examples/custom-parsers/README.md
# Socket.IO custom parsers
Since Socket.IO version 2.0.0, you can provide your custom parser, according to the needs of your application.
Several parsers are showcased here:
- the default one: [socket.io-parser](https://github.com/socketio/socket.io-parser)
- one based on msgpack: [socket.io-msgpack-parser](https://github.com/darrachequesne/socket.io-msgpack-parser)
- one based on native JSON: [socket.io-json-parser](https://github.com/darrachequesne/socket.io-json-parser)
- a custom one based on [schemapack](https://github.com/phretaddin/schemapack)
They are tested with various payloads:
- string: `['1', '2', ... '1000']`
- numeric: `[1, 2, ... 1000]`
- binary: `Buffer.allocUnsafe(1000), where buf[i] = i`
## How to use
```
$ npm i && npm start
```
## Results
| bytes / packet | CONNECT packet | string | numeric | binary |
|----------------|----------------|--------|---------|-----------|
| default | 1 | 5903 | 3904 | 43 + 1000 |
| msgpack | 20 | 3919 | 2646 | 1029 |
| JSON | 20 | 5930 | 3931 | 3625 |
| schemapack | 20 | 3895 | 2005 | 1005 |
## Comparison
`default parser`
- supports any serializable datastructure, including Blob and File
- **but** binary payload is encoded as 2 packets
`msgpack`
- the size of payloads containing mostly numeric values will be greatly reduced
- **but** rely on [ArrayBuffer](https://caniuse.com/#feat=typedarrays) in the browser (IE > 9)
`JSON`
- optimized
- **but** does not support binary payloads
`schemapack`
- the most efficient in both speed and size
- **but** you have to provide a schema for each packet