webpack/lib/optimize/RemoveParentModulesPlugin.js

108 lines
3.4 KiB
JavaScript

/*
MIT License http://www.opensource.org/licenses/mit-license.php
Author Tobias Koppers @sokra
*/
"use strict";
const Queue = require("../util/Queue");
const hasModule = (chunk, module, checkedChunks) => {
if(chunk.containsModule(module)) return [chunk];
if(chunk.getNumberOfParents() === 0) return false;
return allHaveModule(chunk.getParents().filter((c) => {
return !checkedChunks.has(c);
}), module, checkedChunks);
};
const allHaveModule = (someChunks, module, checkedChunks) => {
if(!checkedChunks) checkedChunks = new Set();
var chunks = new Set();
for(var i = 0; i < someChunks.length; i++) {
checkedChunks.add(someChunks[i]);
var subChunks = hasModule(someChunks[i], module, checkedChunks);
if(!subChunks) return false;
for(var index = 0; index < subChunks.length; index++) {
var item = subChunks[index];
chunks.add(item);
}
}
return chunks;
};
class RemoveParentModulesPlugin {
apply(compiler) {
compiler.hooks.compilation.tap("RemoveParentModulesPlugin", (compilation) => {
const handler = (chunks) => {
const queue = new Queue(chunks);
const availableModulesMap = new Map();
for(const chunk of chunks) {
// initialize available modules for chunks without parents
if(chunk.getNumberOfParents() === 0)
availableModulesMap.set(chunk, new Set());
}
while(queue.length > 0) {
const chunk = queue.dequeue();
let availableModules = availableModulesMap.get(chunk);
let changed = false;
for(const parent of chunk.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 m of parent.modulesIterable)
availableModules.add(m);
availableModulesMap.set(chunk, 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 chunk.chunksIterable)
queue.enqueue(child);
}
}
// now we have available modules for every chunk
for(const chunk of chunks) {
// remove modules from chunk if they are already available
const availableModules = availableModulesMap.get(chunk);
const modules = new Set(chunk.modulesIterable);
const toRemove = new Set();
if(modules.size < availableModules.size) {
for(const m of modules)
if(availableModules.has(m))
toRemove.add(m);
} else {
for(const m of availableModules)
if(modules.has(m))
toRemove.add(m);
}
for(const module of toRemove) {
const parentChunksWithModule = allHaveModule(chunk.getParents(), module);
module.rewriteChunkInReasons(chunk, Array.from(parentChunksWithModule));
chunk.removeModule(module);
}
}
};
compilation.hooks.optimizeChunksBasic.tap("RemoveParentModulesPlugin", handler);
compilation.hooks.optimizeExtractedChunksBasic.tap("RemoveParentModulesPlugin", handler);
});
}
}
module.exports = RemoveParentModulesPlugin;