.

wcfs/internal/zdata/δftail.go

@@ -81,13 +81,27 @@ type setOid = set.Oid
 type ΔFtail struct {
 	// ΔFtail merges ΔBtail with history of ZBlk
 	δBtail  *xbtree.ΔBtail
-	fileIdx map[zodb.Oid]setOid   // tree-root -> {} ZBigFile<oid>  as of @head
-	rootIdx map[zodb.Oid]zodb.Oid // file -> tree-root              as of @head
+	fileIdx map[zodb.Oid]setOid   // tree-root -> {} ZBigFile<oid>  as of @head  XXX -> root2file ?
+//	rootIdx map[zodb.Oid]zodb.Oid // file -> tree-root              as of @head
+	byFile  map[zodb.Oid]*_ΔFileTail // file -> δf tail	XXX
 
-	trackSetZFile setOid                  // set of tracked ZBigFiles	as of @head
+//	trackSetZFile setOid                  // set of tracked ZBigFiles	as of @head
 	trackSetZBlk  map[zodb.Oid]*zblkTrack // zblk -> {} root -> {}blk	as of @head
 }
 
+// _ΔFileTail represents tail of revisional changes to one file.
+type _ΔFileTail struct {
+	root zodb.Oid      // .blktab as of @head
+	vδE  []_ΔFileEpoch // changes to ZBigFile object itself  ; nil if not yet rebuilt
+}
+
+// _ΔFileEpoch represent change to ZBigFile object.
+type _ΔFileEpoch struct {
+	Rev        zodb.Tid
+	newRoot    zodb.Oid // .blktab was changed to point to newRoot  ; VDEL if ZBigFile deleted
+	newBlkSize int64    // .blksize was changed to newBlkSize       ; -1   if ZBigFile deleted
+}
+
 // zblkTrack keeps information in which root/blocks ZBlk is present as of @head.
 type zblkTrack struct {
 	inroot map[zodb.Oid]setI64  // {} root -> {}blk
@@ -118,8 +132,9 @@ func NewΔFtail(at0 zodb.Tid, db *zodb.DB) *ΔFtail {
 	return &ΔFtail{
 		δBtail:        xbtree.NewΔBtail(at0, db),
 		fileIdx:       map[zodb.Oid]setOid{},
-		rootIdx:       map[zodb.Oid]zodb.Oid{},
-		trackSetZFile: setOid{},
+//		rootIdx:       map[zodb.Oid]zodb.Oid{},
+//		trackSetZFile: setOid{},
+		byFile:        map[zodb.Oid]*_ΔFileTail{},
 		trackSetZBlk:  map[zodb.Oid]*zblkTrack{},
 	}
 }
@@ -163,17 +178,17 @@ func (δFtail *ΔFtail) Track(file *ZBigFile, blk int64, path []btree.LONode, zb
 	}
 	files.Add(foid)
 
-	roid_, ok := δFtail.rootIdx[foid]
-	if ok {
-		if roid != roid_ {
-			panicf("zfile<%s> changed root from %s -> %s", foid, roid_, roid)
-		}
-	} else {
-		δFtail.rootIdx[foid] = roid
+	δftail, ok := δFtail.byFile[foid]
+	if !ok {
+		δftail = &_ΔFileTail{root: roid, vδE: nil /*will need to be rebuilt till past*/}
+		δFtail.byFile[foid] = δftail
+	}
+	if δftail.root != roid {
+		panicf("zfile<%s> changed root from %s -> %s", foid, δftail.root, roid)
 	}
 
 
-	δFtail.trackSetZFile.Add(foid)
+//	δFtail.trackSetZFile.Add(foid)
 
 	// associate zblk with file, if it was not hole
 	if zblk != nil {
@@ -282,7 +297,8 @@ func (δFtail *ΔFtail) Update(δZ *zodb.EventCommit) (_ ΔF, err error) {
 	// take zblk changes into account
 	δzfile := map[zodb.Oid]*_ΔZBigFile{} // which tracked ZBigFiles are changed
 	for _, oid := range δZ.Changev {
-		if δFtail.trackSetZFile.Has(oid) {
+		δftail, ok := δFtail.byFile[oid]
+		if ok {
 			δ, err := zfilediff(δFtail.δBtail.DB(), oid, headOld, δZ.Tid)
 			if err != nil {
 				return ΔF{}, err
@@ -290,6 +306,11 @@ func (δFtail *ΔFtail) Update(δZ *zodb.EventCommit) (_ ΔF, err error) {
 
 			if δ != nil {
 				δzfile[oid] = δ
+				δftail.vδE = append(δftail.vδE, _ΔFileEpoch{
+					Rev:        δZ.Tid,
+					newRoot:    δ.blktabNew,
+					newBlkSize: δ.blksizeNew,
+				})
 			}
 
 			continue
@@ -373,6 +394,7 @@ func (δFtail *ΔFtail) SliceByFileRev(zfile *ZBigFile, lo, hi zodb.Tid) /*reado
 	// query .δBtail.SliceByRootRev(file.blktab, lo, hi) +
 	// merge δZBlk history with that.
 
+
 	// merging tree (δT) and Zblk (δZblk) histories into file history (δFile):
 
 	// δT		────────·──────────────·─────────────────·────────────
@@ -387,7 +409,8 @@ func (δFtail *ΔFtail) SliceByFileRev(zfile *ZBigFile, lo, hi zodb.Tid) /*reado
 	// δFile	────────o───────o──────x─────x────────────────────────
 
 
-	root := δFtail.rootIdx[zfile.POid()]
+	δftail := δFtail.byFile[zfile.POid()]
+	root := δftail.root	// XXX take epochs into account
 	vδT := δFtail.δBtail.SliceByRootRev(root, lo, δFtail.Head()) // NOTE @head, not hi
 	vδZ := δFtail.δBtail.ΔZtail().SliceByRev(lo, hi)
 
@@ -514,6 +537,8 @@ func (δFtail *ΔFtail) LastBlkRev(ctx context.Context, zf *ZBigFile, blk int64,
 	}
 	defer zf.PDeactivate()
 
+	// XXX take epochs into account
+
 	// XXX tabRev -> treeRev ?
 	zblkOid, ok, tabRev, tabRevExact, err := δFtail.δBtail.GetAt(ctx, zf.blktab, blk, at)
 	//fmt.Printf("GetAt  #%d @%s  ->  %s, %v, @%s, %v\n", blk, at, zblkOid, ok, tabRev, tabRevExact)