webpack/lib/ids/OccurrenceModuleIdsPlugin.js

Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support 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 { validate } = require("schema-utils");
const schema = require("../../schemas/plugins/ids/OccurrenceModuleIdsPlugin.json");
const {
	compareModulesByPreOrderIndexOrIdentifier
} = require("../util/comparators");
const { assignAscendingModuleIds } = require("./IdHelpers");

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

class OccurrenceModuleIdsPlugin {
	/**
	 * @param {OccurrenceModuleIdsPluginOptions=} options options object
	 */
	constructor(options = {}) {
		validate(schema, options, {
			name: "Occurrence Order Module Ids Plugin",
			baseDataPath: "options"
		});
		this.options = options;
	}

	/**
	 * Apply the plugin
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		const prioritiseInitial = this.options.prioritiseInitial;
		compiler.hooks.compilation.tap("OccurrenceModuleIdsPlugin", compilation => {
			const moduleGraph = compilation.moduleGraph;

			compilation.hooks.moduleIds.tap("OccurrenceModuleIdsPlugin", modules => {
				const chunkGraph = compilation.chunkGraph;

				const modulesInOccurrenceOrder = Array.from(modules).filter(
					m =>
						m.needId &&
						chunkGraph.getNumberOfModuleChunks(m) > 0 &&
						chunkGraph.getModuleId(m) === null
				);

				const occursInInitialChunksMap = new Map();
				const occursInAllChunksMap = new Map();

				const initialChunkChunkMap = new Map();
				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);
				}

				/**
				 * @param {Iterable<ModuleGraphConnection>} connections connections
				 * @returns {number} count of occurs
				 */
				const countOccursInEntry = connections => {
					let sum = 0;
					for (const c of connections) {
						if (!c.isTargetActive(undefined)) continue;
						if (!c.originModule) continue;
						sum += initialChunkChunkMap.get(c.originModule);
					}
					return sum;
				};

				/**
				 * @param {Iterable<ModuleGraphConnection>} connections connections
				 * @returns {number} count of occurs
				 */
				const countOccurs = connections => {
					let sum = 0;
					for (const c of connections) {
						if (!c.isTargetActive(undefined)) continue;
						if (!c.originModule) continue;
						if (!c.dependency) continue;
						const factor = c.dependency.getNumberOfIdOccurrences();
						if (factor === 0) continue;
						sum += factor * chunkGraph.getNumberOfModuleChunks(c.originModule);
					}
					return sum;
				};

				if (prioritiseInitial) {
					for (const m of modulesInOccurrenceOrder) {
						const result =
							countOccursInEntry(moduleGraph.getIncomingConnections(m)) +
							initialChunkChunkMap.get(m) +
							entryCountMap.get(m);
						occursInInitialChunksMap.set(m, result);
					}
				}

				for (const m of modules) {
					const result =
						countOccurs(moduleGraph.getIncomingConnections(m)) +
						chunkGraph.getNumberOfModuleChunks(m) +
						entryCountMap.get(m);
					occursInAllChunksMap.set(m, result);
				}

				const naturalCompare = compareModulesByPreOrderIndexOrIdentifier(
					compilation.moduleGraph
				);

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

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

module.exports = OccurrenceModuleIdsPlugin;