mirror of https://github.com/webpack/webpack.git
97 lines
2.9 KiB
JavaScript
97 lines
2.9 KiB
JavaScript
/*
|
|
MIT License http://www.opensource.org/licenses/mit-license.php
|
|
Author Tobias Koppers @sokra
|
|
*/
|
|
|
|
"use strict";
|
|
|
|
const { STAGE_BASIC } = require("../OptimizationStages");
|
|
|
|
/** @typedef {import("../Compiler")} Compiler */
|
|
|
|
class MergeDuplicateChunksPlugin {
|
|
/**
|
|
* @param {Compiler} compiler the compiler
|
|
* @returns {void}
|
|
*/
|
|
apply(compiler) {
|
|
compiler.hooks.compilation.tap(
|
|
"MergeDuplicateChunksPlugin",
|
|
compilation => {
|
|
compilation.hooks.optimizeChunks.tap(
|
|
/** @type {TODO} */ ({
|
|
name: "MergeDuplicateChunksPlugin",
|
|
stage: STAGE_BASIC
|
|
}),
|
|
chunks => {
|
|
const chunkGraph = compilation.chunkGraph;
|
|
|
|
// remember already tested chunks for performance
|
|
const notDuplicates = new Set();
|
|
|
|
// for each chunk
|
|
for (const chunk of chunks) {
|
|
// track a Set of all chunk that could be duplicates
|
|
let possibleDuplicates;
|
|
for (const module of chunkGraph.getChunkModulesIterable(chunk)) {
|
|
if (possibleDuplicates === undefined) {
|
|
// when possibleDuplicates is not yet set,
|
|
// create a new Set from chunks of the current module
|
|
// including only chunks with the same number of modules
|
|
for (const dup of chunkGraph.getModuleChunksIterable(
|
|
module
|
|
)) {
|
|
if (
|
|
dup !== chunk &&
|
|
chunkGraph.getNumberOfChunkModules(chunk) ===
|
|
chunkGraph.getNumberOfChunkModules(dup) &&
|
|
!notDuplicates.has(dup)
|
|
) {
|
|
// delay allocating the new Set until here, reduce memory pressure
|
|
if (possibleDuplicates === undefined) {
|
|
possibleDuplicates = new Set();
|
|
}
|
|
possibleDuplicates.add(dup);
|
|
}
|
|
}
|
|
// when no chunk is possible we can break here
|
|
if (possibleDuplicates === undefined) break;
|
|
} else {
|
|
// validate existing possible duplicates
|
|
for (const dup of possibleDuplicates) {
|
|
// remove possible duplicate when module is not contained
|
|
if (!chunkGraph.isModuleInChunk(module, dup)) {
|
|
possibleDuplicates.delete(dup);
|
|
}
|
|
}
|
|
// when all chunks has been removed we can break here
|
|
if (possibleDuplicates.size === 0) break;
|
|
}
|
|
}
|
|
|
|
// when we found duplicates
|
|
if (
|
|
possibleDuplicates !== undefined &&
|
|
possibleDuplicates.size > 0
|
|
) {
|
|
for (const otherChunk of possibleDuplicates) {
|
|
if (otherChunk.hasRuntime() !== chunk.hasRuntime()) continue;
|
|
// merge them
|
|
if (chunkGraph.canChunksBeIntegrated(chunk, otherChunk)) {
|
|
chunkGraph.integrateChunks(chunk, otherChunk);
|
|
compilation.chunks.delete(otherChunk);
|
|
}
|
|
}
|
|
}
|
|
|
|
// don't check already processed chunks twice
|
|
notDuplicates.add(chunk);
|
|
}
|
|
}
|
|
);
|
|
}
|
|
);
|
|
}
|
|
}
|
|
module.exports = MergeDuplicateChunksPlugin;
|