Node-queue is a node.js module for multiple databases. It can be very useful if you work with (d)ddd, cqrs, eventsourcing, commands and events, etc.
$ npm install node-queue
var queue = require('node-queue');
queue.createQueue(function(err, myQueue) {
if(err) {
console.log('ohhh :-(');
return;
}
// you can now use myQueue variable to go on...
});
Make shure you have installed the required driver, in this example run: 'npm install mongodb'.
var queue = require('node-queue');
queue.createQueue(
{
type: 'mongoDb',
host: 'localhost', // optional
port: 27017, // optional
dbName: 'queuedb', // optional
collectionName: 'queue' // optional
timeout: 10000 // optional
},
function(err, myQueue) {
if(err) {
console.log('ohhh :-(');
return;
}
// you can now use myQueue variable to go on...
}
);
myQueue.push('myId', { some: 'data' }, function(err) {
if(err) {
console.log('ohhh :-(');
return;
}
});
myQueue.remove('myId', function(err) {
if(err) {
console.log('ohhh :-(');
return;
}
});
myQueue.isQueued('myId', function(err, isQueued) {
if(isQueued) {
console.log('Already queued!');
} else {
console.log('Not queued!');
}
});
myQueue.getAll(function(err, items) {
if(err) {
console.log('ohhh :-(');
return;
}
// items is an array of all what is in the queue
var firstItem = items[0];
console.log('the id: ' + firstItem.id);
console.log('the pushed data: ' + firstItem.data);
});
myQueue.getNewId(function(err, newId) {
if(err) {
console.log('ohhh :-(');
return;
}
console.log('the new id is: ' + newId);
});
var q = queue.createQueue({ type: 'mongodb' }, function(err, q) {
console.log('hello from callback');
// use queue here...
});
q.on('connect', function() {
console.log('hello from event');
// or here
});
q.on('disconnect', function() {
console.log('bye');
});
Decrement (can be very useful if you want to create a eventQueue for eventdenormalizers, cqrs, eventsourcing)
// if you push yout items with a workers property...
myQueue.push('myId', { some: 'data', workers: 2 }, function(err) {
if(err) {
console.log('ohhh :-(');
return;
}
});
...
// then you can decrement the workers property
myQueue.decrement('myId', function(err, hasBeenRemoved) {
if(err) {
console.log('ohhh :-(');
return;
}
// Now the workers value is decremented,
// but if the workers value after the decrement is 0,
// the record will be automatically removed.
// You can check this with the flag hasBeenRemoved!
if(hasBeenRemoved) {
console.log('All workers finished!');
}
});
Currently these databases are supported:
- inmemory
- mongodb ([node-mongodb-native] (https://github.com/mongodb/node-mongodb-native))
- couchdb ([cradle] (https://github.com/cloudhead/cradle))
- tingodb ([tingodb] (https://github.com/sergeyksv/tingodb))
- redis ([redis] (https://github.com/mranney/node_redis))
You can use your own db implementation by extending this... (pass the Queue as type in the options)
var Queue = require('node-queue').Queue,
util = require('util'),
_ = require('lodash');
function MyDB(options) {
Queue.call(this, options);
}
util.inherits(MyDB, Queue);
_.extend(MyDB.prototype, {
...
});
module.exports = MyDB;
Copyright (c) 2015 Adriano Raiano
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