celery-node-routing
Version:
celery written in nodejs
113 lines (112 loc) • 3.61 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
const amqplib = require("amqplib");
class AMQPBackend {
/**
* AMQP backend class
* @constructor AMQPBackend
* @param {string} url the connection string of amqp
* @param {object} opts the options object for amqp connect of amqplib
*/
constructor(url, opts) {
this.opts = opts;
this.connect = amqplib.connect(url, opts);
this.channel = this.connect
.then((conn) => conn.createChannel())
.then((ch) => ch
.assertExchange("default", "direct", {
durable: true,
autoDelete: true,
internal: false,
// nowait: false,
arguments: null,
})
.then(() => Promise.resolve(ch)));
}
/**
* @method AMQPBackend#isReady
* @returns {Promise} promises that continues if amqp connected.
*/
isReady() {
return this.connect;
}
/**
* @method AMQPBackend#disconnect
* @returns {Promise} promises that continues if amqp disconnected.
*/
disconnect() {
return this.connect.then((conn) => conn.close());
}
/**
* store result method on backend
* @method AMQPBackend#storeResult
* @param {String} taskId
* @param {any} result result of task. i.e the return value of task handler
* @param {String} state
* @returns {Promise}
*/
storeResult(taskId, result, state) {
const queue = taskId.replace(/-/g, "");
return this.channel
.then((ch) => ch
.assertQueue(queue, {
durable: true,
autoDelete: true,
exclusive: false,
// nowait: false,
arguments: {
"x-expires": this.opts.CELERY_RESULT_EXPIRES || 86400000,
},
})
.then(() => Promise.resolve(ch)))
.then((ch) => ch.publish("", queue, Buffer.from(JSON.stringify({
status: state,
result: state == "FAILURE" ? null : result,
traceback: null,
children: [],
task_id: taskId,
date_done: new Date().toISOString(),
})), {
contentType: "application/json",
contentEncoding: "utf-8",
}));
}
/**
* get result data from backend
* @method AMQPBackend#getTaskMeta
* @param {String} taskId
* @returns {Promise}
*/
getTaskMeta(taskId) {
const queue = taskId.replace(/-/g, "");
return this.channel
.then((ch) => ch
.assertQueue(queue, {
durable: true,
autoDelete: true,
exclusive: false,
// nowait: false,
arguments: {
"x-expires": this.opts.CELERY_RESULT_EXPIRES || 86400000,
},
})
.then(() => Promise.resolve(ch)))
.then((ch) => ch.get(queue, {
noAck: false,
}))
.then((msg) => {
if (msg === false) {
return null;
}
if (msg.properties.contentType !== "application/json") {
throw new Error(`unsupported content type ${msg.properties.contentType}`);
}
if (msg.properties.contentEncoding !== "utf-8") {
throw new Error(`unsupported content encoding ${msg.properties.contentEncoding}`);
}
const body = msg.content.toString("utf-8");
return JSON.parse(body);
});
}
}
exports.default = AMQPBackend;