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

Moving it from top-level to the `tar-split` command

README.md

@@ -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 .
 ```
 
-```
+```bash
-go build ./checksize.go	
+$ go get github.com/vbatts/tar-split/cmd/tar-split
-```
+$ tar-split checksize ./tar-split.tar
-
-```
-$ ./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)

cmd/tar-split/asm.go

@@ -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)
+}

cmd/tar-split/checksize.go

@@ -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 (
+func CommandChecksize(c *cli.Context) {
-	flCleanup = flag.Bool("cleanup", true, "cleanup tempfiles")
+	if len(c.Args()) == 0 {
-)
+		logrus.Fatalf("please specify tar archives to check ('-' will check stdin)")
-
+	}
-func main() {
+	for _, arg := range c.Args() {
-	flag.Parse()
-
-	for _, arg := range flag.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())
 		}
 

cmd/tar-split/disasm.go

@@ -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)
+}

cmd/tar-split/main.go

@@ -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)
-}