package torrent
import (
- "bitbucket.org/anacrolix/go.torrent/mmap_span"
- "crypto"
"errors"
- "math/rand"
- "os"
- "path/filepath"
- "time"
-
- "bitbucket.org/anacrolix/go.torrent/peer_protocol"
- metainfo "github.com/nsf/libtorgo/torrent"
- "launchpad.net/gommap"
+ "net"
+
+ "github.com/RoaringBitmap/roaring"
+ "github.com/anacrolix/missinggo/v2"
+ "golang.org/x/time/rate"
+
+ "github.com/anacrolix/torrent/metainfo"
+ pp "github.com/anacrolix/torrent/peer_protocol"
+ "github.com/anacrolix/torrent/types"
+ "github.com/anacrolix/torrent/types/infohash"
+)
+
+type (
+ Request = types.Request
+ ChunkSpec = types.ChunkSpec
+ piecePriority = types.PiecePriority
)
const (
- pieceHash = crypto.SHA1
- maxRequests = 250 // Maximum pending requests we allow peers to send us.
- chunkSize = 0x4000 // 16KiB
- BEP20 = "-GT0000-" // Peer ID client identifier prefix
- dialTimeout = time.Second * 15
+ PiecePriorityNormal = types.PiecePriorityNormal
+ PiecePriorityNone = types.PiecePriorityNone
+ PiecePriorityNow = types.PiecePriorityNow
+ PiecePriorityReadahead = types.PiecePriorityReadahead
+ PiecePriorityNext = types.PiecePriorityNext
+ PiecePriorityHigh = types.PiecePriorityHigh
)
-type InfoHash [20]byte
+func newRequest(index, begin, length pp.Integer) Request {
+ return Request{index, ChunkSpec{begin, length}}
+}
-type pieceSum [20]byte
+func newRequestFromMessage(msg *pp.Message) Request {
+ switch msg.Type {
+ case pp.Request, pp.Cancel, pp.Reject:
+ return newRequest(msg.Index, msg.Begin, msg.Length)
+ case pp.Piece:
+ return newRequest(msg.Index, msg.Begin, pp.Integer(len(msg.Piece)))
+ default:
+ panic(msg.Type)
+ }
+}
-func copyHashSum(dst, src []byte) {
- if len(dst) != len(src) || copy(dst, src) != len(dst) {
- panic("hash sum sizes differ")
+// The size in bytes of a metadata extension piece.
+func metadataPieceSize(totalSize, piece int) int {
+ ret := totalSize - piece*(1<<14)
+ if ret > 1<<14 {
+ ret = 1 << 14
}
+ return ret
}
-func BytesInfoHash(b []byte) (ih InfoHash) {
- if len(b) != len(ih) || copy(ih[:], b) != len(ih) {
- panic("bad infohash bytes")
+// Return the request that would include the given offset into the torrent data.
+func torrentOffsetRequest(
+ torrentLength, pieceSize, chunkSize, offset int64,
+) (
+ r Request, ok bool,
+) {
+ if offset < 0 || offset >= torrentLength {
+ return
+ }
+ r.Index = pp.Integer(offset / pieceSize)
+ r.Begin = pp.Integer(offset % pieceSize / chunkSize * chunkSize)
+ r.Length = pp.Integer(chunkSize)
+ pieceLeft := pp.Integer(pieceSize - int64(r.Begin))
+ if r.Length > pieceLeft {
+ r.Length = pieceLeft
}
+ torrentLeft := torrentLength - int64(r.Index)*pieceSize - int64(r.Begin)
+ if int64(r.Length) > torrentLeft {
+ r.Length = pp.Integer(torrentLeft)
+ }
+ ok = true
return
}
-type piece struct {
- Hash pieceSum
- PendingChunkSpecs map[chunkSpec]struct{}
- Hashing bool
- QueuedForHash bool
- EverHashed bool
+func torrentRequestOffset(torrentLength, pieceSize int64, r Request) (off int64) {
+ off = int64(r.Index)*pieceSize + int64(r.Begin)
+ if off < 0 || off >= torrentLength {
+ panic("invalid Request")
+ }
+ return
}
-func (p *piece) shuffledPendingChunkSpecs() (css []chunkSpec) {
- css = make([]chunkSpec, 0, len(p.PendingChunkSpecs))
- for cs := range p.PendingChunkSpecs {
- css = append(css, cs)
+func validateInfo(info *metainfo.Info) error {
+ if len(info.Pieces)%20 != 0 {
+ return errors.New("pieces has invalid length")
}
- for i := range css {
- j := rand.Intn(i + 1)
- css[i], css[j] = css[j], css[i]
+ if info.PieceLength == 0 {
+ if info.TotalLength() != 0 {
+ return errors.New("zero piece length")
+ }
+ } else {
