optimize SideEffectsFlagPlugin performance

lib/ModuleGraphConnection.js

@@ -15,7 +15,7 @@ class ModuleGraphConnection {
 	 * @param {Module} module the referenced module
 	 * @param {string=} explanation some extra detail
 	 * @param {boolean=} weak the reference is weak
-	 * @param {function(): boolean=} condition condition for the connection
+	 * @param {function(ModuleGraphConnection): boolean=} condition condition for the connection
 	 */
 	constructor(
 		originModule,
@@ -33,7 +33,7 @@ class ModuleGraphConnection {
 		this.weak = weak;
 		this.conditional = !!condition;
 		this._active = true;
-		/** @type {function(): boolean} */
+		/** @type {function(ModuleGraphConnection): boolean} */
 		this.condition = condition;
 		/** @type {Set<string>} */
 		this.explanations = undefined;
@@ -44,13 +44,13 @@ class ModuleGraphConnection {
 	}
 
 	/**
-	 * @param {function(): boolean} condition condition for the connection
+	 * @param {function(ModuleGraphConnection): boolean} condition condition for the connection
 	 * @returns {void}
 	 */
 	addCondition(condition) {
 		if (this.conditional) {
 			const old = this.condition;
-			this.condition = () => old() && condition();
+			this.condition = c => old(c) && condition(c);
 		} else if (this._active) {
 			this.conditional = true;
 			this.condition = condition;
@@ -75,7 +75,7 @@ class ModuleGraphConnection {
 
 	get active() {
 		if (!this.conditional) return this._active;
-		return this.condition();
+		return this.condition(this);
 	}
 
 	set active(value) {

lib/dependencies/HarmonyImportSideEffectDependency.js

@@ -23,6 +23,21 @@ class HarmonyImportSideEffectDependency extends HarmonyImportDependency {
 	get type() {
 		return "harmony side effect evaluation";
 	}
+
+	/**
+	 * @param {ModuleGraph} moduleGraph module graph
+	 * @returns {function(): boolean} function to determine if the connection is active
+	 */
+	getCondition(moduleGraph) {
+		return connection => {
+			const refModule = connection.resolvedModule;
+			return (
+				!refModule ||
+				refModule.factoryMeta === undefined ||
+				!refModule.factoryMeta.sideEffectFree
+			);
+		};
+	}
 }
 
 makeSerializable(

lib/optimize/SideEffectsFlagPlugin.js

@@ -8,7 +8,6 @@
 const glob2regexp = require("glob-to-regexp");
 const { STAGE_DEFAULT } = require("../OptimizationStages");
 const HarmonyExportImportedSpecifierDependency = require("../dependencies/HarmonyExportImportedSpecifierDependency");
-const HarmonyImportSideEffectDependency = require("../dependencies/HarmonyImportSideEffectDependency");
 const HarmonyImportSpecifierDependency = require("../dependencies/HarmonyImportSpecifierDependency");
 
 /** @typedef {import("../Compiler")} Compiler */
@@ -104,12 +103,12 @@ class SideEffectsFlagPlugin {
 
 					// Capture reexports of sideEffectFree modules
 					for (const module of modules) {
-						for (const dep of module.dependencies) {
-							if (dep instanceof HarmonyExportImportedSpecifierDependency) {
 						if (
 							module.factoryMeta !== undefined &&
 							module.factoryMeta.sideEffectFree
 						) {
+							for (const dep of module.dependencies) {
+								if (dep instanceof HarmonyExportImportedSpecifierDependency) {
 									const mode = dep.getMode(moduleGraph, true);
 									if (mode.type === "normal-reexport") {
 										let map = reexportMaps.get(module);
@@ -127,18 +126,6 @@ class SideEffectsFlagPlugin {
 										}
 									}
 								}
-							} else if (dep instanceof HarmonyImportSideEffectDependency) {
-								const connection = moduleGraph.getConnection(dep);
-								if (connection) {
-									const refModule = connection.resolvedModule;
-									if (
-										refModule &&
-										refModule.factoryMeta !== undefined &&
-										refModule.factoryMeta.sideEffectFree
-									) {
-										connection.active = false;
-									}
-								}
 							}
 						}
 					}