Loki: Bring back processed bytes as meta info (#34092)

* Loki: Bring back processed bytes as meta info

* style: Lint

public/app/core/logs_model.test.ts

@@ -698,6 +698,8 @@ describe('logSeriesToLogsModel', () => {
         meta: {
           searchWords: ['test'],
           limit: 1000,
+          stats: [{ displayName: 'Summary: total bytes processed', value: 97048, unit: 'decbytes' }],
+          custom: { lokiQueryStatKey: 'Summary: total bytes processed' },
           preferredVisualisationType: 'logs',
         },
       },
@@ -705,7 +707,10 @@ describe('logSeriesToLogsModel', () => {
 
     const metaData = {
       hasUniqueLabels: false,
-      meta: [{ label: LIMIT_LABEL, value: 1000, kind: 0 }],
+      meta: [
+        { label: LIMIT_LABEL, value: 1000, kind: 0 },
+        { label: 'Total bytes processed', value: '97.0  kB', kind: 1 },
+      ],
       rows: [],
     };
 
@@ -739,6 +744,8 @@ describe('logSeriesToLogsModel', () => {
         meta: {
           searchWords: ['test'],
           limit: 1000,
+          stats: [{ displayName: 'Summary: total bytes processed', value: 97048, unit: 'decbytes' }],
+          custom: { lokiQueryStatKey: 'Summary: total bytes processed' },
           preferredVisualisationType: 'logs',
         },
       }),
@@ -749,6 +756,8 @@ describe('logSeriesToLogsModel', () => {
         meta: {
           searchWords: ['test'],
           limit: 1000,
+          stats: [{ displayName: 'Summary: total bytes processed', value: 97048, unit: 'decbytes' }],
+          custom: { lokiQueryStatKey: 'Summary: total bytes processed' },
           preferredVisualisationType: 'logs',
         },
       }),
@@ -758,6 +767,7 @@ describe('logSeriesToLogsModel', () => {
     expect(logsModel.meta).toMatchObject([
       { kind: 2, label: 'Common labels', value: { foo: 'bar', level: 'dbug' } },
       { kind: 0, label: LIMIT_LABEL, value: 2000 },
+      { kind: 1, label: 'Total bytes processed', value: '194  kB' },
     ]);
     expect(logsModel.rows).toHaveLength(3);
     expect(logsModel.rows).toMatchObject([

public/app/core/logs_model.ts

@@ -33,6 +33,7 @@ import {
   DataQuery,
 } from '@grafana/data';
 import { getThemeColor } from 'app/core/utils/colors';
+import { SIPrefix } from '@grafana/data/src/valueFormats/symbolFormatters';
 import { config } from '@grafana/runtime';
 
 export const LIMIT_LABEL = 'Line limit';
@@ -443,10 +444,16 @@ export function logSeriesToLogsModel(logSeries: DataFrame[]): LogsModel | undefi
       kind: LogsMetaKind.Number,
     });
   }
+
+  let totalBytes = 0;
+  const queriesVisited: { [refId: string]: boolean } = {};
   // To add just 1 error message
   let errorMetaAdded = false;
 
   for (const series of logSeries) {
+    const totalBytesKey = series.meta?.custom?.lokiQueryStatKey;
+    const { refId } = series; // Stats are per query, keeping track by refId
+
     if (!errorMetaAdded && series.meta?.custom?.error) {
       meta.push({
         label: '',
@@ -455,7 +462,28 @@ export function logSeriesToLogsModel(logSeries: DataFrame[]): LogsModel | undefi
       });
       errorMetaAdded = true;
     }
+
+    if (refId && !queriesVisited[refId]) {
+      if (totalBytesKey && series.meta?.stats) {
+        const byteStat = series.meta.stats.find((stat) => stat.displayName === totalBytesKey);
+        if (byteStat) {
+          totalBytes += byteStat.value;
+        }
+      }
+
+      queriesVisited[refId] = true;
+    }
   }
+
+  if (totalBytes > 0) {
+    const { text, suffix } = SIPrefix('B')(totalBytes);
+    meta.push({
+      label: 'Total bytes processed',
+      value: `${text} ${suffix}`,
+      kind: LogsMetaKind.String,
+    });
+  }
+
   return {
     hasUniqueLabels,
     meta,