.

wcfs/internal/zdata/δftail.go

@@ -96,7 +96,7 @@ type ΔFtail struct {
 
 // zblkTrack keeps information in which root/blocks ZBlk is present as of @head.
 type zblkTrack struct {
-	inroot map[zodb.Oid]setI64  // {} root -> {}blk		XXX later switch to this
+	inroot map[zodb.Oid]setI64  // {} root -> {}blk
 }
 
 // ΔF represents a change in files space.
@@ -395,6 +395,8 @@ func (δFtail *ΔFtail) ForgetPast(revCut zodb.Tid) {
 func (δFtail *ΔFtail) SliceByFileRev(zfile *ZBigFile, lo, hi zodb.Tid) /*readonly*/[]*ΔFile {
 	xtail.AssertSlice(δFtail, lo, hi)
 
+	// XXX locking
+
 	// query .δBtail.SliceByRootRev(file.blktab, lo, hi) +
 	// merge δZBlk history with that.
 
@@ -412,10 +414,110 @@ func (δFtail *ΔFtail) SliceByFileRev(zfile *ZBigFile, lo, hi zodb.Tid) /*reado
 	// δFile	────────o───────o──────x─────x────────────────────────
 
 
-	vδT := δFtail.δBtail.SliceByRootRev(zfile.blktab, lo, hi) // XXX needs activate zfile
+//	vδT := δFtail.δBtail.SliceByRootRev(zfile.blktab, lo, hi) // XXX needs activate zfile
+	// XXX needs activate zfile
+	root := zfile.blktab.POid()
+	vδT := δFtail.δBtail.SliceByRootRev(root, lo, δFtail.Head()) // NOTE @head, not hi
 	vδZ := δFtail.δBtail.ΔZtail().SliceByRev(lo, hi)
+
 	var vδf []*ΔFile
+	// vδfTail returns or creates vδf entry for revision tail
+	// tail must be <= all vδf revisions
+	vδfTail := func(tail zodb.Tid) *ΔFile {
+		if l := len(vδf); l > 0 {
+			δfTail := vδf[l-1]
+			if δfTail.Rev == tail {
+				return δfTail
+			}
+			if !(tail <= δfTail.Rev) {
+				panic("tail not ↓")
+			}
+		}
+
+		δfTail := &ΔFile{Rev: tail, Blocks: setI64{}}
+		vδf = append(vδf, δfTail)
+		return δfTail
+	}
+
+
+	// state of Zinblk as we are scanning ←
+	// initially corresponds to @head = vδT[-1]
+	Zinblk := map[zodb.Oid]setI64{} // zblk -> which #blk refer to it
+	var ZinblkAt zodb.Tid           // Zinblk covers [ZinblkAt,<next δT>)
+	for zblk, zt := range δFtail.trackSetZBlk {
+		inblk, ok := zt.inroot[root]
+		if ok {
+			Zinblk[zblk] = inblk.Clone()
+		}
+	}
+	it := len(vδT) - 1
+	if it >= 0 {
+		ZinblkAt = vδT[it].Rev
+	} else {
+		ZinblkAt = lo
+	}
+//	it--
 
+	iz := len(vδZ) - 1
+	for (iz >= 0 || it >= 0) {
+		// δZ that is covered by current Zinblk
+		// -> update δf
+		if iz >= 0 {
+			δZ := vδZ[iz]
+			if ZinblkAt <= δZ.Rev {
+				for _, oid := range δZ.Changev {
+					inblk, ok := Zinblk[oid]
+					if ok {
+						δf := vδfTail(δZ.Rev)
+						δf.Blocks.Update(inblk)
+					}
+				}
+				iz--
+				continue
+			}
+		}
+
+		// δT -> adjust Zinblk + update δf
+		if it >= 0 {
+			δT := vδT[it]
+			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 = lo
+			}
+		}
+	}
+
+
+	// XXX reverse vδf before return
+	return vδf
+
+/*
 	// state of `{} blk -> zblk` as we are scanning ↓
 	δblktab := map[int64]struct {
 		zblk   zodb.Oid // blk points to this zblk
@@ -444,6 +546,7 @@ func (δFtail *ΔFtail) SliceByFileRev(zfile *ZBigFile, lo, hi zodb.Tid) /*reado
 	}
 
 	return vδf
+*/
 
 
 /*