refac: dedeuplicate labeldiff checks

Signed-off-by: Manik Rana <manikrana54@gmail.com>

model/labels/labels.go

@@ -31,25 +31,6 @@ func (ls Labels) Len() int           { return len(ls) }
 func (ls Labels) Swap(i, j int)      { ls[i], ls[j] = ls[j], ls[i] }
 func (ls Labels) Less(i, j int) bool { return ls[i].Name < ls[j].Name }
 
-// ExtractNames returns an array of all Name in ls.
-func (ls Labels) ExtractNames() []string {
-	names := make([]string, len(ls))
-	for i, label := range ls {
-		names[i] = label.Name
-	}
-	return names
-}
-
-// Contains returns true if the label set contains the provided label name.
-func (ls Labels) Contains(name string) bool {
-	for _, label := range ls {
-		if label.Name == name {
-			return true
-		}
-	}
-	return false
-}
-
 // Bytes returns ls as a byte slice.
 // It uses an byte invalid character as a separator and so should not be used for printing.
 func (ls Labels) Bytes(buf []byte) []byte {
@@ -392,6 +373,29 @@ func (ls Labels) ReleaseStrings(release func(string)) {
 	}
 }
 
+// ExtractNames returns an array of all Name in ls.
+func (ls Labels) ExtractNames() []string {
+	names := make([]string, len(ls))
+	for i, label := range ls {
+		names[i] = label.Name
+	}
+	return names
+}
+
+// Method to check if the Labels contains any of the provided label Names
+// returns true if any of the provided label names are present in the Labels
+// return false if no Names are provided
+func (ls Labels) Contains(names ...string) bool {
+	for _, name := range names {
+		for _, label := range ls {
+			if label.Name == name {
+				return true
+			}
+		}
+	}
+	return false
+}
+
 // Builder allows modifying Labels.
 type Builder struct {
 	base Labels

model/textparse/openmetricsparse.go

@@ -252,21 +252,10 @@ loop:
 
 			newLbs = newLbs.DropMetricName()
 			switch p.mtype {
-			case model.MetricTypeCounter:
+			case model.MetricTypeCounter, model.MetricTypeHistogram, model.MetricTypeSummary:
-				if !labels.Equal(lbs, newLbs) {
-					return nil
-				}
-			case model.MetricTypeSummary:
 				labelDiffs := lbs.MatchLabels(false, newLbs.ExtractNames()...)
 				if labelDiffs.Len() != 0 {
-					if !labelDiffs.Contains("quantile") || labelDiffs.Len() != 1 {
+					if !labelDiffs.Contains("quantile", "le") || labelDiffs.Len() != 1 {
-						return nil
-					}
-				}
-			case model.MetricTypeHistogram:
-				labelDiffs := lbs.MatchLabels(false, newLbs.ExtractNames()...)
-				if labelDiffs.Len() != 0 {
-					if !labelDiffs.Contains("le") || labelDiffs.Len() != 1 {
 						return nil
 					}
 				}