add support for asynchronous datastores

go.sum

@@ -76,8 +76,7 @@ github.com/ipfs/go-datastore v0.0.1/go.mod h1:d4KVXhMt913cLBEI/PXAy6ko+W7e9AhyAK
 github.com/ipfs/go-datastore v0.0.5/go.mod h1:d4KVXhMt913cLBEI/PXAy6ko+W7e9AhyAKBGh803qeE=
 github.com/ipfs/go-datastore v0.1.0 h1:TOxI04l8CmO4zGtesENhzm4PwkFwJXY3rKiYaaMf9fI=
 github.com/ipfs/go-datastore v0.1.0/go.mod h1:d4KVXhMt913cLBEI/PXAy6ko+W7e9AhyAKBGh803qeE=
-github.com/ipfs/go-datastore v0.1.1 h1:F4k0TkTAZGLFzBOrVKDAvch6JZtuN4NHkfdcEZL50aI=
-github.com/ipfs/go-datastore v0.1.1/go.mod h1:w38XXW9kVFNp57Zj5knbKWM2T+KOZCGDRVNdgPHtbHw=
+github.com/ipfs/go-datastore v0.3.0 h1:9au0tYi/+n7xeUnGHG6davnS8x9hWbOzP/388Vx3CMs=
 github.com/ipfs/go-datastore v0.3.0/go.mod h1:w38XXW9kVFNp57Zj5knbKWM2T+KOZCGDRVNdgPHtbHw=
 github.com/ipfs/go-detect-race v0.0.1 h1:qX/xay2W3E4Q1U7d9lNs1sU9nvguX0a7319XbyQ6cOk=
 github.com/ipfs/go-detect-race v0.0.1/go.mod h1:8BNT7shDZPo99Q74BpGMK+4D8Mn4j46UU0LZ723meps=

pin.go

@@ -192,6 +192,11 @@ type pinner struct {
 	dstore      ds.Datastore
 }
 
+type syncDAGService interface {
+	ipld.DAGService
+	Sync() error
+}
+
 // NewPinner creates a new pinner using the given datastore as a backend
 func NewPinner(dstore ds.Datastore, serv, internal ipld.DAGService) Pinner {
 
@@ -576,6 +581,19 @@ func (p *pinner) Flush(ctx context.Context) error {
 	k := root.Cid()
 
 	internalset.Add(k)
+
+	if syncDServ, ok := p.dserv.(syncDAGService); ok {
+		if err := syncDServ.Sync(); err != nil {
+			return fmt.Errorf("cannot sync pinned data: %v", err)
+		}
+	}
+
+	if syncInternal, ok := p.internal.(syncDAGService); ok {
+		if err := syncInternal.Sync(); err != nil {
+			return fmt.Errorf("cannot sync pinning data: %v", err)
+		}
+	}
+
 	if err := p.dstore.Put(pinDatastoreKey, k.Bytes()); err != nil {
 		return fmt.Errorf("cannot store pin state: %v", err)
 	}