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    deferred.js indexer.js procession.js pumper.js shifter.js splitter.js throttle.js transformer.js window.js

  • window.js

  • ¶

    Node.js API.

    var assert = require('assert')
var util = require('util')

var Pumper = require('./pumper')
var Procession = require('./procession')
var Deferred = require('./deferred')

function Window () {
    Procession.call(this)
    this.trailer = this.shifter(this, '_shift')
    this._header = this.shifter()
    this._undecorated = []
    this._listeners = []
  • ¶

    We’re not shifting, we’re pushing so it has to wait, because it is synchronous and no one else will have an opportunity to push.

        this._header.pump(this, '_push')
}
util.inherits(Window, Procession)
  • ¶

    Add a listener that can track values as they are enqueued and dequeued. The listener’s push and shift methods will only be invoked for values enqueued after it is added to to the procession.

  • ¶
  • ¶

    We decorate the listener with a deferred decorator. We keep a parallel arrays of undecorated listeners do we can find its array index if we’re asked to remove it before it undecorates itself.

    Window.prototype.addListener = function (listener) {
    this._undecorated.push(listener)
    this._listeners.push(new Deferred(this._listeners, listener))
}
  • ¶

    Remove a listener.

  • ¶ 
    Window.prototype.removeListener = function (listener) {
    var index = this._undecorated.indexOf(this)
    this._undecorated.splice(index, 1)
    this._listeners.splice(index, 1)
}

Window.prototype._push = function (value) {
    if (value != null) {
        assert(this._header.node == this.head)
        for (var i = 0, I = this._listeners.length; i < I; i++) {
            this._listeners[i].pushed(this._header.node)
        }
    }
}

Window.prototype._shift = function (node) {
    if (node.body != null) {
        for (var i = 0, I = this._listeners.length; i < I; i++) {
            this._listeners[i].shifted(node)
        }
    }
}

module.exports = Window