FedP2P/file.go

147 lines
3.2 KiB
Go

package torrent
import (
"strings"
"github.com/anacrolix/torrent/metainfo"
pwp "github.com/anacrolix/torrent/peer_protocol"
)
// Provides access to regions of torrent data that correspond to its files.
type File struct {
t *Torrent
path string
offset int64
length int64
fi metainfo.FileInfo
prio piecePriority
}
func (f *File) Torrent() *Torrent {
return f.t
}
// Data for this file begins this many bytes into the Torrent.
func (f *File) Offset() int64 {
return f.offset
}
// The FileInfo from the metainfo.Info to which this file corresponds.
func (f File) FileInfo() metainfo.FileInfo {
return f.fi
}
// The file's path components joined by '/'.
func (f File) Path() string {
return f.path
}
// The file's length in bytes.
func (f *File) Length() int64 {
return f.length
}
// The relative file path for a multi-file torrent, and the torrent name for a
// single-file torrent.
func (f *File) DisplayPath() string {
fip := f.FileInfo().Path
if len(fip) == 0 {
return f.t.info.Name
}
return strings.Join(fip, "/")
}
// The download status of a piece that comprises part of a File.
type FilePieceState struct {
Bytes int64 // Bytes within the piece that are part of this File.
PieceState
}
// Returns the state of pieces in this file.
func (f *File) State() (ret []FilePieceState) {
f.t.cl.mu.RLock()
defer f.t.cl.mu.RUnlock()
pieceSize := int64(f.t.usualPieceSize())
off := f.offset % pieceSize
remaining := f.length
for i := int(f.offset / pieceSize); ; i++ {
if remaining == 0 {
break
}
len1 := pieceSize - off
if len1 > remaining {
len1 = remaining
}
ps := f.t.pieceState(i)
ret = append(ret, FilePieceState{len1, ps})
off = 0
remaining -= len1
}
return
}
// Requests that all pieces containing data in the file be downloaded.
func (f *File) Download() {
f.SetPriority(PiecePriorityNormal)
}
func byteRegionExclusivePieces(off, size, pieceSize int64) (begin, end int) {
begin = int((off + pieceSize - 1) / pieceSize)
end = int((off + size) / pieceSize)
return
}
func (f *File) exclusivePieces() (begin, end int) {
return byteRegionExclusivePieces(f.offset, f.length, int64(f.t.usualPieceSize()))
}
// Deprecated: Use File.SetPriority.
func (f *File) Cancel() {
f.SetPriority(PiecePriorityNone)
}
func (f *File) NewReader() Reader {
tr := reader{
mu: &f.t.cl.mu,
t: f.t,
readahead: 5 * 1024 * 1024,
offset: f.Offset(),
length: f.Length(),
}
f.t.addReader(&tr)
return &tr
}
// Sets the minimum priority for pieces in the File.
func (f *File) SetPriority(prio piecePriority) {
f.t.cl.mu.Lock()
defer f.t.cl.mu.Unlock()
if prio == f.prio {
return
}
f.prio = prio
f.t.updatePiecePriorities(f.firstPieceIndex().Int(), f.endPieceIndex().Int())
}
// Returns the priority per File.SetPriority.
func (f *File) Priority() piecePriority {
f.t.cl.mu.Lock()
defer f.t.cl.mu.Unlock()
return f.prio
}
func (f *File) firstPieceIndex() pwp.Integer {
if f.t.usualPieceSize() == 0 {
return 0
}
return pwp.Integer(f.offset / int64(f.t.usualPieceSize()))
}
func (f *File) endPieceIndex() pwp.Integer {
if f.t.usualPieceSize() == 0 {
return 0
}
return pwp.Integer((f.offset+f.length-1)/int64(f.t.usualPieceSize())) + 1
}