topological-promise-queue

Run promises in order of a directed acyclic graph

In a dependency graph like below, we need to run dependencies first:

     A
   /   \
  B     C
  |
  C

That means, order of execution would be first C, then B, then A.

---

The queue could run tasks in parallel, this means we will try to reduce the time of execution as much as possible.

Given the following graph:

     A
   / | \
  B  C  D

This means, order of execution would be B, C and D in parallel, then A.

The amount of concurrency could be defined for limiting resource usage.

---

Usage

import { run } from "topological-promise-queue";

await run({
  concurrency: 10,
  edges: [
    // a depends on b
    ["a", "b"],
    // a depends on c
    ["a", "c"],
    // b depends on c
    ["b", "c"],
  ],
  async runner(node) {
    console.log(node);
    // this will output:
    // c
    // b
    // a
  },
});