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javascriptnode.jsstreamhighland.js

Slowing stream down to one chunk per second

I have a highland stream that is reading a file line by line, and I want to slow it down to one chunk per second. I have looked through the docs, and the only functions I found were throttle() and debounce(). Both of those drop values. I need to keep all my values and just slow down the rate.

Solution

  • I'd suggest mapping the chunks to delayed streams and sequencing them:

    var _ = require('highland');

function delay(x) {
    return _(function (push, next) {
        setTimeout(function () {
            push(null, x);
            push(null, _.nil);
        }, 1000);
    });
}

_([1, 2, 3, 4]).map(delay).series().each(_.log);

    The delay function used here seems fairly easy to generalise, so if you're interested in sending a pull request on this I'd be happy to review it :)