From 9ba3af19ba811a8513c235712a3dc8d7b990099a Mon Sep 17 00:00:00 2001 From: Matt Joiner Date: Thu, 3 Apr 2014 23:16:59 +1100 Subject: [PATCH] Break up client.go into several files and a few fixes Suppress expected errors when initiating connections. Add an explicit timeout to initiate connections. Put a lock on closing a connection to prevent data race warnings. --- client.go | 486 +++----------------------------------------------- connection.go | 174 ++++++++++++++++++ misc.go | 133 ++++++++++++++ torrent.go | 189 ++++++++++++++++++++ 4 files changed, 521 insertions(+), 461 deletions(-) create mode 100644 connection.go create mode 100644 misc.go create mode 100644 torrent.go diff --git a/client.go b/client.go index a0e375c6..fac59b75 100644 --- a/client.go +++ b/client.go @@ -3,7 +3,6 @@ package torrent import ( "bufio" "container/list" - "crypto" "crypto/rand" "encoding" "errors" @@ -13,9 +12,8 @@ import ( mathRand "math/rand" "net" "os" - "path/filepath" - "sort" "sync" + "syscall" "time" metainfo "github.com/nsf/libtorgo/torrent" @@ -23,290 +21,8 @@ import ( "bitbucket.org/anacrolix/go.torrent/peer_protocol" "bitbucket.org/anacrolix/go.torrent/tracker" _ "bitbucket.org/anacrolix/go.torrent/tracker/udp" - "launchpad.net/gommap" ) -const ( - PieceHash = crypto.SHA1 - maxRequests = 250 - chunkSize = 0x4000 // 16KiB - BEP20 = "-GT0000-" -) - -type InfoHash [20]byte - -type pieceSum [20]byte - -func copyHashSum(dst, src []byte) { - if len(dst) != len(src) || copy(dst, src) != len(dst) { - panic("hash sum sizes differ") - } -} - -func BytesInfoHash(b []byte) (ih InfoHash) { - if len(b) != len(ih) || copy(ih[:], b) != len(ih) { - panic("bad infohash bytes") - } - return -} - -type piece struct { - Hash pieceSum - PendingChunkSpecs map[ChunkSpec]struct{} - Hashing bool - QueuedForHash bool - EverHashed bool -} - -func (p *piece) Complete() bool { - return len(p.PendingChunkSpecs) == 0 && p.EverHashed -} - -func lastChunkSpec(pieceLength peer_protocol.Integer) (cs ChunkSpec) { - cs.Begin = (pieceLength - 1) / chunkSize * chunkSize - cs.Length = pieceLength - cs.Begin - return -} - -func (t *Torrent) PieceNumPendingBytes(index peer_protocol.Integer) (count peer_protocol.Integer) { - pendingChunks := t.Pieces[index].PendingChunkSpecs - count = peer_protocol.Integer(len(pendingChunks)) * chunkSize - _lastChunkSpec := lastChunkSpec(t.PieceLength(index)) - if _lastChunkSpec.Length != chunkSize { - if _, ok := pendingChunks[_lastChunkSpec]; ok { - count += _lastChunkSpec.Length - chunkSize - } - } - return -} - -type ChunkSpec struct { - Begin, Length peer_protocol.Integer -} - -type Request struct { - Index peer_protocol.Integer - ChunkSpec -} - -type Connection struct { - Socket net.Conn - Closed bool - post chan encoding.BinaryMarshaler - write chan []byte - - // Stuff controlled by the local peer. - Interested bool - Choked bool - Requests map[Request]struct{} - - // Stuff controlled by the remote peer. - PeerId [20]byte - PeerInterested bool - PeerChoked bool - PeerRequests map[Request]struct{} - PeerExtensions [8]byte - PeerPieces []bool -} - -func (c *Connection) Close() { - if c.Closed { - return - } - c.Socket.Close() - close(c.post) - c.Closed = true -} - -func (c *Connection) PeerHasPiece(index peer_protocol.Integer) bool { - if c.PeerPieces == nil { - return false - } - return c.PeerPieces[index] -} - -func (c *Connection) Post(msg