perf: Adjust queue track size automatically for shared layers.

CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Improvements
 
 - Support polygon annotations with holes through geojson ([#1201](../../pull/1201))
+- Adjust queue track size based on number of tile layers ([#1202](../../pull/1202))
 
 ## Version 1.8.3
 

src/fetchQueue.js

@@ -40,6 +40,7 @@ var fetchQueue = function (options) {
   this._size = options.size || 6;
   this._initialSize = options.initialSize || 0;
   this._track = options.track || 600;
+  this._initialTrack = this._track;
   this._needed = options.needed || null;
   this._batch = false;
 
@@ -76,6 +77,30 @@ var fetchQueue = function (options) {
     }
   });
 
+  /**
+   * Get/set the track size.  This is used to determine when to check if
+   * entries can be discarded.
+   * @property {number} track The number of entries to track without checking
+   *    for discards.
+   * @name geo.fetchQueue#track
+   */
+  Object.defineProperty(this, 'track', {
+    get: function () { return m_this._track; },
+    set: function (n) { m_this._track = n; }
+  });
+
+  /**
+   * Get/set the initial track size.  Unless changed, this is the value used
+   * for track on class initialization.
+   * @property {number} initialTrack The number of entries to track without
+   *    checking for discards.
+   * @name geo.fetchQueue#intitialTrack
+   */
+  Object.defineProperty(this, 'initialTrack', {
+    get: function () { return m_this._initialTrack; },
+    set: function (n) { m_this._initialTrack = n; }
+  });
+
   /**
    * Get the current queue size.  Read only.
    * @property {number} length The current queue size.
@@ -157,7 +182,7 @@ var fetchQueue = function (options) {
     defer.__fetchQueue._batch = m_this._batch;
     if (atEnd) {
       m_this._queue.push(defer);
-    } else if (!this._batch) {
+    } else if (!m_this._batch) {
       m_this._queue.unshift(defer);
     } else {
       for (var i = 0; i < m_this._queue.length; i += 1) {

src/tileLayer.js

@@ -16,7 +16,7 @@ var featureLayer = require('./featureLayer');
  * @property {function} [tilesAtZoom=null] A function that is given a zoom
  *   level and returns `{x: (num), y: (num)}` with the number of tiles at that
  *   zoom level.
- * @property {number} [cacheSize=400] The maximum number of tiles to cache.
+ * @property {number} [cacheSize=600] The maximum number of tiles to cache.
  *   The default is 200 if keepLower is false.
  * @property {geo.fetchQueue} [queue] A fetch queue to use.  If unspecified, a
  *   new queue is created.
@@ -193,6 +193,10 @@ var tileLayer = function (arg) {
   arg = $.extend(true, {}, this.constructor.defaults, arg || {});
   if (!arg.cacheSize) {
     // this size should be sufficient for a 4k display
+    // where display size is (w, h), minimum tile dimension is ts, and total
+    // number of levels is ml, this is roughly
+    // sum([(math.ceil((w**2+h**2)**0.5 / (ts*2**l)) + 1) *
+    //      (math.ceil(min(w, h) / (ts*2**l)) + 1) for l in range(ml)])
     arg.cacheSize = arg.keepLower ? 600 : 200;
   }
   if ($.type(arg.subdomains) === 'string') {
@@ -261,6 +265,9 @@ var tileLayer = function (arg) {
   });
   this._queue._tileLayers = this._queue._tileLayers || [];
   this._queue._tileLayers.push(m_this);
+  if (this._queue.initialTrack && this._queue.track) {
+    this._queue.track = this._queue.initialTrack * this._queue._tileLayers.length;
+  }
 
   var m_tileOffsetValues = {};
 
@@ -310,10 +317,16 @@ var tileLayer = function (arg) {
       if (m_this._queue !== queue) {
         if (this._queue && this._queue._tileLayers && this._queue._tileLayers.indexOf(m_this) >= 0) {
           this._queue._tileLayers.splice(this._queue._tileLayers.indexOf(m_this), 1);
+          if (this._queue.initialTrack && this._queue.track && this._queue._tileLayers.length) {
+            this._queue.track = this._queue.initialTrack * this._queue._tileLayers.length;
+          }
         }
         m_this._queue = queue;
         m_this._queue._tileLayers = m_this._queue._tileLayers || [];
         m_this._queue._tileLayers.push(m_this);
+        if (m_this._queue.initialTrack && m_this._queue.track) {
+          m_this._queue.track = m_this._queue.initialTrack * m_this._queue._tileLayers.length;
+        }
       }
     }
   });
@@ -1736,6 +1749,9 @@ var tileLayer = function (arg) {
     m_exited = true;
     if (this._queue && this._queue._tileLayers && this._queue._tileLayers.indexOf(m_this) >= 0) {
       this._queue._tileLayers.splice(this._queue._tileLayers.indexOf(m_this), 1);
+      if (this._queue.initialTrack && this._queue.track && this._queue._tileLayers.length) {
+        this._queue.track = this._queue.initialTrack * this._queue._tileLayers.length;
+      }
     }
     return m_this;
   };
@@ -1765,7 +1781,7 @@ tileLayer.defaults = {
   topDown: false,
   keepLower: true,
   idleAfter: 'view',
-  // cacheSize: 400,  // set depending on keepLower
+  // cacheSize: 600,  // set depending on keepLower
   tileRounding: Math.round,
   attribution: '',
   animationDuration: 0

tests/cases/fetchQueue.js

@@ -273,5 +273,17 @@ describe('geo.core.fetchQueue', function () {
 
       process();
     });
+
+    it('track and initialTrack size', function () {
+      var q = geo.fetchQueue({track: 10});
+      expect(q.track).toBe(10);
+      expect(q.initialTrack).toBe(10);
+      q.track = 20;
+      expect(q.track).toBe(20);
+      expect(q.initialTrack).toBe(10);
+      q.initialTrack = 30;
+      expect(q.track).toBe(20);
+      expect(q.initialTrack).toBe(30);
+    });
   });
 });

tests/cases/tileLayer.js

@@ -464,8 +464,10 @@ describe('geo.tileLayer', function () {
       var origQueue = layer2.queue;
       layer2.queue = layer.queue;
       expect(layer.queue._tileLayers.length).toBe(2);
+      expect(layer.queue.track).toBe(layer.queue.initialTrack * 2);
       layer2.queue = origQueue;
       expect(layer.queue._tileLayers.length).toBe(1);
+      expect(layer.queue.track).toBe(layer.queue.initialTrack);
     });
     it('reference', function () {
       var m = map(), layer;