From 90d2b08a278dfe3d9a010403316e15fca3c9e4ee Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20Zag=C3=B3rski?= <zbigniew@cartodb.com>
Date: Fri, 18 Oct 2024 14:16:55 +0200
Subject: [PATCH] carto: RasterLayer fix perf issue caused by spurious data
 changes

---
 modules/carto/src/layers/raster-layer.ts | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/modules/carto/src/layers/raster-layer.ts b/modules/carto/src/layers/raster-layer.ts
index 6d529a19455..5e177254e74 100644
--- a/modules/carto/src/layers/raster-layer.ts
+++ b/modules/carto/src/layers/raster-layer.ts
@@ -81,6 +81,15 @@ type _RasterLayerProps = {
   tileIndex: bigint;
 };
 
+type RasterColumnLayerData = {
+  data: Raster;
+  length: number;
+};
+
+function wrappedDataComparator(oldData: RasterColumnLayerData, newData: RasterColumnLayerData) {
+  return oldData.data === newData.data && oldData.length === newData.length;
+}
+
 // Adapter layer around RasterColumnLayer that converts data & accessors into correct format
 export default class RasterLayer<DataT = any, ExtraProps = {}> extends CompositeLayer<
   Required<RasterLayerProps<DataT>> & ExtraProps
@@ -91,6 +100,7 @@ export default class RasterLayer<DataT = any, ExtraProps = {}> extends Composite
   state!: {
     highlightedObjectIndex: number;
     highlightColor: number[];
+    dataWrapper?: {data: Raster; length: number};
   };
 
   renderLayers(): Layer | null | LayersList {
@@ -130,6 +140,7 @@ export default class RasterLayer<DataT = any, ExtraProps = {}> extends Composite
           data, // Pass through data for getSubLayerAccessor()
           length: blockSize * blockSize
         },
+        dataComparator: wrappedDataComparator,
         offset,
         lineWidthScale, // Re-use widthScale prop to pass cell scale,
         highlightedObjectIndex,