.

wcfs/wcfs.go

@@ -1472,7 +1472,7 @@ func (w *Watch) _pin(ctx context.Context, blk int64, rev zodb.Tid) (err error) {
 // XXX do we really need to use/propagate caller context here? ideally update
 // watchers should be synchronous, and in practice we just use 30s timeout.
 // Should a READ interrupt cause watch update failure? -> probably no
-func (f *BigFile) readPinWatchers(ctx context.Context, blk int64, treepath []btree.LONode, zblk zBlk, blkrevMax zodb.Tid) {
+func (f *BigFile) readPinWatchers(ctx context.Context, blk int64, treepath []btree.LONode, zblk ZBlk, blkrevMax zodb.Tid) {
 	// only head/ is being watched for
 	if f.head.rev != 0 {
 		return

wcfs/zblk.go

@@ -55,9 +55,10 @@ import (
 	"lab.nexedi.com/nexedi/wendelin.core/wcfs/internal/pycompat"
 )
 
-// zBlk is the interface that every ZBlk* block implements.
-type zBlk interface {
+// ZBlk is the interface that every ZBlk* block implements.
+type ZBlk interface {
 	zodb.IPersistent
+	_IZBlkInΔFtail
 
 	// loadBlkData loads from database and returns data block stored by this ZBlk.
 	//
@@ -66,82 +67,17 @@ type zBlk interface {
 	//
 	// returns data and revision of ZBlk.
 	loadBlkData(ctx context.Context) (data []byte, rev zodb.Tid, _ error)
-
-	// inΔFtail returns pointer to struct zblkInΔFtail embedded into this ZBlk.
-	inΔFtail() *zblkInΔFtail
-
-// XXX kill - in favour of inΔFtail
-/*
-	// bindFile associates ZBlk as being used by file to store block #blk.
-	//
-	// A ZBlk may be bound to several blocks inside one file, and to
-	// several files.
-	//
-	// The information is preserved even when ZBlk comes to ghost
-	// state, but is lost if ZBlk is garbage collected.
-	//
-	// it is safe to call multiple bindFile simultaneously.
-	// it is not safe to call bindFile and boundTo simultaneously.
-	//
-	// XXX link to overview.
-	bindFile(file *BigFile, blk int64)
-
-	// XXX unbindFile
-	// XXX zfile -> bind map for it
-
-	// blkBoundTo returns ZBlk association with file(s)/#blk(s).
-	//
-	// The association returned is that was previously set by bindFile.
-	//
-	// blkBoundTo must not be called simultaneously wrt bindFile.
-	blkBoundTo() map[*BigFile]SetI64
-*/
-}
-
-var _ zBlk = (*ZBlk0)(nil)
-var _ zBlk = (*ZBlk1)(nil)
-
-// XXX kill
-/*
-// ---- zBlkBase ----
-
-// zBlkBase provides common functionality to implement ZBlk* -> zfile, #blk binding.
-//
-// The data stored by zBlkBase is transient - it is _not_ included into
-// persistent state.
-type zBlkBase struct {
-	bindMu  sync.Mutex          // used only for binding to support multiple loaders
-	infile  map[*BigFile]SetI64 // {} file -> set(#blk)
-}
-
-// bindFile implements zBlk.
-func (zb *zBlkBase) bindFile(file *BigFile, blk int64) {
-	zb.bindMu.Lock()
-	defer zb.bindMu.Unlock()
-
-	blkmap, ok := zb.infile[file]
-	if !ok {
-		blkmap = make(SetI64, 1)
-		if zb.infile == nil {
-			zb.infile = make(map[*BigFile]SetI64)
-		}
-		zb.infile[file] = blkmap
-	}
-	blkmap.Add(blk)
 }
 
-// blkBoundTo implementss zBlk.
-func (zb *zBlkBase) blkBoundTo() map[*BigFile]SetI64 {
-	return zb.infile
-}
-*/
+var _ ZBlk = (*ZBlk0)(nil)
+var _ ZBlk = (*ZBlk1)(nil)
 
 // ---- ZBlk0 ----
 
 // ZBlk0 mimics ZBlk0 from python.
 type ZBlk0 struct {
-	zblkInΔFtail
 	zodb.Persistent
+	zblkInΔFtail
 
 	// NOTE py source uses bytes(buf) but on python2 it still results in str
 	blkdata string
@@ -149,14 +85,17 @@ type ZBlk0 struct {
 
 type zBlk0State ZBlk0 // hide state methods from public API
 
+// DropState implements zodb.Ghostable.
 func (zb *zBlk0State) DropState() {
 	zb.blkdata = ""
 }
 
