@behance/router/vendor/deps/backburner.js

A lightweight JavaScript library is built on top of route-recognizer and rsvp.js to provide an API for handling routes

define("backburner/queue",
  ["exports"],
  function(__exports__) {
    "use strict";
    function Queue(daq, name, options) {
      this.daq = daq;
      this.name = name;
      this.options = options;
      this._queue = [];
    }

    Queue.prototype = {
      daq: null,
      name: null,
      options: null,
      _queue: null,

      push: function(target, method, args, stack) {
        var queue = this._queue;
        queue.push(target, method, args, stack);
        return {queue: this, target: target, method: method};
      },

      pushUnique: function(target, method, args, stack) {
        var queue = this._queue, currentTarget, currentMethod, i, l;

        for (i = 0, l = queue.length; i < l; i += 4) {
          currentTarget = queue[i];
          currentMethod = queue[i+1];

          if (currentTarget === target && currentMethod === method) {
            queue[i+2] = args; // replace args
            queue[i+3] = stack; // replace stack
            return {queue: this, target: target, method: method}; // TODO: test this code path
          }
        }

        this._queue.push(target, method, args, stack);
        return {queue: this, target: target, method: method};
      },

      // TODO: remove me, only being used for Ember.run.sync
      flush: function() {
        var queue = this._queue,
            options = this.options,
            before = options && options.before,
            after = options && options.after,
            target, method, args, stack, i, l = queue.length;

        if (l && before) { before(); }
        for (i = 0; i < l; i += 4) {
          target = queue[i];
          method = queue[i+1];
          args   = queue[i+2];
          stack  = queue[i+3]; // Debugging assistance

          // TODO: error handling
          if (args && args.length > 0) {
            method.apply(target, args);
          } else {
            method.call(target);
          }
        }
        if (l && after) { after(); }

        // check if new items have been added
        if (queue.length > l) {
          this._queue = queue.slice(l);
          this.flush();
        } else {
          this._queue.length = 0;
        }
      },

      cancel: function(actionToCancel) {
        var queue = this._queue, currentTarget, currentMethod, i, l;

        for (i = 0, l = queue.length; i < l; i += 4) {
          currentTarget = queue[i];
          currentMethod = queue[i+1];

          if (currentTarget === actionToCancel.target && currentMethod === actionToCancel.method) {
            queue.splice(i, 4);
            return true;
          }
        }

        // if not found in current queue
        // could be in the queue that is being flushed
        queue = this._queueBeingFlushed;
        if (!queue) {
          return;
        }
        for (i = 0, l = queue.length; i < l; i += 4) {
          currentTarget = queue[i];
          currentMethod = queue[i+1];

          if (currentTarget === actionToCancel.target && currentMethod === actionToCancel.method) {
            // don't mess with array during flush
            // just nullify the method
            queue[i+1] = null;
            return true;
          }
        }
      }
    };


    __exports__.Queue = Queue;
  });

define("backburner/deferred_action_queues",
  ["backburner/queue","exports"],
  function(__dependency1__, __exports__) {
    "use strict";
    var Queue = __dependency1__.Queue;

    function DeferredActionQueues(queueNames, options) {
      var queues = this.queues = {};
      this.queueNames = queueNames = queueNames || [];

      var queueName;
      for (var i = 0, l = queueNames.length; i < l; i++) {
        queueName = queueNames[i];
        queues[queueName] = new Queue(this, queueName, options[queueName]);
      }
    }

    DeferredActionQueues.prototype = {
      queueNames: null,
      queues: null,

      schedule: function(queueName, target, method, args, onceFlag, stack) {
        var queues = this.queues,
            queue = queues[queueName];

        if (!queue) { throw new Error("You attempted to schedule an action in a queue (" + queueName + ") that doesn't exist"); }

        if (onceFlag) {
          return queue.pushUnique(target, method, args, stack);
        } else {
          return queue.push(target, method, args, stack);
        }
      },

      flush: function() {
        var queues = this.queues,
            queueNames = this.queueNames,
            queueName, queue, queueItems, priorQueueNameIndex,
            queueNameIndex = 0, numberOfQueues = queueNames.length;

        outerloop:
        while (queueNameIndex < numberOfQueues) {
          queueName = queueNames[queueNameIndex];
          queue = queues[queueName];
          queueItems = queue._queueBeingFlushed = queue._queue.slice();
          queue._queue = [];

          var options = queue.options,
              before = options && options.before,
              after = options && options.after,
              target, method, args, stack,
              queueIndex = 0, numberOfQueueItems = queueItems.length;

          if (numberOfQueueItems && before) { before(); }
          while (queueIndex < numberOfQueueItems) {
            target = queueItems[queueIndex];
            method = queueItems[queueIndex+1];
            args   = queueItems[queueIndex+2];
            stack  = queueItems[queueIndex+3]; // Debugging assistance

            if (typeof method === 'string') { method = target[method]; }

            // method could have been nullified / canceled during flush
            if (method) {
              // TODO: error handling
              if (args && args.length > 0) {
                method.apply(target, args);
              } else {
                method.call(target);
              }
            }

