Cache base layers but don't clear on bbox clear

app/src/tiles/dataDefinition.ts

@@ -111,6 +111,14 @@ const BUILDING_LAYER_DEFINITIONS = {
 
 const GEOMETRY_FIELD = 'geometry_geom';
 
+function getBuildingLayerNames() {
+    return Object.keys(BUILDING_LAYER_DEFINITIONS);
+}
+
+function getAllLayerNames() {
+    return ['highlight', ...getBuildingLayerNames()];
+}
+
 function getBuildingsDataConfig(tileset: string, dataParams: any): DataConfig {
     const table = BUILDING_LAYER_DEFINITIONS[tileset];
 
@@ -149,7 +157,8 @@ function getHighlightDataConfig(tileset: string, dataParams: any): DataConfig {
 }
 
 export {
-    BUILDING_LAYER_DEFINITIONS,
+    getBuildingLayerNames,
+    getAllLayerNames,
     getBuildingsDataConfig,
     getHighlightDataConfig
 };

app/src/tiles/rendererDefinition.ts

@@ -1,6 +1,6 @@
 import { TileCache } from "./tileCache";
 import { BoundingBox, TileParams, Tile } from "./types";
-import { getBuildingsDataConfig, getHighlightDataConfig, BUILDING_LAYER_DEFINITIONS } from "./dataDefinition";
+import { getBuildingsDataConfig, getHighlightDataConfig, getAllLayerNames, getBuildingLayerNames } from "./dataDefinition";
 import { isOutsideExtent } from "./util";
 import { renderDataSourceTile } from "./renderers/renderDataSourceTile";
 import { getTileWithCaching } from "./renderers/getTileWithCaching";
@@ -10,7 +10,7 @@ import { createBlankTile } from "./renderers/createBlankTile";
 /**
  * A list of all tilesets handled by the tile server
  */
-const allTilesets = ['highlight', ...Object.keys(BUILDING_LAYER_DEFINITIONS)];
+const allTilesets = getAllLayerNames();
 
 /**
  * Zoom level when we switch from rendering direct from database to instead composing tiles
@@ -27,14 +27,19 @@ const EXTENT_BBOX: BoundingBox = [-61149.622628, 6667754.851372, 28128.826409, 6
 const tileCache = new TileCache(
     process.env.TILECACHE_PATH,
     {
-        tilesets: ['date_year', 'size_storeys', 'location', 'likes', 'conservation_area', 'sust_dec', 'building_attachment_form'],
+        tilesets: getBuildingLayerNames(),
         minZoom: 9,
         maxZoom: 18,
         scales: [1, 2]
     },
+
+    // cache age data and base building outlines for more zoom levels than other layers
     ({ tileset, z }: TileParams) => (tileset === 'date_year' && z <= 16) ||
         ((tileset === 'base_light' || tileset === 'base_night') && z <= 17) ||
-        z <= 13
+        z <= 13,
+    
+    // don't clear base_light and base_night on bounding box cache clear
+    (tileset: string) => tileset !== 'base_light' && tileset !== 'base_night'
 );
 
 const renderBuildingTile = (t: TileParams, d: any) => renderDataSourceTile(t, d, getBuildingsDataConfig);

app/src/tiles/tileCache.ts

@@ -70,7 +70,9 @@ class TileCache {
         /** Domain definition for the cache */
         private cacheDomain: CacheDomain,
         /** Function for defining custom caching rules (optional) */
-        private shouldCacheFn?: (TileParams) => boolean
+        private shouldCacheFn?: (TileParams) => boolean,
+        /** Function for defining whether the tileset should be cleared when clearing cache for bounding box */
+        private shouldBulkClearTilesetFn?: (tileset: string) => boolean
     ) {}
 
     async get(tileParams: TileParams): Promise<Image> {
@@ -108,6 +110,8 @@ class TileCache {
     async removeAllAtBbox(bbox: BoundingBox): Promise<void[]> {
         const removePromises: Promise<void>[] = [];
         for (const tileset of this.cacheDomain.tilesets) {
+            if(!this.shouldBulkClearTileset(tileset)) continue;
+
             for (let z = this.cacheDomain.minZoom; z <= this.cacheDomain.maxZoom; z++) {
                 let tileBounds = getXYZ(bbox, z)
                 for (let x = tileBounds.minX; x <= tileBounds.maxX; x++) {
@@ -137,6 +141,10 @@ class TileCache {
             this.cacheDomain.scales.includes(tileParams.scale) &&
             (this.shouldCacheFn == undefined || this.shouldCacheFn(tileParams));
     }
+
+    private shouldBulkClearTileset(tileset: string): boolean {
+        return this.shouldCacheFn == undefined || this.shouldBulkClearTilesetFn(tileset);
+    }
 }
 
 export {