DataFrame: split DataFrameHelper into MutableDataFrame and FieldCache (#18795)

* add appending utility

* add appending utility

* update comment

* rename to mutable

* move mutable functions out of DataFrameHelper

* move mutable functions out of DataFrameHelper

* move mutable functions out of DataFrameHelper

* turn DataFrameHelper into FieldCache

* guess time from name

* graph the numbers

* return the timeField, not just the index

* just warn on duplicate field names

* only use a parser if the input is a string

* append init all fields to the same length

* typo

* only parse string if value is a string

* DataFrame: test fixes

* Switch to null for missing values

* Fixed tests

packages/grafana-ui/src/components/Logs/LogRowContextProvider.test.ts

@@ -1,4 +1,4 @@
-import { DataFrameHelper, FieldType, LogRowModel } from '@grafana/data';
+import { FieldType, LogRowModel, MutableDataFrame } from '@grafana/data';
 import { getRowContexts } from './LogRowContextProvider';
 import { Labels, LogLevel } from '@grafana/data/src';
 import { DataQueryResponse } from '../../types';
@@ -6,7 +6,7 @@ import { DataQueryResponse } from '../../types';
 describe('getRowContexts', () => {
   describe('when called with a DataFrame and results are returned', () => {
     it('then the result should be in correct format', async () => {
-      const firstResult = new DataFrameHelper({
+      const firstResult = new MutableDataFrame({
         refId: 'B',
         labels: {},
         fields: [
@@ -14,7 +14,7 @@ describe('getRowContexts', () => {
           { name: 'line', type: FieldType.string, values: ['3', '2', '1'] },
         ],
       });
-      const secondResult = new DataFrameHelper({
+      const secondResult = new MutableDataFrame({
         refId: 'B',
         labels: {},
         fields: [

packages/grafana-ui/src/utils/fieldDisplay.test.ts

@@ -1,5 +1,5 @@
 import { getFieldProperties, getFieldDisplayValues, GetFieldDisplayValuesOptions } from './fieldDisplay';
-import { ReducerID, Threshold, DataFrameHelper } from '@grafana/data';
+import { ReducerID, Threshold, toDataFrame } from '@grafana/data';
 import { GrafanaThemeType } from '../types/theme';
 import { getTheme } from '../themes/index';
 
@@ -34,7 +34,7 @@ describe('FieldDisplay', () => {
   // Simple test dataset
   const options: GetFieldDisplayValuesOptions = {
     data: [
-      new DataFrameHelper({
+      toDataFrame({
         name: 'Series Name',
         fields: [
           { name: 'Field 1', values: ['a', 'b', 'c'] },

packages/grafana-ui/src/utils/fieldDisplay.ts

@@ -7,6 +7,7 @@ import {
   DisplayValue,
   GraphSeriesValue,
   DataFrameView,
+  getTimeField,
 } from '@grafana/data';
 
 import toNumber from 'lodash/toNumber';
@@ -82,17 +83,6 @@ export interface GetFieldDisplayValuesOptions {
 
 export const DEFAULT_FIELD_DISPLAY_VALUES_LIMIT = 25;
 
-const getTimeColumnIdx = (series: DataFrame) => {
-  let timeColumn = -1;
-  for (let i = 0; i < series.fields.length; i++) {
-    if (series.fields[i].type === FieldType.time) {
-      timeColumn = i;
-      break;
-    }
-  }
-  return timeColumn;
-};
-
 export const getFieldDisplayValues = (options: GetFieldDisplayValuesOptions): FieldDisplay[] => {
   const { data, replaceVariables, fieldOptions } = options;
   const { defaults, override } = fieldOptions;
@@ -117,7 +107,7 @@ export const getFieldDisplayValues = (options: GetFieldDisplayValuesOptions): Fi
 
       scopedVars[DataLinkBuiltInVars.seriesName] = { text: 'Series', value: series.name };
 
-      const timeColumn = getTimeColumnIdx(series);
+      const { timeField } = getTimeField(series);
       const view = new DataFrameView(series);
 
       for (let i = 0; i < series.fields.length && !hitLimit; i++) {
@@ -184,9 +174,9 @@ export const getFieldDisplayValues = (options: GetFieldDisplayValuesOptions): Fi
           let sparkline: GraphSeriesValue[][] | undefined = undefined;
 
           // Single sparkline for every reducer
-          if (options.sparkline && timeColumn >= 0) {
+          if (options.sparkline && timeField) {
             sparkline = getFlotPairs({
-              xField: series.fields[timeColumn],
+              xField: timeField,
               yField: series.fields[i],
             });
           }

packages/grafana-ui/src/utils/flotPairs.test.ts

@@ -1,8 +1,8 @@
 import { getFlotPairs } from './flotPairs';
-import { DataFrameHelper } from '@grafana/data';
+import { MutableDataFrame } from '@grafana/data';
 
 describe('getFlotPairs', () => {
-  const series = new DataFrameHelper({
+  const series = new MutableDataFrame({
     fields: [
       { name: 'a', values: [1, 2, 3] },
       { name: 'b', values: [100, 200, 300] },