            queueIndex += 4;
          }
          queue._queueBeingFlushed = null;
          if (numberOfQueueItems && after) { after(); }

          if ((priorQueueNameIndex = indexOfPriorQueueWithActions(this, queueNameIndex)) !== -1) {
            queueNameIndex = priorQueueNameIndex;
            continue outerloop;
          }

          queueNameIndex++;
        }
      }
    };

    function indexOfPriorQueueWithActions(daq, currentQueueIndex) {
      var queueName, queue;

      for (var i = 0, l = currentQueueIndex; i <= l; i++) {
        queueName = daq.queueNames[i];
        queue = daq.queues[queueName];
        if (queue._queue.length) { return i; }
      }

      return -1;
    }


    __exports__.DeferredActionQueues = DeferredActionQueues;
  });

define("backburner",
  ["backburner/deferred_action_queues","exports"],
  function(__dependency1__, __exports__) {
    "use strict";
    var DeferredActionQueues = __dependency1__.DeferredActionQueues;

    var slice = [].slice,
        pop = [].pop,
        throttlers = [],
        debouncees = [],
        timers = [],
        autorun, laterTimer, laterTimerExpiresAt,
        global = this,
        NUMBER = /\d+/;

    function isCoercableNumber(number) {
      return typeof number === 'number' || NUMBER.test(number);
    }

    function Backburner(queueNames, options) {
      this.queueNames = queueNames;
      this.options = options || {};
      if (!this.options.defaultQueue) {
        this.options.defaultQueue = queueNames[0];
      }
      this.instanceStack = [];
    }

    Backburner.prototype = {
      queueNames: null,
      options: null,
      currentInstance: null,
      instanceStack: null,

      begin: function() {
        var onBegin = this.options && this.options.onBegin,
            previousInstance = this.currentInstance;

        if (previousInstance) {
          this.instanceStack.push(previousInstance);
        }

        this.currentInstance = new DeferredActionQueues(this.queueNames, this.options);
        if (onBegin) {
          onBegin(this.currentInstance, previousInstance);
        }
      },

      end: function() {
        var onEnd = this.options && this.options.onEnd,
            currentInstance = this.currentInstance,
            nextInstance = null;

        try {
          currentInstance.flush();
        } finally {
          this.currentInstance = null;

          if (this.instanceStack.length) {
            nextInstance = this.instanceStack.pop();
            this.currentInstance = nextInstance;
          }

          if (onEnd) {
            onEnd(currentInstance, nextInstance);
          }
        }
      },

      run: function(target, method /*, args */) {
        var ret;
        this.begin();

        if (!method) {
          method = target;
          target = null;
        }

        if (typeof method === 'string') {
          method = target[method];
        }

        // Prevent Safari double-finally.
        var finallyAlreadyCalled = false;
        try {
          if (arguments.length > 2) {
            ret = method.apply(target, slice.call(arguments, 2));
          } else {
            ret = method.call(target);
          }
        } finally {
          if (!finallyAlreadyCalled) {
            finallyAlreadyCalled = true;
            this.end();
          }
        }
        return ret;
      },

      defer: function(queueName, target, method /* , args */) {
        if (!method) {
          method = target;
          target = null;
        }

        if (typeof method === 'string') {
          method = target[method];
        }

        var stack = this.DEBUG ? new Error().stack : undefined,
            args = arguments.length > 3 ? slice.call(arguments, 3) : undefined;
        if (!this.currentInstance) { createAutorun(this); }
        return this.currentInstance.schedule(queueName, target, method, args, false, stack);
      },

      deferOnce: function(queueName, target, method /* , args */) {
        if (!method) {
          method = target;
          target = null;
        }

        if (typeof method === 'string') {
          method = target[method];
        }

        var stack = this.DEBUG ? new Error().stack : undefined,
            args = arguments.length > 3 ? slice.call(arguments, 3) : undefined;
        if (!this.currentInstance) { createAutorun(this); }
        return this.currentInstance.schedule(queueName, target, method, args, true, stack);
      },

      setTimeout: function() {
        var args = slice.call(arguments);
        var length = args.length;
        var method, wait, target;
        var self = this;
        var methodOrTarget, methodOrWait, methodOrArgs;

        if (length === 0) {
          return;
        } else if (length === 1) {
          method = args.shift();
          wait = 0;
        } else if (length === 2) {
          methodOrTarget = args[0];
          methodOrWait = args[1];

          if (typeof methodOrWait === 'function' || typeof  methodOrTarget[methodOrWait] === 'function') {
            target = args.shift();
            method = args.shift();
            wait = 0;
          } else if (isCoercableNumber(methodOrWait)) {
            method = args.shift();
            wait = args.shift();
          } else {
            method = args.shift();
            wait =  0;
          }
        } else {
          var last = args[args.length - 1];

          if (isCoercableNumber(last)) {
            wait = args.pop();
          }

          methodOrTarget = args[0];
          methodOrArgs = args[1];

          if (typeof methodOrArgs === 'function' || (typeof methodOrArgs === 'string' &&
                                                     methodOrTarget !== null &&
                                                     methodOrArgs in methodOrTarget)) {
            target = args.shift();
            method = args.shift();
          } else {
            method = args.shift();
          }
        }

