perf(tsdb): return full slice to pool after use (#20969)

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

Author: bboreham

pkg/storage/stores/shipper/indexshipper/tsdb/index/index.go

@@ -2255,7 +2255,7 @@ func (dec *Decoder) readChunkStatsV3(d *encoding.Decbuf, from, through int64) (r
 	nMarkers := d.Uvarint()
 
 	relevantPages := chunkPageMarkersPool.Get(nMarkers)
-	defer chunkPageMarkersPool.Put(relevantPages)
+	defer func() { chunkPageMarkersPool.Put(relevantPages) }()
 	for i := 0; i < nMarkers; i++ {
 		var marker chunkPageMarker
 		marker.decode(d)
@@ -2351,7 +2351,7 @@ func (dec *Decoder) accumulateChunkStats(d *encoding.Decbuf, nChunks int, from,
 func (dec *Decoder) readChunkStatsPriorV3(d *encoding.Decbuf, seriesRef storage.SeriesRef, from, through int64) (res ChunkStats, err error) {
 	// prior to v3, chunks needed iteration for stats aggregation
 	chks := ChunkMetasPool.Get()
-	defer ChunkMetasPool.Put(chks)
+	defer func() { ChunkMetasPool.Put(chks) }()
 	err = dec.readChunks(FormatV2, d, seriesRef, from, through, &chks)
 	if err != nil {
 		return ChunkStats{}, err

pkg/storage/stores/shipper/indexshipper/tsdb/index_client.go

@@ -309,7 +309,7 @@ func (c *IndexClient) GetShards(ctx context.Context, userID string, from, throug
 	resp := &logproto.ShardsResponse{}
 
 	series := sharding.SizedFPs(sharding.SizedFPsPool.Get(len(m)))
-	defer sharding.SizedFPsPool.Put(series)
+	defer func() { sharding.SizedFPsPool.Put(series) }()
 
 	for fp, chks := range m {
 		x := sharding.SizedFP{Fp: fp}

pkg/storage/stores/shipper/indexshipper/tsdb/single_file_index.go

@@ -166,7 +166,7 @@ func (i *TSDBIndex) ForSeries(ctx context.Context, _ string, fpFilter index.Fing
 
 	var ls labels.Labels
 	chks := ChunkMetasPool.Get()
-	defer ChunkMetasPool.Put(chks)
+	defer func() { ChunkMetasPool.Put(chks) }()
 
 	var filterer chunk.Filterer
 	if i.chunkFilter != nil {

pkg/storage/stores/shipper/indexshipper/tsdb/single_file_index_test.go

@@ -264,6 +264,7 @@ func BenchmarkTSDBIndex_GetChunkRefs(b *testing.B) {
 		chkRefs, err := tsdbIndex.GetChunkRefs(context.Background(), "fake", queryFrom, queryThrough, nil, nil, labels.MustNewMatcher(labels.MatchEqual, "foo", "bar"))
 		require.NoError(b, err)
 		require.Len(b, chkRefs, numChunksToMatch*2)
+		ChunkRefsPool.Put(chkRefs)
 	}
 }