store/bucket: remove sort.Slice data race

The matchers slice is now sorted in each call but that introduces a data
race because the slice is shared between all calls. Do the sorting once
on the outermost function.

Signed-off-by: Giedrius Statkevičius <giedrius.statkevicius@vinted.com>

pkg/store/bucket.go

@@ -1284,6 +1284,17 @@ func (s *BucketStore) Series(req *storepb.SeriesRequest, srv storepb.Store_Serie
 			continue
 		}
 
+		// Sort matchers to make sure we generate the same cache key.
+		sort.Slice(blockMatchers, func(i, j int) bool {
+			if blockMatchers[i].Type == blockMatchers[j].Type {
+				if blockMatchers[i].Name == blockMatchers[j].Name {
+					return blockMatchers[i].Value < blockMatchers[j].Value
+				}
+				return blockMatchers[i].Name < blockMatchers[j].Name
+			}
+			return blockMatchers[i].Type < blockMatchers[j].Type
+		})
+
 		blocks := bs.getFor(req.MinTime, req.MaxTime, req.MaxResolutionWindow, reqBlockMatchers)
 
 		if s.debugLogging {
@@ -1527,6 +1538,17 @@ func (s *BucketStore) LabelNames(ctx context.Context, req *storepb.LabelNamesReq
 			continue
 		}
 
+		// Sort matchers to make sure we generate the same cache key.
+		sort.Slice(reqSeriesMatchersNoExtLabels, func(i, j int) bool {
+			if reqSeriesMatchersNoExtLabels[i].Type == reqSeriesMatchersNoExtLabels[j].Type {
+				if reqSeriesMatchersNoExtLabels[i].Name == reqSeriesMatchersNoExtLabels[j].Name {
+					return reqSeriesMatchersNoExtLabels[i].Value < reqSeriesMatchersNoExtLabels[j].Value
+				}
+				return reqSeriesMatchersNoExtLabels[i].Name < reqSeriesMatchersNoExtLabels[j].Name
+			}
+			return reqSeriesMatchersNoExtLabels[i].Type < reqSeriesMatchersNoExtLabels[j].Type
+		})
+
 		resHints.AddQueriedBlock(b.meta.ULID)
 
 		indexr := b.indexReader()
@@ -1727,6 +1749,17 @@ func (s *BucketStore) LabelValues(ctx context.Context, req *storepb.LabelValuesR
 			reqSeriesMatchersNoExtLabels = append(reqSeriesMatchersNoExtLabels, m)
 		}
 
+		// Sort matchers to make sure we generate the same cache key.
+		sort.Slice(reqSeriesMatchersNoExtLabels, func(i, j int) bool {
+			if reqSeriesMatchersNoExtLabels[i].Type == reqSeriesMatchersNoExtLabels[j].Type {
+				if reqSeriesMatchersNoExtLabels[i].Name == reqSeriesMatchersNoExtLabels[j].Name {
+					return reqSeriesMatchersNoExtLabels[i].Value < reqSeriesMatchersNoExtLabels[j].Value
+				}
+				return reqSeriesMatchersNoExtLabels[i].Name < reqSeriesMatchersNoExtLabels[j].Name
+			}
+			return reqSeriesMatchersNoExtLabels[i].Type < reqSeriesMatchersNoExtLabels[j].Type
+		})
+
 		resHints.AddQueriedBlock(b.meta.ULID)
 
 		indexr := b.indexReader()
@@ -2203,16 +2236,6 @@ func (r *bucketIndexReader) ExpandedPostings(ctx context.Context, ms []*labels.M
 		return nil, nil
 	}
 
-	// Sort matchers to make sure we generate the same cache key.
-	sort.Slice(ms, func(i, j int) bool {
-		if ms[i].Type == ms[j].Type {
-			if ms[i].Name == ms[j].Name {
-				return ms[i].Value < ms[j].Value
-			}
-			return ms[i].Name < ms[j].Name
-		}
-		return ms[i].Type < ms[j].Type
-	})
 	hit, postings, err := r.fetchExpandedPostingsFromCache(ctx, ms, bytesLimiter)
 	if err != nil {
 		return nil, err