        var executeAt = (+new Date()) + parseInt(wait, 10);

        if (typeof method === 'string') {
          method = target[method];
        }

        function fn() {
          method.apply(target, args);
        }

        // find position to insert - TODO: binary search
        var i, l;
        for (i = 0, l = timers.length; i < l; i += 2) {
          if (executeAt < timers[i]) { break; }
        }

        timers.splice(i, 0, executeAt, fn);

        if (laterTimer && laterTimerExpiresAt < executeAt) { return fn; }

        if (laterTimer) {
          clearTimeout(laterTimer);
          laterTimer = null;
        }
        laterTimer = global.setTimeout(function() {
          executeTimers(self);
          laterTimer = null;
          laterTimerExpiresAt = null;
        }, wait);
        laterTimerExpiresAt = executeAt;

        return fn;
      },

      throttle: function(target, method /* , args, wait */) {
        var self = this,
            args = arguments,
            wait = parseInt(pop.call(args), 10),
            throttler;

        for (var i = 0, l = throttlers.length; i < l; i++) {
          throttler = throttlers[i];
          if (throttler[0] === target && throttler[1] === method) { return; } // do nothing
        }

        var timer = global.setTimeout(function() {
          self.run.apply(self, args);

          // remove throttler
          var index = -1;
          for (var i = 0, l = throttlers.length; i < l; i++) {
            throttler = throttlers[i];
            if (throttler[0] === target && throttler[1] === method) {
              index = i;
              break;
            }
          }

          if (index > -1) { throttlers.splice(index, 1); }
        }, wait);

        throttlers.push([target, method, timer]);
      },

      debounce: function(target, method /* , args, wait, [immediate] */) {
        var self = this,
            args = arguments,
            immediate = pop.call(args),
            wait,
            index,
            debouncee;

        if (typeof immediate === "number" || typeof immediate === "string") {
          wait = immediate;
          immediate = false;
        } else {
          wait = pop.call(args);
        }

        wait = parseInt(wait, 10);
        // Remove debouncee
        index = findDebouncee(target, method);

        if (index !== -1) {
          debouncee = debouncees[index];
          debouncees.splice(index, 1);
          clearTimeout(debouncee[2]);
        }

        var timer = global.setTimeout(function() {
          if (!immediate) {
            self.run.apply(self, args);
          }
          index = findDebouncee(target, method);
          if (index) {
            debouncees.splice(index, 1);
          }
        }, wait);

        if (immediate && index === -1) {
          self.run.apply(self, args);
        }

        debouncees.push([target, method, timer]);
      },

      cancelTimers: function() {
        var i, len;

        for (i = 0, len = throttlers.length; i < len; i++) {
          clearTimeout(throttlers[i][2]);
        }
        throttlers = [];

        for (i = 0, len = debouncees.length; i < len; i++) {
          clearTimeout(debouncees[i][2]);
        }
        debouncees = [];

        if (laterTimer) {
          clearTimeout(laterTimer);
          laterTimer = null;
        }
        timers = [];

        if (autorun) {
          clearTimeout(autorun);
          autorun = null;
        }
      },

      hasTimers: function() {
        return !!timers.length || autorun;
      },

      cancel: function(timer) {
        if (timer && typeof timer === 'object' && timer.queue && timer.method) { // we're cancelling a deferOnce
          return timer.queue.cancel(timer);
        } else if (typeof timer === 'function') { // we're cancelling a setTimeout
          for (var i = 0, l = timers.length; i < l; i += 2) {
            if (timers[i + 1] === timer) {
              timers.splice(i, 2); // remove the two elements
              return true;
            }
          }
        } else {
          return; // timer was null or not a timer
        }
      }
    };

    Backburner.prototype.schedule = Backburner.prototype.defer;
    Backburner.prototype.scheduleOnce = Backburner.prototype.deferOnce;
    Backburner.prototype.later = Backburner.prototype.setTimeout;

    function createAutorun(backburner) {
      backburner.begin();
      autorun = global.setTimeout(function() {
        autorun = null;
        backburner.end();
      });
    }

    function executeTimers(self) {
      var now = +new Date(),
          time, fns, i, l;

      self.run(function() {
        // TODO: binary search
        for (i = 0, l = timers.length; i < l; i += 2) {
          time = timers[i];
          if (time > now) { break; }
        }

        fns = timers.splice(0, i);

        for (i = 1, l = fns.length; i < l; i += 2) {
          self.schedule(self.options.defaultQueue, null, fns[i]);
        }
      });

      if (timers.length) {
        laterTimer = global.setTimeout(function() {
          executeTimers(self);
          laterTimer = null;
          laterTimerExpiresAt = null;
        }, timers[0] - now);
        laterTimerExpiresAt = timers[0];
      }
    }

    function findDebouncee(target, method) {
      var debouncee,
          index = -1;

      for (var i = 0, l = debouncees.length; i < l; i++) {
        debouncee = debouncees[i];
        if (debouncee[0] === target && debouncee[1] === method) {
          index = i;
          break;
        }
      }

      return index;
    }


    __exports__.Backburner = Backburner;
  });