@push-stream-std/push-sample (0.0.6)
Installation
@push-stream-std:registry=https://hub.kl1.tenere.ai/api/packages/push-stream-std/npm/npm install @push-stream-std/push-sample@0.0.6"@push-stream-std/push-sample": "0.0.6"About this package
push-sample
Sample a push-stream at regular intervals or on an external signal.
Published as @push-stream-std/push-sample.
Synopsis
import { sample } from '@push-stream-std/push-sample';
import { values } from '@push-stream-std/push-values';
import { collect } from '@push-stream-std/push-collect';
const sampler = sample(100); // sample every 100ms
values([1, 2, 3, 4, 5]).pipe(sampler);
sampler.pipe(collect((err, results) => {
console.log(results); // latest value at each 100ms interval
}));
With a signal source:
import { sample } from '@push-stream-std/push-sample';
import { values } from '@push-stream-std/push-values';
import { collect } from '@push-stream-std/push-collect';
const clock = values([null, null, null]); // trigger 3 samples
const sampler = sample({ signal: clock });
values([10, 20, 30, 40, 50]).pipe(sampler).pipe(collect((err, results) => {
console.log(results); // [10, 20, 30] — one per signal end event
}));
Install
npm config set @push-stream-std:registry https://hub.kl1.tenere.ai/api/packages/push-stream-std/npm/
npm config set -- //hub.kl1.tenere.ai/api/packages/push-stream-std/npm/:_authToken "$PACKAGE_TOKEN"
npm install @push-stream-std/push-sample
Description
A push-stream through operator that periodically emits the most recently received value. It can be driven by a time interval (using setInterval) or by an external signal stream. When driven by a signal, each time the signal source ends (end-of-signal event), the latest buffered value is emitted. The operator stores only the latest value; intermediate values between sample ticks are overwritten.
API
sample(options)
options— Either a number (interval in milliseconds) or an object:options.interval(number, default1000) — Sample interval in milliseconds. Ignored ifsignalis provided. Set to 0 to never auto-sample.options.signal(push-stream source, optional) — A source stream whose end events trigger samples. The signal stream is piped internally; each time its proxy end handler fires, the latest value is emitted.
Returns a push-stream through. Writes update the buffered latest value; the value is emitted on each timer tick or signal tick. Only values received since the last sample are emitted (hasValue resets after each sample).
Tests
npm test
Tests cover interval-driven sampling, signal-driven sampling, emitting only the latest value between samples, and ending the stream.
Requirements
Node.js 18 or later. ESM only.
License
MIT