You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 

78 lines
2.4 KiB

/*
MIT License http://www.opensource.org/licenses/mit-license.php
Author Tobias Koppers @sokra
*/
"use strict";
class MergeDuplicateChunksPlugin {
apply(compiler) {
compiler.hooks.compilation.tap(
"MergeDuplicateChunksPlugin",
compilation => {
compilation.hooks.optimizeChunksBasic.tap(
"MergeDuplicateChunksPlugin",
chunks => {
// 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 chunk.modulesIterable) {
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 module.chunksIterable) {
if (
dup !== chunk &&
chunk.getNumberOfModules() === dup.getNumberOfModules() &&
!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 (!dup.containsModule(module)) {
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 (chunk.integrate(otherChunk, "duplicate")) {
chunks.splice(chunks.indexOf(otherChunk), 1);
}
}
}
// don't check already processed chunks twice
notDuplicates.add(chunk);
}
}
);
}
);
}
}
module.exports = MergeDuplicateChunksPlugin;