cmd/torrent-verify/main.go

   1 package main
   2
   3 import (
   4         "bytes"
   5         "crypto/sha1"
   6         "flag"
   7         "fmt"
   8         "io"
   9         "log"
  10         "os"
  11         "path/filepath"
  12
  13         "github.com/bradfitz/iter"
  14         "github.com/edsrzf/mmap-go"
  15
  16         "github.com/anacrolix/torrent/metainfo"
  17         "github.com/anacrolix/torrent/mmap_span"
  18 )
  19
  20 var (
  21         torrentPath = flag.String("torrent", "/path/to/the.torrent", "path of the torrent file")
  22         dataPath    = flag.String("path", "/torrent/data", "path of the torrent data")
  23 )
  24
  25 func fileToMmap(filename string, length int64) mmap.MMap {
  26         osFile, err := os.Open(filename)
  27         if os.IsNotExist(err) {
  28                 return nil
  29         }
  30         if err != nil {
  31                 log.Fatal(err)
  32         }
  33         goMMap, err := mmap.MapRegion(osFile, int(length), mmap.RDONLY, mmap.COPY, 0)
  34         if err != nil {
  35                 log.Fatal(err)
  36         }
  37         if int64(len(goMMap)) != length {
  38                 log.Printf("file mmap has wrong size: %#v", filename)
  39         }
  40         osFile.Close()
  41
  42         return goMMap
  43 }
  44
  45 func main() {
  46         log.SetFlags(log.Flags() | log.Lshortfile)
  47         flag.Parse()
  48         metaInfo, err := metainfo.LoadFromFile(*torrentPath)
  49         if err != nil {
  50                 log.Fatal(err)
  51         }
  52         info, err := metaInfo.UnmarshalInfo()
  53         if err != nil {
  54                 log.Fatalf("error unmarshalling info: %s", err)
  55         }
  56         mMapSpan := &mmap_span.MMapSpan{}
  57         if len(info.Files) > 0 {
  58                 for _, file := range info.Files {
  59                         filename := filepath.Join(append([]string{*dataPath, info.Name}, file.Path...)...)
  60                         goMMap := fileToMmap(filename, file.Length)
  61                         mMapSpan.Append(goMMap)
  62                 }
  63                 log.Println(len(info.Files))
  64         } else {
  65                 goMMap := fileToMmap(*dataPath, info.Length)
  66                 mMapSpan.Append(goMMap)
  67         }
  68         log.Println(mMapSpan.Size())
  69         log.Println(len(info.Pieces))
  70         for i := range iter.N(info.NumPieces()) {
  71                 p := info.Piece(i)
  72                 hash := sha1.New()
  73                 _, err := io.Copy(hash, io.NewSectionReader(mMapSpan, p.Offset(), p.Length()))
  74                 if err != nil {
  75                         log.Fatal(err)
  76                 }
  77                 fmt.Printf("%d: %x: %v\n", i, p.Hash(), bytes.Equal(hash.Sum(nil), p.Hash().Bytes()))
  78         }
  79 }