perf: use Date.now() instead of +new Date()

JLHwung · JLHwung · commit 94d0641ba40d · 2017-05-04T10:19:10.000+08:00
+new Date() is 2x slower than Date.now(), see https://jsperf.com/new-date-vs-date-now-vs-performance-now/6
diff --git a/lib/Compilation.js b/lib/Compilation.js
@@ -201,7 +201,7 @@ class Compilation extends Tapable {
 
 	addModuleDependencies(module, dependencies, bail, cacheGroup, recursive, callback) {
 		let _this = this;
-		const start = _this.profile && +new Date();
+		const start = _this.profile && Date.now();
 
 		const factories = [];
 		for(let i = 0; i < dependencies.length; i++) {
@@ -270,7 +270,7 @@ class Compilation extends Tapable {
 					if(!dependentModule.profile) {
 						dependentModule.profile = {};
 					}
-					afterFactory = +new Date();
+					afterFactory = Date.now();
 					dependentModule.profile.factory = afterFactory - start;
 				}
 
@@ -290,7 +290,7 @@ class Compilation extends Tapable {
 						if(!module.profile) {
 							module.profile = {};
 						}
-						const time = +new Date() - start;
+						const time = Date.now() - start;
 						if(!module.profile.dependencies || time > module.profile.dependencies) {
 							module.profile.dependencies = time;
 						}
@@ -311,7 +311,7 @@ class Compilation extends Tapable {
 					iterationDependencies(dependencies);
 
 					if(_this.profile) {
-						const afterBuilding = +new Date();
+						const afterBuilding = Date.now();
 						module.profile.building = afterBuilding - afterFactory;
 					}
 
@@ -332,7 +332,7 @@ class Compilation extends Tapable {
 					}
 
 					if(_this.profile) {
-						const afterBuilding = +new Date();
+						const afterBuilding = Date.now();
 						dependentModule.profile.building = afterBuilding - afterFactory;
 					}
 
@@ -360,7 +360,7 @@ class Compilation extends Tapable {
 	}
 
 	_addModuleChain(context, dependency, onModule, callback) {
-		const start = this.profile && +new Date();
+		const start = this.profile && Date.now();
 
 		const errorAndCallback = this.bail ? function errorAndCallback(err) {
 			callback(err);
@@ -397,7 +397,7 @@ class Compilation extends Tapable {
 				if(!module.profile) {
 					module.profile = {};
 				}
-				afterFactory = +new Date();
+				afterFactory = Date.now();
 				module.profile.factory = afterFactory - start;
 			}
 
@@ -408,7 +408,7 @@ class Compilation extends Tapable {
 				onModule(module);
 
 				if(this.profile) {
-					const afterBuilding = +new Date();
+					const afterBuilding = Date.now();
 					module.profile.building = afterBuilding - afterFactory;
 				}
 
@@ -436,7 +436,7 @@ class Compilation extends Tapable {
 				}
 
 				if(this.profile) {
-					const afterBuilding = +new Date();
+					const afterBuilding = Date.now();
 					module.profile.building = afterBuilding - afterFactory;
 				}
 
diff --git a/lib/ProgressPlugin.js b/lib/ProgressPlugin.js
@@ -157,9 +157,9 @@ class ProgressPlugin {
 				state = state.replace(/^\d+\/\d+\s+/, "");
 				if(percentage === 0) {
 					lastState = null;
-					lastStateTime = +new Date();
+					lastStateTime = Date.now();
 				} else if(state !== lastState || percentage === 1) {
-					const now = +new Date();
+					const now = Date.now();
 					if(lastState) {
 						const stateMsg = `${now - lastStateTime}ms ${lastState}`;
 						goToLineStart(stateMsg);

