.

wcfs/internal/zdata/δftail.go

@@ -101,6 +101,9 @@ type _ΔFileEpoch struct {
 	newRoot    zodb.Oid // .blktab was changed to point to newRoot  ; ----//----
 	newBlkSize int64    // .blksize was changed to newBlkSize       ; -1   if ZBigFile deleted
 	// XXX +oldBlkSize ?
+
+	// snapshot of trackSetZBlk for this file right before this epoch
+	oldTrackSetZBlk map[zodb.Oid]setI64 // {} zblk -> {}blk
 }
 
 // zblkTrack keeps information in which root/blocks ZBlk is present as of @head.
@@ -452,17 +455,132 @@ func (δFtail *ΔFtail) SliceByFileRev(zfile *ZBigFile, lo, hi zodb.Tid) /*reado
 
 	δftail := δFtail.byFile[zfile.POid()]
 
-	vδE := δftail.vδE
-	ie := len(vδE) - 1
-	_ = ie
-
 	vδZ := δFtail.δBtail.ΔZtail().SliceByRev(lo, hi)
 	iz := len(vδZ) - 1
 
-	root := δftail.root	// XXX take epochs into account
-	vδT := δFtail.δBtail.SliceByRootRev(root, lo, δFtail.Head()) // NOTE @head, not hi
+	// find epoch that covers hi
+	vδE := δftail.vδE
+	le := len(vδE)
+	ie := sort.Search(le, func(i int) bool {
+		return hi < vδE[i].Rev
+	})
+	// vδE[ie]   is next epoch
+	// vδE[ie-1] is epoch that covers hi
+
+	// loop through all epochs till lo
+	for lastEpoch := false; !lastEpoch ; {
+		// current epoch
+		var epoch zodb.Tid
+		ie--
+		if ie < 0 {
+			epoch = δFtail.Tail()
+		} else {
+			epoch = vδE[ie].Rev
+		}
+
+		if epoch <= lo {
+			epoch = lo
+			lastEpoch = true
+		}
+
+		var root zodb.Oid // root of blktab in current epoch
+		var head zodb.Tid // head] of current epoch coverage
+		// state of Zinblk as we are scanning ← current epoch
+		// initially corresponds to head of the epoch (= @head for latest epoch)
+		Zinblk := map[zodb.Oid]setI64{} // zblk -> which #blk refers to it
+		var ZinblkAt zodb.Tid           // Zinblk covers [ZinblkAt,<next δT>)
+		if ie+1 == le {
+			// head
+			root = δftail.root
+			head = δFtail.Head()
+			for zblk, zt := range δFtail.trackSetZBlk {
+				inblk, ok := zt.inroot[root]
+				if ok {
+					Zinblk[zblk] = inblk.Clone()
+				}
+			}
+			// XXX ZinblkAt
+		} else {
+			δE := vδE[ie+1]
+			root = δE.oldRoot
+			head = δE.Rev - 1 // XXX ok?
+			for zblk, inblk := range δE.oldTrackSetZBlk {
+				Zinblk[zblk] = inblk.Clone()
+			}
+		}
+
+		// vδT for current epoch
+		vδT := δFtail.δBtail.SliceByRootRev(root, epoch, head) // NOTE @head, not hi
+		it := len(vδT) - 1
+		if it >= 0 {
+			ZinblkAt = vδT[it].Rev
+		} else {
+			ZinblkAt = epoch
+		}
+
+		// merge current vδZ and vδT
+		for ((iz >= 0 && vδZ[iz].Rev >= epoch) || it >= 0) {
+			// δZ that is covered by current Zinblk
+			// -> update δf
+			if iz >= 0 {
+				δZ := vδZ[iz]
+				if ZinblkAt <= δZ.Rev {
+					//fmt.Printf("δZ @%s\n", δZ.Rev)
+					for _, oid := range δZ.Changev {
+						inblk, ok := Zinblk[oid]
+						if ok && len(inblk) != 0 {
+							δf := vδfTail(δZ.Rev)
+							δf.Blocks.Update(inblk)
+						}
+					}
+					iz--
+					continue
+				}
+			}
+
+			// δT -> adjust Zinblk + update δf
+			if it >= 0 {
+				δT := vδT[it]
+				//fmt.Printf("δT @%s\n", δT.Rev)
+				for blk, δzblk := range δT.ΔKV {
+					// apply in reverse as we go ←
+					if δzblk.New != xbtree.VDEL {
+						inblk, ok := Zinblk[δzblk.New]
+						if ok {
+							inblk.Del(blk)
+						}
+					}
+					if δzblk.Old != xbtree.VDEL {
+						inblk, ok := Zinblk[δzblk.Old]
+						if !ok {
+							inblk = setI64{}
+							Zinblk[δzblk.Old] = inblk
+						}
+						inblk.Add(blk)
+					}
+
+					if δT.Rev <= hi {
+						δf := vδfTail(δT.Rev)
+						δf.Blocks.Add(blk)
+						δf.Size = true // see Update
+					}
+				}
+
+				it--
+				if it >= 0 {
+					ZinblkAt = vδT[it].Rev
+				} else {
+					ZinblkAt = epoch
+				}
+			}
+		}
+
+
+	}
+
 
 
+/*
 	// state of Zinblk as we are scanning ←
 	// initially corresponds to @head = vδT[-1]
 	Zinblk := map[zodb.Oid]setI64{} // zblk -> which #blk refers to it
@@ -480,7 +598,7 @@ func (δFtail *ΔFtail) SliceByFileRev(zfile *ZBigFile, lo, hi zodb.Tid) /*reado
 		ZinblkAt = lo
 	}
 
-	for (iz >= 0 || it >= 0) { // XXX + ie
+	for (iz >= 0 || it >= 0) {
 		// δZ that is covered by current Zinblk
 		// -> update δf
 		if iz >= 0 {
@@ -535,6 +653,7 @@ func (δFtail *ΔFtail) SliceByFileRev(zfile *ZBigFile, lo, hi zodb.Tid) /*reado
 			}
 		}
 	}
+*/
 
 
 	// vδf was built in reverse order