gc: invoke CollectGarbage() on badger to reclaim disk space

gc.go

@@ -1,6 +1,10 @@
 package main
 
-import "context"
+import (
+	"context"
+
+	badger4 "github.com/ipfs/go-ds-badger4"
+)
 
 // GC is a really stupid simple algorithm where we just delete things until
 // weve deleted enough things
@@ -10,11 +14,12 @@ func (nd *Node) GC(ctx context.Context, todelete int64) error {
 		return err
 	}
 
+deleteBlocks:
 	for todelete > 0 {
 		select {
 		case k, ok := <-keys:
 			if !ok {
-				return nil
+				break deleteBlocks
 			}
 
 			size, err := nd.blockstore.GetSize(ctx, k)
@@ -32,5 +37,12 @@ func (nd *Node) GC(ctx context.Context, todelete int64) error {
 		}
 	}
 
+	if ds, ok := nd.datastore.(*badger4.Datastore); ok {
+		err = ds.CollectGarbage(ctx)
+		if err != nil {
+			return err
+		}
+	}
+
 	return nil
 }