.

wcfs/internal/zdata/δftail.go

@@ -62,6 +62,7 @@ package zdata
 // Concurrency
 //
 // XXX
+// XXX note about SliceByFileRev Zinblk snapshotting
 
 import (
 	"context"
@@ -138,10 +139,10 @@ type ΔFtail struct {
 	// ΔFtail merges ΔBtail with history of ZBlk
 	δBtail      *xbtree.ΔBtail
 
-	// mu protects ΔFtail data _and_ all _ΔFileTail data for all files.
+	// mu protects ΔFtail data _and_ all _ΔFileTail/_RootTrack data for all files and roots.
 	//
-	// NOTE: even though this lock is global, since ... XXX
-	// working with retrieved vδE snapshot(?) does not need to hold the lock.
+	// NOTE: even though this lock is global it is used only for brief periouds of time. In
+	// particular working with retrieved vδE and Zinblk snapshot does not need to hold the lock.
 	mu sync.Mutex
 
 	byFile map[zodb.Oid]*_ΔFileTail // file -> vδf tail
@@ -150,9 +151,8 @@ type ΔFtail struct {
 	// set of files, which are newly tracked and for which byFile[foid].vδE was not yet rebuilt
 	ftrackNew setOid // {}foid
 
-	// set of tracked ZBlk objects mapped to trees  as of @head
-	// XXX -> ztrackInRoot ?
-	zinroot map[zodb.Oid]setOid // {} zblk -> {}root
+	// set of tracked ZBlk objects mapped to tree roots  as of @head
+	ztrackInRoot map[zodb.Oid]setOid // {} zblk -> {}root
 }
 
 // _ΔFileTail represents tail of revisional changes to one file.
@@ -171,17 +171,14 @@ type _ΔFileEpoch struct {
 	oldBlkSize int64    // .blksize was oldBlkSize                  ; -1   if ZBigFile deleted
 	newBlkSize int64    // .blksize was changed to newBlkSize       ; ----//----
 
-	// snapshot of trackSetZBlk for this file right before this epoch
+	// snapshot of ztrackInBlk for this file right before this epoch
 	oldZinblk map[zodb.Oid]setI64 // {} zblk -> {}blk
 }
 
 // _RootTrack represents tracking information about one particular tree as of @head.
-// XXX -> _TreeTrack ?  _BlktabTrack ?
 type _RootTrack struct {
-	// XXX -> ftrackSet ?
-	files  setOid              // {}foid		which ZBigFiles refer to this tree
-	// XXX -> ztrackInBlk ?  trackZInblk ?
-	Zinblk map[zodb.Oid]setI64 // {} zblk -> {}blk	which blocks map to zblk
+	ftrackSet   setOid              // {}foid		which ZBigFiles refer to this tree
+	ztrackInBlk map[zodb.Oid]setI64 // {} zblk -> {}blk	which blocks map to zblk
 }
 
 // _RebuildJob represents currently in-progress vδE rebuilding job.
@@ -215,11 +212,11 @@ type ΔFile struct {
 // ZODB when needed.
 func NewΔFtail(at0 zodb.Tid, db *zodb.DB) *ΔFtail {
 	return &ΔFtail{
-		δBtail:    xbtree.NewΔBtail(at0, db),
-		byFile:    map[zodb.Oid]*_ΔFileTail{},
-		byRoot:    map[zodb.Oid]*_RootTrack{},
-		ftrackNew: setOid{},
-		zinroot:   map[zodb.Oid]setOid{},
+		δBtail:       xbtree.NewΔBtail(at0, db),
+		byFile:       map[zodb.Oid]*_ΔFileTail{},
+		byRoot:       map[zodb.Oid]*_RootTrack{},
+		ftrackNew:    setOid{},
+		ztrackInRoot: map[zodb.Oid]setOid{},
 	}
 }
 
@@ -266,12 +263,12 @@ func (δFtail *ΔFtail) Track(file *ZBigFile, blk int64, path []btree.LONode, bl
 	rt, ok := δFtail.byRoot[root]
 	if !ok {
 		rt = &_RootTrack{
-			files:  setOid{},
-			Zinblk: map[zodb.Oid]setI64{},
+			ftrackSet:   setOid{},
+			ztrackInBlk: map[zodb.Oid]setI64{},
 		}
 		δFtail.byRoot[root] = rt
 	}
-	rt.files.Add(foid)
+	rt.ftrackSet.Add(foid)
 
