Expose the content of Maps and WeakMaps through MapMirror.

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index d980d327aa89640d2b44cbef8e08b58be0eb3257..42f319cd422b4e3d8bf544db3f560c448ca3d146 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -1706,6 +1706,52 @@ RUNTIME_FUNCTION(Runtime_MapIteratorInitialize) {
 }
 
 
+RUNTIME_FUNCTION(Runtime_GetMapEntries) {

[rossberg, 2014/07/16 09:51:07]

Is this necessary? You can easily get the array of entries of an ordinary map
through its public JS interface, so we shouldn't need to add an extra runtime
function for that.

[Alexandra Mikhaylova, 2014/07/16 10:21:13]

Thanks, I'll use the map iterator to get entries then.

+  HandleScope scope(isolate);
+  ASSERT(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSMap, holder, 0);
+  Handle<OrderedHashMap> table(OrderedHashMap::cast(holder->table()));
+  Handle<FixedArray> entries = isolate->factory()->NewFixedArray(
+      table->NumberOfElements() * 2);
+  int number_of_non_hole_elements = 0;
+  { DisallowHeapAllocation no_gc;
+    for (int i = 0; i < table->UsedCapacity(); i++) {
+        Handle<Object> key(table->KeyAt(i), isolate);
+        if (!key->IsTheHole()) {
+            entries->set(number_of_non_hole_elements * 2, *key);
+            entries->set(number_of_non_hole_elements * 2 + 1,
+                         table->ValueAt(i));
+            number_of_non_hole_elements++;
+        }
+    }
+  }
+  return *isolate->factory()->NewJSArrayWithElements(entries);
+}
+
+
+RUNTIME_FUNCTION(Runtime_GetWeakMapEntries) {
+  HandleScope scope(isolate);
+  ASSERT(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSWeakCollection, holder, 0);
+  Handle<ObjectHashTable> table(ObjectHashTable::cast(holder->table()));
+  Handle<FixedArray> entries = isolate->factory()->NewFixedArray(
+      table->NumberOfElements() * 2);
+  int number_of_non_hole_elements = 0;
+  { DisallowHeapAllocation no_gc;
+    for (int i = 0; i < table->Capacity(); i++) {
+        Handle<Object> key(table->KeyAt(i), isolate);

[Yang, 2014/07/16 12:10:58]

Indentation size is weird. We use 4 spaces for line break and 2 spaces for
scopes. You could also use "git cl format" to have it formatted for you.

[Alexandra Mikhaylova, 2014/07/16 17:00:37]

Done.

+        if (table->IsKey(*key)) {
+            entries->set(number_of_non_hole_elements * 2, *key);
+            entries->set(number_of_non_hole_elements * 2 + 1,
+                         table->Lookup(key));
+            number_of_non_hole_elements++;
+        }
+    }
+  }
+  return *isolate->factory()->NewJSArrayWithElements(entries);
+}
+
+
 RUNTIME_FUNCTION(Runtime_MapIteratorNext) {
   SealHandleScope shs(isolate);
   ASSERT(args.length() == 2);