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cmd/tar-split: make checksize a sub-command

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Moving it from top-level to the `tar-split` command
This commit is contained in:
Vincent Batts 2015-08-10 16:20:22 -04:00
parent 5d0b967302
commit 6c671d7267
5 changed files with 149 additions and 121 deletions
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14
README.md
View file

@ -65,16 +65,13 @@ naive storage implementation.
First we'll get an archive to work with. For repeatability, we'll make an
archive from what you've just cloned:
```
```bash
git archive --format=tar -o tar-split.tar HEAD .
```
```
go build ./checksize.go
```
```
$ ./checksize ./tar-split.tar
```bash
$ go get github.com/vbatts/tar-split/cmd/tar-split
$ tar-split checksize ./tar-split.tar
inspecting "tar-split.tar" (size 210k)
-- number of files: 50
-- size of metadata uncompressed: 53k
@ -87,7 +84,7 @@ implications are as little as 3kb.
But let's look at a larger archive, with many files.
```
```bash
$ ls -sh ./d.tar
1.4G ./d.tar
$ ./checksize ~/d.tar
@ -116,6 +113,7 @@ bytes-per-file rate for the storage implications.
* cli tooling to assemble/disassemble a provided tar archive
* would be interesting to have an assembler stream that implements `io.Seeker`
## License
See [LICENSE](LICENSE)

64
cmd/tar-split/asm.go Normal file
View file

@ -0,0 +1,64 @@
package main
import (
"compress/gzip"
"io"
"os"
"github.com/Sirupsen/logrus"
"github.com/codegangsta/cli"
"github.com/vbatts/tar-split/tar/asm"
"github.com/vbatts/tar-split/tar/storage"
)
func CommandAsm(c *cli.Context) {
if len(c.Args()) > 0 {
logrus.Warnf("%d additional arguments passed are ignored", len(c.Args()))
}
if len(c.String("input")) == 0 {
logrus.Fatalf("--input filename must be set")
}
if len(c.String("output")) == 0 {
logrus.Fatalf("--output filename must be set ([FILENAME|-])")
}
if len(c.String("path")) == 0 {
logrus.Fatalf("--path must be set")
}
var outputStream io.Writer
if c.String("output") == "-" {
outputStream = os.Stdout
} else {
fh, err := os.Create(c.String("output"))
if err != nil {
logrus.Fatal(err)
}
defer fh.Close()
outputStream = fh
}
// Get the tar metadata reader
mf, err := os.Open(c.String("input"))
if err != nil {
logrus.Fatal(err)
}
defer mf.Close()
mfz, err := gzip.NewReader(mf)
if err != nil {
logrus.Fatal(err)
}
defer mfz.Close()
metaUnpacker := storage.NewJSONUnpacker(mfz)
// XXX maybe get the absolute path here
fileGetter := storage.NewPathFileGetter(c.String("path"))
ots := asm.NewOutputTarStream(fileGetter, metaUnpacker)
defer ots.Close()
i, err := io.Copy(outputStream, ots)
if err != nil {
logrus.Fatal(err)
}
logrus.Infof("created %s from %s and %s (wrote %d bytes)", c.String("output"), c.String("path"), c.String("input"), i)
}

24
checksize.go → cmd/tar-split/checksize.go
View file

@ -1,29 +1,25 @@
// +build ignore
package main
import (
"archive/tar"
"compress/gzip"
"flag"
"fmt"
"io"
"io/ioutil"
"log"
"os"
"github.com/Sirupsen/logrus"
"github.com/codegangsta/cli"
"github.com/vbatts/tar-split/tar/asm"
"github.com/vbatts/tar-split/tar/storage"
)
var (
flCleanup = flag.Bool("cleanup", true, "cleanup tempfiles")
)
func main() {
flag.Parse()
for _, arg := range flag.Args() {
func CommandChecksize(c *cli.Context) {
if len(c.Args()) == 0 {
logrus.Fatalf("please specify tar archives to check ('-' will check stdin)")
}
for _, arg := range c.Args() {
fh, err := os.Open(arg)
if err != nil {
log.Fatal(err)
@ -40,8 +36,10 @@ func main() {
log.Fatal(err)
}
defer packFh.Close()
if *flCleanup {
if !c.Bool("work") {
defer os.Remove(packFh.Name())
} else {
fmt.Printf(" -- working file preserved: %s\n", packFh.Name())
}
sp := storage.NewJSONPacker(packFh)
@ -83,7 +81,7 @@ func main() {
log.Fatal(err)
}
defer gzPackFh.Close()
if *flCleanup {
if !c.Bool("work") {
defer os.Remove(gzPackFh.Name())
}

56
cmd/tar-split/disasm.go Normal file
View file

@ -0,0 +1,56 @@
package main
import (
"compress/gzip"
"io"
"os"
"github.com/Sirupsen/logrus"
"github.com/codegangsta/cli"
