.

wcfs/wcfs.go

@@ -24,7 +24,7 @@
 // Each wendelin.core array (ZBigArray) is actually a linear file (ZBigFile)
 // and array metadata like dtype, shape and strides associated with it. This
 // program exposes as files only ZBigFile data and leaves rest of
-// array-specific handling to client. Every ZBigFile is exposed as one separate
+// array-specific handling to clients. Every ZBigFile is exposed as one separate
 // file that represents whole ZBigFile's data.
 //
 // For a client, the primary way to access a bigfile should be to mmap
@@ -227,6 +227,8 @@ package main
 //   timings depending on clients). No harm here as different bigfiles use
 //   completely different ZODB BTree and data objects.
 //
+//   For every ZODB connection a dedicated read-only transaction is maintained.
+//
 //
 // Notes on OS pagecache control:
 //
@@ -273,7 +275,7 @@ import (
 	"github.com/pkg/errors"
 )
 
-// /bigfile/	- represented by BigFileRoot.
+// /bigfile/	- served by BigFileRoot.
 type BigFileRoot struct {
 	nodefs.Node
 	zstor zodb.IStorage
@@ -283,29 +285,25 @@ type BigFileRoot struct {
 	tab map[zodb.Oid]*BigFileDir
 }
 
-// /bigfile/<bigfileX>/	- represented by BigFileDir.
+// /bigfile/<bigfileX>/	- served by BigFileDir.
 type BigFileDir struct {
 	nodefs.Node
-
 	zdb *zodb.DB
 
-	// head/	(XXX just by fs entry)
+	// head/ is implicitly linked to by fs
 
 	// {} rev -> @<rev>/ bigfile snapshot
 	revMu  sync.Mutex
-	//revTab map[zodb.Tid]*BigFileRev
+	revTab map[zodb.Tid]*BigFileRev
 }
 
-// /bigfile/<bigfileX>/head/	- represented by BigFileHead.
-// XXX -> BigFileRev  (with head | @tid) ?
-type BigFileHead struct {
+// /bigfile/<bigfileX>/(head|<rev>)/	- served by BigFileRev.
+type BigFileRev struct {
 	nodefs.Node
-
-	data *BigFileData
-	//inv  *BigFileInvalidations
+	// data, at, invalidations, etc - all implicitly linked to by fs
 }
 
-// /bigfile/<bigfileX>/(head|<rev>)/{data,at}	- internally served by BigFile.
+// /bigfile/<bigfileX>/(head|<rev>)/*	- internally served by BigFile.
 type BigFile struct {
 	// current read-only transaction under which we access ZODB data
 	txnCtx context.Context // XXX -> better directly store txn
@@ -317,15 +315,14 @@ type BigFile struct {
 	// ZBigFile top-level object. Kept activated during lifetime of current transaction.
 	zbf	*ZBigFile
 
-	// zbf.Size(). It is constant during liftime of a transaction
-	// (we do only read-only txn) XXX -> organization overview.
+	// zbf.Size(). It is constant during liftime of current transaction.
 	zbfSize int64
 
 	// TODO
 	// lastChange	zodb.Tid // last change to whole bigfile as of .zconn.At view
 }
 
-// /bigfile/<bigfileX>/(head|<rev>)/data	- represented by BigFileData.
+// /bigfile/<bigfileX>/(head|<rev>)/data	- served by BigFileData.
 type BigFileData struct {
 	nodefs.Node
 
@@ -333,6 +330,8 @@ type BigFileData struct {
 
 	// inflight loadings of ZBigFile from ZODB.
 	// successfull load results are kept here until blkdata is put into OS pagecache.
+	//
+	// XXX -> BigFile ?
 	loadMu  sync.Mutex
 	loading map[int64]*blkLoadState // #blk -> {... blkdata}
 }
@@ -354,7 +353,7 @@ type blkLoadState struct {
 
 // /bigfile -> Mkdir receives client request to create /bigfile/<bigfileX>.
 //
-// It creates <bigfileX>/head/data along the way.
+// It creates <bigfileX>/head/* along the way.
 func (bfroot *BigFileRoot) Mkdir(name string, mode uint32, fctx *fuse.Context) (_ *nodefs.Inode, status fuse.Status) {
 	oid, err := zodb.ParseOid(name)
 	if err != nil {
@@ -448,7 +447,7 @@ func (bfroot *BigFileRoot) Mkdir(name string, mode uint32, fctx *fuse.Context) (
 		zdb:  zdb,
 	}
 
-	bfhead := &BigFileHead{
+	bfhead := &BigFileRev{
 		Node: nodefs.NewDefaultNode(),
 	}
 
@@ -465,8 +464,6 @@ func (bfroot *BigFileRoot) Mkdir(name string, mode uint32, fctx *fuse.Context) (
 		loading: make(map[int64]*blkLoadState),
 	}
 
-	bfhead.data = bfdata
-
 	bfroot.tab[oid] = bfdir
 	bfroot.mu.Unlock()
 

wcfs/zblk.go

@@ -125,7 +125,7 @@ func (zd *zDataState) DropState() {
 }
 
 func (zd *zDataState) PySetState(pystate interface{}) error {
-	log.Printf("ZData.PySetState")
+	//log.Printf("ZData.PySetState")
 	data, ok := pystate.(string)
 	if !ok {
 		return fmt.Errorf("expect str; got %s", typeOf(pystate))