FieldOverrides: Optimize doStandardCalcs() (#67881)

Co-authored-by: Torkel Ödegaard <torkel@grafana.com>

packages/grafana-data/src/transformations/fieldReducer.test.ts

@@ -1,7 +1,7 @@
 import { difference } from 'lodash';
 
 import { createDataFrame, guessFieldTypeFromValue } from '../dataframe/processDataFrame';
-import { Field, FieldType } from '../types/index';
+import { Field, FieldType, NullValueMode } from '../types/index';
 
 import { fieldReducers, ReducerID, reduceField } from './fieldReducer';
 
@@ -171,4 +171,23 @@ describe('Stats Calculators', () => {
       }
     }
   });
+
+  it('count should ignoreNulls by default', () => {
+    const someNulls = createField('x', [1, null, null, 1]);
+    expect(reduce(someNulls, ReducerID.count)).toEqual(2);
+  });
+
+  it('count should use fieldConfig nullValueMode.Ignore and not count nulls', () => {
+    const someNulls = createField('x', [1, null, null, 1]);
+    someNulls.config.nullValueMode = NullValueMode.Ignore;
+
+    expect(reduce(someNulls, ReducerID.count)).toEqual(2);
+  });
+
+  it('count should use fieldConfig nullValueMode.Null and count nulls', () => {
+    const someNulls = createField('x', [1, null, null, 1]);
+    someNulls.config.nullValueMode = NullValueMode.Null;
+
+    expect(reduce(someNulls, ReducerID.count)).toEqual(4);
+  });
 });

packages/grafana-data/src/transformations/fieldReducer.ts

@@ -88,7 +88,9 @@ export function reduceField(options: ReduceFieldOptions): FieldCalcs {
     return (field.state.calcs = calcs);
   }
 
-  const { nullValueMode } = field.config;
+  // Default to Ignore for nullValueMode.
+  const { nullValueMode = NullValueMode.Ignore } = field.config;
+
   const ignoreNulls = nullValueMode === NullValueMode.Ignore;
   const nullAsZero = nullValueMode === NullValueMode.AsZero;
 
@@ -291,9 +293,8 @@ export function doStandardCalcs(field: Field, ignoreNulls: boolean, nullAsZero:
   };
 
   const data = field.values;
-  calcs.count = ignoreNulls ? data.length : data.filter((val) => val != null).length;
 
-  const isNumberField = field.type === FieldType.number || FieldType.time;
+  const isNumberField = field.type === FieldType.number || field.type === FieldType.time;
 
   for (let i = 0; i < data.length; i++) {
     let currentValue = data[i];
@@ -304,7 +305,7 @@ export function doStandardCalcs(field: Field, ignoreNulls: boolean, nullAsZero:
 
     calcs.last = currentValue;
 
-    if (currentValue === null) {
+    if (currentValue == null) {
       if (ignoreNulls) {
         continue;
       }
@@ -313,6 +314,8 @@ export function doStandardCalcs(field: Field, ignoreNulls: boolean, nullAsZero:
       }
     }
 
+    calcs.count++;
+
     if (currentValue != null) {
       // null || undefined
       const isFirst = calcs.firstNotNull === null;

packages/grafana-data/src/transformations/transformers/groupBy.test.ts

@@ -83,7 +83,7 @@ describe('GroupBy transformer', () => {
       fields: [
         { name: 'time', type: FieldType.time, values: [3000, 4000, 5000, 6000, 7000, 8000] },
         { name: 'message', type: FieldType.string, values: ['one', 'two', 'two', 'three', 'three', 'three'] },
-        { name: 'values', type: FieldType.string, values: [1, 2, 2, 3, 3, 3] },
+        { name: 'values', type: FieldType.number, values: [1, 2, 2, 3, 3, 3] },
       ],
     });
 
@@ -130,7 +130,7 @@ describe('GroupBy transformer', () => {
       fields: [
         { name: 'time', type: FieldType.time, values: [3000, 4000, 5000, 6000, 7000, 8000] },
         { name: 'message', type: FieldType.string, values: ['one', 'two', 'two', 'three', 'three', 'three'] },
-        { name: 'values', type: FieldType.string, values: [1, 2, 2, 3, 3, 3] },
+        { name: 'values', type: FieldType.number, values: [1, 2, 2, 3, 3, 3] },
       ],
     });
 
@@ -194,7 +194,7 @@ describe('GroupBy transformer', () => {
         fields: [
           { name: 'time', type: FieldType.time, values: [3000, 4000, 5000, 6000, 7000, 8000] },
           { name: 'message', type: FieldType.string, values: ['one', 'two', 'two', 'three', 'three', 'three'] },
-          { name: 'values', type: FieldType.string, values: [1, 2, 2, 3, 3, 3] },
+          { name: 'values', type: FieldType.number, values: [1, 2, 2, 3, 3, 3] },
         ],
       }),
       toDataFrame({
@@ -202,7 +202,7 @@ describe('GroupBy transformer', () => {
         fields: [
           { name: 'time', type: FieldType.time, values: [3000, 4000, 5000, 6000, 7000, 8000] },
           { name: 'message', type: FieldType.string, values: ['one', 'two', 'two', 'three', 'three', 'three'] },
-          { name: 'values', type: FieldType.string, values: [0, 2, 5, 3, 3, 2] },
+          { name: 'values', type: FieldType.number, values: [0, 2, 5, 3, 3, 2] },
         ],
       }),
     ];