webpack/lib/ids/OccurrenceModuleIdsPlugin.js

Packs ECMAScript/CommonJs/AMD modules for the browser. Allows you to split your codebase into multiple bundles, which can be loaded on demand. Supports loaders to preprocess files, i.e. json, jsx, es7, css, less, ... and your custom stuff.

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/

"use strict";

const {
	compareModulesByPreOrderIndexOrIdentifier
} = require("../util/comparators");
const {
	assignAscendingModuleIds,
	getUsedModuleIdsAndModules
} = require("./IdHelpers");

/** @typedef {import("../../declarations/plugins/ids/OccurrenceModuleIdsPlugin").OccurrenceModuleIdsPluginOptions} OccurrenceModuleIdsPluginOptions */
/** @typedef {import("../Compiler")} Compiler */
/** @typedef {import("../Module")} Module */

const PLUGIN_NAME = "OccurrenceModuleIdsPlugin";

class OccurrenceModuleIdsPlugin {
	/**
	 * Creates an instance of OccurrenceModuleIdsPlugin.
	 * @param {OccurrenceModuleIdsPluginOptions=} options options object
	 */
	constructor(options = {}) {
		/** @type {OccurrenceModuleIdsPluginOptions} */
		this.options = options;
	}

	/**
	 * Applies the plugin by registering its hooks on the compiler.
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		compiler.hooks.validate.tap(PLUGIN_NAME, () => {
			compiler.validate(
				() =>
					require("../../schemas/plugins/ids/OccurrenceModuleIdsPlugin.json"),
				this.options,
				{
					name: "Occurrence Order Module Ids Plugin",
					baseDataPath: "options"
				},
				(options) =>
					require("../../schemas/plugins/ids/OccurrenceModuleIdsPlugin.check")(
						options
					)
			);
		});
		compiler.hooks.compilation.tap(PLUGIN_NAME, (compilation) => {
			const moduleGraph = compilation.moduleGraph;

			compilation.hooks.moduleIds.tap(PLUGIN_NAME, () => {
				const chunkGraph = compilation.chunkGraph;

				const [usedIds, modulesInOccurrenceOrder] =
					getUsedModuleIdsAndModules(compilation);

				/** @type {Map<Module, number>} */
				const occursInInitialChunksMap = new Map();
				/** @type {Map<Module, number>} */
				const occursInAllChunksMap = new Map();

				/** @type {Map<Module, number>} */
				const initialChunkChunkMap = new Map();
				/** @type {Map<Module, number>} */
				const entryCountMap = new Map();
				for (const m of modulesInOccurrenceOrder) {
					let initial = 0;
					let entry = 0;
					for (const c of chunkGraph.getModuleChunksIterable(m)) {
						if (c.canBeInitial()) initial++;
						if (chunkGraph.isEntryModuleInChunk(m, c)) entry++;
					}
					initialChunkChunkMap.set(m, initial);
					entryCountMap.set(m, entry);
				}

				/**
				 * Count occurs in entry.
				 * @param {Module} module module
				 * @returns {number} count of occurs
				 */
				const countOccursInEntry = (module) => {
					let sum = 0;
					for (const [
						originModule,
						connections
					] of moduleGraph.getIncomingConnectionsByOriginModule(module)) {
						if (!originModule) continue;
						if (!connections.some((c) => c.isTargetActive(undefined))) continue;
						sum += initialChunkChunkMap.get(originModule) || 0;
					}
					return sum;
				};

				/**
				 * Returns count of occurs.
				 * @param {Module} module module
				 * @returns {number} count of occurs
				 */
				const countOccurs = (module) => {
					let sum = 0;
					for (const [
						originModule,
						connections
					] of moduleGraph.getIncomingConnectionsByOriginModule(module)) {
						if (!originModule) continue;
						const chunkModules =
							chunkGraph.getNumberOfModuleChunks(originModule);
						for (const c of connections) {
							if (!c.isTargetActive(undefined)) continue;
							if (!c.dependency) continue;
							const factor = c.dependency.getNumberOfIdOccurrences();
							if (factor === 0) continue;
							sum += factor * chunkModules;
						}
					}
					return sum;
				};

				if (this.options.prioritiseInitial) {
					for (const m of modulesInOccurrenceOrder) {
						const result =
							countOccursInEntry(m) +
							/** @type {number} */ (initialChunkChunkMap.get(m)) +
							/** @type {number} */ (entryCountMap.get(m));
						occursInInitialChunksMap.set(m, result);
					}
				}

				for (const m of modulesInOccurrenceOrder) {
					const result =
						countOccurs(m) +
						chunkGraph.getNumberOfModuleChunks(m) +
						/** @type {number} */ (entryCountMap.get(m));
					occursInAllChunksMap.set(m, result);
				}

				const naturalCompare = compareModulesByPreOrderIndexOrIdentifier(
					compilation.moduleGraph
				);

				modulesInOccurrenceOrder.sort((a, b) => {
					if (this.options.prioritiseInitial) {
						const aEntryOccurs =
							/** @type {number} */
							(occursInInitialChunksMap.get(a));
						const bEntryOccurs =
							/** @type {number} */
							(occursInInitialChunksMap.get(b));
						if (aEntryOccurs > bEntryOccurs) return -1;
						if (aEntryOccurs < bEntryOccurs) return 1;
					}
					const aOccurs = /** @type {number} */ (occursInAllChunksMap.get(a));
					const bOccurs = /** @type {number} */ (occursInAllChunksMap.get(b));
					if (aOccurs > bOccurs) return -1;
					if (aOccurs < bOccurs) return 1;
					return naturalCompare(a, b);
				});

				assignAscendingModuleIds(
					usedIds,
					modulesInOccurrenceOrder,
					compilation
				);
			});
		});
	}
}

module.exports = OccurrenceModuleIdsPlugin;