+ if int((info.TotalLength()+info.PieceLength-1)/info.PieceLength) != info.NumPieces() {
+ return errors.New("piece count and file lengths are at odds")
+ }
}
- return
+ return nil
}
-func (p *piece) Complete() bool {
- return len(p.PendingChunkSpecs) == 0 && p.EverHashed
+func chunkIndexSpec(index, pieceLength, chunkSize pp.Integer) ChunkSpec {
+ ret := ChunkSpec{pp.Integer(index) * chunkSize, chunkSize}
+ if ret.Begin+ret.Length > pieceLength {
+ ret.Length = pieceLength - ret.Begin
+ }
+ return ret
}
-func lastChunkSpec(pieceLength peer_protocol.Integer) (cs chunkSpec) {
- cs.Begin = (pieceLength - 1) / chunkSize * chunkSize
- cs.Length = pieceLength - cs.Begin
- return
+func connLessTrusted(l, r *Peer) bool {
+ return l.trust().Less(r.trust())
}
-type chunkSpec struct {
- Begin, Length peer_protocol.Integer
+func connIsIpv6(nc interface {
+ LocalAddr() net.Addr
+},
+) bool {
+ ra := nc.LocalAddr()
+ rip := addrIpOrNil(ra)
+ return rip.To4() == nil && rip.To16() != nil
}
-type request struct {
- Index peer_protocol.Integer
- chunkSpec
+func clamp(min, value, max int64) int64 {
+ if min > max {
+ panic("harumph")
+ }
+ if value < min {
+ value = min
+ }
+ if value > max {
+ value = max
+ }
+ return value
}
-func newRequest(index, begin, length peer_protocol.Integer) request {
- return request{index, chunkSpec{begin, length}}
+func max(as ...int64) int64 {
+ ret := as[0]
+ for _, a := range as[1:] {
+ if a > ret {
+ ret = a
+ }
+ }
+ return ret
}
-type pieceByBytesPendingSlice struct {
- Pending, Indices []peer_protocol.Integer
+func maxInt(as ...int) int {
+ ret := as[0]
+ for _, a := range as[1:] {
+ if a > ret {
+ ret = a
+ }
+ }
+ return ret
}
-func (pcs pieceByBytesPendingSlice) Len() int {
- return len(pcs.Indices)
+func min(as ...int64) int64 {
+ ret := as[0]
+ for _, a := range as[1:] {
+ if a < ret {
+ ret = a
+ }
+ }
+ return ret
}
-func (me pieceByBytesPendingSlice) Less(i, j int) bool {
- return me.Pending[me.Indices[i]] < me.Pending[me.Indices[j]]
+func minInt(as ...int) int {
+ ret := as[0]
+ for _, a := range as[1:] {
+ if a < ret {
+ ret = a
+ }
+ }
+ return ret
}
-func (me pieceByBytesPendingSlice) Swap(i, j int) {
- me.Indices[i], me.Indices[j] = me.Indices[j], me.Indices[i]
-}
+var unlimited = rate.NewLimiter(rate.Inf, 0)
-var (
- // Requested data not yet available.
- ErrDataNotReady = errors.New("data not ready")
+type (
+ pieceIndex = int
+ // Deprecated: Use infohash.T directly to avoid unnecessary imports.
+ InfoHash = infohash.T
+ IpPort = missinggo.IpPort
)
-func mmapTorrentData(metaInfo *metainfo.MetaInfo, location string) (mms mmap_span.MMapSpan, err error) {
- defer func() {
- if err != nil {
- mms.Close()
- mms = nil
- }
- }()
- for _, miFile := range metaInfo.Files {
- fileName := filepath.Join(append([]string{location, metaInfo.Name}, miFile.Path...)...)
- err = os.MkdirAll(filepath.Dir(fileName), 0777)
- if err != nil {
- return
- }
- var file *os.File
- file, err = os.OpenFile(fileName, os.O_CREATE|os.O_RDWR, 0666)
- if err != nil {
- return
- }
- func() {
- defer file.Close()
- var fi os.FileInfo
- fi, err = file.Stat()
- if err != nil {
- return
- }
- if fi.Size() < miFile.Length {
- err = file.Truncate(miFile.Length)
- if err != nil {
- return
- }
- }
- var mMap gommap.MMap
- mMap, err = gommap.MapRegion(file.Fd(), 0, miFile.Length, gommap.PROT_READ|gommap.PROT_WRITE, gommap.MAP_SHARED)
- if err != nil {
- return
- }
- if int64(len(mMap)) != miFile.Length {
- panic("mmap has wrong length")
- }
- mms = append(mms, mMap)
- }()
- if err != nil {
- return
+func boolSliceToBitmap(slice []bool) (rb roaring.Bitmap) {
+ for i, b := range slice {
+ if b {
+ rb.AddInt(i)
}
}
return