Improve chunk assignment performance (#4736)

* Slightly simplify graph analysis Also generates dynamicImportsByEntry that will help us to track already loaded modules more efficiently. * Implement new algorithm with hopefully better performance * Further refine chunking algorithm * Add cut-off condition to only back-track modules if there are few imports * Use shared Set generator
rollup · Dec 10, 2022 · f368adf · f368adf
1 parent 2c23141
commit f368adf
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Showing 43 changed files with 386 additions and 114 deletions.
diff --git a/cli/run/batchWarnings.ts b/cli/run/batchWarnings.ts
@@ -1,6 +1,6 @@
 import type { RollupWarning } from '../../src/rollup/types';
 import { bold, gray, yellow } from '../../src/utils/colors';
-import { getOrCreate } from '../../src/utils/getOrCreate';
+import { getNewArray, getOrCreate } from '../../src/utils/getOrCreate';
 import { printQuotedStringList } from '../../src/utils/printStringList';
 import relativeId from '../../src/utils/relativeId';
 import { stderr } from '../logging';
@@ -23,7 +23,7 @@ export default function batchWarnings(): BatchWarnings {
 			warningOccurred = true;
 
 			if (warning.code! in deferredHandlers) {
-				getOrCreate(deferredWarnings, warning.code!, () => []).push(warning);
+				getOrCreate(deferredWarnings, warning.code!, getNewArray).push(warning);
 			} else if (warning.code! in immediateHandlers) {
 				immediateHandlers[warning.code!](warning);
 			} else {
@@ -220,7 +220,7 @@ const deferredHandlers: {
 
 		const dependencies = new Map<string, string[]>();
 		for (const warning of warnings) {
-			getOrCreate(dependencies, relativeId(warning.exporter!), () => []).push(
+			getOrCreate(dependencies, relativeId(warning.exporter!), getNewArray).push(
 				relativeId(warning.id!)
 			);
 		}

diff --git a/src/Chunk.ts b/src/Chunk.ts
@@ -41,7 +41,7 @@ import { assignExportsToMangledNames, assignExportsToNames } from './utils/expor
 import type { GenerateCodeSnippets } from './utils/generateCodeSnippets';
 import getExportMode from './utils/getExportMode';
 import getIndentString from './utils/getIndentString';
-import { getOrCreate } from './utils/getOrCreate';
+import { getNewArray, getOrCreate } from './utils/getOrCreate';
 import { getStaticDependencies } from './utils/getStaticDependencies';
 import type { HashPlaceholderGenerator } from './utils/hashPlaceholders';
 import { replacePlaceholders } from './utils/hashPlaceholders';
@@ -911,7 +911,7 @@ export default class Chunk {
 				dependency = this.chunkByModule.get(module)!;
 				imported = dependency.getVariableExportName(variable);
 			}
-			getOrCreate(importsByDependency, dependency, () => []).push({
+			getOrCreate(importsByDependency, dependency, getNewArray).push({
 				imported,
 				local: variable.getName(this.snippets.getPropertyAccess)
 			});
@@ -1023,7 +1023,7 @@ export default class Chunk {
 						(imported !== 'default' || isDefaultAProperty(interop(module.id), true));
 				}
 			}
-			getOrCreate(reexportSpecifiers, dependency, () => []).push({
+			getOrCreate(reexportSpecifiers, dependency, getNewArray).push({
 				imported,
 				needsLiveBinding,
 				reexported: exportName

diff --git a/src/Module.ts b/src/Module.ts
@@ -63,7 +63,7 @@ import {
 	warnDeprecation
 } from './utils/error';
 import { getId } from './utils/getId';
-import { getOrCreate } from './utils/getOrCreate';
+import { getNewSet, getOrCreate } from './utils/getOrCreate';
 import { getOriginalLocation } from './utils/getOriginalLocation';
 import { makeLegal } from './utils/identifierHelpers';
 import {
@@ -164,10 +164,10 @@ function getVariableForExportNameRecursive(
 }
 
 function getAndExtendSideEffectModules(variable: Variable, module: Module): Set<Module> {
-	const sideEffectModules = getOrCreate(
+	const sideEffectModules = getOrCreate<Variable, Set<Module>>(
 		module.sideEffectDependenciesByVariable,
 		variable,
-		() => new Set()
+		getNewSet
 	);
 	let currentVariable: Variable | null = variable;
 	const referencedVariables = new Set([currentVariable]);
@@ -613,7 +613,7 @@ export default class Module {
 				getOrCreate(
 					importerForSideEffects.sideEffectDependenciesByVariable,
 					variable,
-					() => new Set()
+					getNewSet
 				).add(this);
 				setAlternativeExporterIfCyclic(variable, importerForSideEffects, this);
 			}

diff --git a/src/ast/utils/PathTracker.ts b/src/ast/utils/PathTracker.ts
@@ -1,4 +1,4 @@
-import { getOrCreate } from '../../utils/getOrCreate';
+import { getNewSet, getOrCreate } from '../../utils/getOrCreate';
 import type { Entity } from '../Entity';
 
 export const UnknownKey = Symbol('Unknown Key');
@@ -98,7 +98,7 @@ export class DiscriminatedPathTracker {
 				currentPaths[pathSegment] ||
 				Object.create(null, { [EntitiesKey]: { value: new Map<unknown, Set<Entity>>() } });
 		}
-		const trackedEntities = getOrCreate(currentPaths[EntitiesKey], discriminator, () => new Set());
+		const trackedEntities = getOrCreate(currentPaths[EntitiesKey], discriminator, getNewSet);
 		if (trackedEntities.has(entity)) return true;
 		trackedEntities.add(entity);
 		return false;