mirror of https://github.com/webpack/webpack.git
				
				
				
			
		
			
				
	
	
		
			101 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
			
		
		
	
	
			101 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
| /*
 | |
| 	MIT License http://www.opensource.org/licenses/mit-license.php
 | |
| 	Author Tobias Koppers @sokra
 | |
| */
 | |
| 
 | |
| "use strict";
 | |
| 
 | |
| const { STAGE_ADVANCED } = require("../OptimizationStages");
 | |
| 
 | |
| /** @typedef {import("../Chunk")} Chunk */
 | |
| /** @typedef {import("../Compiler")} Compiler */
 | |
| 
 | |
| /**
 | |
|  * @typedef {object} AggressiveMergingPluginOptions
 | |
|  * @property {number=} minSizeReduce minimal size reduction to trigger merging
 | |
|  */
 | |
| 
 | |
| class AggressiveMergingPlugin {
 | |
| 	/**
 | |
| 	 * @param {AggressiveMergingPluginOptions=} [options] options object
 | |
| 	 */
 | |
| 	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 the plugin
 | |
| 	 * @param {Compiler} compiler the compiler instance
 | |
| 	 * @returns {void}
 | |
| 	 */
 | |
| 	apply(compiler) {
 | |
| 		const options = this.options;
 | |
| 		const minSizeReduce = options.minSizeReduce || 1.5;
 | |
| 
 | |
| 		compiler.hooks.thisCompilation.tap(
 | |
| 			"AggressiveMergingPlugin",
 | |
| 			compilation => {
 | |
| 				compilation.hooks.optimizeChunks.tap(
 | |
| 					{
 | |
| 						name: "AggressiveMergingPlugin",
 | |
| 						stage: STAGE_ADVANCED
 | |
| 					},
 | |
| 					chunks => {
 | |
| 						const chunkGraph = compilation.chunkGraph;
 | |
| 						/** @type {{a: Chunk, b: Chunk, improvement: number}[]} */
 | |
| 						let combinations = [];
 | |
| 						for (const a of chunks) {
 | |
| 							if (a.canBeInitial()) continue;
 | |
| 							for (const b of chunks) {
 | |
| 								if (b.canBeInitial()) continue;
 | |
| 								if (b === a) break;
 | |
| 								if (!chunkGraph.canChunksBeIntegrated(a, b)) {
 | |
| 									continue;
 | |
| 								}
 | |
| 								const aSize = chunkGraph.getChunkSize(b, {
 | |
| 									chunkOverhead: 0
 | |
| 								});
 | |
| 								const bSize = chunkGraph.getChunkSize(a, {
 | |
| 									chunkOverhead: 0
 | |
| 								});
 | |
| 								const abSize = chunkGraph.getIntegratedChunksSize(b, a, {
 | |
| 									chunkOverhead: 0
 | |
| 								});
 | |
| 								const improvement = (aSize + bSize) / abSize;
 | |
| 								combinations.push({
 | |
| 									a,
 | |
| 									b,
 | |
| 									improvement
 | |
| 								});
 | |
| 							}
 | |
| 						}
 | |
| 
 | |
| 						combinations.sort((a, b) => {
 | |
| 							return b.improvement - a.improvement;
 | |
| 						});
 | |
| 
 | |
| 						const pair = combinations[0];
 | |
| 
 | |
| 						if (!pair) return;
 | |
| 						if (pair.improvement < minSizeReduce) return;
 | |
| 
 | |
| 						chunkGraph.integrateChunks(pair.b, pair.a);
 | |
| 						compilation.chunks.delete(pair.a);
 | |
| 						return true;
 | |
| 					}
 | |
| 				);
 | |
| 			}
 | |
| 		);
 | |
| 	}
 | |
| }
 | |
| 
 | |
| module.exports = AggressiveMergingPlugin;
 |