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refactor: Decompose tar writer initialization

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This commit is contained in:
Felix Pojtinger
2021-11-26 17:08:20 +01:00
parent 70937a4d85
commit 21dcaf194f
2 changed files with 75 additions and 146 deletions
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87
cmd/stbak/cmd/archive.go
View File

@@ -2,7 +2,6 @@ package cmd
import (
"archive/tar"
"bufio"
"context"
"io"
"io/fs"
@@ -11,7 +10,6 @@ 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/pojntfx/stfs/pkg/persisters"
"github.com/spf13/cobra"
@@ -76,89 +74,12 @@ func archive(
src string,
overwrite bool,
) error {
isRegular := true
stat, err := os.Stat(tape)
if err == nil {
isRegular = stat.Mode().IsRegular()
} else {
if os.IsNotExist(err) {
isRegular = true
} else {
return err
}
}
var f *os.File
if isRegular {
if overwrite {
f, err = os.OpenFile(tape, os.O_WRONLY|os.O_CREATE, 0600)
if err != nil {
return err
}
if err := f.Truncate(0); err != nil {
return err
}
} else {
f, err = os.OpenFile(tape, os.O_APPEND|os.O_WRONLY|os.O_CREATE, 0600)
if err != nil {
return err
}
}
// No need to go to end manually due to `os.O_APPEND`
} else {
f, err = os.OpenFile(tape, os.O_APPEND|os.O_WRONLY, os.ModeCharDevice)
if err != nil {
return err
}
if overwrite {
// Go to start of tape
if err := controllers.SeekToRecordOnTape(f, 0); err != nil {
return err
}
} else {
// Go to end of tape
if err := controllers.GoToEndOfTape(f); err != nil {
return err
}
}
}
defer f.Close()
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*recordSize)
counter = &counters.CounterWriter{Writer: bw, BytesRead: 0}
tw = tar.NewWriter(counter)
tw, isRegular, cleanup, err := openTapeWriter(viper.GetString(tapeFlag))
if err != nil {
return err
}
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*recordSize-counter.BytesRead > 0 {
// Fill the rest of the record with zeros
if _, err := bw.Write(make([]byte, controllers.BlockSize*recordSize-counter.BytesRead)); err != nil {
panic(err)
}
}
if err := bw.Flush(); err != nil {
panic(err)
}
}
}
}()
defer cleanup(dirty)
first := true
return filepath.Walk(src, func(path string, info fs.FileInfo, err error) error {

134
cmd/stbak/cmd/remove.go
View File

@@ -30,71 +30,12 @@ var removeCmd = &cobra.Command{
return err
}
isRegular := true
stat, err := os.Stat(viper.GetString(tapeFlag))
if err == nil {
isRegular = stat.Mode().IsRegular()
} else {
if os.IsNotExist(err) {
isRegular = true
} else {
return err
}
}
var f *os.File
if isRegular {
f, err = os.OpenFile(viper.GetString(tapeFlag), os.O_APPEND|os.O_WRONLY|os.O_CREATE, 0600)
if err != nil {
return err
}
// No need to go to end manually due to `os.O_APPEND`
} else {
f, err = os.OpenFile(viper.GetString(tapeFlag), os.O_APPEND|os.O_WRONLY, os.ModeCharDevice)
if err != nil {
return err
}
// Go to end of tape
if err := controllers.GoToEndOfTape(f); err != nil {
return err
}
}
defer f.Close()
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))
counter = &counters.CounterWriter{Writer: bw, BytesRead: 0}
tw = tar.NewWriter(counter)
tw, _, cleanup, err := openTapeWriter(viper.GetString(tapeFlag))
if err != nil {
return err
}
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)
}
}
}
}()
defer cleanup(dirty)
metadataPersister := persisters.NewMetadataPersister(viper.GetString(metadataFlag))
if err := metadataPersister.Open(); err != nil {
@@ -153,6 +94,73 @@ var removeCmd = &cobra.Command{
},
}
func openTapeWriter(path string) (tw *tar.Writer, isRegular bool, cleanup func(dirty bool) error, err error) {
stat, err := os.Stat(path)
if err == nil {
isRegular = stat.Mode().IsRegular()
} else {
if os.IsNotExist(err) {
isRegular = true
} else {
return nil, false, nil, err
}
}
var f *os.File
if isRegular {
f, err = os.OpenFile(path, os.O_APPEND|os.O_WRONLY|os.O_CREATE, 0600)
if err != nil {
return nil, false, nil, err
}
// No need to go to end manually due to `os.O_APPEND`
} else {
f, err = os.OpenFile(path, os.O_APPEND|os.O_WRONLY, os.ModeCharDevice)
if err != nil {
return nil, false, nil, err
}
// Go to end of tape
if err := controllers.GoToEndOfTape(f); err != nil {
return nil, false, nil, err
}
}
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)
}
return tw, isRegular, func(dirty bool) error {
// Only write the trailer if we wrote to the archive
if dirty {
if err := tw.Close(); err != nil {
return 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 {
return err
}
}
if err := bw.Flush(); err != nil {
return err
}
}
}
return f.Close()
}, nil
}
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")