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    Class ClusteredRedisQueue

    Class ClusteredRedisQueue Implements the possibility to scale queues horizontally between several redis instances.

    Implements

    Index

    Constructors

    Properties

    logger: ILogger

    Logger instance associated with this queue instance

    name: string

    Methods

    • Synchronously calls each of the listeners registered for the event named eventName, in the order they were registered, passing the supplied arguments to each.

      Returns true if the event had listeners, false otherwise.

      import { EventEmitter } from 'node:events';
      const myEmitter = new EventEmitter();

      // First listener
      myEmitter.on('event', function firstListener() {
      console.log('Helloooo! first listener');
      });
      // Second listener
      myEmitter.on('event', function secondListener(arg1, arg2) {
      console.log(`event with parameters ${arg1}, ${arg2} in second listener`);
      });
      // Third listener
      myEmitter.on('event', function thirdListener(...args) {
      const parameters = args.join(', ');
      console.log(`event with parameters ${parameters} in third listener`);
      });

      console.log(myEmitter.listeners('event'));

      myEmitter.emit('event', 1, 2, 3, 4, 5);

      // Prints:
      // [
      // [Function: firstListener],
      // [Function: secondListener],
      // [Function: thirdListener]
      // ]
      // Helloooo! first listener
      // event with parameters 1, 2 in second listener
      // event with parameters 1, 2, 3, 4, 5 in third listener

      Parameters

      • ...args: any[]

      Returns boolean

      v0.1.26

    • Returns an array listing the events for which the emitter has registered listeners. The values in the array are strings or Symbols.

      import { EventEmitter } from 'node:events';

      const myEE = new EventEmitter();
      myEE.on('foo', () => {});
      myEE.on('bar', () => {});

      const sym = Symbol('symbol');
      myEE.on(sym, () => {});

      console.log(myEE.eventNames());
      // Prints: [ 'foo', 'bar', Symbol(symbol) ]

      Parameters

      • ...args: any[]

      Returns any

      v6.0.0

    • Returns the current max listener value for the EventEmitter which is either set by emitter.setMaxListeners(n) or defaults to EventEmitter.defaultMaxListeners.

      Returns number

      v1.0.0

    • Returns the number of listeners listening for the event named eventName. If listener is provided, it will return how many times the listener is found in the list of the listeners of the event.

      Parameters

      • ...args: any[]

      Returns any

      v3.2.0

    • Returns a copy of the array of listeners for the event named eventName.

      server.on('connection', (stream) => {
      console.log('someone connected!');
      });
      console.log(util.inspect(server.listeners('connection')));
      // Prints: [ [Function] ]

      Parameters

      • ...args: any[]

      Returns any[]

      v0.1.26

    • Adds the listener function to the end of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

      server.on('connection', (stream) => {
      console.log('someone connected!');
      });

      Returns a reference to the EventEmitter, so that calls can be chained.

      By default, event listeners are invoked in the order they are added. The emitter.prependListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

      import { EventEmitter } from 'node:events';
      const myEE = new EventEmitter();
      myEE.on('foo', () => console.log('a'));
      myEE.prependListener('foo', () => console.log('b'));
      myEE.emit('foo');
      // Prints:
      // b
      // a

      Parameters

      • ...args: any[]

      Returns ClusteredRedisQueue

      v0.1.101

    • Adds a one-time listener function for the event named eventName. The next time eventName is triggered, this listener is removed and then invoked.

      server.once('connection', (stream) => {
      console.log('Ah, we have our first user!');
      });

      Returns a reference to the EventEmitter, so that calls can be chained.

      By default, event listeners are invoked in the order they are added. The emitter.prependOnceListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

      import { EventEmitter } from 'node:events';
      const myEE = new EventEmitter();
      myEE.once('foo', () => console.log('a'));
      myEE.prependOnceListener('foo', () => console.log('b'));
      myEE.emit('foo');
      // Prints:
      // b
      // a

      Parameters

      • ...args: any[]

      Returns ClusteredRedisQueue

      v0.3.0

    • Adds the listener function to the beginning of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

      server.prependListener('connection', (stream) => {
      console.log('someone connected!');
      });

      Returns a reference to the EventEmitter, so that calls can be chained.

      Parameters

      • ...args: any[]

      Returns ClusteredRedisQueue

      v6.0.0

    • Adds a one-timelistener function for the event named eventName to the beginning of the listeners array. The next time eventName is triggered, this listener is removed, and then invoked.

      server.prependOnceListener('connection', (stream) => {
      console.log('Ah, we have our first user!');
      });

      Returns a reference to the EventEmitter, so that calls can be chained.

