GraphNG: fix and optimize spanNulls (#29633)

* fix and optimize spanNulls

* AsZero implies spanNulls = true, to prevent null-scanning

* move spanNulls toggle below fillOpacity

packages/grafana-ui/src/components/GraphNG/GraphNG.tsx

@@ -147,6 +147,7 @@ export const GraphNG: React.FC<GraphNGProps> = ({
         pointColor: seriesColor,
         fillOpacity: customConfig.fillOpacity,
         fillColor: seriesColor,
+        spanNulls: customConfig.spanNulls || false,
       });
 
       if (hasLegend.current) {

packages/grafana-ui/src/components/GraphNG/utils.ts

@@ -43,7 +43,7 @@ export function mapDimesions(match: XYFieldMatchers, frame: DataFrame, frames?:
 export function alignDataFrames(frames: DataFrame[], fields?: XYFieldMatchers): AlignedFrameWithGapTest | null {
   const valuesFromFrames: AlignedData[] = [];
   const sourceFields: Field[] = [];
-  let spanNulls = false;
+  const skipGaps: boolean[][] = [];
 
   // Default to timeseries config
   if (!fields) {
@@ -55,6 +55,7 @@ export function alignDataFrames(frames: DataFrame[], fields?: XYFieldMatchers):
 
   for (const frame of frames) {
     const dims = mapDimesions(fields, frame, frames);
+
     if (!(dims.x.length && dims.y.length)) {
       continue; // both x and y matched something!
     }
@@ -63,9 +64,12 @@ export function alignDataFrames(frames: DataFrame[], fields?: XYFieldMatchers):
       throw new Error('Only a single x field is supported');
     }
 
+    let skipGapsFrame: boolean[] = [];
+
     // Add the first X axis
     if (!sourceFields.length) {
       sourceFields.push(dims.x[0]);
+      skipGapsFrame.push(true);
     }
 
     const alignedData: AlignedData = [
@@ -75,21 +79,23 @@ export function alignDataFrames(frames: DataFrame[], fields?: XYFieldMatchers):
     // Add the Y values
     for (const field of dims.y) {
       let values = field.values.toArray();
+      let spanNulls = field.config.custom.spanNulls || false;
+
       if (field.config.nullValueMode === NullValueMode.AsZero) {
         values = values.map(v => (v === null ? 0 : v));
-      }
-      alignedData.push(values);
-
-      if (field.config.custom.spanNulls) {
         spanNulls = true;
       }
 
+      alignedData.push(values);
+      skipGapsFrame.push(spanNulls);
+
       // This will cache an appropriate field name in the field state
       getFieldDisplayName(field, frame, frames);
       sourceFields.push(field);
     }
 
     valuesFromFrames.push(alignedData);
+    skipGaps.push(skipGapsFrame);
   }
 
   if (valuesFromFrames.length === 0) {
@@ -97,22 +103,12 @@ export function alignDataFrames(frames: DataFrame[], fields?: XYFieldMatchers):
   }
 
   // do the actual alignment (outerJoin on the first arrays)
-  let { data: alignedData, isGap } = outerJoinValues(valuesFromFrames);
+  let { data: alignedData, isGap } = outerJoinValues(valuesFromFrames, skipGaps);
 
   if (alignedData!.length !== sourceFields.length) {
     throw new Error('outerJoinValues lost a field?');
   }
 
-  // Wrap the gap function when span nulls exists
-  if (spanNulls) {
-    isGap = (u: uPlot, seriesIdx: number, dataIdx: number) => {
-      if (sourceFields[seriesIdx].config?.custom?.spanNulls) {
-        return false;
-      }
-      return isGap(u, seriesIdx, dataIdx);
-    };
-  }
-
   // Replace the values from the outer-join field
   return {
     frame: {
@@ -126,18 +122,20 @@ export function alignDataFrames(frames: DataFrame[], fields?: XYFieldMatchers):
   };
 }
 
-export function outerJoinValues(tables: AlignedData[]): AlignedDataWithGapTest {
+// skipGaps is a tables-matched bool array indicating which series can skip storing indices of original nulls
+export function outerJoinValues(tables: AlignedData[], skipGaps?: boolean[][]): AlignedDataWithGapTest {
   if (tables.length === 1) {
     return {
       data: tables[0],
-      isGap: () => true,
+      isGap: skipGaps ? (u: uPlot, seriesIdx: number, dataIdx: number) => !skipGaps[0][seriesIdx] : () => true,
     };
   }
 
   let xVals: Set<number> = new Set();
   let xNulls: Array<Set<number>> = [new Set()];
 
