hfs/src/makeQ.js

HTTP File Server

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.makeQ = makeQ;
function makeQ(parallelization = 1) {
    const running = new Set();
    const queued = [];
    return {
        add(toAdd) {
            queued.push(toAdd);
            setTimeout(startNextIfPossible); // avoid nesting/stacking of jobs
        },
        isWorking() { return running.size > 0; },
        isFree() { return running.size < parallelization; },
    };
    function startNextIfPossible() {
        while (running.size < parallelization) {
            const job = queued.pop();
            if (!job)
                break; // finished
            const working = job(); // start the job
            if (!working)
                continue; // it was canceled
            running.add(working);
            working.then(() => {
                running.delete(working);
                startNextIfPossible();
            });
        }
    }
}