tsdb: Introduced new constructor for LeveledCompactor to take in metrics (prometheus#16408)

* Introduced new constructor for LeveledCompactor to take in metrics

Signed-off-by: Alex Le <leqiyue@amazon.com>

* Added Metrics to LeveledCompactorOptions

Signed-off-by: Alex Le <leqiyue@amazon.com>

---------

Signed-off-by: Alex Le <leqiyue@amazon.com>

Author: alexqyle

tsdb/compact.go

@@ -169,6 +169,8 @@ type LeveledCompactorOptions struct {
 	// EnableOverlappingCompaction enables compaction of overlapping blocks. In Prometheus it is always enabled.
 	// It is useful for downstream projects like Mimir, Cortex, Thanos where they have a separate component that does compaction.
 	EnableOverlappingCompaction bool
+	// Metrics is set of metrics for Compactor. By default, NewCompactorMetrics would be called to initialize metrics unless it is provided.
+	Metrics *CompactorMetrics
 }
 
 type PostingsDecoderFactory func(meta *BlockMeta) index.PostingsDecoder
@@ -214,11 +216,14 @@ func NewLeveledCompactorWithOptions(ctx context.Context, r prometheus.Registerer
 	if pe == nil {
 		pe = index.EncodePostingsRaw
 	}
+	if opts.Metrics == nil {
+		opts.Metrics = NewCompactorMetrics(r)
+	}
 	return &LeveledCompactor{
 		ranges:                      ranges,
 		chunkPool:                   pool,
 		logger:                      l,
-		metrics:                     NewCompactorMetrics(r),
+		metrics:                     opts.Metrics,
 		ctx:                         ctx,
 		maxBlockChunkSegmentSize:    maxBlockChunkSegmentSize,
 		mergeFunc:                   mergeFunc,