package torrent import ( "errors" "net" "github.com/RoaringBitmap/roaring" "github.com/anacrolix/missinggo/v2" "github.com/anacrolix/torrent/types" "golang.org/x/time/rate" "github.com/anacrolix/torrent/metainfo" pp "github.com/anacrolix/torrent/peer_protocol" ) type ( Request = types.Request ChunkSpec = types.ChunkSpec piecePriority = types.PiecePriority ) const ( PiecePriorityNormal = types.PiecePriorityNormal PiecePriorityNone = types.PiecePriorityNone PiecePriorityNow = types.PiecePriorityNow PiecePriorityReadahead = types.PiecePriorityReadahead PiecePriorityNext = types.PiecePriorityNext PiecePriorityHigh = types.PiecePriorityHigh ) func newRequest(index, begin, length pp.Integer) Request { return Request{index, ChunkSpec{begin, length}} } 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) } } // 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 } // 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 } 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 validateInfo(info *metainfo.Info) error { if len(info.Pieces)%20 != 0 { return errors.New("pieces has invalid length") } 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 nil } 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 connLessTrusted(l, r *Peer) bool { return l.trust().Less(r.trust()) } func connIsIpv6(nc interface { LocalAddr() net.Addr }) bool { ra := nc.LocalAddr() rip := addrIpOrNil(ra) return rip.To4() == nil && rip.To16() != nil } 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 max(as ...int64) int64 { ret := as[0] for _, a := range as[1:] { if a > ret { ret = a } } return ret } func maxInt(as ...int) int { ret := as[0] for _, a := range as[1:] { if a > ret { ret = a } } return ret } func min(as ...int64) int64 { ret := as[0] for _, a := range as[1:] { if a < ret { ret = a } } return ret } func minInt(as ...int) int { ret := as[0] for _, a := range as[1:] { if a < ret { ret = a } } return ret } var unlimited = rate.NewLimiter(rate.Inf, 0) type ( pieceIndex = int InfoHash = metainfo.Hash IpPort = missinggo.IpPort ) func boolSliceToBitmap(slice []bool) (rb roaring.Bitmap) { for i, b := range slice { if b { rb.AddInt(i) } } return }