Bug 1394290 - Optimize Proxy::get/set by avoiding unnecessary receive…

…r checking. r=jandem MozReview-Commit-ID: 7K67zt3JrQl --HG-- extra : rebase_source : 3a4796844a922c59949f787b0e40d9470e4c94f8
dothq · Aug 28, 2017 · e5727d7 · e5727d7
1 parent f1a8845
commit e5727d7
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Showing 2 changed files with 39 additions and 19 deletions.
diff --git a/js/src/proxy/Proxy.cpp b/js/src/proxy/Proxy.cpp
@@ -300,17 +300,19 @@ js::ProxyHasOwn(JSContext* cx, HandleObject proxy, HandleValue idVal, MutableHan
 }
 
 static MOZ_ALWAYS_INLINE Value
-ValueToWindowProxyIfWindow(const Value& v)
+ValueToWindowProxyIfWindow(const Value& v, JSObject* proxy)
 {
-    if (v.isObject())
+    if (v.isObject() && v != ObjectValue(*proxy))
         return ObjectValue(*ToWindowProxyIfWindow(&v.toObject()));
     return v;
 }
 
 MOZ_ALWAYS_INLINE bool
-Proxy::get(JSContext* cx, HandleObject proxy, HandleValue receiver_, HandleId id,
-           MutableHandleValue vp)
+Proxy::getInternal(JSContext* cx, HandleObject proxy, HandleValue receiver,
+                   HandleId id, MutableHandleValue vp)
 {
+    MOZ_ASSERT_IF(receiver.isObject(), !IsWindow(&receiver.toObject()));
+
     if (!CheckRecursionLimit(cx))
         return false;
     const BaseProxyHandler* handler = proxy->as<ProxyObject>().handler();
@@ -319,10 +321,6 @@ Proxy::get(JSContext* cx, HandleObject proxy, HandleValue receiver_, HandleId id
     if (!policy.allowed())
         return policy.returnValue();
 
-    // Use the WindowProxy as receiver if receiver_ is a Window. Proxy handlers
-    // shouldn't have to know about the Window/WindowProxy distinction.
-    RootedValue receiver(cx, ValueToWindowProxyIfWindow(receiver_));
-
     if (handler->hasPrototype()) {
         bool own;
         if (!handler->hasOwn(cx, proxy, id, &own))
@@ -340,11 +338,21 @@ Proxy::get(JSContext* cx, HandleObject proxy, HandleValue receiver_, HandleId id
     return handler->get(cx, proxy, receiver, id, vp);
 }
 
+bool
+Proxy::get(JSContext* cx, HandleObject proxy, HandleValue receiver_, HandleId id,
+           MutableHandleValue vp)
+{
+    // Use the WindowProxy as receiver if receiver_ is a Window. Proxy handlers
+    // shouldn't have to know about the Window/WindowProxy distinction.
+    RootedValue receiver(cx, ValueToWindowProxyIfWindow(receiver_, proxy));
+    return getInternal(cx, proxy, receiver, id, vp);
+}
+
 bool
 js::ProxyGetProperty(JSContext* cx, HandleObject proxy, HandleId id, MutableHandleValue vp)
 {
     RootedValue receiver(cx, ObjectValue(*proxy));
-    return Proxy::get(cx, proxy, receiver, id, vp);
+    return Proxy::getInternal(cx, proxy, receiver, id, vp);
 }
 
 bool
@@ -356,13 +364,15 @@ js::ProxyGetPropertyByValue(JSContext* cx, HandleObject proxy, HandleValue idVal
         return false;
 
     RootedValue receiver(cx, ObjectValue(*proxy));
-    return Proxy::get(cx, proxy, receiver, id, vp);
+    return Proxy::getInternal(cx, proxy, receiver, id, vp);
 }
 
-bool
-Proxy::set(JSContext* cx, HandleObject proxy, HandleId id, HandleValue v, HandleValue receiver_,
-           ObjectOpResult& result)
+MOZ_ALWAYS_INLINE bool
+Proxy::setInternal(JSContext* cx, HandleObject proxy, HandleId id, HandleValue v,
+                   HandleValue receiver, ObjectOpResult& result)
 {
+    MOZ_ASSERT_IF(receiver.isObject(), !IsWindow(&receiver.toObject()));
+
     if (!CheckRecursionLimit(cx))
         return false;
     const BaseProxyHandler* handler = proxy->as<ProxyObject>().handler();
@@ -373,23 +383,29 @@ Proxy::set(JSContext* cx, HandleObject proxy, HandleId id, HandleValue v, Handle
         return result.succeed();
     }
 
-    // Use the WindowProxy as receiver if receiver_ is a Window. Proxy handlers
-    // shouldn't have to know about the Window/WindowProxy distinction.
-    RootedValue receiver(cx, ValueToWindowProxyIfWindow(receiver_));
-
     // Special case. See the comment on BaseProxyHandler::mHasPrototype.
     if (handler->hasPrototype())
         return handler->BaseProxyHandler::set(cx, proxy, id, v, receiver, result);
 
     return handler->set(cx, proxy, id, v, receiver, result);
 }
 
+bool
+Proxy::set(JSContext* cx, HandleObject proxy, HandleId id, HandleValue v, HandleValue receiver_,
+           ObjectOpResult& result)
+{
+    // Use the WindowProxy as receiver if receiver_ is a Window. Proxy handlers
+    // shouldn't have to know about the Window/WindowProxy distinction.
+    RootedValue receiver(cx, ValueToWindowProxyIfWindow(receiver_, proxy));
+    return setInternal(cx, proxy, id, v, receiver, result);
+}
+
 bool
 js::ProxySetProperty(JSContext* cx, HandleObject proxy, HandleId id, HandleValue val, bool strict)
 {
     ObjectOpResult result;
     RootedValue receiver(cx, ObjectValue(*proxy));
-    if (!Proxy::set(cx, proxy, id, val, receiver, result))
+    if (!Proxy::setInternal(cx, proxy, id, val, receiver, result))
         return false;
     return result.checkStrictErrorOrWarning(cx, proxy, id, strict);
 }
@@ -404,7 +420,7 @@ js::ProxySetPropertyByValue(JSContext* cx, HandleObject proxy, HandleValue idVal
 
     ObjectOpResult result;
     RootedValue receiver(cx, ObjectValue(*proxy));
-    if (!Proxy::set(cx, proxy, id, val, receiver, result))
+    if (!Proxy::setInternal(cx, proxy, id, val, receiver, result))
         return false;
     return result.checkStrictErrorOrWarning(cx, proxy, id, strict);
 }

diff --git a/js/src/proxy/Proxy.h b/js/src/proxy/Proxy.h
@@ -42,8 +42,12 @@ class Proxy
     static bool has(JSContext* cx, HandleObject proxy, HandleId id, bool* bp);
     static bool get(JSContext* cx, HandleObject proxy, HandleValue receiver, HandleId id,
                     MutableHandleValue vp);
+    static bool getInternal(JSContext* cx, HandleObject proxy, HandleValue receiver,
+                            HandleId id, MutableHandleValue vp);
     static bool set(JSContext* cx, HandleObject proxy, HandleId id, HandleValue v,
                     HandleValue receiver, ObjectOpResult& result);
+    static bool setInternal(JSContext* cx, HandleObject proxy, HandleId id, HandleValue v,
+                            HandleValue receiver, ObjectOpResult& result);
     static bool call(JSContext* cx, HandleObject proxy, const CallArgs& args);
     static bool construct(JSContext* cx, HandleObject proxy, const CallArgs& args);