 	δftail, ok := δFtail.byFile[foid]
 	if !ok {
@@ -289,17 +286,17 @@ func (δFtail *ΔFtail) Track(file *ZBigFile, blk int64, path []btree.LONode, bl
 	if zblk != nil {
 		zoid := zblk.POid()
 
-		inroot, ok := δFtail.zinroot[zoid]
+		inroot, ok := δFtail.ztrackInRoot[zoid]
 		if !ok {
 			inroot = make(setOid, 1)
-			δFtail.zinroot[zoid] = inroot
+			δFtail.ztrackInRoot[zoid] = inroot
 		}
 		inroot.Add(root)
 
-		inblk, ok := rt.Zinblk[zoid]
+		inblk, ok := rt.ztrackInBlk[zoid]
 		if !ok {
 			inblk = make(setI64, 1)
-			rt.Zinblk[zoid] = inblk
+			rt.ztrackInBlk[zoid] = inblk
 		}
 		inblk.Add(blk)
 	}
@@ -435,20 +432,21 @@ func (δFtail *ΔFtail) Update(δZ *zodb.EventCommit) (_ ΔF, err error) {
 
 			rt, ok := δFtail.byRoot[δftail.root]
 			if ok {
-				for zoid, inblk := range rt.Zinblk {
+				for zoid, inblk := range rt.ztrackInBlk {
 					δE.oldZinblk[zoid] = inblk.Clone()
-					inroot, ok := δFtail.zinroot[zoid]
+					inroot, ok := δFtail.ztrackInRoot[zoid]
 					if ok {
 						inroot.Del(δftail.root)
 						if len(inroot) == 0 {
-							delete(δFtail.zinroot, zoid)
+							delete(δFtail.ztrackInRoot, zoid)
 						}
 					}
 				}
 			}
 
 			δftail.root = δE.newRoot
-			δftail.vδE  = append(δftail.vδE, δE) // XXX note that we do not change older snapshots
+			// NOTE no need to clone vδE: we are writer, vδE is not returned to outside
+			δftail.vδE  = append(δftail.vδE, δE)
 		}
 	}
 
@@ -464,7 +462,7 @@ func (δFtail *ΔFtail) Update(δZ *zodb.EventCommit) (_ ΔF, err error) {
 			continue
 		}
 
-		for file := range rt.files {
+		for file := range rt.ftrackSet {
 			δfile, ok := δF.ByFile[file]
 			if !ok {
 				δfile = &ΔFile{Rev: δF.Rev, Blocks: make(setI64)}
@@ -481,32 +479,32 @@ func (δFtail *ΔFtail) Update(δZ *zodb.EventCommit) (_ ΔF, err error) {
 			δfile.Size = true
 		}
 
-		// update Zinblk according to btree changes
+		// update ztrackInBlk according to btree changes
 		for blk, δzblk := range δt {
 			if δzblk.Old != xbtree.VDEL {
-				inblk, ok := rt.Zinblk[δzblk.Old]
+				inblk, ok := rt.ztrackInBlk[δzblk.Old]
 				if ok {
 					inblk.Del(blk)
 					if len(inblk) == 0 {
-						delete(rt.Zinblk, δzblk.Old)
-						inroot := δFtail.zinroot[δzblk.Old]
+						delete(rt.ztrackInBlk, δzblk.Old)
+						inroot := δFtail.ztrackInRoot[δzblk.Old]
 						inroot.Del(root)
 						if len(inroot) == 0 {
-							delete(δFtail.zinroot, δzblk.Old)
+							delete(δFtail.ztrackInRoot, δzblk.Old)
 						}
 					}
 				}
 			}
 
 			if δzblk.New != xbtree.VDEL {
-				inblk, ok := rt.Zinblk[δzblk.New]
+				inblk, ok := rt.ztrackInBlk[δzblk.New]
 				if !ok {
 					inblk = make(setI64, 1)
-					rt.Zinblk[δzblk.New] = inblk
-					inroot, ok := δFtail.zinroot[δzblk.New]
+					rt.ztrackInBlk[δzblk.New] = inblk
+					inroot, ok := δFtail.ztrackInRoot[δzblk.New]
 					if !ok {
 						inroot = make(setOid, 1)
-						δFtail.zinroot[δzblk.New] = inroot
+						δFtail.ztrackInRoot[δzblk.New] = inroot
 					}
 					inroot.Add(root)
 				}
@@ -517,19 +515,19 @@ func (δFtail *ΔFtail) Update(δZ *zodb.EventCommit) (_ ΔF, err error) {
 
