refactor StatsReporter (#4549)

Author: Feiyang1

packages/database/src/core/Repo.ts

@@ -59,7 +59,7 @@ import {
   statsManagerGetCollection,
   statsManagerGetOrCreateReporter
 } from './stats/StatsManager';
-import { StatsReporter } from './stats/StatsReporter';
+import { StatsReporter, statsReporterIncludeStat } from './stats/StatsReporter';
 import { StatsListener } from './stats/StatsListener';
 import {
   EventQueue,
@@ -776,7 +776,7 @@ export function repoStats(repo: Repo, showDelta: boolean = false): void {
 
 export function repoStatsIncrementCounter(repo: Repo, metric: string): void {
   repo.stats_.incrementCounter(metric);
-  repo.statsReporter_.includeStat(metric);
+  statsReporterIncludeStat(repo.statsReporter_, metric);
 }
 
 function repoLog(repo: Repo, ...varArgs: unknown[]): void {

packages/database/src/core/stats/StatsReporter.ts

@@ -32,7 +32,7 @@ const REPORT_STATS_INTERVAL = 5 * 60 * 1000;
 
 export class StatsReporter {
   private statsListener_: StatsListener;
-  private statsToReport_: { [k: string]: boolean } = {};
+  statsToReport_: { [k: string]: boolean } = {};
 
   /**
    * @param collection
@@ -47,10 +47,6 @@ export class StatsReporter {
     setTimeoutNonBlocking(this.reportStats_.bind(this), Math.floor(timeout));
   }
 
-  includeStat(stat: string) {
-    this.statsToReport_[stat] = true;
-  }
-
   private reportStats_() {
     const stats = this.statsListener_.get();
     const reportedStats: typeof stats = {};
@@ -74,3 +70,10 @@ export class StatsReporter {
     );
   }
 }
+
+export function statsReporterIncludeStat(
+  reporter: StatsReporter,
+  stat: string
+) {
+  reporter.statsToReport_[stat] = true;
+}