.

wcfs/δbtail.go

@@ -119,13 +119,24 @@ type ΔBtail struct {
 	// tracked index: BTree|Bucket -> top tree element.
 	// XXX allow only single root (else it is "tree corrupt") ?
 	// XXX as of @head state
-	trackIdx map[zodb.Oid]SetOid // oid -> {} roots
+//	trackIdx map[zodb.Oid]SetOid // oid -> {} roots
 
 	// tracked objects that are not yet taken into account in current δBtail
 	trackNew SetOid
 
 	// tracked keys that are not in current version of the tree.
 	tkdel SetKey
+
+
+	// tracked nodes index: node -> parent + keys tracked under this node
+	trackIdx map[zodb.Oid]nodeTrack
+}
+
+// XXX place
+// nodeTrack represents tracking information about a node.
+type nodeTrack struct {
+	parent      zodb.Oid // parent node | InvalidOid for root
+	trackedKeys SetKey   // keys tracked under this node; nil for root
 }
 
 // ΔB represents a change in BTrees space.
@@ -173,7 +184,8 @@ func NewΔBtail(at0 zodb.Tid, db *zodb.DB) *ΔBtail {
 	return &ΔBtail{
 		δZtail:   zodb.NewΔTail(at0),
 		byRoot:   make(map[zodb.Oid]*ΔTtail),
-		trackIdx: make(map[zodb.Oid]SetOid),
+//		trackIdx: make(map[zodb.Oid]SetOid),
+		trackIdx: map[zodb.Oid]nodeTrack{},
 		tkdel:    SetKey{},
 		db:       db,
 	}
@@ -227,16 +239,26 @@ func (δBtail *ΔBtail) Track(key Key, keyPresent bool, path []Node, flags Track
 	for _, node := range path { oidv = append(oidv, node.POid()) }
 	fmt.Printf("Track %v\n", oidv)
 
+	parent := zodb.InvalidOid
 	for _, node := range path {
 		oid := node.POid()
 		// XXX check for InvalidOid  (e.g. T/B1:a with bucket not having its own oid.
-		nodeRoots, ok := δBtail.trackIdx[oid]
+		track, ok := δBtail.trackIdx[oid]
 		if !ok {
-			nodeRoots = make(SetOid)
-			δBtail.trackIdx[oid] = nodeRoots
+			track = nodeTrack{parent: parent}
+			if parent != zodb.InvalidOid {
+				track.trackedKeys = SetKey{}
+			}
+			δBtail.trackIdx[oid] = track
 			// XXX .trackNew += oid
 		}
-		nodeRoots.Add(root)
+		if track.parent != parent {
+			// XXX -> error (e.g. due to corrupt data in ZODB)
+			panicf("node %s is reachable from multiple parents: %s %s",
+				oid, track.parent, parent)
+		}
+		track.trackedKeys.Add(key)
+		parent = oid
 	}
 
 	_, ok := δBtail.byRoot[root]