.

t/neo/cmd/neostorage-go/neostorage.go

@@ -5,7 +5,7 @@
 package main
 
 import (
-	_ "../../storage"	// XXX rel ok?
+	//_ "../../storage"	// XXX rel ok?
 	neo "../.."
 	"fmt"
 	"context"

t/neo/storage/fs1/cmd/fstail/fstail.go

@@ -30,6 +30,8 @@ import (
 	"os"
 
 	"../../../../storage/fs1"
+
+	"../../../../xcommon/xfmt"
 )
 
 
@@ -86,6 +88,9 @@ func fsTail(w io.Writer, path string, ntxn int) (err error) {
 		return fmt.Errorf("@%v: previous record could not be read", topPos)
 	}
 
+	// buffer for formatting
+	xbuf := xfmt.Buffer{}
+
 	// now loop loading transactions backwards until EOF / ntxn limit
 	for i := ntxn; i > 0; i-- {
 		err = txnh.LoadPrev(fSeq, fs1.LoadAll)
@@ -114,17 +119,30 @@ func fsTail(w io.Writer, path string, ntxn int) (err error) {
 		}
 
 		// print information about read txn record
-		_, err = fmt.Fprintf(w, "%s: hash=%x\nuser=%s description=%s length=%d offset=%d (+%d)\n\n",
-				txnh.Tid.Time(), sha1.Sum(data),
+		xbuf.Reset()
+		xbuf .S(txnh.Tid.Time()) .S("hash=") .X(sha1.Sum(data))
 
 		// fstail.py uses repr to print user/description:
 		// https://github.com/zopefoundation/ZODB/blob/5.2.0-4-g359f40ec7/src/ZODB/scripts/fstail.py#L39
-				pyQuoteBytes(txnh.User), pyQuoteBytes(txnh.Description),
+		xbuf .S("\nuser=") .Qpyb(txnh.User) .S(" description=") .Qpyb(txnh.Description)
 
 		// NOTE in zodb/py .length is len - 8, in zodb/go - whole txn record length
-				txnh.Len - 8,
+		xbuf .S(" length=") .D(txnh.Len - 8)
+		xbuf .S(" offset=") .D(txnh.Pos) .S(" (+") .D(txnh.HeaderLen()) .S(")\n\n")
 
-				txnh.Pos, txnh.HeaderLen())
+//		// print information about read txn record
+//		_, err = fmt.Fprintf(w, "%s: hash=%x\nuser=%s description=%s length=%d offset=%d (+%d)\n\n",
+//				txnh.Tid.Time(), sha1.Sum(data),
+//
+//				// fstail.py uses repr to print user/description:
+//				// https://github.com/zopefoundation/ZODB/blob/5.2.0-4-g359f40ec7/src/ZODB/scripts/fstail.py#L39
+//				pyQuoteBytes(txnh.User), pyQuoteBytes(txnh.Description),
+//
+//				// NOTE in zodb/py .length is len - 8, in zodb/go - whole txn record length
+//				txnh.Len - 8,
+//
+//				txnh.Pos, txnh.HeaderLen())
+		_, err = w.Write(xbuf.Bytes())
 		if err != nil {
 			break
 		}

t/neo/xcommon/xfmt/fmt_test.go

@@ -80,3 +80,11 @@ func TestXFmt(t *testing.T) {
 		}
 	}
 }
+
+func BenchmarkFmt(t *testing.T) {
+	// TODO
+}
+
+func BenchmarkXFmt(t *testing.T) {
+	// TODO
+}

t/neo/storage/fs1/cmd/fstail/xstrconv.go → t/neo/xcommon/xfmt/python.go

-// XXX move me out of here
-
-package main
+package xmft
 
 import (
 	"bytes"
@@ -83,3 +81,16 @@ func pyAppendQuoteBytes(buf, b []byte) []byte {
 	buf = append(buf, quote)
 	return buf
 }
+
+
+// Qpy appends string quoted as Python would do
+func (b *Buffer) Qpy(s string) *Buffer {
+	*b = ...	// TODO
+	return b
+}
+
+// Qpyb appends []byte quoted as Python would do
+func (b *Buffer) Qpyb(x []byte) *Buffer {
+	*b = ...	// TODO
+	return b
+}

t/neo/storage/fs1/cmd/fstail/xstrconv_test.go → t/neo/xcommon/xfmt/python_test.go

-// XXX move me to common place
-
-package main
+package xfmt
 
 import (
 	"testing"