KCP

Zero-copy KCP protocol for the web

1npm i @hazae41/kcp

Node Package 📦

Features

Current features

• 100% TypeScript and ESM
• Zero-copy reading and writing
• Works in the browser

Usage

1import { KcpDuplex } from "@hazae41/kcp"
2import { Opaque, Writable } from "@hazae41/binary"
3import { SuperTransformStream } from "@hazae41/cascade"
4import { None } from "@hazae41/kcp"
5
6const conversation = 12345
7
8function pipeToKcp(raw: { outer: ReadableWritablePair<Opaque, Writable> }): { outer: ReadableWritablePair<Opaque, Writable> } {
9  const kcp = new KcpDuplex({ conversation })
10
11  raw.outer.readable
12    .pipeTo(kcp.inner.writable)
13    .catch(() => { })
14
15  kcp.inner.readable
16    .pipeTo(raw.outer.writable)
17    .catch(() => { })
18
19  return kcp
20}
21
22function pipeToDummy(kcp: { outer: ReadableWritablePair<Opaque, Writable> }) {
23  const dummy = new Dummy()
24
25  kcp.outer.readable
26    .pipeTo(dummy.inner.writable)
27    .catch(() => { })
28
29  dummy.inner.readable
30    .pipeTo(kcp.outer.writable)
31    .catch(() => { })
32
33  return dummy
34}
35
36class Dummy extends HalfDuplex<Opaque, Writable> {
37
38  constructor() {
39    super()
40  }
41
42  send(data: Writable) {
43    this.output.enqueue(data)
44  }
45
46}
47
48const forward = new TransformStream<Writable, Opaque>({ transform: (chunk, controller) => controller.enqueue(Opaque.writeFromOrThrow(chunk)) })
49const backward = new TransformStream<Writable, Opaque>({ transform: (chunk, controller) => controller.enqueue(Opaque.writeFromOrThrow(chunk)) })
50
51const rawA = { outer: { readable: forward.readable, writable: backward.writable } }
52const rawB = { outer: { readable: backward.readable, writable: forward.writable } }
53
54const kcpA = pipeToKcp(rawA)
55const kcpB = pipeToKcp(rawB)
56
57const dummyA = pipeToDummy(kcpA)
58const dummyB = pipeToDummy(kcpB)
59
60dummyB.input.events.on("message", (data) => {
61  console.log("b", data.bytes)
62  return new None()
63})
64
65dummyA.input.events.on("message", (data) => {
66  console.log("a", data.bytes)
67  return new None()
68})
69
70dummyA.send(new Opaque(new Uint8Array([1, 2, 3])))
71dummyB.send(new Opaque(new Uint8Array([4, 5, 6])))
72