From 5856611291297d017765caca1f239c2f85b0beee Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@gmail.com>
Date: Mon, 18 Jan 2021 17:30:09 +0200
Subject: [PATCH] app/vmselect/graphite: extract getCanonicalPath() function
 from loop body inside getCanonicalPaths()

---
 app/vmselect/graphite/tags_api.go | 31 +++++++++++++++++--------------
 1 file changed, 17 insertions(+), 14 deletions(-)

diff --git a/app/vmselect/graphite/tags_api.go b/app/vmselect/graphite/tags_api.go
index f41a2041f8..521785cb01 100644
--- a/app/vmselect/graphite/tags_api.go
+++ b/app/vmselect/graphite/tags_api.go
@@ -366,26 +366,29 @@ func TagsFindSeriesHandler(startTime time.Time, at *auth.Token, w http.ResponseW
 
 func getCanonicalPaths(mns []storage.MetricName) []string {
 	paths := make([]string, 0, len(mns))
-	var b []byte
-	var tags []storage.Tag
 	for _, mn := range mns {
-		b = append(b[:0], mn.MetricGroup...)
-		tags = append(tags[:0], mn.Tags...)
-		sort.Slice(tags, func(i, j int) bool {
-			return string(tags[i].Key) < string(tags[j].Key)
-		})
-		for _, tag := range tags {
-			b = append(b, ';')
-			b = append(b, tag.Key...)
-			b = append(b, '=')
-			b = append(b, tag.Value...)
-		}
-		paths = append(paths, string(b))
+		path := getCanonicalPath(&mn)
+		paths = append(paths, path)
 	}
 	sort.Strings(paths)
 	return paths
 }
 
+func getCanonicalPath(mn *storage.MetricName) string {
+	b := append([]byte{}, mn.MetricGroup...)
+	tags := append([]storage.Tag{}, mn.Tags...)
+	sort.Slice(tags, func(i, j int) bool {
+		return string(tags[i].Key) < string(tags[j].Key)
+	})
+	for _, tag := range tags {
+		b = append(b, ';')
+		b = append(b, tag.Key...)
+		b = append(b, '=')
+		b = append(b, tag.Value...)
+	}
+	return string(b)
+}
+
 var tagsFindSeriesDuration = metrics.NewSummary(`vm_request_duration_seconds{path="/tags/findSeries"}`)
 
 // TagValuesHandler implements /tags/<tag_name> endpoint from Graphite Tags API.