simple-rabbitmq-message-broker
Version:
245 lines (243 loc) • 12.3 kB
JavaScript
"use strict";
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
return new (P || (P = Promise))(function (resolve, reject) {
function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
step((generator = generator.apply(thisArg, _arguments || [])).next());
});
};
var __generator = (this && this.__generator) || function (thisArg, body) {
var _ = { label: 0, sent: function() { if (t[0] & 1) throw t[1]; return t[1]; }, trys: [], ops: [] }, f, y, t, g;
return g = { next: verb(0), "throw": verb(1), "return": verb(2) }, typeof Symbol === "function" && (g[Symbol.iterator] = function() { return this; }), g;
function verb(n) { return function (v) { return step([n, v]); }; }
function step(op) {
if (f) throw new TypeError("Generator is already executing.");
while (_) try {
if (f = 1, y && (t = op[0] & 2 ? y["return"] : op[0] ? y["throw"] || ((t = y["return"]) && t.call(y), 0) : y.next) && !(t = t.call(y, op[1])).done) return t;
if (y = 0, t) op = [op[0] & 2, t.value];
switch (op[0]) {
case 0: case 1: t = op; break;
case 4: _.label++; return { value: op[1], done: false };
case 5: _.label++; y = op[1]; op = [0]; continue;
case 7: op = _.ops.pop(); _.trys.pop(); continue;
default:
if (!(t = _.trys, t = t.length > 0 && t[t.length - 1]) && (op[0] === 6 || op[0] === 2)) { _ = 0; continue; }
if (op[0] === 3 && (!t || (op[1] > t[0] && op[1] < t[3]))) { _.label = op[1]; break; }
if (op[0] === 6 && _.label < t[1]) { _.label = t[1]; t = op; break; }
if (t && _.label < t[2]) { _.label = t[2]; _.ops.push(op); break; }
if (t[2]) _.ops.pop();
_.trys.pop(); continue;
}
op = body.call(thisArg, _);
} catch (e) { op = [6, e]; y = 0; } finally { f = t = 0; }
if (op[0] & 5) throw op[1]; return { value: op[0] ? op[1] : void 0, done: true };
}
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.MessageBroker = void 0;
var amqplib = require("amqplib");
var _ = require("lodash");
var uuid_1 = require("uuid");
/**
* Broker for async messaging
*/
var MessageBroker = /** @class */ (function () {
/**
* Trigger init connection method
*/
function MessageBroker() {
this.queues = {};
}
Object.defineProperty(MessageBroker.prototype, "channel", {
get: function () {
if (this._channel) {
return this._channel;
}
throw new Error('Channel not created');
},
enumerable: false,
configurable: true
});
/**
* Initialize connection to rabbitMQ
*/
MessageBroker.prototype.init = function () {
var _a;
return __awaiter(this, void 0, void 0, function () {
var path, _b, _c, e_1;
return __generator(this, function (_d) {
switch (_d.label) {
case 0:
_d.trys.push([0, 3, , 5]);
path = process.env.RABBITMQ_URL || 'amqp://localhost';
console.log('Connecting Rabbit MQ: ' + path);
_b = this;
return [4 /*yield*/, amqplib.connect(path)];
case 1:
_b.connection = _d.sent();
_c = this;
return [4 /*yield*/, ((_a = this.connection) === null || _a === void 0 ? void 0 : _a.createChannel())];
case 2:
_c._channel = _d.sent();
console.log('Connected to Rabbit MQ ' + path);
return [2 /*return*/, this];
case 3:
e_1 = _d.sent();
return [4 /*yield*/, new Promise(function (_) { return setTimeout(_, 1000); })];
case 4:
_d.sent();
console.log('Rabbit MQ Error: ' + e_1);
return [2 /*return*/, this.init()];
case 5: return [2 /*return*/];
}
});
});
};
/**
/**
* Send message to queue
* @param {String} queue Queue name
* @param {Object} msg Message as Buffer
*/
MessageBroker.prototype.send = function (queue, msg) {
return __awaiter(this, void 0, void 0, function () {
return __generator(this, function (_a) {
switch (_a.label) {
case 0:
if (!!this.connection) return [3 /*break*/, 2];
