Class: AsyncQueue

H .util.AsyncQueue

new H.util.AsyncQueue (mode, processFn)

AsyncQueue represents a queue of task items that are processed asynchronously. Items can be added and cancelled before they are processed by the queue.

The AsyncQueue constructor expects to receive a task processing function as an argument. The function MUST call task#done with no arguments when it finishes a task. If an error occurs during the processing, the done() function MUST be called on the task object with an error message.

Name	Type	Description
`mode`	H.util.AsyncQueue.Mode	The processing mode for the given queue
`processFn`	function(H.util.AsyncQueue.Task, *)	The function implementing the actual processing of the task item (it receives the the task item and the task data as arguments).

Example

//---------------------------------
// a simple example
//---------------------------------
var additionQueue = new H.util.AsyncQueue(3, function(task, data) {
  // process data
  var operandA = data.operandA,
      operandB = data.operandB,
      result = operandA + operandB;
  // call task.done
  task.done(result);
});

// push tasks with data to process
additionQueue.push({
   operandA: 1,
   operandB: 1
}, function(task, result, opt_error) { console.log(result); });

//---------------------------------
// an example with an error
//---------------------------------
var divisionQueue = new H.util.AsyncQueue(3, function(task, data) {
  // process data
  var operandA = data.operandA,
      operandB = data.operandB;
  if(operandB === 0) {
    // call task.done with an error message
    task.done(null, 'Division by zero!');
  }
  else {
    result = operandA / operandB;
    // call task.done
    task.done(result);
  }
});
// push tasks with data to process
divisionQueue.push({
   operandA: 1,
   operandB: 0
}, function(task, result, opt_error) {
  if(opt_error) console.log("Oh noes: ", opt_error);
  else console.log("Yay: ", result);
});

Classes

Task

Methods

push (data, onDone)H.util.AsyncQueue.Task

This method pushes a task item to the queue for processing.

Name	Type	Description
`data`	*	The task data to be passed to the process function
`onDone`	function(H.util.AsyncQueue.Task, *, ?)	A function to be called once the task has been processed (an optional error string can be provided for use in the even of an error or if the task is cancelled).

Returns:

Type	Description
H.util.AsyncQueue.Task	An object representing the new task pushed to the queue

Interface Definitions

H.util.AsyncQueue.Mode

This interface defines a processing mode object which is used by an asynchronous queue to determine how many items to process in one cycle.