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wwl

2025-07-30 61b58bd03d04d2eb50ac2d93a188c819fe67e01e

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/*
    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
 */
 
const PLUGIN_NAME = "AggressiveMergingPlugin";
 
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(PLUGIN_NAME, (compilation) => {
            compilation.hooks.optimizeChunks.tap(
                {
                    name: PLUGIN_NAME,
                    stage: STAGE_ADVANCED
                },
                (chunks) => {
                    const chunkGraph = compilation.chunkGraph;
                    /** @type {{a: Chunk, b: Chunk, improvement: number}[]} */
                    const 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) => 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;