Merge pull request #12405 from ahocevar/vectortile-getsourcetiles

VectorTile getSourceTiles behaviour with loading source tiles

src/ol/source/VectorTile.js

@@ -18,7 +18,7 @@ import {
   createXYZ,
   extentFromProjection,
 } from '../tilegrid.js';
-import {fromKey, getKeyZXY} from '../tilecoord.js';
+import {fromKey, getCacheKeyForTileKey, getKeyZXY} from '../tilecoord.js';
 import {isEmpty} from '../obj.js';
 import {loadFeaturesXhr} from '../featureloader.js';
 import {toSize} from '../size.js';
@@ -237,8 +237,19 @@ class VectorTile extends UrlTile {
    * @param {!Object<string, boolean>} usedTiles Used tiles.
    */
   expireCache(projection, usedTiles) {
+    const tileCache = this.getTileCacheForProjection(projection);
+    const usedSourceTiles = Object.keys(usedTiles).reduce((acc, key) => {
+      const cacheKey = getCacheKeyForTileKey(key);
+      if (tileCache.containsKey(cacheKey)) {
+        const sourceTiles = tileCache.get(cacheKey).sourceTiles;
+        for (let i = 0, ii = sourceTiles.length; i < ii; ++i) {
+          acc[sourceTiles[i].getKey()] = true;
+        }
+      }
+      return acc;
+    }, {});
     super.expireCache(projection, usedTiles);
-    this.sourceTileCache.expireCache({});
+    this.sourceTileCache.expireCache(usedSourceTiles);
   }
 
   /**
@@ -281,15 +292,7 @@ class VectorTile extends UrlTile {
             );
         tile.sourceTiles.push(sourceTile);
         const sourceTileState = sourceTile.getState();
-        if (sourceTileState === TileState.IDLE) {
-          sourceTile.extent = sourceTileGrid.getTileCoordExtent(
-            sourceTileCoord
-          );
-          sourceTile.projection = projection;
-          sourceTile.resolution = sourceTileGrid.getResolution(
-            sourceTileCoord[0]
-          );
-          this.sourceTileCache.set(tileUrl, sourceTile);
+        if (sourceTileState < TileState.LOADED) {
           const listenChange = (event) => {
             this.handleTileChange(event);
             const state = sourceTile.getState();
@@ -318,6 +321,16 @@ class VectorTile extends UrlTile {
           };
           sourceTile.addEventListener(EventType.CHANGE, listenChange);
           tile.loadingSourceTiles++;
+        }
+        if (sourceTileState === TileState.IDLE) {
+          sourceTile.extent = sourceTileGrid.getTileCoordExtent(
+            sourceTileCoord
+          );
+          sourceTile.projection = projection;
+          sourceTile.resolution = sourceTileGrid.getResolution(
+            sourceTileCoord[0]
+          );
+          this.sourceTileCache.set(tileUrl, sourceTile);
           sourceTile.load();
         }
       });
@@ -458,6 +471,9 @@ class VectorTile extends UrlTile {
    */
   updateCacheSize(tileCount, projection) {
     super.updateCacheSize(tileCount * 2, projection);
+    this.sourceTileCache.highWaterMark = this.getTileCacheForProjection(
+      projection
+    ).highWaterMark;
   }
 }
 

src/ol/tilecoord.js

@@ -46,6 +46,19 @@ export function getKey(tileCoord) {
   return getKeyZXY(tileCoord[0], tileCoord[1], tileCoord[2]);
 }
 
+/**
+ * Get the tile cache key for a tile key obtained through `tile.getKey()`.
+ * @param {string} tileKey The tile key.
+ * @return {string} The cache key.
+ */
+export function getCacheKeyForTileKey(tileKey) {
+  const [z, x, y] = tileKey
+    .substring(tileKey.lastIndexOf('/') + 1, tileKey.length)
+    .split(',')
+    .map(Number);
+  return getKeyZXY(z, x, y);
+}
+
 /**
  * Get a tile coord given a key.
  * @param {string} key The tile coord key.