return [4 /*yield*/, this.init()];
case 1:
_a.sent();
_a.label = 2;
case 2: return [4 /*yield*/, this.channel.assertQueue(queue, { durable: true })];
case 3:
_a.sent();
return [2 /*return*/, this.channel.sendToQueue(queue, msg)];
}
});
});
};
MessageBroker.prototype.sendWithReply = function (queue, msg) {
return __awaiter(this, void 0, void 0, function () {
var ch;
return __generator(this, function (_a) {
switch (_a.label) {
case 0:
ch = this.channel;
if (!!this.connection) return [3 /*break*/, 2];
return [4 /*yield*/, this.init()];
case 1:
_a.sent();
_a.label = 2;
case 2: return [4 /*yield*/, ch.assertQueue(queue, { durable: true })];
case 3:
_a.sent();
return [2 /*return*/, new Promise(function (resolve, reject) {
return __awaiter(this, void 0, void 0, function () {
function maybeAnswer(msg) {
if (msg.properties.correlationId === corrId) {
resolve(msg);
}
}
var corrId, replyTo;
return __generator(this, function (_a) {
switch (_a.label) {
case 0:
corrId = (0, uuid_1.v1)();
return [4 /*yield*/, ch.assertQueue('', { exclusive: true })];
case 1:
replyTo = (_a.sent()).queue;
return [4 /*yield*/, ch.consume(replyTo, maybeAnswer, { noAck: true })];
case 2:
_a.sent();
ch.sendToQueue(queue, msg, {
correlationId: corrId,
replyTo: replyTo,
});
return [2 /*return*/];
}
});
});
})];
}
});
});
};
/**
* @param {String} queue Queue name
* @param {Function} handler Handler that will be invoked with given message and acknowledge function (msg, ack)
*/
MessageBroker.prototype.subscribe = function (queue, handler) {
return __awaiter(this, void 0, void 0, function () {
var existingHandler_1;
var _this = this;
return __generator(this, function (_a) {
switch (_a.label) {
case 0:
if (!!this.connection) return [3 /*break*/, 2];
return [4 /*yield*/, this.init()];
case 1:
_a.sent();
_a.label = 2;
case 2:
if (this.queues[queue]) {
existingHandler_1 = _.find(this.queues[queue], function (h) { return h === handler; });
if (existingHandler_1) {
return [2 /*return*/, function () { return _this.unsubscribe(queue, existingHandler_1); }];
}
this.queues[queue].push(handler);
return [2 /*return*/, function () { return _this.unsubscribe(queue, handler); }];
}
return [4 /*yield*/, this.channel.assertQueue(queue, { durable: true })];
case 3:
_a.sent();
this.queues[queue] = [handler];
// this.channel.prefetch(1);
this.channel.consume(queue, function (msg) { return __awaiter(_this, void 0, void 0, function () {
var _i, _a, handler_1, data;
return __generator(this, function (_b) {
switch (_b.label) {
case 0:
console.log("[ ".concat(new Date(), " ] Message received: ").concat(JSON.stringify(JSON.parse(msg.content.toString('utf8')))));
if (!(msg !== null)) return [3 /*break*/, 4];
_i = 0, _a = this.queues[queue];
_b.label = 1;
case 1:
if (!(_i < _a.length)) return [3 /*break*/, 4];
handler_1 = _a[_i];
return [4 /*yield*/, handler_1(msg, function () { })];
case 2:
data = _b.sent();
if (msg.properties.replyTo) {
this.channel.sendToQueue(msg.properties.replyTo, Buffer.from(JSON.stringify(data !== null && data !== void 0 ? data : {})), {
correlationId: msg.properties.correlationId,
});
}
_b.label = 3;
case 3:
_i++;
return [3 /*break*/, 1];
case 4:
this.channel.ack(msg);
return [2 /*return*/];
}
});
}); });
return [2 /*return*/, function () { return _this.unsubscribe(queue, handler); }];
}
});
});
};
MessageBroker.prototype.unsubscribe = function (queue, handler) {
return __awaiter(this, void 0, void 0, function () {
return __generator(this, function (_a) {
_.pull(this.queues[queue], handler);
return [2 /*return*/];
});
});
};
return MessageBroker;
}());
exports.MessageBroker = MessageBroker;