webpack/lib/optimize/RemoveParentModulesPlugin.js

103 lines
3.3 KiB
JavaScript

/*
MIT License http://www.opensource.org/licenses/mit-license.php
Author Tobias Koppers @sokra
*/
"use strict";
const Queue = require("../util/Queue");
const intersect = require("../util/SetHelpers").intersect;
const getParentChunksWithModule = (currentChunk, module) => {
const chunks = [];
const stack = new Set(currentChunk.parentsIterable);
for(const chunk of stack) {
if(chunk.containsModule(module)) {
chunks.push(chunk);
} else {
for(const parent of chunk.parentsIterable) {
stack.add(parent);
}
}
}
return chunks;
};
class RemoveParentModulesPlugin {
apply(compiler) {
compiler.hooks.compilation.tap("RemoveParentModulesPlugin", (compilation) => {
const handler = (chunks, chunkGroups) => {
const queue = new Queue();
const availableModulesMap = new Map();
for(const chunkGroup of compilation.entrypoints.values()) {
// initialize available modules for chunks without parents
availableModulesMap.set(chunkGroup, new Set());
for(const child of chunkGroup.childrenIterable)
queue.enqueue(child);
}
while(queue.length > 0) {
const chunkGroup = queue.dequeue();
let availableModules = availableModulesMap.get(chunkGroup);
let changed = false;
for(const parent of chunkGroup.parentsIterable) {
const availableModulesInParent = availableModulesMap.get(parent);
if(availableModulesInParent !== undefined) {
// If we know the available modules in parent: process these
if(availableModules === undefined) {
// if we have not own info yet: create new entry
availableModules = new Set(availableModulesInParent);
for(const chunk of parent.chunks) {
for(const m of chunk.modulesIterable)
availableModules.add(m);
}
availableModulesMap.set(chunkGroup, availableModules);
changed = true;
} else {
for(const m of availableModules) {
if(!parent.containsModule(m) && !availableModulesInParent.has(m)) {
availableModules.delete(m);
changed = true;
}
}
}
}
}
if(changed) {
// if something changed: enqueue our children
for(const child of chunkGroup.childrenIterable)
queue.enqueue(child);
}
}
// now we have available modules for every chunk
for(const chunk of chunks) {
const availableModulesSets = Array.from(chunk.groupsIterable, chunkGroup => availableModulesMap.get(chunkGroup));
if(availableModulesSets.some(s => s === undefined)) continue; // No info about this chunk group
const availableModules = intersect(availableModulesSets);
const numberOfModules = chunk.getNumberOfModules();
const toRemove = new Set();
if(numberOfModules < availableModules.size) {
for(const m of chunk.modulesIterable)
if(availableModules.has(m))
toRemove.add(m);
} else {
for(const m of availableModules)
if(chunk.containsModule(m))
toRemove.add(m);
}
for(const module of toRemove) {
module.rewriteChunkInReasons(chunk, getParentChunksWithModule(chunk, module));
chunk.removeModule(module);
}
}
};
compilation.hooks.optimizeChunksBasic.tap("RemoveParentModulesPlugin", handler);
compilation.hooks.optimizeExtractedChunksBasic.tap("RemoveParentModulesPlugin", handler);
});
}
}
module.exports = RemoveParentModulesPlugin;