Original file line number	Diff line number	Diff line change
`@@ -201,7 +201,7 @@ class Compilation extends Tapable {`
`201`	`201`
`202`	`202`	`addModuleDependencies(module, dependencies, bail, cacheGroup, recursive, callback) {`
`203`	`203`	`let _this = this;`
`204`		`- const start = _this.profile && +new Date();`
	`204`	`+ const start = _this.profile && Date.now();`
`205`	`205`
`206`	`206`	`const factories = [];`
`207`	`207`	`for(let i = 0; i < dependencies.length; i++) {`
`@@ -270,7 +270,7 @@ class Compilation extends Tapable {`
`270`	`270`	`if(!dependentModule.profile) {`
`271`	`271`	`dependentModule.profile = {};`
`272`	`272`	`}`
`273`		`- afterFactory = +new Date();`
	`273`	`+ afterFactory = Date.now();`
`274`	`274`	`dependentModule.profile.factory = afterFactory - start;`
`275`	`275`	`}`
`276`	`276`
`@@ -290,7 +290,7 @@ class Compilation extends Tapable {`
`290`	`290`	`if(!module.profile) {`
`291`	`291`	`module.profile = {};`
`292`	`292`	`}`
`293`		`- const time = +new Date() - start;`
	`293`	`+ const time = Date.now() - start;`
`294`	`294`	`if(!module.profile.dependencies \|\| time > module.profile.dependencies) {`
`295`	`295`	`module.profile.dependencies = time;`
`296`	`296`	`}`
`@@ -311,7 +311,7 @@ class Compilation extends Tapable {`
`311`	`311`	`iterationDependencies(dependencies);`
`312`	`312`
`313`	`313`	`if(_this.profile) {`
`314`		`- const afterBuilding = +new Date();`
	`314`	`+ const afterBuilding = Date.now();`
`315`	`315`	`module.profile.building = afterBuilding - afterFactory;`
`316`	`316`	`}`
`317`	`317`
`@@ -332,7 +332,7 @@ class Compilation extends Tapable {`
`332`	`332`	`}`
`333`	`333`
`334`	`334`	`if(_this.profile) {`
`335`		`- const afterBuilding = +new Date();`
	`335`	`+ const afterBuilding = Date.now();`
`336`	`336`	`dependentModule.profile.building = afterBuilding - afterFactory;`
`337`	`337`	`}`
`338`	`338`
`@@ -360,7 +360,7 @@ class Compilation extends Tapable {`
`360`	`360`	`}`
`361`	`361`
`362`	`362`	`_addModuleChain(context, dependency, onModule, callback) {`
`363`		`- const start = this.profile && +new Date();`
	`363`	`+ const start = this.profile && Date.now();`
`364`	`364`
`365`	`365`	`const errorAndCallback = this.bail ? function errorAndCallback(err) {`
`366`	`366`	`callback(err);`
`@@ -397,7 +397,7 @@ class Compilation extends Tapable {`
`397`	`397`	`if(!module.profile) {`
`398`	`398`	`module.profile = {};`
`399`	`399`	`}`
`400`		`- afterFactory = +new Date();`
	`400`	`+ afterFactory = Date.now();`
`401`	`401`	`module.profile.factory = afterFactory - start;`
`402`	`402`	`}`
`403`	`403`
`@@ -408,7 +408,7 @@ class Compilation extends Tapable {`
`408`	`408`	`onModule(module);`
`409`	`409`
`410`	`410`	`if(this.profile) {`
`411`		`- const afterBuilding = +new Date();`
	`411`	`+ const afterBuilding = Date.now();`
`412`	`412`	`module.profile.building = afterBuilding - afterFactory;`
`413`	`413`	`}`
`414`	`414`
`@@ -436,7 +436,7 @@ class Compilation extends Tapable {`
`436`	`436`	`}`
`437`	`437`
`438`	`438`	`if(this.profile) {`
`439`		`- const afterBuilding = +new Date();`
	`439`	`+ const afterBuilding = Date.now();`
`440`	`440`	`module.profile.building = afterBuilding - afterFactory;`
`441`	`441`	`}`
`442`	`442`