From 5bf40bf7cbea5c4111f8e1ccdfe351a84ca5b116 Mon Sep 17 00:00:00 2001
From: Felicitas Pojtinger <felicitas@pojtinger.com>
Date: Sun, 21 Nov 2021 19:14:47 +0100
Subject: [PATCH] fix: Ensure that full records are written to tape so that EOF
 marks work

---
 cmd/stbak/cmd/archive.go   | 21 +++++++++++++++++++--
 cmd/stbak/cmd/remove.go    | 27 ++++++++++++++++++++++++++-
 pkg/counters/read_write.go | 31 +++++++++++++++++++++++++++++++
 pkg/readers/counter.go     | 17 -----------------
 4 files changed, 76 insertions(+), 20 deletions(-)
 create mode 100644 pkg/counters/read_write.go
 delete mode 100644 pkg/readers/counter.go

diff --git a/cmd/stbak/cmd/archive.go b/cmd/stbak/cmd/archive.go
index d3a1778..cb7b61b 100644
--- a/cmd/stbak/cmd/archive.go
+++ b/cmd/stbak/cmd/archive.go
@@ -10,6 +10,7 @@ import (
 
 	"github.com/pojntfx/stfs/pkg/adapters"
 	"github.com/pojntfx/stfs/pkg/controllers"
+	"github.com/pojntfx/stfs/pkg/counters"
 	"github.com/pojntfx/stfs/pkg/formatting"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
@@ -83,11 +84,14 @@ var archiveCmd = &cobra.Command{
 
 		dirty := false
 		var tw *tar.Writer
+		var bw *bufio.Writer
+		var counter *counters.CounterWriter
 		if isRegular {
 			tw = tar.NewWriter(f)
 		} else {
-			bw := bufio.NewWriterSize(f, controllers.BlockSize*viper.GetInt(recordSizeFlag))
-			tw = tar.NewWriter(bw)
+			bw = bufio.NewWriterSize(f, controllers.BlockSize*viper.GetInt(recordSizeFlag))
+			counter = &counters.CounterWriter{Writer: bw, BytesRead: 0}
+			tw = tar.NewWriter(counter)
 		}
 		defer func() {
 			// Only write the trailer if we wrote to the archive
@@ -95,6 +99,19 @@ var archiveCmd = &cobra.Command{
 				if err := tw.Close(); err != nil {
 					panic(err)
 				}
+
+				if !isRegular {
+					if controllers.BlockSize*viper.GetInt(recordSizeFlag)-counter.BytesRead > 0 {
+						// Fill the rest of the record with zeros
+						if _, err := bw.Write(make([]byte, controllers.BlockSize*viper.GetInt(recordSizeFlag)-counter.BytesRead)); err != nil {
+							panic(err)
+						}
+					}
+
+					if err := bw.Flush(); err != nil {
+						panic(err)
+					}
+				}
 			}
 		}()
 
diff --git a/cmd/stbak/cmd/remove.go b/cmd/stbak/cmd/remove.go
index 0735f57..4b91410 100644
--- a/cmd/stbak/cmd/remove.go
+++ b/cmd/stbak/cmd/remove.go
@@ -2,11 +2,13 @@ package cmd
 
 import (
 	"archive/tar"
+	"bufio"
 	"context"
 	"os"
 
 	"github.com/pojntfx/stfs/pkg/controllers"
 	"github.com/pojntfx/stfs/pkg/converters"
+	"github.com/pojntfx/stfs/pkg/counters"
 	"github.com/pojntfx/stfs/pkg/formatting"
 	"github.com/pojntfx/stfs/pkg/pax"
 	"github.com/pojntfx/stfs/pkg/persisters"
@@ -61,13 +63,35 @@ var removeCmd = &cobra.Command{
 		defer f.Close()
 
 		dirty := false
-		tw := tar.NewWriter(f)
+		var tw *tar.Writer
+		var bw *bufio.Writer
+		var counter *counters.CounterWriter
+		if isRegular {
+			tw = tar.NewWriter(f)
+		} else {
+			bw = bufio.NewWriterSize(f, controllers.BlockSize*viper.GetInt(recordSizeFlag))
+			counter = &counters.CounterWriter{Writer: bw, BytesRead: 0}
+			tw = tar.NewWriter(counter)
+		}
 		defer func() {
 			// Only write the trailer if we wrote to the archive
 			if dirty {
 				if err := tw.Close(); err != nil {
 					panic(err)
 				}
+
+				if !isRegular {
+					if controllers.BlockSize*viper.GetInt(recordSizeFlag)-counter.BytesRead > 0 {
+						// Fill the rest of the record with zeros
+						if _, err := bw.Write(make([]byte, controllers.BlockSize*viper.GetInt(recordSizeFlag)-counter.BytesRead)); err != nil {
+							panic(err)
+						}
+					}
+
+					if err := bw.Flush(); err != nil {
+						panic(err)
+					}
+				}
 			}
 		}()
 
@@ -109,6 +133,7 @@ var removeCmd = &cobra.Command{
 }
 
 func init() {
+	removeCmd.PersistentFlags().IntP(recordSizeFlag, "e", 20, "Amount of 512-bit blocks per record")
 	removeCmd.PersistentFlags().StringP(nameFlag, "n", "", "Name of the file to remove")
 
 	viper.AutomaticEnv()
diff --git a/pkg/counters/read_write.go b/pkg/counters/read_write.go
new file mode 100644
index 0000000..a964c28
--- /dev/null
+++ b/pkg/counters/read_write.go
@@ -0,0 +1,31 @@
+package counters
+
+import "io"
+
+type CounterReader struct {
+	Reader io.Reader
+
+	BytesRead int
+}
+
+func (r *CounterReader) Read(p []byte) (n int, err error) {
+	n, err = r.Reader.Read(p)
+
+	r.BytesRead += n
+
+	return n, err
+}
+
+type CounterWriter struct {
+	Writer io.Writer
+
+	BytesRead int
+}
+
+func (w *CounterWriter) Write(p []byte) (n int, err error) {
+	n, err = w.Writer.Write(p)
+
+	w.BytesRead += n
+
+	return n, err
+}
diff --git a/pkg/readers/counter.go b/pkg/readers/counter.go
deleted file mode 100644
index bf133aa..0000000
--- a/pkg/readers/counter.go
+++ /dev/null
@@ -1,17 +0,0 @@
-package readers
-
-import "io"
-
-type Counter struct {
-	Reader io.Reader
-
-	BytesRead int
-}
-
-func (r *Counter) Read(p []byte) (n int, err error) {
-	n, err = r.Reader.Read(p)
-
-	r.BytesRead += n
-
-	return n, err
-}