background-process-js/lib/consumer.js

A set of util tools for create background process.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.Consumer = exports.Events = void 0;
const node_events_1 = require("node:events");
var Events;
(function (Events) {
    Events["STOP_REQUEST"] = "stop-request";
    Events["START_REQUEST"] = "start-request";
    Events["RECEIVED_MESSAGE"] = "received-message";
})(Events || (exports.Events = Events = {}));
class Consumer {
    constructor(provider) {
        this.provider = provider;
        this.emitter = new node_events_1.EventEmitter();
    }
    process(pollingStrategy, hook) {
        this.pollingStrategy = pollingStrategy;
        this.emitter.on(Events.RECEIVED_MESSAGE, hook);
        this.emitter.on(Events.START_REQUEST, async () => {
            const incomingAllMessages = await this.pollingStrategy.exec(this.provider);
            this.emitter.emit(Events.RECEIVED_MESSAGE, incomingAllMessages, this.finish.bind(this));
        });
        this.emitter.once(Events.STOP_REQUEST, () => {
            this.emitter.removeAllListeners(Events.START_REQUEST);
            this.emitter.removeAllListeners(Events.RECEIVED_MESSAGE);
        });
    }
    stop() {
        this.emitter.emit(Events.STOP_REQUEST);
    }
    start() {
        this.emitter.emit(Events.START_REQUEST);
    }
    async finish(restartStrategy, messages) {
        if (this.provider.hasDeadQueue() && messages.dead) {
            await this.provider.markAsDeadMessages(messages.dead);
        }
        await this.provider.deleteMessages(messages.finished);
        await restartStrategy.exec(this);
    }
}
exports.Consumer = Consumer;