ES6: Adding support for size to Set and Map

src/runtime.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * 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
@@ skipping 765 matching lines @@
   ASSERT(args.length() == 2);
   CONVERT_ARG_HANDLE_CHECKED(JSSet, holder, 0);
   Handle<Object> key(args[1]);
   Handle<ObjectHashSet> table(ObjectHashSet::cast(holder->table()));
   table = ObjectHashSetRemove(table, key);
   holder->set_table(*table);
   return isolate->heap()->undefined_value();
 }
 
 
+RUNTIME_FUNCTION(MaybeObject*, Runtime_SetSize) {
+  HandleScope scope(isolate);
+  ASSERT(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSSet, holder, 0);
+  Handle<ObjectHashSet> table(ObjectHashSet::cast(holder->table()));
+  return Smi::FromInt(table->NumberOfElements());
+}
+
+
 RUNTIME_FUNCTION(MaybeObject*, Runtime_MapInitialize) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 1);
   CONVERT_ARG_HANDLE_CHECKED(JSMap, holder, 0);
   Handle<ObjectHashTable> table = isolate->factory()->NewObjectHashTable(0);
   holder->set_table(*table);
   return *holder;
 }
 
 
@@ skipping 39 matching lines @@
   CONVERT_ARG_HANDLE_CHECKED(JSMap, holder, 0);
   CONVERT_ARG_HANDLE_CHECKED(Object, key, 1);
   CONVERT_ARG_HANDLE_CHECKED(Object, value, 2);
   Handle<ObjectHashTable> table(ObjectHashTable::cast(holder->table()));
   Handle<ObjectHashTable> new_table = PutIntoObjectHashTable(table, key, value);
   holder->set_table(*new_table);
   return isolate->heap()->undefined_value();
 }
 
 
+RUNTIME_FUNCTION(MaybeObject*, Runtime_MapSize) {
+  HandleScope scope(isolate);
+  ASSERT(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSMap, holder, 0);
+  Handle<ObjectHashTable> table(ObjectHashTable::cast(holder->table()));
+  return Smi::FromInt(table->NumberOfElements());
+}
+
+
 RUNTIME_FUNCTION(MaybeObject*, Runtime_WeakMapInitialize) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 1);
   CONVERT_ARG_HANDLE_CHECKED(JSWeakMap, weakmap, 0);
   ASSERT(weakmap->map()->inobject_properties() == 0);
   Handle<ObjectHashTable> table = isolate->factory()->NewObjectHashTable(0);
   weakmap->set_table(*table);
   weakmap->set_next(Smi::FromInt(0));
   return *weakmap;
 }
@@ skipping 12446 matching lines @@
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                        "Runtime::PerformGC");
   }
 }
 
 
 } }  // namespace v8::internal