tools/queue.js


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// A generalized queue object for rapid responses (doesn't do prioritization or algorithmic timesharing)

module.exports = function(delayms, maxExport, call){
  let queue = [];
  let open = true; // The meaning of this variable is complicated, so watch closely
  let getObjs = (maxExport == 1) ?
    () => queue.shift() :
    () => queue.splice(0, maxExport) ;
  this.enqueue = function(){
    for (let i = 0; i < arguments.length; i++)
      queue.push(arguments[i]);
    if (open) dequeue();
  }

  disabled = true; // Used to disable pushes when non-sensical like if a socket is down
  this.disable = function(){
    disabled = true;
  }
  this.enable = function(){
    disabled = false;
    if (open) dequeue();
  }
  function dequeue(){
    if (disabled){
      open = true;
      return;
    }
    if (queue.length == 0)
      open = true;
    else {
      open = false;
      call(getObjs());
      setTimeout(dequeue, delayms);
    }
  }
}