Prune all except for the most recent z on URL change

2017-10-07 10:29:40 -06:00
parent a4e0c54200
commit 97745c50af
3 changed files with 60 additions and 0 deletions
@@ -2,6 +2,7 @@ goog.provide('ol.TileCache');

 goog.require('ol');
 goog.require('ol.structs.LRUCache');
+goog.require('ol.tilecoord');


 /**
@@ -33,3 +34,22 @@ ol.TileCache.prototype.expireCache = function(usedTiles) {
    }
  }
 };
+
+
+/**
+ * Prune all tiles from the cache that don't have the same z as the newest tile.
+ */
+ol.TileCache.prototype.pruneExceptNewestZ = function() {
+  if (this.getCount() === 0) {
+    return;
+  }
+  var key = this.peekFirstKey();
+  var tileCoord = ol.tilecoord.fromKey(key);
+  var z = tileCoord[0];
+  this.forEach(function(tile) {
+    if (tile.tileCoord[0] !== z) {
+      this.remove(ol.tilecoord.getKey(tile.tileCoord));
+      tile.dispose();
+    }
+  }, this);
+};