Singleflight

A wrapper for de-duplicating in-flight requests

Singleflight allows you to simply wrap asynchronous functions of the form
function(key, callback) where key is a single string argument and callback
can be a function of any signature.

$3

``javascript
var singleflight = require('singleflight');
var request = require('request');

var wrappedget = singleflight(request.get);

wrappedget('https://www.example.com/cool.jpg', function(error, response) {
...
});
wrappedget('https://www.example.com/cool.jpg', function(error, response) {
...
});
`

will result in only one call to fetch https://www.example.com/cool.jpg.

Useful applications include re-validation and re-population of caches, and any
other de-duplication of longish running asynchronous tasks. Combines well with
other async flow control tools like Promises and the
async and
vasync libraries.

$3


npm test`