From 57daf79192485494cb49b04c5dab5265ece3ed4e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Peter=20S=CC=8Ctibrany=CC=81?= <peter.stibrany@grafana.com>
Date: Tue, 28 Sep 2021 10:29:54 +0200
Subject: [PATCH] More review feedback.

---
 tsdb/compact.go | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/tsdb/compact.go b/tsdb/compact.go
index 79ec8f60f..167378bd7 100644
--- a/tsdb/compact.go
+++ b/tsdb/compact.go
@@ -605,7 +605,7 @@ func (c *LeveledCompactor) write(dest string, outBlocks []shardedBlock, blocks .
 			if ob.tmpDir != "" {
 				// RemoveAll returns no error when tmp doesn't exist so it is safe to always run it.
 				if removeErr := os.RemoveAll(ob.tmpDir); removeErr != nil {
-					level.Error(c.logger).Log("msg", "removed tmp folder after failed compaction", "dir", ob.tmpDir, "err", removeErr.Error())
+					level.Error(c.logger).Log("msg", "Failed to remove temp folder after failed compaction", "dir", ob.tmpDir, "err", removeErr.Error())
 				}
 			}
 
@@ -615,7 +615,7 @@ func (c *LeveledCompactor) write(dest string, outBlocks []shardedBlock, blocks .
 			if err != nil && ob.blockDir != "" {
 				// RemoveAll returns no error when tmp doesn't exist so it is safe to always run it.
 				if removeErr := os.RemoveAll(ob.blockDir); removeErr != nil {
-					level.Error(c.logger).Log("msg", "removed block folder after failed compaction", "dir", ob.blockDir, "err", removeErr.Error())
+					level.Error(c.logger).Log("msg", "Failed to remove block folder after failed compaction", "dir", ob.blockDir, "err", removeErr.Error())
 				}
 			}
 		}
@@ -828,7 +828,7 @@ func (c *LeveledCompactor) populateBlock(blocks []BlockReader, minT, maxT int64,
 	}
 
 	var (
-		ref  = uint64(0)
+		refs = make([]uint64, len(outBlocks))
 		chks []chunks.Meta
 	)
 
@@ -864,22 +864,22 @@ func (c *LeveledCompactor) populateBlock(blocks []BlockReader, minT, maxT int64,
 			continue
 		}
 
-		ob := outBlocks[0]
+		obIx := uint64(0)
 		if len(outBlocks) > 1 {
-			ob = outBlocks[s.Labels().Hash()%uint64(len(outBlocks))]
+			obIx = s.Labels().Hash() % uint64(len(outBlocks))
 		}
 
-		if err := ob.chunkw.WriteChunks(chks...); err != nil {
+		if err := outBlocks[obIx].chunkw.WriteChunks(chks...); err != nil {
 			return errors.Wrap(err, "write chunks")
 		}
-		if err := ob.indexw.AddSeries(ref, s.Labels(), chks...); err != nil {
+		if err := outBlocks[obIx].indexw.AddSeries(refs[obIx], s.Labels(), chks...); err != nil {
 			return errors.Wrap(err, "add series")
 		}
 
-		ob.meta.Stats.NumChunks += uint64(len(chks))
-		ob.meta.Stats.NumSeries++
+		outBlocks[obIx].meta.Stats.NumChunks += uint64(len(chks))
+		outBlocks[obIx].meta.Stats.NumSeries++
 		for _, chk := range chks {
-			ob.meta.Stats.NumSamples += uint64(chk.Chunk.NumSamples())
+			outBlocks[obIx].meta.Stats.NumSamples += uint64(chk.Chunk.NumSamples())
 		}
 
 		for _, chk := range chks {
@@ -887,7 +887,7 @@ func (c *LeveledCompactor) populateBlock(blocks []BlockReader, minT, maxT int64,
 				return errors.Wrap(err, "put chunk")
 			}
 		}
-		ref++
+		refs[obIx]++
 	}
 	if set.Err() != nil {
 		return errors.Wrap(set.Err(), "iterate compaction set")