Async flow control for directed-acyclic-graph iteration.
npm install breeze-dag> Async flow control for directed-acyclic-graph iteration.
breeze-dag is available on npm.
$ npm install breeze-dag
breeze-dag is available as a component.
$ component install qualiancy/breeze-dag
* @param _{Array}_ edges
* @param _{Number}_ concurrency
* @param _{Function}_ iterator
* @param _{Function}_ callback
DAG, directed-acyclic-graph, is a graph of nodes in
which there are no cyclic references, and therefor has
a specific starting and ending point. The dag async
method will take an array of edges and resolve a best
fit path of execution. It will then iterate over each
edge in parallel up to a set amount of threads (concurrency).
Furthermore, an edge will not begin it's processing until
all of its dependancies have indicated successful execution.
A set of edges is defined as an array, with each element being
an array of x, y pairs, where x must complete before y
can begin.
``js`
var edges = [
[ 'a', 'b' ]
, [ 'a', 'c' ]
, [ 'd', 'e' ]
, [ 'b', 'd' ]
];
With the above edges, we expect a to start processing. Uponb
completion, and c will start. Upon b completion, d
will execute, then .
`js
var dag = require('breeze-dag');
dag(edges, 2, function (e, next) {
setTimeout(function () {
next(); // or next(err);
}, 1000);
}, function (err) {
// our done callback
should.not.exist(err);
});
`
If there are cyclical references in the set of edges, the done
callback will be immediately called with an error indicating
the problem.
If an error occurs the done` callback will
be executed immediately. No more items will begin processing,
but items that have already started will run to completion.
(The MIT License)
Copyright (c) 2012 Jake Luer
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