+// PyGetState implements zodb.PyStateful.
 func (zb *zBlk0State) PyGetState() interface{} {
 	return zb.blkdata
 }
 
+// PySetState implements zodb.PyStateful.
 func (zb *zBlk0State) PySetState(pystate interface{}) error {
 	blkdata, ok := pystate.(string)
 	if !ok {
@@ -167,6 +106,7 @@ func (zb *zBlk0State) PySetState(pystate interface{}) error {
 	return nil
 }
 
+// loadBlkData implements _ZBlk.
 func (zb *ZBlk0) loadBlkData(ctx context.Context) (_ []byte, _ zodb.Tid, err error) {
 	defer xerr.Contextf(&err, "ZBlk0(%s): loadBlkData", zb.POid())
 
@@ -191,14 +131,17 @@ type ZData struct {
 
 type zDataState ZData // hide state methods from public API
 
+// DropState implements zodb.Ghostable.
 func (zd *zDataState) DropState() {
 	zd.data = ""
 }
 
+// PyGetState implements zodb.PyStateful.
 func (zd *zDataState) PyGetState() interface{} {
 	return zd.data
 }
 
+// PySetState implements zodb.PyStateful.
 func (zd *zDataState) PySetState(pystate interface{}) error {
 	data, ok := pystate.(string)
 	if !ok {
@@ -211,22 +154,25 @@ func (zd *zDataState) PySetState(pystate interface{}) error {
 
 // ZBlk1 mimics ZBlk1 from python.
 type ZBlk1 struct {
-	zblkInΔFtail
 	zodb.Persistent
+	zblkInΔFtail
 
 	chunktab *btree.IOBTree // {} offset -> ZData(chunk)
 }
 
 type zBlk1State ZBlk1 // hide state methods from public API
 
+// DropState implements zodb.Ghostable.
 func (zb *zBlk1State) DropState() {
 	zb.chunktab = nil
 }
 
+// PyGetState implements zodb.PyStateful.
 func (zb *zBlk1State) PyGetState() interface{} {
 	return zb.chunktab
 }
 
+// PySetState implements zodb.PyStateful.
 func (zb *zBlk1State) PySetState(pystate interface{}) error {
 	chunktab, ok := pystate.(*btree.IOBTree)
 	if !ok {
@@ -237,6 +183,7 @@ func (zb *zBlk1State) PySetState(pystate interface{}) error {
 	return nil
 }
 
+// loadBlkData implements ZBlk.
 func (zb *ZBlk1) loadBlkData(ctx context.Context) (_ []byte, _ zodb.Tid, err error) {
 	defer xerr.Contextf(&err, "ZBlk1(%s): loadBlkData", zb.POid())
 
@@ -416,7 +363,7 @@ type ZBigFile struct {
 type zBigFileState ZBigFile // hide state methods from public API
 
 
-// DropState implements zodb.Stateful.
+// DropState implements zodb.Ghostable.
 func (bf *zBigFileState) DropState() {
 	bf.blksize = 0
 	bf.blktab  = nil
@@ -464,7 +411,7 @@ func (bf *zBigFileState) PySetState(pystate interface{}) (err error) {
 //	  which provides a rough upper-bound estimate for file[blk] revision.
 //
 // TODO load into user-provided buf.
-func (bf *ZBigFile) LoadBlk(ctx context.Context, blk int64) (_ []byte, treePath []btree.LONode, zblk zBlk, blkRevMax zodb.Tid, err error) {
+func (bf *ZBigFile) LoadBlk(ctx context.Context, blk int64) (_ []byte, treePath []btree.LONode, zblk ZBlk, blkRevMax zodb.Tid, err error) {
 	defer xerr.Contextf(&err, "bigfile %s: loadblk %d", bf.POid(), blk)
 
 	err = bf.PActivate(ctx)
@@ -485,7 +432,7 @@ func (bf *ZBigFile) LoadBlk(ctx context.Context, blk int64) (_ []byte, treePath
 		return make([]byte, bf.blksize), treePath, nil, blkRevMax, nil
 	}
 