encoding.BinaryMarshaler) { - c.post <- msg -} - -// Returns true if more requests can be sent. -func (c *Connection) Request(chunk Request) bool { - if len(c.Requests) >= maxRequests { - return false - } - if !c.PeerPieces[chunk.Index] { - return true - } - c.SetInterested(true) - if c.PeerChoked { - return false - } - if _, ok := c.Requests[chunk]; !ok { - c.Post(peer_protocol.Message{ - Type: peer_protocol.Request, - Index: chunk.Index, - Begin: chunk.Begin, - Length: chunk.Length, - }) - } - if c.Requests == nil { - c.Requests = make(map[Request]struct{}, maxRequests) - } - c.Requests[chunk] = struct{}{} - return true -} - -func (c *Connection) Unchoke() { - if !c.Choked { - return - } - c.Post(peer_protocol.Message{ - Type: peer_protocol.Unchoke, - }) - c.Choked = false -} - -func (c *Connection) SetInterested(interested bool) { - if c.Interested == interested { - return - } - c.Post(peer_protocol.Message{ - Type: func() peer_protocol.MessageType { - if interested { - return peer_protocol.Interested - } else { - return peer_protocol.NotInterested - } - }(), - }) - c.Interested = interested -} - -var ( - keepAliveBytes [4]byte -) - -func (conn *Connection) writer() { - timer := time.NewTimer(0) - defer timer.Stop() - for { - if !timer.Reset(time.Minute) { - <-timer.C - } - var b []byte - select { - case <-timer.C: - b = keepAliveBytes[:] - case b = <-conn.write: - if b == nil { - return - } - } - n, err := conn.Socket.Write(b) - if err != nil { - log.Print(err) - break - } - if n != len(b) { - panic("didn't write all bytes") - } - } -} - -func (conn *Connection) writeOptimizer() { - pending := list.New() - var nextWrite []byte - defer close(conn.write) - for { - write := conn.write - if pending.Len() == 0 { - write = nil - } else { - var err error - nextWrite, err = pending.Front().Value.(encoding.BinaryMarshaler).MarshalBinary() - if err != nil { - panic(err) - } - } - select { - case msg, ok := <-conn.post: - if !ok { - return - } - pending.PushBack(msg) - case write <- nextWrite: - pending.Remove(pending.Front()) - } - } -} - -type Torrent struct { - InfoHash InfoHash - Pieces []*piece - Data MMapSpan - MetaInfo *metainfo.MetaInfo - Conns []*Connection - Peers []Peer - Priorities *list.List - // BEP 12 Multitracker Metadata Extension. The tracker.Client instances - // mirror their respective URLs from the announce-list key. - Trackers [][]tracker.Client -} - -func (t *Torrent) NumPieces() int { - return len(t.MetaInfo.Pieces) / PieceHash.Size() -} - -func (t *Torrent) NumPiecesCompleted() (num int) { - for _, p := range t.Pieces { - if p.Complete() { - num++ - } - } - return -} - -func (t *Torrent) Length() int64 { - return int64(t.PieceLength(peer_protocol.Integer(len(t.Pieces)-1))) + int64(len(t.Pieces)-1)*int64(t.PieceLength(0)) -} - -func (t *Torrent) Close() (err error) { - t.Data.Close() - for _, conn := range t.Conns { - conn.Close() - } - return -} - -type pieceByBytesPendingSlice struct { - Pending, Indices []peer_protocol.Integer -} - -func (pcs pieceByBytesPendingSlice) Len() int { - return len(pcs.Indices) -} - -func (me pieceByBytesPendingSlice) Less(i, j int) bool { - return me.Pending[me.Indices[i]] < me.Pending[me.Indices[j]] -} - -func (me pieceByBytesPendingSlice) Swap(i, j int) { - me.Indices[i], me.Indices[j] = me.Indices[j], me.Indices[i] -} - -func (t *Torrent) piecesByPendingBytesDesc() (indices []peer_protocol.Integer) { - slice := pieceByBytesPendingSlice{ - Pending: make([]peer_protocol.Integer, 0, len(t.Pieces)), - Indices: make([]peer_protocol.Integer, 0, len(t.Pieces)), - } - for i := range t.Pieces { - slice.Pending = append(slice.Pending, t.PieceNumPendingBytes(peer_protocol.Integer(i))) - slice.Indices = append(slice.Indices, peer_protocol.Integer(i)) - } - sort.Sort(sort.Reverse(slice)) - return slice.Indices -} - // Currently doesn't really queue, but should in the future. func (cl *Client) queuePieceCheck(t *Torrent, pieceIndex peer_protocol.Integer) { piece := t.Pieces[pieceIndex] @@ -317,25 +33,6 @@ func (cl *Client) queuePieceCheck(t *Torrent, pieceIndex peer_protocol.Integer) go cl.verifyPiece(t, pieceIndex) } -func (t *Torrent) offsetRequest(off int64) (req Request, ok bool) { - req.Index = peer_protocol.Integer(off / t.MetaInfo.PieceLength) - if req.Index < 0 || int(req.Index) >= len(t.Pieces) { - return - } - off %= t.MetaInfo.PieceLength - pieceLeft := t.PieceLength(req.Index) - peer_protocol.Integer(off) - if pieceLeft <= 0 { - return - } - req.Begin = chunkSize * (peer_protocol.Integer(off) / chunkSize) - req.Length = chunkSize - if req.Length > pieceLeft { - req.Length = pieceLeft - } - ok = true - return -} - func (cl *Client) PrioritizeDataRegion(ih InfoHash, off, len_ int64) { cl.mu.Lock() defer cl.mu.Unlock() @@ -369,79 +66,6 @@ func (cl *Client) PrioritizeDataRegion(ih InfoHash, off, len_ int64) { } } -func (t *Torrent) WriteChunk(piece int, begin int64, data []byte) (err error) { - _, err = t.Data.WriteAt(data, int64(piece)*t.MetaInfo.PieceLength+begin) - return -} - -func (t *Torrent) bitfield() (bf []bool) { - for _, p := range t.Pieces { - bf = append(bf, p.EverHashed && len(p.PendingChunkSpecs) == 0) - } - return -} - -func (t *Torrent) pendAllChunkSpecs(index peer_protocol.Integer) { - piece := t.Pieces[index] - if piece.PendingChunkSpecs == nil { - piece.PendingChunkSpecs = make( - map[ChunkSpec]struct{}, - (t.MetaInfo.PieceLength+chunkSize-1)/chunkSize) - } - c := ChunkSpec{ - Begin: 0, - } - cs := piece.PendingChunkSpecs - for left := peer_protocol.Integer(t.PieceLength(index)); left != 0; left -= c.Length { - c.Length = left - if c.Length > chunkSize { - c.Length = chunkSize - } - cs[c] = struct{}{} - c.Begin += c.Length - } - return -} - -func (t *Torrent) requestHeat() (ret map[Request]int) { - ret = make(map[Request]int) - for _, conn := range t.Conns { - for req, _ := range conn.Requests { - ret[req]++ - } - } - return -} - -type Peer struct { - Id [20]byte - IP net.IP - Port int -} - -func (t *Torrent) PieceLength(piece peer_protocol.Integer) (len_ peer_protocol.Integer) { - if int(piece) == t.NumPieces()-1 { - len_ = peer_protocol.Integer(t.Data.Size() % t.MetaInfo.PieceLength) - } - if len_ == 0 { - len_ = peer_protocol.Integer(t.MetaInfo.PieceLength) - } - return -} - -func (t *Torrent) HashPiece(piece peer_protocol.Integer) (ps pieceSum) { - hash := PieceHash.New() - n, err := t.Data.WriteSectionTo(hash, int64(piece)*t.MetaInfo.PieceLength, t.MetaInfo.PieceLength) - if err != nil { - panic(err) - } - if peer_protocol.Integer(n) != t.PieceLength(piece) { - panic(fmt.Sprintf("hashed wrong number of bytes: expected %d; did %d; piece %d", t.PieceLength(piece), n, piece)) - } - copyHashSum(ps[:], hash.Sum(nil)) - return -} - type DataSpec struct { InfoHash Request @@ -464,10 +88,6 @@ type Client struct { dataWaiter chan struct{} } -var ( - ErrDataNotReady = errors.New("data not ready") -) - func (cl *Client) TorrentReadAt(ih InfoHash, off int64, p []byte) (n int, err error) { cl.mu.Lock() defer cl.mu.Unlock() @@ -576,54 +196,6 @@ func (cl *Client) acceptConnections() { } } -func mmapTorrentData(metaInfo *metainfo.MetaInfo, location string) (mms 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{mMap}) - }() - if err != nil { - return - } - } - return -} - func (me *Client) torrent(ih InfoHash) *Torrent { for _, t := range me.torrents { if t.InfoHash == ih { @@ -639,18 +211,33 @@ func (me *Client) initiateConn(peer Peer, torrent *Torrent) { } me.halfOpen++ go func() { - conn, err := net.DialTCP("tcp", nil, &net.TCPAddr{ + addr := &net.TCPAddr{ IP: peer.IP, Port: peer.Port, - }) + } + conn, err := net.DialTimeout(addr.Network(), addr.String(), dialTimeout) - me.mu.Lock() - me.halfOpen-- - me.openNewConns() - me.mu.Unlock() + go func() { + me.mu.Lock() + defer me.mu.Unlock() + if me.halfOpen == 0 { + panic("assert") + } + me.halfOpen-- + me.openNewConns() + }() + if netOpErr, ok := err.(*net.OpError); ok { + if netOpErr.Timeout() { + return + } + switch netOpErr.Err { + case syscall.ECONNREFUSED: + return + } + } if err != nil { - log.Printf("error connecting to peer: %s", err) + log.Printf("error connecting to peer: %s %#v", err, err) return } log.Printf("connected to %s", conn.RemoteAddr()) @@ -661,24 +248,6 @@ func (me *Client) initiateConn(peer Peer, torrent *Torrent) { }() } -func (t *Torrent) haveAllPieces() bool { - for _, piece := range t.Pieces { - if !piece.Complete() { - return false - } - } - return true -} - -func (me *Torrent) haveAnyPieces() bool { - for _, piece := range me.Pieces { - if piece.Complete() { - return true - } - } - return false -} - func (me *Client) runConnection(sock net.Conn, torrent *Torrent) (err error) { conn := &Connection{ Socket: sock, @@ -765,11 +334,6 @@ func (me *Client) peerGotPiece(torrent *Torrent, conn *Connection, piece int) { } } -func (t *Torrent) wantPiece(index int) bool { - p := t.Pieces[index] - return p.EverHashed && len(p.PendingChunkSpecs) != 0 -} - func (me *Client) peerUnchoked(torrent *Torrent, conn *Connection) { me.replenishConnRequests(torrent, conn) } @@ -851,7 +415,7 @@ func (me *Client) connectionLoop(torrent *Torrent, conn *Connection) error { case peer_protocol.Piece: request_ := Request{msg.Index, ChunkSpec{msg.Begin, peer_protocol.Integer(len(msg.Piece))}} if _, ok := conn.Requests[request_]; !ok { - err = errors.New("unexpected piece") + err = fmt.Errorf("unexpected piece: %s", request_) break } delete(conn.Requests, request_) @@ -1086,7 +650,7 @@ func (me *Client) replenishConnRequests(torrent *Torrent, conn *Connection) { } } } - // Then finish of incomplete pieces in order of bytes remaining. + // Then finish off incomplete pieces in order of bytes remaining. for _, index := range torrent.piecesByPendingBytesDesc() { if torrent.PieceNumPendingBytes(index) == torrent.PieceLength(index) { continue diff --git a/connection.go b/connection.go new file mode 100644 index 00000000..cbe0e91c --- /dev/null +++ b/connection.go @@ -0,0 +1,174 @@ +package torrent + +import ( + "container/list" + "encoding" + "log" + "net" + "sync" + "time" + + "bitbucket.org/anacrolix/go.torrent/peer_protocol" +) + +// Maintains the state of a connection with a peer. +type Connection struct { + Socket net.Conn + closed bool + mu