streaming-poller

A node.js stream that executes another stream at regular intervals

Installation

Install via npm:

$ npm install streaming-poller

Usage

Provide a factory function that returns your inner stream, and a time interval in milliseconds. The resultant streaming-poller stream will immediately act as the inner stream would, but once the inner stream has ended, it will wait for the time interval and then use the factory to re-create the inner stream.

The obvious use case for this is regularly polling some source of IO that is itself a stream. The original import source is streamed through the streaming-poller stream, handling piping and backpressure in the normal way. Once it has finished and the streaming-poller stream is waiting for the specified interval, it can also be paused (which will pause the interval timer), meaning that backpressure can cause the polling to slow down.

Examples

Stream the numbers 4, 5 & 6 every two seconds.

streamingPoller = require('streaming-poller')
streamify = require('stream-array')
 
streamFactory = () ->
  streamify([4,5,6])
 
poller = streamingPoller streamFactory, interval: 2000