-	zblk, ok = xzblk.(zBlk)
+	zblk, ok = xzblk.(ZBlk)
 	if !ok {
 		return nil, nil, nil, 0, fmt.Errorf("expect ZBlk*; got %s", typeOf(xzblk))
 	}

wcfs/δbtail_test.go

@@ -461,7 +461,7 @@ func _xwalkDFS(ctx context.Context, lo, hi_ Key, ztree *Tree, rparent *RTree, bv
 		for _, __ := range bentryv {
 			k  := __.Key()
 			xv := __.Value()
-			zv, ok := xv.(zBlk)
+			zv, ok := xv.(ZBlk)
 			if !ok {
 				exc.Raisef("[%d] -> %s;  want ZBlk", k, typeOf(xv))
 			}
@@ -506,7 +506,7 @@ func xzgetBlkData(ctx context.Context, zconn *zodb.Connection, zblkOid zodb.Oid)
 	}
 
 	xblk, err := zconn.Get(ctx, zblkOid); X(err)
-	zblk := xblk.(zBlk)
+	zblk := xblk.(ZBlk)
 	data, _, err := zblk.loadBlkData(ctx); X(err)
 	return string(data)
 }

wcfs/δftail.go

@@ -94,6 +94,44 @@ type ΔFile struct {
 }
 
 
+// XXX doc
+/*
+	// bindFile associates ZBlk as being used by file to store block #blk.
+	//
+	// A ZBlk may be bound to several blocks inside one file, and to
+	// several files.
+	//
+	// The information is preserved even when ZBlk comes to ghost
+	// state, but is lost if ZBlk is garbage collected.
+	//
+	// it is safe to call multiple bindFile simultaneously.
+	// it is not safe to call bindFile and boundTo simultaneously.
+	//
+	// XXX link to overview.
+	bindFile(file *BigFile, blk int64)
+
+	// XXX unbindFile
+	// XXX zfile -> bind map for it
+
+	// blkBoundTo returns ZBlk association with file(s)/#blk(s).
+	//
+	// The association returned is that was previously set by bindFile.
+	//
+	// blkBoundTo must not be called simultaneously wrt bindFile.
+	blkBoundTo() map[*BigFile]SetI64
+*/
+// XXX -> _IInΔFtail ?
+type _IZBlkInΔFtail interface {
+	// inΔFtail returns pointer to struct zblkInΔFtail embedded into this ZBlk.
+	//
+	// this structure is volatile in-RAM only and is used to track
+	// ZBlk->File|parent(XXX) relation for data blocks loaded with this ZBlk.
+	//
+	// XXX data stored by zBlkBase is transient - it is _not_ included into persistent state
+	inΔFtail() *zblkInΔFtail
+
+}
+
 // zblkInΔFtail is part of ΔFtail embedded into ZBlk*.
 //
 // The data stored by zblkInΔFtail is transient - it is _not_ included into
@@ -101,7 +139,11 @@ type ΔFile struct {
 type zblkInΔFtail struct {
 	mu  sync.Mutex          // used only for binding to support multiple loaders
 
-	// with which files/blocks this ZBlk is associated.	XXX as of @head state?
+	// XXX change vvv to intree_parent? {} Bucket -> set(#blk)
+	// (this is uniform with building in-RAM reverse child->parents relation for
+	//  tree nodes and for tree_root->file)
+
+	// with which files/blocks this ZBlk is associated with as of @head state
 	infile  map[*BigFile]SetI64 // {} file -> set(#blk)
 }
 
@@ -136,7 +178,7 @@ func (δFtail *ΔFtail) Tail() zodb.Tid { return δFtail.δBtail.Tail() }
 // XXX text
 //
 // A root can be associated with several files (each provided on different Track call).
-func (δFtail *ΔFtail) Track(file *BigFile, blk int64, path []btree.LONode, zblk zBlk) {
+func (δFtail *ΔFtail) Track(file *BigFile, blk int64, path []btree.LONode, zblk ZBlk) {
 	if blk == -1 {
 		// XXX blk = ∞ from beginning ?
 		blk = KeyMax
@@ -251,7 +293,7 @@ func (δFtail *ΔFtail) Update(δZ *zodb.EventCommit, zhead *ZConn) (_ ΔF, err
 		//fmt.Printf("%s:     in cache (%s)\n", oid, typeOf(obj))
 
 		switch obj := obj.(type) {
-		case zBlk:	// ZBlk*
+		case ZBlk:	// ZBlk*
 			// z.infile locking: since we write-locked head.zheadMu
 			// - no other fuse reads are running, and thus no one
 			// is mutating z.infile. XXX recheck