cmd/torrent-verify/main.go

   1 package main
   2
   3 import (
   4         "bitbucket.org/anacrolix/go.torrent/mmap_span"
   5         "bytes"
   6         "crypto/sha1"
   7         "flag"
   8         "fmt"
   9
  10         // "github.com/davecheney/profile"
  11         "log"
  12         "os"
  13         "path/filepath"
  14
  15         metainfo "github.com/nsf/libtorgo/torrent"
  16         "launchpad.net/gommap"
  17 )
  18
  19 var (
  20         filePath = flag.String("torrent", "/path/to/the.torrent", "path of the torrent file")
  21         dirPath  = flag.String("path", "/torrent/data", "path of the torrent data")
  22 )
  23
  24 func init() {
  25         flag.Parse()
  26 }
  27
  28 func main() {
  29         // defer profile.Start(profile.CPUProfile).Stop()
  30         metaInfo, err := metainfo.LoadFromFile(*filePath)
  31         if err != nil {
  32                 log.Fatal(err)
  33         }
  34         devZero, err := os.Open("/dev/zero")
  35         if err != nil {
  36                 log.Print(err)
  37         }
  38         defer devZero.Close()
  39         var mMapSpan mmap_span.MMapSpan
  40         for _, file := range metaInfo.Files {
  41                 filename := filepath.Join(append([]string{*dirPath, metaInfo.Name}, file.Path...)...)
  42                 osFile, err := os.Open(filename)
  43                 mmapFd := osFile.Fd()
  44                 if err != nil {
  45                         if pe, ok := err.(*os.PathError); ok && pe.Err.Error() == "no such file or directory" {
  46                                 mmapFd = devZero.Fd()
  47                         } else {
  48                                 log.Fatal(err)
  49                         }
  50                 }
  51                 goMMap, err := gommap.MapRegion(mmapFd, 0, file.Length, gommap.PROT_READ, gommap.MAP_PRIVATE)
  52                 if err != nil {
  53                         log.Fatal(err)
  54                 }
  55                 if int64(len(goMMap)) != file.Length {
  56                         log.Printf("file mmap has wrong size: %#v", filename)
  57                 }
  58                 osFile.Close()
  59                 mMapSpan = append(mMapSpan, goMMap)
  60         }
  61         log.Println(len(metaInfo.Files))
  62         log.Println(mMapSpan.Size())
  63         log.Println(len(metaInfo.Pieces))
  64         for piece := 0; piece < (len(metaInfo.Pieces)+sha1.Size-1)/sha1.Size; piece++ {
  65                 expectedHash := metaInfo.Pieces[sha1.Size*piece : sha1.Size*(piece+1)]
  66                 if len(expectedHash) == 0 {
  67                         break
  68                 }
  69                 hash := sha1.New()
  70                 _, err := mMapSpan.WriteSectionTo(hash, int64(piece)*metaInfo.PieceLength, metaInfo.PieceLength)
  71                 if err != nil {
  72                         log.Fatal(err)
  73                 }
  74                 fmt.Println(piece, bytes.Equal(hash.Sum(nil), expectedHash))
  75         }
  76 }