Create async pools with automatic retry
npm i @hazae41/piscine- 100% TypeScript and ESM
- No external dependency
- Simple API
- Automatic retry
- Get a fast random value using Math's PRNG
- Get a secure random value using WebCrypto's CSPRNG
Create a pool of WebSockets
import "@hazae41/symbol-dispose-polyfill";
import "@hazae41/disposable-stack-polyfill";
import { Disposer } from "@hazae41/disposer"
import { Box } from "@hazae41/box"
import { Pool } from "@hazae41/piscine"
import { Future } from "@hazae41/future"
async function openOrThrow(socket: WebSocket, signal: AbortSignal) {
using stack = new DisposableStack()
const future = new Future<void>()
const onOpen = () => future.resolve()
const onError = () => future.reject(new Error("Errored"))
const onAbort = () => future.reject(new Error("Aborted"))
socket.addEventListener("open", onOpen, { passive: true })
stack.defer(() => socket.removeEventListener("open", onOpen))
socket.addEventListener("error", onError, { passive: true })
stack.defer(() => socket.removeEventListener("error", onError))
signal.addEventListener("abort", onAbort, { passive: true })
stack.defer(() => signal.removeEventListener("abort", onAbort))
return await future.promise
}
const pool = new Pool<Disposer<WebSocket>>(async ({ pool, index, signal }) => {
using stack = new Box(new DisposableStack())
const raw = new WebSocket(`/api`)
await waitOrThrow(raw, signal)
const socket = new Disposer(raw, () => raw.close())
const box = new Box(socket)
stack.getOrThrow().use(box)
const onClose = () => pool.restart(index)
raw.addEventListener("close", onClose, { passive: true })
stack.getOrThrow().defer(() => raw.removeEventListener("close", onClose))
const unstack = stack.unwrapOrThrow()
return new Disposer(box, () => unstack.dispose())
})Start 5 of them
for (let i = 0; i < 5; i++)
pool.start(i)You can get the second one
const socket = await pool.getOrThrow(1)You can get a random one using Math's PRNG
const socket = await pool.getRandomOrThrow()
socket.get().send("Hello world")You can get a random one using WebCrypto's CSPRNG
const socket = await pool.getCryptoRandomOrThrow()
socket.get().send("Hello world")You can iterate on them
for (const socket of pool)
socket.get().send("Hello world")Or grab all of them
const sockets = [...pool]You can take a random one from the pool (and restart its index)
import { Mutex } from "@hazae41/mutex"
const mutex = new Mutex(pool)
{
using socket = await Pool.takeCryptoRandomOrThrow(mutex)
socket.get().send("Hello world")
// Close socket
}