Merge pull request #10313 from webpack/perf/caching

Performance improvements of cache builds

lib/ChunkGraph.js

@@ -24,6 +24,9 @@ const findGraphRoots = require("./util/findGraphRoots");
 /** @typedef {import("./ModuleGraph")} ModuleGraph */
 /** @typedef {import("./RuntimeModule")} RuntimeModule */
 
+/** @type {ReadonlySet<string>} */
+const EMPTY_SET = new Set();
+
 const compareModuleIterables = compareIterables(compareModulesByIdentifier);
 
 /** @typedef {(c: Chunk, chunkGraph: ChunkGraph) => boolean} ChunkFilterPredicate */
@@ -167,8 +170,8 @@ class ChunkGraphModule {
 		this.renderedHash = undefined;
 		/** @type {string | number} */
 		this.id = null;
-		/** @type {Set<string>} */
-		this.runtimeRequirements = new Set();
+		/** @type {Set<string> | undefined} */
+		this.runtimeRequirements = undefined;
 	}
 }
 
@@ -180,8 +183,8 @@ class ChunkGraphChunk {
 		this.entryModules = new Map();
 		/** @type {SortableSet<RuntimeModule>} */
 		this.runtimeModules = new SortableSet();
-		/** @type {Set<string>} */
-		this.runtimeRequirements = new Set();
+		/** @type {Set<string> | undefined} */
+		this.runtimeRequirements = undefined;
 		/** @type {Set<string>} */
 		this.runtimeRequirementsInTree = new Set();
 	}
@@ -1135,24 +1138,38 @@ class ChunkGraph {
 
 	/**
 	 * @param {Module} module the module
-	 * @param {Iterable<string>} items runtime requirements to be added
+	 * @param {Set<string>} items runtime requirements to be added (ownership of this Set is given to ChunkGraph)
 	 * @returns {void}
 	 */
 	addModuleRuntimeRequirements(module, items) {
 		const cgm = this._getChunkGraphModule(module);
 		const runtimeRequirements = cgm.runtimeRequirements;
-		for (const item of items) runtimeRequirements.add(item);
+		if (runtimeRequirements === undefined) {
+			cgm.runtimeRequirements = items;
+		} else if (runtimeRequirements.size >= items.size) {
+			for (const item of items) runtimeRequirements.add(item);
+		} else {
+			for (const item of runtimeRequirements) items.add(item);
+			cgm.runtimeRequirements = items;
+		}
 	}
 
 	/**
 	 * @param {Chunk} chunk the chunk
-	 * @param {Iterable<string>} items runtime requirements to be added
+	 * @param {Set<string>} items runtime requirements to be added (ownership of this Set is given to ChunkGraph)
 	 * @returns {void}
 	 */
 	addChunkRuntimeRequirements(chunk, items) {
 		const cgc = this._getChunkGraphChunk(chunk);
 		const runtimeRequirements = cgc.runtimeRequirements;
-		for (const item of items) runtimeRequirements.add(item);
+		if (runtimeRequirements === undefined) {
+			cgc.runtimeRequirements = items;
+		} else if (runtimeRequirements.size >= items.size) {
+			for (const item of items) runtimeRequirements.add(item);
+		} else {
+			for (const item of runtimeRequirements) items.add(item);
+			cgc.runtimeRequirements = items;
+		}
 	}
 
 	/**
@@ -1168,25 +1185,27 @@ class ChunkGraph {
 
 	/**
 	 * @param {Module} module the module
-	 * @returns {Set<string>} runtime requirements
+	 * @returns {ReadonlySet<string>} runtime requirements
 	 */
 	getModuleRuntimeRequirements(module) {
 		const cgm = this._getChunkGraphModule(module);
-		return cgm.runtimeRequirements;
+		const runtimeRequirements = cgm.runtimeRequirements;
+		return runtimeRequirements === undefined ? EMPTY_SET : runtimeRequirements;
 	}
 
 	/**
 	 * @param {Chunk} chunk the chunk
-	 * @returns {Set<string>} runtime requirements
+	 * @returns {ReadonlySet<string>} runtime requirements
 	 */
 	getChunkRuntimeRequirements(chunk) {
 		const cgc = this._getChunkGraphChunk(chunk);
-		return cgc.runtimeRequirements;
+		const runtimeRequirements = cgc.runtimeRequirements;
+		return runtimeRequirements === undefined ? EMPTY_SET : runtimeRequirements;
 	}
 
 	/**
 	 * @param {Chunk} chunk the chunk
-	 * @returns {Set<string>} runtime requirements
+	 * @returns {ReadonlySet<string>} runtime requirements
 	 */
 	getTreeRuntimeRequirements(chunk) {
 		const cgc = this._getChunkGraphChunk(chunk);

