forked from anacrolix/torrent
/
file.go
136 lines (125 loc) · 2.36 KB
/
file.go
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package file
import (
"io"
"os"
"path/filepath"
"github.com/anacrolix/torrent/metainfo"
)
type data struct {
info *metainfo.Info
loc string
completed []bool
}
func TorrentData(md *metainfo.Info, location string) data {
return data{md, location, make([]bool, md.NumPieces())}
}
func (me data) Close() {}
func (me data) PieceComplete(piece int) bool {
return me.completed[piece]
}
func (me data) PieceCompleted(piece int) error {
me.completed[piece] = true
return nil
}
func (me data) ReadAt(p []byte, off int64) (n int, err error) {
for _, fi := range me.info.UpvertedFiles() {
if off >= fi.Length {
off -= fi.Length
continue
}
n1 := len(p)
if int64(n1) > fi.Length-off {
n1 = int(fi.Length - off)
}
var f *os.File
f, err = os.Open(me.fileInfoName(fi))
if err != nil {
return
}
n1, err = f.ReadAt(p[:n1], off)
f.Close()
if err != nil {
return
}
n += n1
off = 0
p = p[n1:]
if len(p) == 0 {
break
}
}
return
}
func (me data) WriteAt(p []byte, off int64) (n int, err error) {
for _, fi := range me.info.UpvertedFiles() {
if off >= fi.Length {
off -= fi.Length
continue
}
n1 := len(p)
if int64(n1) > fi.Length-off {
n1 = int(fi.Length - off)
}
name := me.fileInfoName(fi)
os.MkdirAll(filepath.Dir(name), 0770)
var f *os.File
f, err = os.OpenFile(name, os.O_WRONLY|os.O_CREATE, 0660)
if err != nil {
return
}
n1, err = f.WriteAt(p[:n1], off)
f.Close()
if err != nil {
return
}
n += n1
off = 0
p = p[n1:]
if len(p) == 0 {
break
}
}
return
}
func (me data) WriteSectionTo(w io.Writer, off, n int64) (written int64, err error) {
for _, fi := range me.info.UpvertedFiles() {
if off >= fi.Length {
off -= fi.Length
continue
}
n1 := fi.Length - off
if n1 > n {
n1 = n
}
var f *os.File
f, err = os.Open(me.fileInfoName(fi))
if os.IsNotExist(err) {
err = io.ErrUnexpectedEOF
}
if err != nil {
return
}
var w1 int64
w1, err = io.Copy(w, io.NewSectionReader(f, off, n1))
f.Close()
written += w1
if w1 != n1 {
if err == nil || err == io.EOF {
err = io.ErrUnexpectedEOF
}
return
} else {
err = nil
}
off = 0
n -= n1
if n == 0 {
return
}
}
err = io.EOF
return
}
func (me data) fileInfoName(fi metainfo.FileInfo) string {
return filepath.Join(append([]string{me.loc, me.info.Name}, fi.Path...)...)
}