6.1 KiB
This example demonstrates the AggressiveSplittingPlugin for splitting the bundle into multiple smaller chunks to improve caching. This works best with a HTTP2 web server, otherwise there is an overhead for the increased number of requests.
AggressiveSplittingPlugin splits every chunk until it reaches the specified maxSize. In this example it tries to create chunks with <50kB raw code, which typically minimizes to ~10kB. It groups modules together by folder structure, because modules in the same folder are likely to have similar repetitive text, making them gzip efficiently together. They are also likely to change together.
AggressiveSplittingPlugin records its splitting in the webpack records. When it is next run, it tries to use the last recorded splitting. Since changes to application code between one run and the next are usually in only a few modules (or just one), re-using the old splittings (and chunks, which are probably still in the client's cache), is highly advantageous.
Only chunks which are bigger than the specified minSize are stored into the records. This ensures that these chunks fill up as your application grows, instead of creating many records of small chunks for every change.
If a module changes, its chunks are declared to be invalid, and are put back into the module pool. New chunks are created from all modules in the pool.
There is a tradeoff here:
The caching improves with smaller maxSize, as chunks change less often and can be reused more often after an update.
The compression improves with bigger maxSize, as gzip works better for bigger files. It's more likely to find duplicate strings, etc.
The backward compatibility (non HTTP2 client) improves with bigger maxSize, as the number of requests decreases.
var path = require("path");
var webpack = require("../../");
module.exports = {
// mode: "development || "production",
cache: true, // better performance for the AggressiveSplittingPlugin
entry: "./example",
output: {
path: path.join(__dirname, "dist"),
filename: "[chunkhash].js",
chunkFilename: "[chunkhash].js"
},
plugins: [
new webpack.optimize.AggressiveSplittingPlugin({
minSize: 30000,
maxSize: 50000
}),
new webpack.DefinePlugin({
"process.env.NODE_ENV": JSON.stringify("production")
})
],
recordsOutputPath: path.join(__dirname, "dist", "records.json")
};
Info
Unoptimized
Hash: 0a1b2c3d4e5f6a7b8c9d
Version: webpack 5.0.0-beta.6
Asset Size
1b3df87d8d004e83a428.js 17.7 KiB [emitted] [immutable] [name: main]
515efe286e0264e81c5c.js 117 KiB [emitted] [immutable] [id hint: vendors]
5ce1f3cb6de70a368806.js 7.15 KiB [emitted] [immutable]
Entrypoint main = 1b3df87d8d004e83a428.js
chunk 1b3df87d8d004e83a428.js (main) 8.77 KiB (javascript) 4.28 KiB (runtime) [entry] [rendered]
> ./example main
(webpack)/node_modules/object-assign/index.js 2.06 KiB [built]
(webpack)/node_modules/react/cjs/react.production.min.js 6.49 KiB [built]
(webpack)/node_modules/react/index.js 190 bytes [built]
./example.js 42 bytes [built]
+ 4 hidden chunk modules
chunk 5ce1f3cb6de70a368806.js 6.51 KiB [rendered]
> react-dom ./example.js 2:0-22
(webpack)/node_modules/react-dom/index.js 1.33 KiB [built]
(webpack)/node_modules/scheduler/cjs/scheduler.production.min.js 4.99 KiB [built]
(webpack)/node_modules/scheduler/index.js 198 bytes [built]
chunk 515efe286e0264e81c5c.js (id hint: vendors) 116 KiB [rendered] [recorded] aggressive splitted, reused as split chunk (cache group: defaultVendors)
> react-dom ./example.js 2:0-22
(webpack)/node_modules/react-dom/cjs/react-dom.production.min.js 116 KiB [built]
Production mode
Hash: 0a1b2c3d4e5f6a7b8c9d
Version: webpack 5.0.0-beta.6
Asset Size
68637c8e1dda08b1fadf.js 114 KiB [emitted] [immutable] [id hint: vendors]
68637c8e1dda08b1fadf.js.LICENSE 247 bytes [emitted]
aaa7fd653ee0bc7bb83b.js 4.98 KiB [emitted] [immutable]
aaa7fd653ee0bc7bb83b.js.LICENSE 246 bytes [emitted]
c3d741758d9e4bf8e4bd.js 8.71 KiB [emitted] [immutable] [name: main]
c3d741758d9e4bf8e4bd.js.LICENSE 295 bytes [emitted]
Entrypoint main = c3d741758d9e4bf8e4bd.js
chunk c3d741758d9e4bf8e4bd.js (main) 8.77 KiB (javascript) 4.28 KiB (runtime) [entry] [rendered]
> ./example main
(webpack)/node_modules/object-assign/index.js 2.06 KiB [built]
(webpack)/node_modules/react/cjs/react.production.min.js 6.49 KiB [built]
(webpack)/node_modules/react/index.js 190 bytes [built]
./example.js 42 bytes [built]
+ 4 hidden chunk modules
chunk aaa7fd653ee0bc7bb83b.js 6.51 KiB [rendered]
> react-dom ./example.js 2:0-22
(webpack)/node_modules/react-dom/index.js 1.33 KiB [built]
(webpack)/node_modules/scheduler/cjs/scheduler.production.min.js 4.99 KiB [built]
(webpack)/node_modules/scheduler/index.js 198 bytes [built]
chunk 68637c8e1dda08b1fadf.js (id hint: vendors) 116 KiB [rendered] [recorded] aggressive splitted, reused as split chunk (cache group: defaultVendors)
> react-dom ./example.js 2:0-22
(webpack)/node_modules/react-dom/cjs/react-dom.production.min.js 116 KiB [built]
Records
{
"aggressiveSplits": [
{
"hash": "515efe286e0264e81c5c93158843db80",
"id": 2,
"modules": [
"../../node_modules/react-dom/cjs/react-dom.production.min.js"
],
"size": 119155
}
],
"chunks": {
"byName": {
"main": 0
},
"bySource": {
"0 ./example.js react-dom": 2,
"1 ./example.js react-dom": 1
},
"usedIds": [
0,
1,
2
]
},
"modules": {
"byIdentifier": {
"../../node_modules/object-assign/index.js": 3,
"../../node_modules/react-dom/cjs/react-dom.production.min.js": 5,
"../../node_modules/react-dom/index.js": 4,
"../../node_modules/react/cjs/react.production.min.js": 2,
"../../node_modules/react/index.js": 1,
"../../node_modules/scheduler/cjs/scheduler.production.min.js": 7,
"../../node_modules/scheduler/index.js": 6,
"./example.js": 0
},
"usedIds": [
0,
1,
2,
3,
4,
5,
6,
7
]
}
}