1 files changed, 164 insertions, 0 deletions
diff --git a/go/cmd/export.go b/go/cmd/export.go
new file mode 100644
index 000000000..fd9d51164
--- /dev/null
+++ b/go/cmd/export.go
@@ -0,0 +1,164 @@
+package main
+
+import (
+	"archive/tar"
+	"bytes"
+	"fmt"
+	"log"
+	"os"
+	"path"
+	"code.google.com/p/weed-fs/go/directory"
+	"code.google.com/p/weed-fs/go/storage"
+	"strconv"
+	"strings"
+	"text/template"
+	"time"
+)
+
+func init() {
+	cmdExport.Run = runExport // break init cycle
+	cmdExport.IsDebug = cmdExport.Flag.Bool("debug", false, "enable debug mode")
+}
+
+const (
+	defaultFnFormat = `{{.Mime}}/{{.Id}}:{{.Name}}`
+)
+
+var cmdExport = &Command{
+	UsageLine: "export -dir=/tmp -volumeId=234 -o=/dir/name.tar -fileNameFormat={{.Name}}",
+	Short:     "list or export files from one volume data file",
+	Long: `List all files in a volume, or Export all files in a volume to a tar file if the output is specified.
+	
+	The format of file name in the tar file can be customized. Default is {{.Mime}}/{{.Id}}:{{.Name}}. Also available is {{Key}}.
+
+  `,
+}
+
+var (
+	exportVolumePath = cmdExport.Flag.String("dir", "/tmp", "input data directory to store volume data files")
+	exportVolumeId   = cmdExport.Flag.Int("volumeId", -1, "a volume id. The volume should already exist in the dir. The volume index file should not exist.")
+	dest             = cmdExport.Flag.String("o", "", "output tar file name, must ends with .tar, or just a \"-\" for stdout")
+	format           = cmdExport.Flag.String("fileNameFormat", defaultFnFormat, "filename format, default to {{.Mime}}/{{.Id}}:{{.Name}}")
+	tarFh            *tar.Writer
+	tarHeader        tar.Header
+	fnTmpl           *template.Template
+	fnTmplBuf        = bytes.NewBuffer(nil)
+)
+
+func runExport(cmd *Command, args []string) bool {
+
+	if *exportVolumeId == -1 {
+		return false
+	}
+
+	var err error
+	if *dest != "" {
+		if *dest != "-" && !strings.HasSuffix(*dest, ".tar") {
+			fmt.Println("the output file", *dest, "should be '-' or end with .tar")
+			return false
+		}
+
+		if fnTmpl, err = template.New("name").Parse(*format); err != nil {
+			fmt.Println("cannot parse format " + *format + ": " + err.Error())
+			return false
+		}
+
+		var fh *os.File
+		if *dest == "-" {
+			fh = os.Stdout
+		} else {
+			if fh, err = os.Create(*dest); err != nil {
+				log.Fatalf("cannot open output tar %s: %s", *dest, err)
+			}
+		}
+		defer fh.Close()
+		tarFh = tar.NewWriter(fh)
+		defer tarFh.Close()
+		t := time.Now()
+		tarHeader = tar.Header{Mode: 0644,
+			ModTime: t, Uid: os.Getuid(), Gid: os.Getgid(),
+			Typeflag:   tar.TypeReg,
+			AccessTime: t, ChangeTime: t}
+	}
+
+	fileName := strconv.Itoa(*exportVolumeId)
+	vid := storage.VolumeId(*exportVolumeId)
+	indexFile, err := os.OpenFile(path.Join(*exportVolumePath, fileName+".idx"), os.O_RDONLY, 0644)
+	if err != nil {
+		log.Fatalf("Create Volume Index [ERROR] %s\n", err)
+	}
+	defer indexFile.Close()
+
+	nm := storage.LoadNeedleMap(indexFile)
+
+	var version storage.Version
+
+	err = storage.ScanVolumeFile(*exportVolumePath, vid, func(superBlock storage.SuperBlock) error {
+		version = superBlock.Version
+		return nil
+	}, func(n *storage.Needle, offset uint32) error {
+		debug("key", n.Id, "offset", offset, "size", n.Size, "disk_size", n.DiskSize(), "gzip", n.IsGzipped())
+		nv, ok := nm.Get(n.Id)
+		if ok && nv.Size > 0 {
+			return walker(vid, n, version)
+		} else {
+			if !ok {
+				debug("This seems deleted", n.Id)
+			} else {
+				debug("Id", n.Id, "size", n.Size)
+			}
+		}
+		return nil
+	})
+	if err != nil {
+		log.Fatalf("Export Volume File [ERROR] %s\n", err)
+	}
+	return true
+}
+
+type nameParams struct {
+	Name string
+	Id   uint64
+	Mime string
+	Key  string
+}
+
+func walker(vid storage.VolumeId, n *storage.Needle, version storage.Version) (err error) {
+	key := directory.NewFileId(vid, n.Id, n.Cookie).String()
+	if tarFh != nil {
+		fnTmplBuf.Reset()
+		if err = fnTmpl.Execute(fnTmplBuf,
+			nameParams{Name: string(n.Name),
+				Id:   n.Id,
+				Mime: string(n.Mime),
+				Key:  key,
+			},
+		); err != nil {
+			return err
+		}
+		nm := fnTmplBuf.String()
+
+		if n.IsGzipped() && path.Ext(nm) != ".gz" {
+			nm = nm + ".gz"
+		}
+
+		tarHeader.Name, tarHeader.Size = nm, int64(len(n.Data))
+		if err = tarFh.WriteHeader(&tarHeader); err != nil {
+			return err
+		}
+		_, err = tarFh.Write(n.Data)
+	} else {
+		size := n.DataSize
+		if version == storage.Version1 {
+			size = n.Size
+		}
+		fmt.Printf("key=%s Name=%s Size=%d gzip=%t mime=%s\n",
+			key,
+			n.Name,
+			size,
+			n.IsGzipped(),
+			n.Mime,
+		)
+	}
+	return
+}