mq-memory

Easy in-memory message queue. Same tool as mq-mongo but storing queue data in memory (not database).

Note:

This tool is much easier and quicker then mq-mongo. Use it if you have no big amount of data and if you don't need persistent queue between script starts.

Install

npm i mq-memory

Usage

const mq = require('mq-memory');
const q = mq(options);
q.get().then(msg => {/* Do something */});

options

• options.ttl - time-to-live (ms) for taken message before it will be acked or returned to queue. Defaults to 30000.
• options.tries - just how many times single message may be taken and returned to queue without ack. Defaults to 10.
• options.strict - if true method get will work in strict mode (throws error instead of returning null). Defaults to false.
• options.insistent - if true then get will begins from last failed (returned to queue without ack) messages. If false then get follow 'FIFO' rule.
• options.items - message or array of messages for adding to queue on start.

methods

• q.add(something) - adds single message or array of messages to queue. Returns number of added messages.
• q.get(ttl) - gets message from queue. Optional parameter is individual ttl for that specific message. Returns message object if there is messages ready. If no waiting messages returns null or (if options.strict set to true) throws error.
• q.ack(tag) - deletes successfully handled message (specified by tag field) from queue. Returns tag string of deleted message or null (if no message with such tag or if ttl expires).
• q.ping(tag, ttl) - prolong ttl of message specified by tag field. Optional parameter ttl defaults to options.ttl of queue.
• q.waiting() - returns quantity of messages in queue.
• q.active() - returns quantity of messages in work (waiting for ack).
• q.failed() - returns quantity of failed messages (all tries is over).
• q.total() - returns total quantity of messages (sum of three above).
• q.stats() - returns object with quantities of waiting, active and failed messages.
• q.options() - getter, returns object with some options ({ttl, tries, insistent}).

message fields

• msg.data - payload data of message.
• msg.created - time (unix TS, number) when message was added to queue.
• msg.expires - time (unix TS, number) when message will returns to queue.
• msg.tries - just how many times this message was getted from queue.
• msg.tag - unique tag for this try (for use in ack and ping).

Example

const mq = require('mq-memory');

const q = mq({
    ttl = 30000, // default message ttl
    tries = 10,  // default tries to handle message
});
q.add('test');
const msg = q.get();
doSomethingWithData(msg.data);
q.ack(msg.tag);

See tests for more complicated examples.

License

MIT