only return the map to the pool if we created a new map, not if we

returned the base map from the labels builder

Signed-off-by: Callum Styan <[email protected]>

pkg/logql/log/fmt.go

@@ -222,8 +222,12 @@ func (lf *LineFormatter) Process(ts int64, line []byte, lbs *LabelsBuilder) ([]b
 	lf.currentTs = ts
 
 	// map now is taking from a pool
-	m := lbs.Map()
-	defer smp.Put(m)
+	m, ret := lbs.Map()
+	defer func() {
+		if ret { // if we return the base map from the labels builder we should not put it back in the pool
+			smp.Put(m)
+		}
+	}()
 	if err := lf.Template.Execute(lf.buf, m); err != nil {
 		lbs.SetErr(errTemplateFormat)
 		lbs.SetErrorDetails(err.Error())

pkg/logql/log/labels.go

@@ -495,12 +495,12 @@ func (b *LabelsBuilder) IntoMap(m map[string]string) {
 	}
 }
 
-func (b *LabelsBuilder) Map() map[string]string {
+func (b *LabelsBuilder) Map() (map[string]string, bool) {
 	if !b.hasDel() && !b.hasAdd() && !b.HasErr() {
 		if b.baseMap == nil {
 			b.baseMap = b.base.Map()
 		}
-		return b.baseMap
+		return b.baseMap, false
 	}
 	b.buf = b.UnsortedLabels(b.buf)
 	// todo should we also cache maps since limited by the result ?
@@ -509,7 +509,7 @@ func (b *LabelsBuilder) Map() map[string]string {
 	for _, l := range b.buf {
 		res[l.Name] = l.Value
 	}
-	return res
+	return res, true
 }
 
 // LabelsResult returns the LabelsResult from the builder.