queue-light

Note: Version 1.2 is a complete factor and rewrite, and introduces breaking changes to version < 1.2. This is mostly due to file changes, we're now using sqlite instead of FS for storage. An effort was made to keep the syntax the same, however.

Light weight file based JSON queuing service using Sqlite database.

Usage:

npm install queue-light

// Bring in the module
var ql = require('queue-light');

// Initialize the queue object.
var queue = ql.init(
  {
    filename: './queue.json',
    finishedFilename: './queue.finished.json',
  }
);

// Set your data
var data = {name: 'first'}

// Push your data to the json file.
queue.push(data, function(err,data){
  console.log(data);
  // Mark the item as "ready"
  queue.setReady(item,function(err,item){
    // Pull oldest from the json file
    queue.pull(function(err,item){
      console.log(item);
      // mark the item as finished, this removes it from the json file
      queue.finish(item, function(err, item){
        console.log(item);
      });
    });
  });
});

Data Flow

API

.init(options)

Initialize JSON queue file.

Options

• filename - (required) The JSON file path for data store. If the file does not exist, it will be created.
• finishedFilename - (optional) the JSON file path for finished items. If the file does not exist, it will be created.

queue.push(data,cb)

Push new data into the queue, and mark it "in queue" (0). Returns the entire queue. CB returns err or item.

queue.setReady(item,cb)

Set the item as ready. CB returns err or item.

queue.pull(cb)

Pull the oldest item out of the queue and mark it as "in progress" (1). CB returns err or item.

queue.finish(item,cb)

Remove item from queue. If finishedFilename is set, the item will be added to the finished items JSON file and marked "Completed" (2) CB returns err or item.

queue.return(item,cb)

Return an item back to the queue, marking it "in queue" (0)

more methods:

setReady(item, cb) - Sets an item as ready, need to make sure that options include defaultReadyState = false

  queue.setReady(item, function(err){
    //...
    })

update (item, cb) - Update data on an item. item data will be replaced with item contents

  queue.update(item, function(err,item){
    //...
  })

return (cb) - Return all items to the queue

  queue.return(function(err){
    //...
  })

backline (cb) - Return all items to the queue and set insertDate as now.

  queue.backline(function(function(err){
    //...
  }))

count (cb) - Return the number of items in the queue in an objet

  queue.count(function(err,count){
    //..
  })

returns an object:

[{"queued":1,"inProgress":1,"finished":9,"queuedAndReady":1}]

TODO:

• move json data to data object
• drop()
• findOne()
• findAll()