npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

abacus-batch

v1.1.5

Published

Batching for async function calls

Downloads

32

Readme

abacus-batch

Batching for async function calls.

This module provides a simple way to implement function call batching. Batching is achieved by wrapping a function in logic that records calls in a batch for some time then calls that function once with the accumulated batch, giving it an opportunity to process all the calls efficiently at once. Unbatching takes a batch of calls, applies then individually to a function, then returns a batch of results.

require('abacus-batch') or require('abacus-batch').batchify

The batch function allows us to delegate the processing of a given function after a number of function calls have occurred.

const batch = require('abacus-batch');

const sumArray = (array) =>
  array.reduce((accumulator, currentValue) =>
    currentValue instanceof Array
      ? accumulator + sumArray(currentValue)
      : accumulator + currentValue
    , 0);

const batchedSum = batch((calls, cb) => {
  // calls will equal to
  // [
  //   [ 1, 2 ],
  //   [ 4, 6 ],
  //   [ 9, 31 ]
  // ]
  cb(sumArray(calls));
});

batchedSum(1, 2, console.log); batchedSum(4, 6, console.log); batchedSum(9, 31, console.log);

We can control the amount of time that calls are accumulated before our batched function is called via an additional argument to batch.

const batchedSum = batch(() => {}, 1000);

The example above will wait 1 second before calling the lambda.

We can also specify a maximum number of invocations before the batched function is called.

const batchedSum = batch(() => {}, 1000, 10);

The function above will wait for 1 second or 10 invocations before it calls the lambda function.

Finally, it is possible to implement a custom count function.

const batchedSum = batch(() => {}, 1000, 10, (name, args) => args.length);

The above function will wait for 1 second or until the number of arguments of all the accumulated functions is equal to 10. The name argument of the last callback is the name of the function.

require('abacus-batch').groupBy

Intended to be used with the batch function. It allows one to group accumulated calls into buckets and then have each bucket sent to the lambda function.

For example:

const batch = require('abacus-batch');
const groupBy = require('abacus-batch').groupBy;

const sumArray = (array) =>
  array.reduce((accumulator, currentValue) =>
    currentValue instanceof Array
      ? accumulator + sumArray(currentValue)
      : accumulator + currentValue
    , 0);

const batchedGroupingSum = batch(groupBy((calls, cb) => {
  // this function will be called twice.
  // the first time, calls will equal to
  // [
  //   [1, 2],
  //   [9, 31]
  // ]
  // the second time, calls will equal to
  // [
  //   [4, 6]
  // ]
  cb(sumArray(calls));
}, (args, cb) => {
  // we will group by whether the first argument is odd or even
  // all we need to do is return an id for each group. in our case, we
  // use the remainder of the division as the bucket id.
  cb(undefined, args[0] % 2);
}));

batchedGroupingSum(1, 2); batchedGroupingSum(4, 6); batchedGroupingSum(9, 31);

require('abacus-batch').unbatchify

This is the reverse of the batchify function. It allows a collection of calls to be split apart, resulting in individual calls.

const unbatch = require('abacus-batch').unbatchify;
const sum = (a, b, callback) => {
  // will be called three times with the following set of arguments
  // 1. a = 1; b = 2
  // 2. a = 5; b = 11
  // 3. a = 8; b = 3
  callback(undefined, a + b);
};
const unbatchedSum = unbatch(sum);

unbatchedSum([
  [1, 2],
  [5, 11],
  [8, 3]
], (err, result) => {
  // results will equal
  // [
  //   [undefined, 3],
  //   [undefined, 16],
  //   [undefined, 11]
  // ]
});