use the new traits for hotstore gc

blockstore/badger/blockstore.go

@@ -180,7 +180,7 @@ func (b *Blockstore) CollectGarbage() error {
 	}
 
 	for err == nil {
-		err = b.db.RunValueLogGC(0.125)
+		err = b.DB.RunValueLogGC(0.125)
 	}
 
 	if err == badger.ErrNoRewrite {

blockstore/splitstore/splitstore.go

@@ -1697,30 +1697,6 @@ func (s *SplitStore) waitForMissingRefs(markSet MarkSet) {
 	}
 }
 
-func (s *SplitStore) gcHotstore() {
-	if compact, ok := s.hot.(interface{ Compact() error }); ok {
-		log.Infof("compacting hotstore")
-		startCompact := time.Now()
-		err := compact.Compact()
-		if err != nil {
-			log.Warnf("error compacting hotstore: %s", err)
-			return
-		}
-		log.Infow("hotstore compaction done", "took", time.Since(startCompact))
-	}
-
-	if gc, ok := s.hot.(interface{ CollectGarbage() error }); ok {
-		log.Infof("garbage collecting hotstore")
-		startGC := time.Now()
-		err := gc.CollectGarbage()
-		if err != nil {
-			log.Warnf("error garbage collecting hotstore: %s", err)
-			return
-		}
-		log.Infow("hotstore garbage collection done", "took", time.Since(startGC))
-	}
-}
-
 func (s *SplitStore) setBaseEpoch(epoch abi.ChainEpoch) error {
 	s.baseEpoch = epoch
 	return s.ds.Put(baseEpochKey, epochToBytes(epoch))

blockstore/splitstore/splitstore_gc.go

@@ -0,0 +1,39 @@
+package splitstore
+
+import (
+	"time"
+
+	bstore "github.com/filecoin-project/lotus/blockstore"
+)
+
+func (s *SplitStore) gcHotstore() {
+	// check if the hotstore is movable; if so, move it.
+	if mover, ok := s.hot.(bstore.BlockstoreMover); ok {
+		log.Info("moving hotstore")
+		startMove := time.Now()
+		err := mover.MoveTo("", nil)
+		if err != nil {
+			log.Warnf("error moving hotstore: %s", err)
+			return
+		}
+
+		log.Infof("moving hotstore done", "took", time.Since(startMove))
+		return
+	}
+
+	// check if the hotstore supports online GC; if so, GC it.
+	if gc, ok := s.hot.(bstore.BlockstoreGC); ok {
+		log.Info("garbage collecting hotstore")
+		startGC := time.Now()
+		err := gc.CollectGarbage()
+		if err != nil {
+			log.Warnf("error garbage collecting hotstore: %s", err)
+			return
+		}
+
+		log.Infof("garbage collecting hotstore done", "took", time.Since(startGC))
+		return
+	}
+
+	return
+}