.

wcfs/internal/xbtree/δbtail.go

@@ -283,6 +283,9 @@ func (orig *_ΔTtail) Clone() *_ΔTtail {
 
 // vδTClone returns deep copy of []ΔTree.
 func vδTClone(orig []ΔTree) []ΔTree {
+	if orig == nil {
+		return nil
+	}
 	klon := make([]ΔTree, 0, len(orig))
 	for _, origδT := range orig {
 		klonδT := ΔTree{
@@ -512,10 +515,16 @@ func (δBtail *ΔBtail) rebuild1KeyIfNeeded(root zodb.Oid, key Key) error {
 func (δBtail *ΔBtail) rebuild1(root zodb.Oid) error {
 	// XXX locking
 	δTtail := δBtail.byRoot[root] // must be there
-	δtrackSet, δrevSet, err := δTtail.rebuild(root, δBtail.δZtail, δBtail.db)
+//	δtrackSet, δrevSet, err := δTtail.rebuild(root, δBtail.δZtail, δBtail.db)
+	trackNew := δTtail.trackNew
+	δTtail.trackNew = blib.PPTreeSubSet{}
+	vδTnew, δtrackSet, err := vδTBuild(root, trackNew, δBtail.δZtail, δBtail.db)
 	if err != nil {
 		return err
 	}
+	// XXX comment about RCU snapshot
+	δTtail.vδT = vδTClone(δTtail.vδT)
+	δrevSet := vδTMergeInplace(&δTtail.vδT, vδTnew)
 	δBtail.trackSet.UnionInplace(δtrackSet)
 	δBtail.vδBroots_Update(root, δrevSet)
 	return nil
@@ -657,19 +666,41 @@ func vδTBuild1(atPrev zodb.Tid, δZ zodb.ΔRevEntry, trackNew blib.PPTreeSubSet
 
 	debugfΔBtail("  -> root<%s>  δkv*: %v  δtrack*: %v  δtkeycov*: %v\n", root, δT, δtrack, δtkeycov)
 
-	for _, δv := range δT {
+	for k, δv := range δT {
 		// the diff was backward; vδT entries are with diff forward
 		δv.New, δv.Old = δv.Old, δv.New
+		δT[k] = δv
 	}
 
 	return δT, δtrack, δtkeycov, nil
 }
 
 
+// vδTMergeInplace merges vδTnew into vδT.
+//
+// δrevSet indicates set of new revisions created in vδT.
+// vδT is modified inplace.
+//
+// XXX test
+func vδTMergeInplace(pvδT *[]ΔTree, vδTnew []ΔTree) (δrevSet setTid) {
+	// TODO optimize to go through vδT and vδTnew sequentially if needed
+	δrevSet = setTid{}
+	for _, δT := range vδTnew {
+		newRevEntry := vδTMerge1Inplace(pvδT, δT)
+		if newRevEntry {
+			δrevSet.Add(δT.Rev)
+		}
+	}
+	return δrevSet
+}
+
 // vδTMerge1Inplace merges one δT entry into vδT.
+//
+// newRevEntry indicates whether δT.Rev was not there before in vδT.
 // vδT is modified inplace.
-// XXX test for vδTMerge
-func vδTMerge1Inplace(pvδT *[]ΔTree, δT ΔTree) {
+//
+// XXX test
+func vδTMerge1Inplace(pvδT *[]ΔTree, δT ΔTree) (newRevEntry bool) {
 	vδT := *pvδT
 
 	l := len(vδT)
@@ -677,7 +708,7 @@ func vδTMerge1Inplace(pvδT *[]ΔTree, δT ΔTree) {
 		return δT.Rev <= vδT[k].Rev
 	})
 	if j == l || vδT[j].Rev != δT.Rev {
-//		newRevEntry = true
+		newRevEntry = true
 		δTcurr := ΔTree{Rev: δT.Rev, KV: map[Key]ΔValue{}}
 		// insert(@j, δTcurr)
 		vδT = append(vδT[:j],
@@ -698,9 +729,11 @@ func vδTMerge1Inplace(pvδT *[]ΔTree, δT ΔTree) {
 	}
 
 	*pvδT = vδT
+	return newRevEntry
 }
 
 
+/*
 // rebuild rebuilds _ΔTtail taking trackNew requests into account.
 //
 // It returns:
@@ -783,7 +816,9 @@ func (δTtail *_ΔTtail) rebuild(root zodb.Oid, δZtail *zodb.ΔTail, db *zodb.D
 
 	return trackNew, δrevSet, nil
 }
+*/
 
+/*
 // rebuild1 rebuilds δT for single δZ.
 //
 // δtrackNew/δtkeycov represents how trackNew changes when going through `atPrev <- δZ.Rev` .
@@ -877,6 +912,7 @@ func (δTtail *_ΔTtail) rebuild1(atPrev zodb.Tid, δZ zodb.ΔRevEntry, trackNew
 
 	return δtrack, δtkeycov, newRevEntry, nil
 }
+*/
 
 // widenTrackNew widens trackNew to cover δtkeycov.
 func widenTrackNew(trackNew blib.PPTreeSubSet, δtkeycov *blib.RangedKeySet, root zodb.Oid, at zodb.Tid, db *zodb.DB) (err error) {
@@ -940,17 +976,22 @@ func (δBtail *ΔBtail) Update(δZ *zodb.EventCommit) (_ ΔB, err error) {
 			if err != nil {
 				return ΔB{}, err
 			}
+			// XXX vvv kill?
 			if !δTtail.trackNew.Empty() {
 				panicf("BUG: ΔBtail.Update: ΔTtail<%s>.trackNew != ø after _Update1", root)
 			}
-			δTtail.trackNew = trackNew
+//			δTtail.trackNew = trackNew
 
 			// NOTE we cannot skip computing diff for HEAD~..HEAD
 			// even after _Update1 because _Update1 was working with different trackNew.
-			δtrackSet, δrevSet, err := δTtail.rebuild(root, δBtail.δZtail, δBtail.db)
+//			δtrackSet, δrevSet, err := δTtail.rebuild(root, δBtail.δZtail, δBtail.db)
+			vδTnew, δtrackSet, err := vδTBuild(root, trackNew, δBtail.δZtail, δBtail.db)
 			if err != nil {
 				return ΔB{}, err
 			}
+			// XXX comment about RCU snapshot
+			δTtail.vδT = vδTClone(δTtail.vδT)
+			δrevSet := vδTMergeInplace(&δTtail.vδT, vδTnew)
 			δBtail.trackSet.UnionInplace(δtrackSet)
 			δBtail.vδBroots_Update(root, δrevSet)
 		}