[#321] endpoint: ListAbstractions: acutally emit one Abstraction per matching hold

endpoint/endpoint_send_abstractions_cache.go

@@ -25,6 +25,10 @@ func init() {
 
 var sendAbstractionsCacheSingleton = newSendAbstractionsCache()
 
+func SendAbstractionsCacheInvalidate(fs string) {
+	sendAbstractionsCacheSingleton.InvalidateFSCache(fs)
+}
+
 type sendAbstractionsCacheDidLoadFSState int
 
 const (

endpoint/endpoint_zfs_abstraction.go

@@ -614,23 +614,23 @@ func listAbstractionsImplFS(ctx context.Context, fs string, query *ListZFSHoldsA
 			panic("implementation error: extractors misconfigured for " + at)
 		}
 		for _, v := range fsvs {
-			var a Abstraction
 			if v.Type == zfs.Bookmark && bmE != nil {
-				a = bmE(fsp, v)
+				if a := bmE(fsp, v); a != nil {
+					emitCandidate(a)
+				}
 			}
-			if v.Type == zfs.Snapshot && holdE != nil && query.CreateTXG.Contains(v.GetCreateTXG()) && (!v.UserRefs.Valid || v.UserRefs.Value > 0) {
+			if v.Type == zfs.Snapshot && holdE != nil && query.CreateTXG.Contains(v.GetCreateTXG()) && (!v.UserRefs.Valid || v.UserRefs.Value > 0) { // FIXME review v.UserRefsValid
 				holds, err := zfs.ZFSHolds(ctx, fsp.ToString(), v.Name)
 				if err != nil {
 					errCb(err, v.ToAbsPath(fsp), "get hold on snap")
 					continue
 				}
 				for _, tag := range holds {
-					a = holdE(fsp, v, tag)
+					if a := holdE(fsp, v, tag); a != nil {
+						emitCandidate(a)
+					}
 				}
 			}
-			if a != nil {
-				emitCandidate(a)
-			}
 		}
 	}
 }

endpoint/endpoint_zfs_abstraction_cursor_and_last_received_hold.go

@@ -183,22 +183,22 @@ func LastReceivedHoldTag(jobID JobID) (string, error) {
 }
 
 func lastReceivedHoldImpl(jobid string) (string, error) {
-	tag := fmt.Sprintf("zrepl_last_received_J_%s", jobid)
+	tag := fmt.Sprintf("%s%s", ReplicationCursorBookmarkNamePrefix, jobid)
 	if err := zfs.ValidHoldTag(tag); err != nil {
 		return "", err
 	}
 	return tag, nil
 }
 
-func MoveLastReceivedHold(ctx context.Context, fs string, to zfs.FilesystemVersion, jobID JobID) error {
+func CreateLastReceivedHold(ctx context.Context, fs string, to zfs.FilesystemVersion, jobID JobID) (Abstraction, error) {
 
 	if !to.IsSnapshot() {
-		return errors.Errorf("last-received-hold: target must be a snapshot: %s", to.FullPath(fs))
+		return nil, errors.Errorf("last-received-hold: target must be a snapshot: %s", to.FullPath(fs))
 	}
 
 	tag, err := LastReceivedHoldTag(jobID)
 	if err != nil {
-		return errors.Wrap(err, "last-received-hold: hold tag")
+		return nil, errors.Wrap(err, "last-received-hold: hold tag")
 	}
 
 	// we never want to be without a hold
@@ -206,7 +206,23 @@ func MoveLastReceivedHold(ctx context.Context, fs string, to zfs.FilesystemVersi
 
 	err = zfs.ZFSHold(ctx, fs, to, tag)
 	if err != nil {
-		return errors.Wrap(err, "last-received-hold: hold newly received")
+		return nil, errors.Wrap(err, "last-received-hold: hold newly received")
+	}
+
+	return &holdBasedAbstraction{
+		Type:              AbstractionLastReceivedHold,
+		FS:                fs,
+		FilesystemVersion: to,
+		JobID:             jobID,
+		Tag:               tag,
+	}, nil
+}
+
+func MoveLastReceivedHold(ctx context.Context, fs string, to zfs.FilesystemVersion, jobID JobID) error {
+
+	_, err := CreateLastReceivedHold(ctx, fs, to, jobID)
+	if err != nil {
+		return err
 	}
 
 	q := ListZFSHoldsAndBookmarksQuery{