 	// take zblk changes into account
 	for _, oid := range δZ.Changev {
-		inroot, ok := δFtail.zinroot[oid]
+		inroot, ok := δFtail.ztrackInRoot[oid]
 		if !ok {
 			continue // not tracked
 		}
 
 		for root := range inroot {
 			rt := δFtail.byRoot[root] // must be there
-			inblk, ok := rt.Zinblk[oid]
+			inblk, ok := rt.ztrackInBlk[oid]
 			if !ok || len(inblk) == 0 {
 				continue
 			}
 			//fmt.Printf("root: %v   inblk: %v\n", root, inblk)
-			for file := range rt.files {
+			for file := range rt.ftrackSet {
 				δfile, ok := δF.ByFile[file]
 				if !ok {
 					δfile = &ΔFile{Rev: δF.Rev, Blocks: make(setI64)}
@@ -558,8 +556,8 @@ func (δFtail *ΔFtail) Update(δZ *zodb.EventCommit) (_ ΔF, err error) {
 		if δ.blktabOld != xbtree.VDEL {
 			rt, ok := δFtail.byRoot[δ.blktabOld]
 			if ok {
-				rt.files.Del(foid)
-				if len(rt.files) == 0 {
+				rt.ftrackSet.Del(foid)
+				if len(rt.ftrackSet) == 0 {
 					delete(δFtail.byRoot, δ.blktabOld)
 					// XXX reset Zinroot -= δ.blktabNew
 				}
@@ -569,13 +567,13 @@ func (δFtail *ΔFtail) Update(δZ *zodb.EventCommit) (_ ΔF, err error) {
 			rt, ok := δFtail.byRoot[δ.blktabNew]
 			if !ok {
 				rt = &_RootTrack{
-					files:  setOid{},
-					Zinblk: map[zodb.Oid]setI64{},
+					ftrackSet:   setOid{},
+					ztrackInBlk: map[zodb.Oid]setI64{},
 					// XXX reset Zinroot -= δ.blktabNew
 				}
 				δFtail.byRoot[δ.blktabNew] = rt
 			}
-			rt.files.Add(foid)
+			rt.ftrackSet.Add(foid)
 		}
 	}
 
@@ -752,7 +750,7 @@ func (δFtail *ΔFtail) SliceByFileRev(zfile *ZBigFile, lo, hi zodb.Tid) /*reado
 			rt, ok := δFtail.byRoot[root]
 			if ok {
 				for oid := range δZAllOid {
-					inblk, ok := rt.Zinblk[oid]
+					inblk, ok := rt.ztrackInBlk[oid]
 					if ok {
 						ZinblkSnap[oid] = inblk.Clone()
 					}

wcfs/internal/zdata/δftail_test.go

@@ -452,7 +452,7 @@ func testΔFtail(t_ *testing.T, testq chan ΔFTestEntry) {
 		// verify byRoot
 		trackRfiles  := map[zodb.Oid]setOid{}
 		for root, rt := range δFtail.byRoot {
-			trackRfiles[root] = rt.files
+			trackRfiles[root] = rt.ftrackSet
 		}
 		filesOK := setOid{}
 		if !delfile {
@@ -468,7 +468,7 @@ func testΔFtail(t_ *testing.T, testq chan ΔFTestEntry) {
 
 		// verify Zinroot
 		trackZinroot := map[string]setOid{}
-		for zoid, inroot := range δFtail.zinroot {
+		for zoid, inroot := range δFtail.ztrackInRoot {
 			zblki := commit.ZBlkTab[zoid]
 			trackZinroot[zblki.Name] = inroot.Clone() // XXX clone needed?
 		}
@@ -492,7 +492,7 @@ func testΔFtail(t_ *testing.T, testq chan ΔFTestEntry) {
 			if !ok {
 				t.Errorf(".byRoot points to unexpected blktab")
 			} else {
-				for zoid, inblk := range rt.Zinblk {
+				for zoid, inblk := range rt.ztrackInBlk {
 					zblki := commit.ZBlkTab[zoid]
 					trackZinblk[zblki.Name] = inblk.Clone()	// XXX clone needed?
 				}