.

wcfs/internal/xbtree/δbtail.go

@@ -38,19 +38,12 @@ type Key    = int64
 type Value  = zodb.Oid // XXX assumes key points to IPersistent
                        // XXX how to represent deletion? InvalidOid?
 
-// ΔB represents a change in BTrees space.
-//
-// XXX place
-type ΔB struct {
-	Rev	zodb.Tid
-	Change	map[*Tree]map[Key]Value // {} root -> {}(key, value)
-}
-
 // ΔTail represents tail of revisional changes to BTrees.
 //
 // It semantically consists of
 //
-//	[]δB			; rev ∈ (tail, head
+//	[]δB			; rev ∈ (tail, head]
+//	atTail
 //
 // where δB represents a change in BTrees space
 //
@@ -58,7 +51,10 @@ type ΔB struct {
 //		.rev↑
 //		{} root -> {}(key, value)
 //
-//	XXX + atTail
+// and atTail keeps set of k/v @tail for keys changed in (tail, head]
+//
+//	atTail:
+//		{} root -> {}(key, value)
 //
 // It covers changes to keys from tracked subset of BTrees parts and
 // semantically consists of
@@ -111,6 +107,13 @@ type ΔTail struct {
 	trackNew map[zodb.Oid]struct{}	// XXX SetOid
 }
 
+// Δ represents a change in BTrees space.
+type Δ struct {
+	Rev	zodb.Tid
+	Change	map[*Tree]map[Key]Value // {} root -> {}(key, value)
+}
+
+
 // ΔRoots describes which BTrees were change in one revision.
 // XXX kill?
 type ΔRoots struct {
@@ -204,9 +207,7 @@ func (δb *ΔTail) Track(path []Node) {	// XXX Tree|Bucket; path[0] = root
 // Only those objects from δZ that belong to tracked set are guaranteed to be
 // taken into account. In other words a tree history will assuredly include
 // only those keys, that correspond to tracked subset of δZ.
-//
-// XXX returned [](root, []key) -> move to separate SliceByRev to get diff?
-func (btail *ΔTail) Update(δZ *zodb.EventCommit) ΔB {
+func (btail *ΔTail) Update(δZ *zodb.EventCommit) Δ {
 	btail.ΔZtail.Append(δZ.Tid, δZ.Changev)
 
 	// {} root -> []oid changed under that root
@@ -221,7 +222,7 @@ func (btail *ΔTail) Update(δZ *zodb.EventCommit) ΔB {
 		}
 	}
 
-	δB := ΔB{Rev: δZ.Tid, Change: make(map[*Tree]map[Key]Value)}
+	δB := Δ{Rev: δZ.Tid, Change: make(map[*Tree]map[Key]Value)}
 
 	if len(δZByRoot) == 0 {
 		return δB // tracked set not changed

wcfs/wcfs.go

@@ -508,7 +508,7 @@ type BigFileDir struct {
 	// δ of tracked BTree nodes of all BigFiles + -> which file
 	// (used only for head/, not revX/)
 	δFmu   sync.RWMutex
-	δFtail *ΔFTail
+	δFtail *ΔFtail
 }
 
 // /(head|<rev>)/bigfile/<bigfileX>	- served by BigFile.

wcfs/δftail.go

@@ -51,7 +51,7 @@ import (
 //
 //
 // XXX only tracked blocks.
-type ΔFTail struct {
+type ΔFtail struct {
 	*xbtree.ΔTail
 	fileIdx map[*btree.LOBTree]SetBigFile	// root -> {} BigFile	XXX root -> oid?
 }
@@ -62,8 +62,8 @@ type ΔF struct {
 	Change	map[*BigFile]SetI64 // file -> δfile (= {}#blk)
 }
 
-func NewΔFTail(at0 zodb.Tid) *ΔFTail {
-	return &ΔFTail{
+func NewΔFTail(at0 zodb.Tid) *ΔFtail {
+	return &ΔFtail{
 		ΔTail:   xbtree.NewΔTail(at0),
 		fileIdx: make(map[*btree.LOBTree]SetBigFile),
 	}
@@ -72,7 +72,7 @@ func NewΔFTail(at0 zodb.Tid) *ΔFTail {
 // Track adds tree path to tracked set and associates path root with file.
 //
 // A root can be associated with several files (each provided on different Track call).
-func (δf *ΔFTail) Track(file *BigFile, path []btree.LONode) {
+func (δf *ΔFtail) Track(file *BigFile, path []btree.LONode) {
 	δf.ΔTail.Track(path)
 	root := path[0].(*btree.LOBTree)
 	files, ok := δf.fileIdx[root]
@@ -86,13 +86,13 @@ func (δf *ΔFTail) Track(file *BigFile, path []btree.LONode) {
 // Update updates δFtail given raw ZODB changes.
 //
 // It returns corresponding change in files space.
-func (δFtail *ΔFTail) Update(δZ *zodb.EventCommit) ΔF {
+func (δFtail *ΔFtail) Update(δZ *zodb.EventCommit) ΔF {
 	δB := δFtail.ΔTail.Update(δZ)
 	δF := ΔF{Rev: δB.Rev, Change: make(map[*BigFile]SetI64)}
 	for root, δt := range δB.Change {
 		files := δFtail.fileIdx[root]
 		if len(files) == 0 {
-			panicf("ΔFTail: root<%s> -> ø file", root.POid())
+			panicf("ΔFtail: root<%s> -> ø file", root.POid())
 		}
 		for file := range files {
 			δfile, ok := δF.Change[file]