.

wcfs/internal/xbtree/δbtail.go

@@ -202,7 +202,7 @@ type ΔTree struct {
 }
 
 
-// _RebuildJob represents currently in-progress rebuilding job. XXX
+// _RebuildJob represents currently in-progress vδT rebuilding job.
 // XXX place
 type _RebuildJob struct {
 	ready chan struct{} // closed when job completes
@@ -316,15 +316,6 @@ func (δBtail *ΔBtail) Tail() zodb.Tid { return δBtail.δZtail.Tail() }
 //
 // XXX put keycov back to come first?
 func (δBtail *ΔBtail) Track(nodePath []Node, keycov KeyRange) {
-/* XXX kill
-	if traceΔBtail {
-		pathv := []string{}
-		for _, node := range nodePath { pathv = append(pathv, vnode(node)) }
-		tracefΔBtail("\nTrack %s %s\n", keycov, strings.Join(pathv, " -> "))
-		tracefΔBtail("trackSet: %s\n", δBtail.trackSet) // XXX locking
-	}
-*/
-
 	head := δBtail.Head()
 	for _, node := range nodePath {
 		nodeAt := node.PJar().At()
@@ -393,16 +384,24 @@ func (δBtail *ΔBtail) track(path []zodb.Oid, keycov KeyRange) {
 		}
 		return
 	}
-	// XXX also check if leaf   ∈ trackNew      ?
-	// XXX also check if keycov ∈ krebuildJobs
 
-	// queue path into trackNew
+	// queue path into trackNew, if not there already
 	δTtail, ok := δBtail.byRoot[root]
 	if !ok {
 		δTtail = newΔTtail()
 		δBtail.byRoot[root] = δTtail
 	}
 
+	if δTtail.trackNew.Has(leaf) {
+		tracefΔBtail("->T: nop\n")
+		path_ := δTtail.trackNew.Path(leaf)
+		if !pathEqual(path, path_) {
+			panicf("BUG: keyrange %s is already in trackNew via path=%v\ntrack requests path=%v", keycov, path_, path)
+		}
+		return
+	}
+	// XXX also check if keycov ∈ krebuildJobs
+
 	δBtail.trackNewRoots.Add(root)
 	δTtail.trackNew.AddPath(path)
 	δTtail.ktrackNew.AddRange(keycov)
@@ -779,6 +778,7 @@ func vδTMerge1Inplace(pvδT *[]ΔTree, δT ΔTree) (newRevEntry bool) {
 		δv_, already := δTcurr.KV[k]
 		if already {
 			if δv != δv_ {
+				// TODO: return "conflict"
 				panicf("[%v] inconsistent δv:\nδTcurr: %v\nδT:  %v", k, δTcurr, δT)
 			}
 		} else {