quargo

Quargo

A mix of async’s queue and cargo, with capacity optimization.

Structure	Tasks per worker (capacity)	Workers per structure (concurrency)
queue	1	x
cargo	y	1
quargo	y	x

var queue = async.queue(worker, concurrency);
var cargo = async.cargo(function(tasks, callback) {
    queue.push(tasks);
    callback();
}, capacity);

cargo.push('a task')

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quargo(worker, [capacity, [concurrency, [delay]]])

Creates a quargo object with the specified capacity, concurrency and delay. Tasks added to the quargo will be processed altogether (up to the capacity limit) in parallel batches (up to the concurrency limit). If all workers are in progress, the task is queued until one becomes available. If the quargo hasn’t reached capacity, the task is queued for maximum delay. Once a worker has completed some tasks, each callback of those tasks is called.

Quargo passes an array of tasks to one of a group of workers, repeating when the worker is finished.

Arguments

• worker(tasks, callback) - An asynchronous function for processing an array of queued tasks, which must call its callback(err) argument when finished, with an optional err argument.
• capacity - An optional integer for determining how many tasks should be processed per round; if omitted, the default is unlimited.
• concurrency - An optional integer for determining how many worker functions should be run in parallel; if omitted, the default is 1.
• delay - An optional integer for determining how long should the quargo wait to reach capacity; if omitted, the default is 0.

Quargo objects

The quargo object returned has the following properties and methods:

• length() - a function returning the number of items waiting to be processed.