Revision: 12747
Author: [email protected]
Date: Wed Oct 17 07:09:42 2012
Log: Eagerly follow transitions to existing maps while json parsing.
Review URL: https://chromiumcodereview.appspot.com/11184006
http://code.google.com/p/v8/source/detail?r=12747
Modified:
/branches/bleeding_edge/src/json-parser.h
/branches/bleeding_edge/src/objects-inl.h
/branches/bleeding_edge/src/objects.cc
/branches/bleeding_edge/src/objects.h
=======================================
--- /branches/bleeding_edge/src/json-parser.h Wed Sep 26 07:59:10 2012
+++ /branches/bleeding_edge/src/json-parser.h Wed Oct 17 07:09:42 2012
@@ -289,6 +289,8 @@
// Parse a JSON object. Position must be right at '{'.
template <bool seq_ascii>
Handle<Object> JsonParser<seq_ascii>::ParseJsonObject() {
+ int current_index = 0;
+ Handle<Object> prototype;
Handle<JSFunction> object_constructor(
isolate()->native_context()->object_function());
Handle<JSObject> json_object =
@@ -309,15 +311,20 @@
if (key->AsArrayIndex(&index)) {
JSObject::SetOwnElement(json_object, index, value, kNonStrictMode);
} else if (key->Equals(isolate()->heap()->Proto_symbol())) {
- SetPrototype(json_object, value);
+ prototype = value;
} else {
- JSObject::SetLocalPropertyIgnoreAttributes(
- json_object, key, value, NONE);
+ if (JSObject::TryTransitionToField(json_object, key)) {
+ json_object->FastPropertyAtPut(current_index++, *value);
+ } else {
+ JSObject::SetLocalPropertyIgnoreAttributes(
+ json_object, key, value, NONE);
+ }
}
} while (MatchSkipWhiteSpace(','));
if (c0_ != '}') {
return ReportUnexpectedCharacter();
}
+ if (!prototype.is_null()) SetPrototype(json_object, prototype);
}
AdvanceSkipWhitespace();
return json_object;
=======================================
--- /branches/bleeding_edge/src/objects-inl.h Wed Oct 17 06:04:49 2012
+++ /branches/bleeding_edge/src/objects-inl.h Wed Oct 17 07:09:42 2012
@@ -1412,6 +1412,36 @@
initialize_elements();
return this;
}
+
+
+MaybeObject* JSObject::AddFastPropertyUsingMap(Map* map) {
+ ASSERT(this->map()->NumberOfOwnDescriptors() + 1 ==
+ map->NumberOfOwnDescriptors());
+ if (this->map()->unused_property_fields() == 0) {
+ int new_size = properties()->length() + map->unused_property_fields()
+ 1;
+ FixedArray* new_properties;
+ MaybeObject* maybe_properties = properties()->CopySize(new_size);
+ if (!maybe_properties->To(&new_properties)) return maybe_properties;
+ set_properties(new_properties);
+ }
+ set_map(map);
+ return this;
+}
+
+
+bool JSObject::TryTransitionToField(Handle<JSObject> object,
+ Handle<String> key) {
+ if (!object->map()->HasTransitionArray()) return false;
+ Handle<TransitionArray> transitions(object->map()->transitions());
+ int transition = transitions->Search(*key);
+ if (transition == TransitionArray::kNotFound) return false;
+ PropertyDetails target_details =
transitions->GetTargetDetails(transition);
+ if (target_details.type() != FIELD) return false;
+ if (target_details.attributes() != NONE) return false;
+ Handle<Map> target(transitions->GetTarget(transition));
+ JSObject::AddFastPropertyUsingMap(object, target);
+ return true;
+}
ACCESSORS(Oddball, to_string, String, kToStringOffset)
=======================================
--- /branches/bleeding_edge/src/objects.cc Wed Oct 17 06:04:49 2012
+++ /branches/bleeding_edge/src/objects.cc Wed Oct 17 07:09:42 2012
@@ -2792,6 +2792,14 @@
bool threw;
return Execution::Call(trap, handler, argc, argv, &threw);
}
+
+
+void JSObject::AddFastPropertyUsingMap(Handle<JSObject> object,
+ Handle<Map> map) {
+ CALL_HEAP_FUNCTION_VOID(
+ object->GetIsolate(),
+ object->AddFastPropertyUsingMap(*map));
+}
MaybeObject* JSObject::SetPropertyForResult(LookupResult* result,
=======================================
--- /branches/bleeding_edge/src/objects.h Wed Oct 17 06:04:49 2012
+++ /branches/bleeding_edge/src/objects.h Wed Oct 17 07:09:42 2012
@@ -1621,6 +1621,16 @@
Handle<Object> value,
PropertyAttributes attributes);
+ // Try to follow an existing transition to a field with attributes NONE.
The
+ // return value indicates whether the transition was successful.
+ static inline bool TryTransitionToField(Handle<JSObject> object,
+ Handle<String> key);
+
+ // Extend the receiver with a single fast property appeared first in the
+ // passed map. This also extends the property backing store if necessary.
+ static void AddFastPropertyUsingMap(Handle<JSObject> object, Handle<Map>
map);
+ inline MUST_USE_RESULT MaybeObject* AddFastPropertyUsingMap(Map* map);
+
// Can cause GC.
MUST_USE_RESULT MaybeObject* SetLocalPropertyIgnoreAttributes(
String* key,
--
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