chushihua

node_modules/webpack/lib/optimize/AggressiveMergingPlugin.js

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+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Tobias Koppers @sokra
+*/
+"use strict";
+
+class AggressiveMergingPlugin {
+	constructor(options) {
+		if(options !== undefined && typeof options !== "object" || Array.isArray(options)) {
+			throw new Error("Argument should be an options object. To use defaults, pass in nothing.\nFor more info on options, see https://webpack.js.org/plugins/");
+		}
+		this.options = options || {};
+	}
+
+	apply(compiler) {
+		const options = this.options;
+		const minSizeReduce = options.minSizeReduce || 1.5;
+
+		function getParentsWeight(chunk) {
+			return chunk.parents.map((p) => {
+				return p.isInitial() ? options.entryChunkMultiplicator || 10 : 1;
+			}).reduce((a, b) => {
+				return a + b;
+			}, 0);
+		}
+		compiler.plugin("this-compilation", (compilation) => {
+			compilation.plugin("optimize-chunks-advanced", (chunks) => {
+				let combinations = [];
+				chunks.forEach((a, idx) => {
+					if(a.isInitial()) return;
+					for(let i = 0; i < idx; i++) {
+						const b = chunks[i];
+						if(b.isInitial()) continue;
+						combinations.push({
+							a,
+							b,
+							improvement: undefined
+						});
+					}
+				});
+
+				combinations.forEach((pair) => {
+					const a = pair.b.size({
+						chunkOverhead: 0
+					});
+					const b = pair.a.size({
+						chunkOverhead: 0
+					});
+					const ab = pair.b.integratedSize(pair.a, {
+						chunkOverhead: 0
+					});
+					let newSize;
+					if(ab === false) {
+						pair.improvement = false;
+						return;
+					} else if(options.moveToParents) {
+						const aOnly = ab - b;
+						const bOnly = ab - a;
+						const common = a + b - ab;
+						newSize = common + getParentsWeight(pair.b) * aOnly + getParentsWeight(pair.a) * bOnly;
+					} else {
+						newSize = ab;
+					}
+
+					pair.improvement = (a + b) / newSize;
+				});
+				combinations = combinations.filter((pair) => {
+					return pair.improvement !== false;
+				});
+				combinations.sort((a, b) => {
+					return b.improvement - a.improvement;
+				});
+
+				const pair = combinations[0];
+
+				if(!pair) return;
+				if(pair.improvement < minSizeReduce) return;
+
+				if(options.moveToParents) {
+					const commonModules = pair.b.modules.filter((m) => {
+						return pair.a.modules.indexOf(m) >= 0;
+					});
+					const aOnlyModules = pair.b.modules.filter((m) => {
+						return commonModules.indexOf(m) < 0;
+					});
+					const bOnlyModules = pair.a.modules.filter((m) => {
+						return commonModules.indexOf(m) < 0;
+					});
+					aOnlyModules.forEach((m) => {
+						pair.b.removeModule(m);
+						m.removeChunk(pair.b);
+						pair.b.parents.forEach((c) => {
+							c.addModule(m);
+							m.addChunk(c);
+						});
+					});
+					bOnlyModules.forEach((m) => {
+						pair.a.removeModule(m);
+						m.removeChunk(pair.a);
+						pair.a.parents.forEach((c) => {
+							c.addModule(m);
+							m.addChunk(c);
+						});
+					});
+				}
+				if(pair.b.integrate(pair.a, "aggressive-merge")) {
+					chunks.splice(chunks.indexOf(pair.a), 1);
+					return true;
+				}
+			});
+		});
+	}
+}
+
+module.exports = AggressiveMergingPlugin;