New tile queue implementation (heapify-powered)

test/jasmine-extensions.js

@@ -4,6 +4,12 @@ beforeEach(function() {
         toBeA: function(type) {
             return this.actual instanceof type;
         },
+        toBeGreaterThanOrEqualTo: function(other) {
+            return this.actual >= other;
+        },
+        toBeLessThanOrEqualTo: function(other) {
+            return this.actual <= other;
+        },
         toRoughlyEqual: function(other, tol) {
             return Math.abs(this.actual - other) <= tol;
         }

test/ol.html

@@ -84,6 +84,7 @@
   <script type="text/javascript" src="spec/ol/source/xyz.test.js"></script>
   <script type="text/javascript" src="spec/ol/tilecoord.test.js"></script>
   <script type="text/javascript" src="spec/ol/tilegrid.test.js"></script>
+  <script type="text/javascript" src="spec/ol/tilequeue.test.js"></script>
   <script type="text/javascript" src="spec/ol/tilerange.test.js"></script>
   <script type="text/javascript" src="spec/ol/tileurlfunction.test.js"></script>
   <script type="text/javascript" src="spec/ol/control/control.test.js"></script>

test/spec/ol/tilequeue.test.js

@@ -0,0 +1,68 @@
+describe('ol.TileQueue', function() {
+
+  // is the tile queue's array a heap?
+  function isHeap(tq) {
+    var heap = tq.heap_;
+    var i;
+    var key;
+    var leftKey;
+    var rightKey;
+    for (i = 0; i < (heap.length >> 1) - 1; i++) {
+      key = heap[i][0];
+      leftKey = heap[tq.getLeftChildIndex_(i)][0];
+      rightKey = heap[tq.getRightChildIndex_(i)][0];
+      if (leftKey < key || rightKey < key) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  function addRandomPriorityTiles(tq, num) {
+    var i, tile, priority;
+    for (i = 0; i < num; i++) {
+      tile = new ol.Tile();
+      priority = Math.floor(Math.random() * 100);
+      tq.heap_.push([priority, tile, new ol.Coordinate(0, 0), 1]);
+      tq.queuedTileKeys_[tile.getKey()] = true;
+    }
+  }
+
+  describe('heapify', function() {
+    it('does convert an arbitrary array into a heap', function() {
+
+      var tq = new ol.TileQueue(function() {});
+      addRandomPriorityTiles(tq, 100);
+
+      tq.heapify_();
+      expect(isHeap(tq)).toBeTruthy();
+    });
+  });
+
+  describe('reprioritize', function() {
+    it('does reprioritize the array', function() {
+
+      var tq = new ol.TileQueue(function() {});
+      addRandomPriorityTiles(tq, 100);
+
+      tq.heapify_();
+
+      // now reprioritize, changing the priority of 50 tiles and removing the
+      // rest
+
+      var i = 0;
+      tq.tilePriorityFunction_ = function() {
+        if ((i++) % 2 === 0) {
+          return undefined;
+        }
+        return Math.floor(Math.random() * 100);
+      };
+
+      tq.reprioritize();
+      expect(tq.heap_.length).toEqual(50);
+      expect(isHeap(tq)).toBeTruthy();
+
+    });
+  });
+});
+