seaweedfs/go/weed/export.go
2013-10-31 12:56:05 -07:00

167 lines
4.2 KiB
Go

package main
import (
"archive/tar"
"bytes"
"code.google.com/p/weed-fs/go/glog"
"code.google.com/p/weed-fs/go/storage"
"fmt"
"os"
"path"
"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 {
glog.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 {
glog.Fatalf("Create Volume Index [ERROR] %s\n", err)
}
defer indexFile.Close()
nm, err := storage.LoadNeedleMap(indexFile)
if err != nil {
glog.Fatalf("cannot load needle map from %s: %s", indexFile, err)
}
var version storage.Version
err = storage.ScanVolumeFile(*exportVolumePath, vid, func(superBlock storage.SuperBlock) error {
version = superBlock.Version
return nil
}, func(n *storage.Needle, offset int64) 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, "size", n.Size)
} else {
debug("Id", n.Id, "size", n.Size)
}
}
return nil
})
if err != nil {
glog.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 := storage.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
}