[PERF] RW: Remove interning hook

It does nothing for standard Prometheus builds with -tags stringlabels,
but the check to see if labels are being replaced has a cost.

Signed-off-by: Bryan Boreham <[email protected]>

storage/remote/queue_manager.go

@@ -957,13 +957,6 @@ func (t *QueueManager) Stop() {
 	if t.mcfg.Send {
 		t.metadataWatcher.Stop()
 	}
-
-	// On shutdown, release the strings in the labels from the intern pool.
-	t.seriesMtx.Lock()
-	for _, labels := range t.seriesLabels {
-		t.releaseLabels(labels)
-	}
-	t.seriesMtx.Unlock()
 	t.metrics.unregister()
 }
 
@@ -985,14 +978,6 @@ func (t *QueueManager) StoreSeries(series []record.RefSeries, index int) {
 			continue
 		}
 		lbls := t.builder.Labels()
-		t.internLabels(lbls)
-
-		// We should not ever be replacing a series labels in the map, but just
-		// in case we do we need to ensure we do not leak the replaced interned
-		// strings.
-		if orig, ok := t.seriesLabels[s.Ref]; ok {
-			t.releaseLabels(orig)
-		}
 		t.seriesLabels[s.Ref] = lbls
 	}
 }
@@ -1037,7 +1022,6 @@ func (t *QueueManager) SeriesReset(index int) {
 	for k, v := range t.seriesSegmentIndexes {
 		if v < index {
 			delete(t.seriesSegmentIndexes, k)
-			t.releaseLabels(t.seriesLabels[k])
 			delete(t.seriesLabels, k)
 			delete(t.seriesMetadata, k)
 			delete(t.droppedSeries, k)
@@ -1059,14 +1043,6 @@ func (t *QueueManager) client() WriteClient {
 	return t.storeClient
 }
 
-func (t *QueueManager) internLabels(lbls labels.Labels) {
-	lbls.InternStrings(t.interner.intern)
-}
-
-func (t *QueueManager) releaseLabels(ls labels.Labels) {
-	ls.ReleaseStrings(t.interner.release)
-}
-
 // processExternalLabels merges externalLabels into b. If b contains
 // a label in externalLabels, the value in b wins.
 func processExternalLabels(b *labels.Builder, externalLabels []labels.Label) {