-  for (const t of tables) {
+  for (let ti = 0; ti < tables.length; ti++) {
+    let t = tables[ti];
     let xs = t[0];
     let len = xs.length;
     let nulls: Set<number> = new Set();
@@ -147,11 +145,13 @@ export function outerJoinValues(tables: AlignedData[]): AlignedDataWithGapTest {
     }
 
     for (let j = 1; j < t.length; j++) {
-      let ys = t[j];
+      if (skipGaps == null || !skipGaps[ti][j]) {
+        let ys = t[j];
 
-      for (let i = 0; i < len; i++) {
-        if (ys[i] == null) {
-          nulls.add(xs[i]);
+        for (let i = 0; i < len; i++) {
+          if (ys[i] == null) {
+            nulls.add(xs[i]);
+          }
         }
       }
     }

packages/grafana-ui/src/components/uPlot/config.ts

@@ -32,6 +32,7 @@ export interface LineConfig {
   lineColor?: string;
   lineWidth?: number;
   lineInterpolation?: LineInterpolation;
+  spanNulls?: boolean;
 }
 
 export interface AreaConfig {
@@ -55,7 +56,6 @@ export interface AxisConfig {
 
 export interface GraphFieldConfig extends LineConfig, AreaConfig, PointsConfig, AxisConfig {
   drawStyle?: DrawStyle;
-  spanNulls?: boolean;
 }
 
 export const graphFieldOptions = {

packages/grafana-ui/src/components/uPlot/config/UPlotConfigBuilder.test.ts

@@ -130,6 +130,7 @@ describe('UPlotConfigBuilder', () => {
       pointColor: '#00ff00',
       lineColor: '#0000ff',
       lineWidth: 1,
+      spanNulls: false,
     });
 
     expect(builder.getConfig()).toMatchInlineSnapshot(`
@@ -147,6 +148,7 @@ describe('UPlotConfigBuilder', () => {
               "stroke": "#00ff00",
             },
             "scale": "scale-x",
+            "spanGaps": false,
             "stroke": "#0000ff",
             "width": 1,
           },

packages/grafana-ui/src/components/uPlot/config/UPlotSeriesBuilder.ts

@@ -22,6 +22,7 @@ export class UPlotSeriesBuilder extends PlotConfigBuilder<SeriesProps, Series> {
       fillColor,
       fillOpacity,
       scaleKey,
+      spanNulls,
     } = this.props;
 
     let lineConfig: Partial<Series> = {};
@@ -87,6 +88,7 @@ export class UPlotSeriesBuilder extends PlotConfigBuilder<SeriesProps, Series> {
 
     return {
       scale: scaleKey,
+      spanGaps: spanNulls,
       ...lineConfig,
       ...pointsConfig,
       ...areaConfig,

public/app/plugins/panel/graph3/module.tsx

@@ -63,6 +63,18 @@ export const plugin = new PanelPlugin<Options, GraphFieldConfig>(GraphPanel)
           },
           showIf: c => c.drawStyle !== DrawStyle.Points,
         })
+        .addRadio({
+          path: 'spanNulls',
+          name: 'Null values',
+          defaultValue: false,
+          settings: {
+            options: [
+              { label: 'Gaps', value: false },
+              { label: 'Connected', value: true },
+            ],
+          },
+          showIf: c => c.drawStyle === DrawStyle.Line,
+        })
         .addRadio({
           path: 'points',
           name: 'Points',
@@ -82,17 +94,6 @@ export const plugin = new PanelPlugin<Options, GraphFieldConfig>(GraphPanel)
           },
           showIf: c => c.points !== PointMode.Never,
         })
-        .addRadio({
-          path: 'spanNulls',
-          name: 'Null values',
-          defaultValue: false,
-          settings: {
-            options: [
-              { label: 'Gaps', value: false },
-              { label: 'Connected', value: true },
-            ],
-          },
-        })
         .addRadio({
           path: 'axisPlacement',
           name: 'Placement',