[Summary view] [Print] [Text view]

   1  /*
   2  YUI 3.17.2 (build 9c3c78e)
   3  Copyright 2014 Yahoo! Inc. All rights reserved.
   4  Licensed under the BSD License.
   5  http://yuilibrary.com/license/
   6  */
   7  
   8  YUI.add('io-queue', function (Y, NAME) {
   9  
  10  /**
  11  Extends IO to implement Queue for synchronous
  12  transaction processing.
  13  @module io
  14  @submodule io-queue
  15  @for IO
  16  **/
  17  var io = Y.io._map['io:0'] || new Y.IO();
  18  
  19  Y.mix(Y.IO.prototype, {
  20     /**
  21      * Array of transactions queued for processing
  22      *
  23      * @property _q
  24      * @private
  25      * @static
  26      * @type {Object}
  27      */
  28      _q: new Y.Queue(),
  29      _qActiveId: null,
  30      _qInit: false,
  31  
  32     /**
  33      * Property to determine whether the queue is set to
  34      * 1 (active) or 0 (inactive).  When inactive, transactions
  35      * will be stored in the queue until the queue is set to active.
  36      *
  37      * @property _qState
  38      * @private
  39      * @static
  40      * @type {Number}
  41      */
  42      _qState: 1,
  43  
  44     /**
  45      * Method Process the first transaction from the
  46      * queue in FIFO order.
  47      *
  48      * @method _qShift
  49      * @private
  50      * @static
  51      */
  52      _qShift: function() {
  53          var io = this,
  54              o = io._q.next();
  55  
  56          io._qActiveId = o.id;
  57          io._qState = 0;
  58          io.send(o.uri, o.cfg, o.id);
  59      },
  60  
  61     /**
  62      * Method for queueing a transaction before the request is sent to the
  63      * resource, to ensure sequential processing.
  64      *
  65      * @method queue
  66      * @static
  67      * @return {Object}
  68      */
  69      queue: function(uri, c) {
  70          var io = this,
  71              o = { uri: uri, cfg:c, id: this._id++ };
  72  
  73          if(!io._qInit) {
  74              Y.on('io:complete', function(id, o) { io._qNext(id); }, io);
  75              io._qInit = true;
  76          }
  77  
  78          io._q.add(o);
  79          if (io._qState === 1) {
  80              io._qShift();
  81          }
  82  
  83          return o;
  84      },
  85  
  86      _qNext: function(id) {
  87          var io = this;
  88          io._qState = 1;
  89          if (io._qActiveId === id && io._q.size() > 0) {
  90              io._qShift();
  91          }
  92      },
  93  
  94     /**
  95      * Method for promoting a transaction to the top of the queue.
  96      *
  97      * @method promote
  98      * @static
  99      */
 100      qPromote: function(o) {
 101          this._q.promote(o);
 102      },
 103  
 104     /**
 105      * Method for removing a specific, pending transaction from
 106      * the queue.
 107      *
 108      * @method remove
 109      * @private
 110      * @static
 111      */
 112      qRemove: function(o) {
 113          this._q.remove(o);
 114      },
 115  
 116     /**
 117      * Method for cancel all pending transaction from
 118      * the queue.
 119      *
 120      * @method empty
 121      * @static
 122      * @since 3.7.3
 123      */
 124      qEmpty: function() {
 125          this._q = new Y.Queue();
 126      },
 127  
 128      qStart: function() {
 129          var io = this;
 130          io._qState = 1;
 131  
 132          if (io._q.size() > 0) {
 133              io._qShift();
 134          }
 135      },
 136  
 137     /**
 138      * Method for setting queue processing to inactive.
 139      * Transaction requests to YUI.io.queue() will be stored in the queue, but
 140      * not processed until the queue is reset to "active".
 141      *
 142      * @method _stop
 143      * @private
 144      * @static
 145      */
 146      qStop: function() {
 147          this._qState = 0;
 148      },
 149  
 150     /**
 151      * Method to query the current size of the queue.
 152      *
 153      * @method _size
 154      * @private
 155      * @static
 156      * @return {Number}
 157      */
 158      qSize: function() {
 159          return this._q.size();
 160      }
 161  
 162  }, true);
 163  
 164  function _queue(u, c) {
 165      return io.queue.apply(io, [u, c]);
 166  }
 167  
 168  _queue.start = function () { io.qStart(); };
 169  _queue.stop = function () { io.qStop(); };
 170  _queue.promote = function (o) { io.qPromote(o); };
 171  _queue.remove = function (o) { io.qRemove(o); };
 172  _queue.size = function () { io.qSize(); };
 173  _queue.empty = function () { io.qEmpty(); };
 174  Y.io.queue = _queue;
 175  
 176  
 177  }, '3.17.2', {"requires": ["io-base", "queue-promote"]});