PMM-8787 Small refactor.

Jiri Ctvrtka · Jiri Ctvrtka · commit e2831abb0c6f · 2021-09-24T15:43:17.000+02:00
diff --git a/cmd/postgres_exporter/postgres_exporter.go b/cmd/postgres_exporter/postgres_exporter.go
@@ -1490,8 +1490,10 @@ func (e *Exporter) checkMapVersions(ch chan<- prometheus.Metric, server *Server)
 
 	// Check if semantic version changed and recalculate maps if needed.
 	server.lastMapVersionMtx.RLock()
-	if semanticVersion.NE(server.lastMapVersion) || metricMap == nil {
-		server.lastMapVersionMtx.RUnlock()
+	isVersionEqual := semanticVersion.NE(server.lastMapVersion)
+	server.lastMapVersionMtx.RUnlock()
+
+	if isVersionEqual || metricMap == nil {
 		log.Infof("Semantic Version Changed on %q: %s -> %s", server, server.lastMapVersion, semanticVersion)
 
 		// Get Default Metrics only for master database
@@ -1525,8 +1527,6 @@ func (e *Exporter) checkMapVersions(ch chan<- prometheus.Metric, server *Server)
 				e.loadCustomQueries(res, semanticVersion, server)
 			}
 		}
-	} else {
-		server.lastMapVersionMtx.RLock()
 	}
 
 	// Output the version as a special metric only for master database

Original file line number	Diff line number	Diff line change
`@@ -1490,8 +1490,10 @@ func (e Exporter) checkMapVersions(ch chan<- prometheus.Metric, server Server)`
`1490`	`1490`
`1491`	`1491`	`// Check if semantic version changed and recalculate maps if needed.`
`1492`	`1492`	`server.lastMapVersionMtx.RLock()`
`1493`		`- if semanticVersion.NE(server.lastMapVersion) \|\| metricMap == nil {`
`1494`		`- server.lastMapVersionMtx.RUnlock()`
	`1493`	`+ isVersionEqual := semanticVersion.NE(server.lastMapVersion)`
	`1494`	`+ server.lastMapVersionMtx.RUnlock()`
	`1495`	`+`
	`1496`	`+ if isVersionEqual \|\| metricMap == nil {`
`1495`	`1497`	`log.Infof("Semantic Version Changed on %q: %s -> %s", server, server.lastMapVersion, semanticVersion)`
`1496`	`1498`
`1497`	`1499`	`// Get Default Metrics only for master database`
`@@ -1525,8 +1527,6 @@ func (e Exporter) checkMapVersions(ch chan<- prometheus.Metric, server Server)`
`1525`	`1527`	`e.loadCustomQueries(res, semanticVersion, server)`
`1526`	`1528`	`}`
`1527`	`1529`	`}`
`1528`		`- } else {`
`1529`		`- server.lastMapVersionMtx.RLock()`
`1530`	`1530`	`}`
`1531`	`1531`
`1532`	`1532`	`// Output the version as a special metric only for master database`