Sage/streamlinejs#328 - optimized fn.apply calls for small number of …

…args
Sage · Mar 1, 2016 · 2a10c01 · 2a10c01
1 parent 7bb74ab
commit 2a10c01
Showing 1 changed file with 18 additions and 7 deletions.
diff --git a/lib/fibers/runtime.js b/lib/fibers/runtime.js
@@ -9,6 +9,16 @@ var g = util.getGlobals('fibers');
 
 var keys = [];
 
+function applyFast(fn, that, args) {
+	switch (args.length) {
+		case 1: return fn.call(that, args[0]);
+		case 2: return fn.call(that, args[0], args[1]);
+		case 3: return fn.call(that, args[0], args[1], args[2]);
+		case 4: return fn.call(that, args[0], args[1], args[2], args[3]);
+		default: return fn.apply(that, args);
+	}
+}
+
 exports.await = function(file, line, object, property, index1, index2, returnArray, args) {
 	var bound = typeof property !== "function";
 	var fn = bound ? object[property] : property;
@@ -18,7 +28,7 @@ exports.await = function(file, line, object, property, index1, index2, returnArr
 		key = keys[index1] || (keys[index1] = 'fiberized-' + index1);
 		wrapper = fn[key];
 		if (!wrapper && bound) {
-			// second chance for foo.call(bar, _, ...).
+			// second chance for foo.call(bar, _, ...). Optimize if bar.foo['fiberized-0'] exists
 			if ((property === 'call') && index1 > 0 && typeof object === 'function') {
 				var key2 = keys[index1 - 1] || (keys[index1 - 1] = 'fiberized-' + (index1 - 1));
 				var fn2 = object[key2];
@@ -30,7 +40,8 @@ exports.await = function(file, line, object, property, index1, index2, returnArr
 		}
 		if (wrapper) {
 			if (g.emitter) wrapper = frameModule.wrap(file, line, wrapper);
-			if (Array.isArray(args)) return wrapper.apply(object, args);
+			// streamline < 2.0 does not pass args - return wrapper in this case
+			if (Array.isArray(args)) return applyFast(wrapper, object, args);
 			else return bound ? wrapper.bind(object) : wrapper;
 		}
 	}
@@ -86,7 +97,7 @@ function awaitSlow(file, line, object, property, index1, index2, returnArray, ar
 
 		// Invoke the function and yield
 		var frame = g.emitter && frameModule.pushFrame(file, line, fn.name);
-		fn.apply(that, args);
+		applyFast(fn, that, args);
 
 		if (yielded) {
 			if (frame) frame.pop();
@@ -117,7 +128,7 @@ function awaitSlow(file, line, object, property, index1, index2, returnArray, ar
 	if (!bound && key) {
 		fn[key] = wrapper;
 	}
-	return Array.isArray(args) ? wrapper.apply(object, args) : wrapper;
+	return Array.isArray(args) ? applyFast(wrapper, object, args) : wrapper;
 };
 
 function arityWrapper(template) {
@@ -173,7 +184,7 @@ var asyncTemplate = arityWrapper(function(fn, index) {
 			g.context = cx;
 			cx = null;
 			try {
-				val = fn.apply(lthat, largs);
+				val = applyFast(fn, lthat, largs);
 			} catch (e) {
 				err = e;
 			} finally {
@@ -196,7 +207,7 @@ exports.new = function(file, line, constructor, index) {
 	return function() {
 		var that = Object.create(constructor.prototype);
 		arguments[index] = true;
-		exports.await(file, line, null, constructor, index, null, false).apply(that, arguments);
+		applyFast(exports.await(file, line, null, constructor, index, null, false), that, arguments);
 		return that;
 	};
 }
@@ -225,7 +236,7 @@ Function.prototype.apply_['fiberized-0'] = function(dummy, thisObj, args, index)
 	if (this['fiberized-0']) {
 		args = Array.prototype.slice.call(args, 0);
 		args.splice(index != null && index >= 0 ? index : args.length, 0, dummy);
-		return this['fiberized-0'].apply(thisObj, args);
+		return applyFast(this['fiberized-0'], thisObj, args);
 	} else {
 		return Function.prototype.apply_.call(this, dummy, thisObj, args, index);
 	}