From ad487470fdee410be0707a48e0cab49c6c86e26c Mon Sep 17 00:00:00 2001
From: Petar Petrov <MindFreeze@users.noreply.github.com>
Date: Wed, 19 Feb 2025 16:05:32 +0200
Subject: [PATCH] Enable downsampling in echarts (#24311)

* Enable downsampling in echarts

* remove unneeded symbol set
---
 src/components/chart/ha-chart-base.ts            | 10 +++++-----
 src/components/chart/state-history-chart-line.ts |  5 +++--
 src/components/chart/statistics-chart.ts         |  5 ++---
 3 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/components/chart/ha-chart-base.ts b/src/components/chart/ha-chart-base.ts
index deb89d24d2..a87b7aa3a2 100644
--- a/src/components/chart/ha-chart-base.ts
+++ b/src/components/chart/ha-chart-base.ts
@@ -521,14 +521,14 @@ export class HaChartBase extends LitElement {
         0
       );
       if (dataSize > 10000) {
-        // for large datasets zr.flush takes 30-40% of the render time
-        // so we delay it a bit to avoid blocking the main thread
+        // delay the last bit of the render to avoid blocking the main thread
+        // this is not that impactful with sampling enabled but it doesn't hurt to have it
         const zr = this.chart.getZr();
-        this._originalZrFlush = zr.flush.bind(zr);
+        this._originalZrFlush = zr.flush;
         zr.flush = () => {
           setTimeout(() => {
-            this._originalZrFlush?.();
-          }, 10);
+            this._originalZrFlush?.call(zr);
+          }, 5);
         };
       }
     }
diff --git a/src/components/chart/state-history-chart-line.ts b/src/components/chart/state-history-chart-line.ts
index f7e60f7804..27de961e41 100644
--- a/src/components/chart/state-history-chart-line.ts
+++ b/src/components/chart/state-history-chart-line.ts
@@ -354,9 +354,10 @@ export class StateHistoryChartLine extends LitElement {
           name: nameY,
           color,
           symbol: "circle",
-          step: "end",
-          animationDurationUpdate: 0,
           symbolSize: 1,
+          step: "end",
+          sampling: "minmax",
+          animationDurationUpdate: 0,
           lineStyle: {
             width: fill ? 0 : 1.5,
           },
diff --git a/src/components/chart/statistics-chart.ts b/src/components/chart/statistics-chart.ts
index 7954d76010..5c2372826c 100644
--- a/src/components/chart/statistics-chart.ts
+++ b/src/components/chart/statistics-chart.ts
@@ -492,8 +492,8 @@ export class StatisticsChart extends LitElement {
               : this.hass.localize(
                   `ui.components.statistics_charts.statistic_types.${type}`
                 ),
-            symbol: "circle",
-            symbolSize: 0,
+            symbol: "none",
+            sampling: "minmax",
             animationDurationUpdate: 0,
             lineStyle: {
               width: 1.5,
@@ -511,7 +511,6 @@ export class StatisticsChart extends LitElement {
           if (band && this.chartType === "line") {
             series.stack = `band-${statistic_id}`;
             series.stackStrategy = "all";
-            (series as LineSeriesOption).symbol = "none";
             if (drawBands && type === "max") {
               (series as LineSeriesOption).areaStyle = {
                 color: color + "3F",