Changeset 252464 in webkit

Timestamp:

Nov 14, 2019 1:59:58 PM (4 years ago)

Author:

commit-queue@webkit.org

Message:

Use toLength() and getIndexQuickly() in JSON.stringify
​https://bugs.webkit.org/show_bug.cgi?id=204122

Patch by Alexey Shvayka <Alexey Shvayka> on 2019-11-14
Reviewed by Yusuke Suzuki.

JSTests:

• microbenchmarks/json-stringify-array-replacer.js: Added.
• microbenchmarks/json-stringify-empty-array.js: Added.

Source/JavaScriptCore:

Using toLength() is semantically equivalent and performance-neutral, while adding
JSObject::getIndexQuickly() advances microbenchmarks/json-stringify-array-replacer.js
by 34%.

• runtime/JSONObject.cpp:

(JSC::Stringifier::Stringifier):
(JSC::Stringifier::Holder::appendNextProperty):

Location:

trunk

Files:

• JSTests/ChangeLog (modified) (1 diff)
• JSTests/microbenchmarks/json-stringify-array-replacer.js (added)
• JSTests/microbenchmarks/json-stringify-empty-array.js (added)
• Source/JavaScriptCore/ChangeLog (modified) (1 diff)
• Source/JavaScriptCore/runtime/JSONObject.cpp (modified) (3 diffs)

trunk/JSTests/ChangeLog

@@ +1 @@
+2019-11-14  Alexey Shvayka  <shvaikalesh@gmail.com>
+
+        Use toLength() and getIndexQuickly() in JSON.stringify
+        https://bugs.webkit.org/show_bug.cgi?id=204122
+
+        Reviewed by Yusuke Suzuki.
+
+        * microbenchmarks/json-stringify-array-replacer.js: Added.
+        * microbenchmarks/json-stringify-empty-array.js: Added.
+
 2019-11-14  Caio Lima  <ticaiolima@gmail.com>
 

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2019-11-14  Alexey Shvayka  <shvaikalesh@gmail.com>
+
+        Use toLength() and getIndexQuickly() in JSON.stringify
+        https://bugs.webkit.org/show_bug.cgi?id=204122
+
+        Reviewed by Yusuke Suzuki.
+
+        Using toLength() is semantically equivalent and performance-neutral, while adding
+        JSObject::getIndexQuickly() advances microbenchmarks/json-stringify-array-replacer.js
+        by 34%.
+
+        * runtime/JSONObject.cpp:
+        (JSC::Stringifier::Stringifier):
+        (JSC::Stringifier::Holder::appendNextProperty):
+
 2019-11-14  Caio Lima  <ticaiolima@gmail.com>
 

trunk/Source/JavaScriptCore/runtime/JSONObject.cpp

@@ -238 +238 @@
             if (isArrayReplacer) {
                 m_usingArrayReplacer = true;
-                JSValue lengthValue = replacerObject->get(globalObject, vm.propertyNames->length);
+                unsigned length = toLength(globalObject, replacerObject);
                 RETURN_IF_EXCEPTION(scope, );
-                unsigned length = lengthValue.toUInt32(globalObject);
-                RETURN_IF_EXCEPTION(scope, );
-                for (unsigned i = 0; i < length; ++i) {
-                    JSValue name = replacerObject->get(globalObject, i);
-                    RETURN_IF_EXCEPTION(scope, );
+                for (unsigned index = 0; index < length; ++index) {
+                    JSValue name;
+                    if (isJSArray(replacerObject) && replacerObject->canGetIndexQuickly(index))
+                        name = replacerObject->getIndexQuickly(index);
+                    else {
+                        name = replacerObject->get(globalObject, index);
+                        RETURN_IF_EXCEPTION(scope, );
+                    }
                     if (name.isObject()) {
                         auto* nameObject = jsCast<JSObject*>(name);
@@ -487 +490 @@
     if (!m_index) {
         if (m_isArray) {
-            if (m_isJSArray)
-                m_size = asArray(m_object)->length();
-            else {
-                JSValue value = m_object->get(globalObject, vm.propertyNames->length);
-                RETURN_IF_EXCEPTION(scope, false);
-                m_size = value.toUInt32(globalObject);
-                RETURN_IF_EXCEPTION(scope, false);
-            }
+            m_size = toLength(globalObject, m_object);
+            RETURN_IF_EXCEPTION(scope, false);
             builder.append('[');
         } else {
@@ -529 +526 @@
         // Get the value.
         JSValue value;
-        if (m_isJSArray && asArray(m_object)->canGetIndexQuickly(index))
-            value = asArray(m_object)->getIndexQuickly(index);
+        if (m_isJSArray && m_object->canGetIndexQuickly(index))
+            value = m_object->getIndexQuickly(index);
         else {
             PropertySlot slot(m_object, PropertySlot::InternalMethodType::Get);