never used so I decided against it.

+                                        Handle<Object> key);
+
  private:
   friend class MarkCompactCollector;
 
   void AddEntry(int entry, Object* key, Object* value);
   void RemoveEntry(int entry);
 
   // Returns the index to the value of an entry.
   static inline int EntryToValueIndex(int entry) {
     return EntryToIndex(entry) + 1;
   }
@@ skipping 44 matching lines @@
       Isolate* isolate, int capacity, PretenureFlag pretenure = NOT_TENURED);
 
   // Returns an OrderedHashTable (possibly |table|) with enough space
   // to add at least one new element.
   static Handle<Derived> EnsureGrowable(Handle<Derived> table);
 
   // Returns an OrderedHashTable (possibly |table|) that's shrunken
   // if possible.
   static Handle<Derived> Shrink(Handle<Derived> table);
 
-  // Returns a new empty OrderedHashTable and updates all the iterators to
-  // point to the new table.
+  // Returns a new empty OrderedHashTable and records the clearing so that
+  // exisiting iterators can be updated.
   static Handle<Derived> Clear(Handle<Derived> table);
 
+  // Returns an OrderedHashTable (possibly |table|) where |key| has been
+  // removed.
+  static Handle<Derived> Remove(Handle<Derived> table, Handle<Object> key,
+      bool* was_present);
+
+  static Handle<Derived> Remove(Handle<Derived> table, Handle<Object> key);

[adamk, 2014/05/30 20:13:58]

I'm not sure you need this anywhere after you update runtime.cc for my comments.

[arv (Not doing code reviews), 2014/05/30 20:53:07]

Done.

+
   // Returns kNotFound if the key isn't present.
   int FindEntry(Handle<Object> key);
 
   int NumberOfElements() {
     return Smi::cast(get(kNumberOfElementsIndex))->value();
   }
 
   int NumberOfDeletedElements() {
     return Smi::cast(get(kNumberOfDeletedElementsIndex))->value();
   }
@@ skipping 103 matching lines @@
     OrderedHashSet, JSSetIterator, 1> {
  public:
   static OrderedHashSet* cast(Object* obj) {
     ASSERT(obj->IsOrderedHashTable());
     return reinterpret_cast<OrderedHashSet*>(obj);
   }
 
   bool Contains(Handle<Object> key);
   static Handle<OrderedHashSet> Add(
       Handle<OrderedHashSet> table, Handle<Object> key);
-  static Handle<OrderedHashSet> Remove(
-      Handle<OrderedHashSet> table, Handle<Object> key, bool* was_present);
 };
 
 
 class JSMapIterator;
 
 
 class OrderedHashMap:public OrderedHashTable<
     OrderedHashMap, JSMapIterator, 2> {
  public:
   static OrderedHashMap* cast(Object* obj) {
@@ skipping 6728 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_