"github.com/vbatts/tar-split/tar/asm"
"github.com/vbatts/tar-split/tar/storage"
)
func CommandDisasm(c *cli.Context) {
if len(c.Args()) != 1 {
logrus.Fatalf("please specify tar to be disabled <NAME|->")
}
if len(c.String("output")) == 0 {
logrus.Fatalf("--output filename must be set")
}
// Set up the tar input stream
var inputStream io.Reader
if c.Args()[0] == "-" {
inputStream = os.Stdin
} else {
fh, err := os.Open(c.Args()[0])
if err != nil {
logrus.Fatal(err)
}
defer fh.Close()
inputStream = fh
}
// Set up the metadata storage
mf, err := os.OpenFile(c.String("output"), os.O_CREATE|os.O_WRONLY|os.O_TRUNC, os.FileMode(0600))
if err != nil {
logrus.Fatal(err)
}
defer mf.Close()
mfz := gzip.NewWriter(mf)
defer mfz.Close()
metaPacker := storage.NewJSONPacker(mfz)
// we're passing nil here for the file putter, because the ApplyDiff will
// handle the extraction of the archive
its, err := asm.NewInputTarStream(inputStream, metaPacker, nil)
if err != nil {
logrus.Fatal(err)
}
i, err := io.Copy(os.Stdout, its)
if err != nil {
logrus.Fatal(err)
}
logrus.Infof("created %s from %s (read %d bytes)", c.String("output"), c.Args()[0], i)
}

112
cmd/tar-split/main.go
View file

@ -2,14 +2,10 @@
package main
import (
"compress/gzip"
"io"
"os"
"github.com/Sirupsen/logrus"
"github.com/codegangsta/cli"
"github.com/vbatts/tar-split/tar/asm"
"github.com/vbatts/tar-split/tar/storage"
)
func main() {
@ -71,105 +67,21 @@ func main() {
},
},
},
{
Name: "checksize",
Usage: "displays size estimates for metadata storage of a Tar archive",
Action: CommandChecksize,
Flags: []cli.Flag{
cli.BoolFlag{
Name: "work",
Usage: "do not delete the working directory",
// defaults to false
},
},
},
}
if err := app.Run(os.Args); err != nil {
logrus.Fatal(err)
}
}
func CommandDisasm(c *cli.Context) {
if len(c.Args()) != 1 {
logrus.Fatalf("please specify tar to be disabled <NAME|->")
}
if len(c.String("output")) == 0 {
logrus.Fatalf("--output filename must be set")
}
// Set up the tar input stream
var inputStream io.Reader
if c.Args()[0] == "-" {
inputStream = os.Stdin
} else {
fh, err := os.Open(c.Args()[0])
if err != nil {
logrus.Fatal(err)
}
defer fh.Close()
inputStream = fh
}
// Set up the metadata storage
mf, err := os.OpenFile(c.String("output"), os.O_CREATE|os.O_WRONLY|os.O_TRUNC, os.FileMode(0600))
if err != nil {
logrus.Fatal(err)
}
defer mf.Close()
mfz := gzip.NewWriter(mf)
defer mfz.Close()
metaPacker := storage.NewJSONPacker(mfz)
// we're passing nil here for the file putter, because the ApplyDiff will
// handle the extraction of the archive
its, err := asm.NewInputTarStream(inputStream, metaPacker, nil)
if err != nil {
logrus.Fatal(err)
}
i, err := io.Copy(os.Stdout, its)
if err != nil {
logrus.Fatal(err)
}
logrus.Infof("created %s from %s (read %d bytes)", c.String("output"), c.Args()[0], i)
}
func CommandAsm(c *cli.Context) {
if len(c.Args()) > 0 {
logrus.Warnf("%d additional arguments passed are ignored", len(c.Args()))
}
if len(c.String("input")) == 0 {
logrus.Fatalf("--input filename must be set")
}
if len(c.String("output")) == 0 {
logrus.Fatalf("--output filename must be set ([FILENAME|-])")
}
if len(c.String("path")) == 0 {
logrus.Fatalf("--path must be set")
}
var outputStream io.Writer
if c.String("output") == "-" {
outputStream = os.Stdout
} else {
fh, err := os.Create(c.String("output"))
if err != nil {
logrus.Fatal(err)
}
defer fh.Close()
outputStream = fh
}
// Get the tar metadata reader
mf, err := os.Open(c.String("input"))
if err != nil {
logrus.Fatal(err)
}
defer mf.Close()
mfz, err := gzip.NewReader(mf)
if err != nil {
logrus.Fatal(err)
}
defer mfz.Close()
metaUnpacker := storage.NewJSONUnpacker(mfz)
// XXX maybe get the absolute path here
fileGetter := storage.NewPathFileGetter(c.String("path"))
ots := asm.NewOutputTarStream(fileGetter, metaUnpacker)
defer ots.Close()
i, err := io.Copy(outputStream, ots)
if err != nil {
logrus.Fatal(err)
}
logrus.Infof("created %s from %s and %s (wrote %d bytes)", c.String("output"), c.String("path"), c.String("input"), i)
}