.

wcfs/misc.go

@@ -668,68 +668,6 @@ func parseWatch(msg string) (oid zodb.Oid, at zodb.Tid, err error) {
 	return oid, at, nil
 }
 
-// ---- btree.ΔTail + root -> BigFile ----
-
-// ΔFTail is btree.ΔTail but additionally tracks tree-root -> file relation.
-type ΔFTail struct {
-	*xbtree.ΔTail
-	fileIdx map[*btree.LOBTree]SetBigFile	// root -> {} BigFile	XXX root -> oid?
-}
-
-type ΔFentry struct {
-	Rev     zodb.Tid
-	Changev []ΔFile
-}
-
-type ΔFile struct {
-	File *BigFile
-	Blkv []int64
-}
-
-func NewΔFTail(at0 zodb.Tid) *ΔFTail {
-	return &ΔFTail{
-		ΔTail:   xbtree.NewΔTail(at0),
-		fileIdx: make(map[*btree.LOBTree]SetBigFile),
-	}
-}
-
-// 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) {
-	δf.ΔTail.Track(path)
-	root := path[0].(*btree.LOBTree)
-	files, ok := δf.fileIdx[root]
-	if !ok {
-		files = SetBigFile{}
-		δf.fileIdx[root] = files
-	}
-	files.Add(file)
-}
-
-func (δf *ΔFTail) Update(δZ *zodb.EventCommit) ΔFentry {
-	δB := δf.ΔTail.Update(δZ)
-	var changev []ΔFile // δB.Changev root -> file (via .fileIdx)
-	for _, δ := range δB.Changev {
-		files := δf.fileIdx[δ.Root]
-		if len(files) == 0 {
-			panic(fmt.Sprintf("ΔFTail: root<%s> -> ø file", δ.Root.POid()))
-		}
-		for file := range files {
-			changev = append(changev, ΔFile{
-				File: file,
-				Blkv: δ.Keyv,
-			})
-		}
-	}
-
-	return ΔFentry{
-		Rev:     δB.Rev,
-		Changev: changev,
-	}
-}
-
-
 // ---- make df happy (else it complains "function not supported") ----
 
 func (root *Root) StatFs() *fuse.StatfsOut {

wcfs/δftail.go

+// Copyright (C) 2019  Nexedi SA and Contributors.
+//                     Kirill Smelkov <kirr@nexedi.com>
+//
+// This program is free software: you can Use, Study, Modify and Redistribute
+// it under the terms of the GNU General Public License version 3, or (at your
+// option) any later version, as published by the Free Software Foundation.
+//
+// You can also Link and Combine this program with other software covered by
+// the terms of any of the Free Software licenses or any of the Open Source
+// Initiative approved licenses and Convey the resulting work. Corresponding
+// source of such a combination shall include the source code for all other
+// software used.
+//
+// This program is distributed WITHOUT ANY WARRANTY; without even the implied
+// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+//
+// See COPYING file for full licensing terms.
+// See https://www.nexedi.com/licensing for rationale and options.
+
+package main
+// ΔFtail - merge btree.ΔTail with history of ZBlk
+
+
+// ΔFTail is like btree.ΔTail but additionally tracks tree-root -> file relation and
+// takes ZBlk history into account.
+type ΔFTail struct {
+	*xbtree.ΔTail
+	fileIdx map[*btree.LOBTree]SetBigFile	// root -> {} BigFile	XXX root -> oid?
+}
+
+type ΔFentry struct {
+	Rev     zodb.Tid
+	Changev []ΔFile
+}
+
+type ΔFile struct {
+	File *BigFile
+	Blkv []int64
+}
+
+func NewΔFTail(at0 zodb.Tid) *ΔFTail {
+	return &ΔFTail{
+		ΔTail:   xbtree.NewΔTail(at0),
+		fileIdx: make(map[*btree.LOBTree]SetBigFile),
+	}
+}
+
+// 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) {
+	δf.ΔTail.Track(path)
+	root := path[0].(*btree.LOBTree)
+	files, ok := δf.fileIdx[root]
+	if !ok {
+		files = SetBigFile{}
+		δf.fileIdx[root] = files
+	}
+	files.Add(file)
+}
+
+// XXX
+func (δf *ΔFTail) Update(δZ *zodb.EventCommit) ΔFentry {
+	δB := δf.ΔTail.Update(δZ)
+	var changev []ΔFile // δB.Changev root -> file (via .fileIdx)
+	for _, δ := range δB.Changev {
+		files := δf.fileIdx[δ.Root]
+		if len(files) == 0 {
+			panic(fmt.Sprintf("ΔFTail: root<%s> -> ø file", δ.Root.POid()))
+		}
+		for file := range files {
+			changev = append(changev, ΔFile{
+				File: file,
+				Blkv: δ.Keyv,
+			})
+		}
+	}
+
+	return ΔFentry{
+		Rev:     δB.Rev,
+		Changev: changev,
+	}
+}
+
+// LastRevOf return last_rev file[blk] @at	XXX
+//
+// XXX -> merge into ZBigFile.LoadBlk?
+// XXX ZBigFile.LoadBlk(blk) -> blkdata, rev
+func (δf *ΔFTail) LastRevOf(file *BigFile, blk int64, at zodb.Tid) (_ zodb.Tid, exact bool) {
+	// revision of when blktab[blk] entry changed last.
+	treeKeyRev := δf.ΔTail.LastRevOf(file.zfile.blktab, blk, at)	// XXX activate?
+
+	// blktab[blk] is only a pointer (to ZBlk) and ZBlk could itself have
+	// been changing after treeKeyRev. We have to check for that.
+	panic("TODO")
+}