lib/Compilation.js

@@ -1292,13 +1292,13 @@ class Compilation {
 						contextDependencies,
 						missingDependencies
 					} = result;
-					if (fileDependencies) {
+					if (fileDependencies && fileDependencies.size > 0) {
 						this.fileDependencies.addAll(fileDependencies);
 					}
-					if (contextDependencies) {
+					if (contextDependencies && contextDependencies.size > 0) {
 						this.contextDependencies.addAll(contextDependencies);
 					}
-					if (missingDependencies) {
+					if (missingDependencies && missingDependencies.size > 0) {
 						this.missingDependencies.addAll(missingDependencies);
 					}
 				}
@@ -1800,7 +1800,7 @@ class Compilation {
 				let set;
 				const runtimeRequirements = this.codeGenerationResults.get(module)
 					.runtimeRequirements;
-				if (runtimeRequirements) {
+				if (runtimeRequirements && runtimeRequirements.size > 0) {
 					set = new Set(runtimeRequirements);
 				} else if (additionalModuleRuntimeRequirements.isUsed()) {
 					set = new Set();
@@ -1892,9 +1892,10 @@ class Compilation {
 		const exportsInfo = this.moduleGraph.getExportsInfo(module);
 		exportsInfo.setHasProvideInfo();
 		exportsInfo.setUsedForSideEffectsOnly();
-		this.chunkGraph.addModuleRuntimeRequirements(module, [
-			RuntimeGlobals.requireScope
-		]);
+		this.chunkGraph.addModuleRuntimeRequirements(
+			module,
+			new Set([RuntimeGlobals.requireScope])
+		);
 
 		// runtime modules don't need ids
 		this.chunkGraph.setModuleId(module, "");

lib/ContextModule.js

@@ -969,25 +969,25 @@ module.exports = webpackEmptyAsyncContext;`;
 			"javascript",
 			this.getSource(this.getSourceString(this.options.mode, context))
 		);
-		const set = [];
+		const set = new Set();
 		const allDeps = /** @type {ContextElementDependency[]} */ (this.dependencies.concat(
 			this.blocks.map(b => b.dependencies[0])
 		));
-		set.push(RuntimeGlobals.module);
-		set.push(RuntimeGlobals.hasOwnProperty);
+		set.add(RuntimeGlobals.module);
+		set.add(RuntimeGlobals.hasOwnProperty);
 		if (allDeps.length > 0) {
 			const asyncMode = this.options.mode;
-			set.push(RuntimeGlobals.require);
+			set.add(RuntimeGlobals.require);
 			if (asyncMode === "weak") {
-				set.push(RuntimeGlobals.moduleFactories);
+				set.add(RuntimeGlobals.moduleFactories);
 			} else if (asyncMode === "async-weak") {
-				set.push(RuntimeGlobals.moduleFactories);
-				set.push(RuntimeGlobals.ensureChunk);
+				set.add(RuntimeGlobals.moduleFactories);
+				set.add(RuntimeGlobals.ensureChunk);
 			} else if (asyncMode === "lazy" || asyncMode === "lazy-once") {
-				set.push(RuntimeGlobals.ensureChunk);
+				set.add(RuntimeGlobals.ensureChunk);
 			}
 			if (this.getFakeMap(allDeps, chunkGraph) !== 9) {
-				set.push(RuntimeGlobals.createFakeNamespaceObject);
+				set.add(RuntimeGlobals.createFakeNamespaceObject);
 			}
 		}
 		return {

lib/DelegatedModule.js

@@ -31,6 +31,10 @@ const StaticExportsDependency = require("./dependencies/StaticExportsDependency"
 /** @typedef {import("./util/fs").InputFileSystem} InputFileSystem */
 
 const TYPES = new Set(["javascript"]);
+const RUNTIME_REQUIREMENTS = new Set([
+	RuntimeGlobals.module,
+	RuntimeGlobals.require
+]);
 
 class DelegatedModule extends Module {
 	constructor(sourceRequest, data, type, userRequest, originalRequest) {
@@ -156,7 +160,7 @@ class DelegatedModule extends Module {
 
 		return {
 			sources,
-			runtimeRequirements: [RuntimeGlobals.module, RuntimeGlobals.require]
+			runtimeRequirements: RUNTIME_REQUIREMENTS
 		};
 	}
 

lib/DllModule.js

@@ -26,6 +26,10 @@ const RuntimeGlobals = require("./RuntimeGlobals");
 /** @typedef {import("./util/fs").InputFileSystem} InputFileSystem */
 
 const TYPES = new Set(["javascript"]);
+const RUNTIME_REQUIREMENTS = new Set([
+	RuntimeGlobals.require,
+	RuntimeGlobals.module
+]);
 
 class DllModule extends Module {
 	constructor(context, dependencies, name) {
@@ -84,7 +88,7 @@ class DllModule extends Module {
 		);
 		return {
 			sources,
-			runtimeRequirements: [RuntimeGlobals.require, RuntimeGlobals.module]
+			runtimeRequirements: RUNTIME_REQUIREMENTS
 		};
 	}
 

lib/ExternalModule.js

@@ -124,6 +124,7 @@ const getSourceForDefaultCase = (optional, request, runtimeTemplate) => {
 };
 
 const TYPES = new Set(["javascript"]);
+const RUNTIME_REQUIREMENTS = new Set([RuntimeGlobals.module]);
 
 class ExternalModule extends Module {
 	constructor(request, type, userRequest) {
@@ -261,7 +262,7 @@ class ExternalModule extends Module {
 			sources.set("javascript", new RawSource(sourceString));
 		}
 
-		return { sources, runtimeRequirements: [RuntimeGlobals.module] };
+		return { sources, runtimeRequirements: RUNTIME_REQUIREMENTS };
 	}
 
 	/**