This repository has been archived on 2023-04-09. You can view files and clone it, but cannot push or open issues or pull requests.
kernel-protomux/README.md

154 lines
3.3 KiB
Markdown

# protomux
Multiplex multiple message oriented protocols over a stream
```
npm install protomux
```
## Usage
``` js
const Protomux = require('protomux')
const c = require('compact-encoding')
// By framed stream, it has be a stream that preserves the messages, ie something that length prefixes
// like @hyperswarm/secret-stream
const mux = new Protomux(aStreamThatFrames)
// Now add some protocol sessions
const cool = mux.open({
protocol: 'cool-protocol',
id: Buffer.from('optional binary id'),
onopen () {
console.log('the other side opened this protocol!')
},
onclose () {
console.log('either side closed the protocol')
}
})
// And add some messages
const one = cool.addMessage({
encoding: c.string,
onmessage (m) {
console.log('recv message (1)', m)
}
})
const two = cool.addMessage({
encoding: c.bool,
onmessage (m) {
console.log('recv message (2)', m)
}
})
// And send some data
one.send('a string')
two.send(true)
```
## API
#### `mux = new Protomux(stream, [options])`
Make a new instance. `stream` should be a framed stream, preserving the messages written.
Options include:
``` js
{
// Called when the muxer wants to allocate a message that is written, defaults to Buffer.allocUnsafe.
alloc (size) {}
}
```
#### `mux = Protomux.from(stream | muxer, [options])`
Helper to accept either an existing muxer instance or a stream (which creates a new one).
#### `const session = mux.open(opts)`
Add a new protocol session.
Options include:
``` js
{
// Used to match the protocol
protocol: 'name of the protocol',
// Optional additional binary id to identify this session
id: buffer,
// Optional array of messages types you want to send/receive.
messages: [],
// Called when the remote side adds this protocol.
// Errors here are caught and forwared to stream.destroy
async onopen () {},
// Called when the session closes - ie the remote side closes or rejects this protocol or we closed it.
// Errors here are caught and forwared to stream.destroy
async onclose () {},
// Called after onclose when all pending promises has resolved.
async ondestroy () {}
}
```
Sessions are paired based on a queue, so the first remote session with the same `protocol` and `id`.
__NOTE__: `mux.open` returns `null` if the session should not be opened, ie it's a duplicate session or the remote has already closed this one.
If you want multiple sessions with the same `protocol` and `id`, set `unique: false` as an option.
#### `const m = session.addMessage(opts)`
Add a message. Options include:
``` js
{
// compact-encoding specifying how to encode/decode this message
encoding: c.binary,
// Called when the remote side sends a message.
// Errors here are caught and forwared to stream.destroy
async onmessage (message) { }
}
```
#### `m.send(data)`
Send a message.
#### `m.onmessage`
Function that is called when a message arrives.
#### `m.encoding`
The encoding for this message.
#### `session.close()`
Closes the protocol session.
#### `sessoin.cork()`
Corking the protocol session, makes it buffer messages and send them all in a batch when it uncorks.
#### `session.uncork()`
Uncork and send the batch.
#### `mux.cork()`
Same as `session.cork` but on the muxer instance.
#### `mux.uncork()`
Same as `session.uncork` but on the muxer instance.
## License
MIT