      Parameters

      • ...args: any[]

      Returns ClusteredRedisQueue

      v6.0.0

    • Publishes data to current queue channel

      If toName specified will publish to pubsub with different name. This can be used to implement broadcasting some messages to other subscribers on other pubsub channels. Different name should be in the same namespace (same imq prefix)

      Parameters

      • data: JsonObject

        data to publish as channel message

      • OptionaltoName: string

        different name of the pubsub to publish to

      Returns Promise<void>

    • Returns a copy of the array of listeners for the event named eventName, including any wrappers (such as those created by .once()).

      import { EventEmitter } from 'node:events';
      const emitter = new EventEmitter();
      emitter.once('log', () => console.log('log once'));

      // Returns a new Array with a function `onceWrapper` which has a property
      // `listener` which contains the original listener bound above
      const listeners = emitter.rawListeners('log');
      const logFnWrapper = listeners[0];

      // Logs "log once" to the console and does not unbind the `once` event
      logFnWrapper.listener();

      // Logs "log once" to the console and removes the listener
      logFnWrapper();

      emitter.on('log', () => console.log('log persistently'));
      // Will return a new Array with a single function bound by `.on()` above
      const newListeners = emitter.rawListeners('log');

      // Logs "log persistently" twice
      newListeners[0]();
      emitter.emit('log');

      Parameters

      • ...args: any[]

      Returns any[]

      v9.4.0

    • Removes all listeners, or those of the specified eventName.

      It is bad practice to remove listeners added elsewhere in the code, particularly when the EventEmitter instance was created by some other component or module (e.g. sockets or file streams).

      Returns a reference to the EventEmitter, so that calls can be chained.

      Parameters

      • ...args: any[]

      Returns ClusteredRedisQueue

      v0.1.26

    • Removes the specified listener from the listener array for the event named eventName.

      const callback = (stream) => {
      console.log('someone connected!');
      };
      server.on('connection', callback);
      // ...
      server.removeListener('connection', callback);

      removeListener() will remove, at most, one instance of a listener from the listener array. If any single listener has been added multiple times to the listener array for the specified eventName, then removeListener() must be called multiple times to remove each instance.

      Once an event is emitted, all listeners attached to it at the time of emitting are called in order. This implies that any removeListener() or removeAllListeners() calls after emitting and before the last listener finishes execution will not remove them fromemit() in progress. Subsequent events behave as expected.

      import { EventEmitter } from 'node:events';
      class MyEmitter extends EventEmitter {}
      const myEmitter = new MyEmitter();

      const callbackA = () => {
      console.log('A');
      myEmitter.removeListener('event', callbackB);
      };

      const callbackB = () => {
      console.log('B');
      };

      myEmitter.on('event', callbackA);

      myEmitter.on('event', callbackB);

      // callbackA removes listener callbackB but it will still be called.
      // Internal listener array at time of emit [callbackA, callbackB]
      myEmitter.emit('event');
      // Prints:
      // A
      // B

      // callbackB is now removed.
      // Internal listener array [callbackA]
      myEmitter.emit('event');
      // Prints:
      // A

      Because listeners are managed using an internal array, calling this will change the position indices of any listener registered after the listener being removed. This will not impact the order in which listeners are called, but it means that any copies of the listener array as returned by the emitter.listeners() method will need to be recreated.

      When a single function has been added as a handler multiple times for a single event (as in the example below), removeListener() will remove the most recently added instance. In the example the once('ping') listener is removed:

      import { EventEmitter } from 'node:events';
      const ee = new EventEmitter();

      function pong() {
      console.log('pong');
      }

      ee.on('ping', pong);
      ee.once('ping', pong);
      ee.removeListener('ping', pong);

      ee.emit('ping');
      ee.emit('ping');

      Returns a reference to the EventEmitter, so that calls can be chained.

      Parameters

      • ...args: any[]

      Returns ClusteredRedisQueue

      v0.1.26

    • Sends a message to given queue name with the given data. Supposed to be an async function.

      Parameters

      • toQueue: string

        queue name to which message should be sent to

      • message: JsonObject

        message data

      • Optionaldelay: number

        if specified, a message will be handled in the target queue after a specified period of time in milliseconds.

      • OptionalerrorHandler: (err: Error) => void

        callback called only when internal error occurs during message send execution.

      Returns Promise<string>

      • message identifier
    • By default EventEmitters will print a warning if more than 10 listeners are added for a particular event. This is a useful default that helps finding memory leaks. The emitter.setMaxListeners() method allows the limit to be modified for this specific EventEmitter instance. The value can be set to Infinity (or 0) to indicate an unlimited number of listeners.

      Returns a reference to the EventEmitter, so that calls can be chained.

      Parameters

      • ...args: any[]

      Returns ClusteredRedisQueue

      v0.3.5