sync.Mutex // Only for closing. + post chan encoding.BinaryMarshaler + write chan []byte + + // Stuff controlled by the local peer. + Interested bool + Choked bool + Requests map[Request]struct{} + + // Stuff controlled by the remote peer. + PeerId [20]byte + PeerInterested bool + PeerChoked bool + PeerRequests map[Request]struct{} + PeerExtensions [8]byte + PeerPieces []bool +} + +func (c *Connection) Close() { + c.mu.Lock() + if c.closed { + return + } + c.Socket.Close() + close(c.post) + c.closed = true + c.mu.Unlock() +} + +func (c *Connection) getClosed() bool { + c.mu.Lock() + defer c.mu.Unlock() + return c.closed +} + +func (c *Connection) PeerHasPiece(index peer_protocol.Integer) bool { + if c.PeerPieces == nil { + return false + } + return c.PeerPieces[index] +} + +func (c *Connection) Post(msg encoding.BinaryMarshaler) { + c.post <- msg +} + +// Returns true if more requests can be sent. +func (c *Connection) Request(chunk Request) bool { + if len(c.Requests) >= maxRequests { + return false + } + if !c.PeerPieces[chunk.Index] { + return true + } + c.SetInterested(true) + if c.PeerChoked { + return false + } + if _, ok := c.Requests[chunk]; !ok { + c.Post(peer_protocol.Message{ + Type: peer_protocol.Request, + Index: chunk.Index, + Begin: chunk.Begin, + Length: chunk.Length, + }) + } + if c.Requests == nil { + c.Requests = make(map[Request]struct{}, maxRequests) + } + c.Requests[chunk] = struct{}{} + return true +} + +func (c *Connection) Unchoke() { + if !c.Choked { + return + } + c.Post(peer_protocol.Message{ + Type: peer_protocol.Unchoke, + }) + c.Choked = false +} + +func (c *Connection) SetInterested(interested bool) { + if c.Interested == interested { + return + } + c.Post(peer_protocol.Message{ + Type: func() peer_protocol.MessageType { + if interested { + return peer_protocol.Interested + } else { + return peer_protocol.NotInterested + } + }(), + }) + c.Interested = interested +} + +var ( + // Four consecutive zero bytes that comprise a keep alive on the wire. + keepAliveBytes [4]byte +) + +func (conn *Connection) writer() { + timer := time.NewTimer(0) + defer timer.Stop() + for { + if !timer.Reset(time.Minute) { + <-timer.C + } + var b []byte + select { + case <-timer.C: + b = keepAliveBytes[:] + case b = <-conn.write: + if b == nil { + return + } + } + _, err := conn.Socket.Write(b) + if conn.getClosed() { + break + } + if err != nil { + log.Print(err) + break + } + } +} + +func (conn *Connection) writeOptimizer() { + pending := list.New() + var nextWrite []byte + defer close(conn.write) + for { + write := conn.write + if pending.Len() == 0 { + write = nil + } else { + var err error + nextWrite, err = pending.Front().Value.(encoding.BinaryMarshaler).MarshalBinary() + if err != nil { + panic(err) + } + } + select { + case msg, ok := <-conn.post: + if !ok { + return + } + pending.PushBack(msg) + case write <- nextWrite: + pending.Remove(pending.Front()) + } + } +} diff --git a/misc.go b/misc.go new file mode 100644 index 00000000..e5644005 --- /dev/null +++ b/misc.go @@ -0,0 +1,133 @@ +package torrent + +import ( + "crypto" + "errors" + "os" + "path/filepath" + "time" + + "bitbucket.org/anacrolix/go.torrent/peer_protocol" + metainfo "github.com/nsf/libtorgo/torrent" + "launchpad.net/gommap" +) + +const ( + PieceHash = crypto.SHA1 + maxRequests = 250 + chunkSize = 0x4000 // 16KiB + BEP20 = "-GT0000-" + dialTimeout = time.Second * 15 +) + +type InfoHash [20]byte + +type pieceSum [20]byte + +func copyHashSum(dst, src []byte) { + if len(dst) != len(src) || copy(dst, src) != len(dst) { + panic("hash sum sizes differ") + } +} + +func BytesInfoHash(b []byte) (ih InfoHash) { + if len(b) != len(ih) || copy(ih[:], b) != len(ih) { + panic("bad infohash bytes") + } + return +} + +type piece struct { + Hash pieceSum + PendingChunkSpecs map[ChunkSpec]struct{} + Hashing bool + QueuedForHash bool + EverHashed bool +} + +func (p *piece) Complete() bool { + return len(p.PendingChunkSpecs) == 0 && p.EverHashed +} + +func lastChunkSpec(pieceLength peer_protocol.Integer) (cs ChunkSpec) { + cs.Begin = (pieceLength - 1) / chunkSize * chunkSize + cs.Length = pieceLength - cs.Begin + return +} + +type ChunkSpec struct { + Begin, Length peer_protocol.Integer +} + +type Request struct { + Index peer_protocol.Integer + ChunkSpec +} + +type pieceByBytesPendingSlice struct { + Pending, Indices []peer_protocol.Integer +} + +func (pcs pieceByBytesPendingSlice) Len() int { + return len(pcs.Indices) +} + +func (me pieceByBytesPendingSlice) Less(i, j int) bool { + return me.Pending[me.Indices[i]] < me.Pending[me.Indices[j]] +} + +func (me pieceByBytesPendingSlice) Swap(i, j int) { + me.Indices[i], me.Indices[j] = me.Indices[j], me.Indices[i] +} + +var ( + ErrDataNotReady = errors.New("data not ready") +) + +func mmapTorrentData(metaInfo *metainfo.MetaInfo, location string) (mms 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{mMap}) + }() + if err != nil { + return + } + } + return +} diff --git a/torrent.go b/torrent.go new file mode 100644 index 00000000..19c64d2f --- /dev/null +++ b/torrent.go @@ -0,0 +1,189 @@ +package torrent + +import ( + "container/list" + "fmt" + "net" + "sort" + + "bitbucket.org/anacrolix/go.torrent/peer_protocol" + "bitbucket.org/anacrolix/go.torrent/tracker" + metainfo "github.com/nsf/libtorgo/torrent" +) + +func (t *Torrent) PieceNumPendingBytes(index peer_protocol.Integer) (count peer_protocol.Integer) { + pendingChunks := t.Pieces[index].PendingChunkSpecs + count = peer_protocol.Integer(len(pendingChunks)) * chunkSize + _lastChunkSpec := lastChunkSpec(t.PieceLength(index)) + if _lastChunkSpec.Length != chunkSize { + if _, ok := pendingChunks[_lastChunkSpec]; ok { + count += _lastChunkSpec.Length - chunkSize + } + } + return +} + +type Torrent struct { + InfoHash InfoHash + Pieces []*piece + Data MMapSpan + MetaInfo *metainfo.MetaInfo + Conns []*Connection + Peers []Peer + Priorities *list.List + // BEP 12 Multitracker Metadata Extension. The tracker.Client instances + // mirror their respective URLs from the announce-list key. + Trackers [][]tracker.Client +} + +func (t *Torrent) NumPieces() int { + return len(t.MetaInfo.Pieces) / PieceHash.Size() +} + +func (t *Torrent) NumPiecesCompleted() (num int) { + for _, p := range t.Pieces { + if p.Complete() { + num++ + } + } + return +} + +func (t *Torrent) Length() int64 { + return int64(t.PieceLength(peer_protocol.Integer(len(t.Pieces)-1))) + int64(len(t.Pieces)-1)*int64(t.PieceLength(0)) +} + +func (t *Torrent) Close() (err error) { + t.Data.Close() + for _, conn := range t.Conns { + conn.Close() + } + return +} + +func (t *Torrent) piecesByPendingBytesDesc() (indices []peer_protocol.Integer) { + slice := pieceByBytesPendingSlice{ + Pending: make([]peer_protocol.Integer, 0, len(t.Pieces)), + Indices: make([]peer_protocol.Integer, 0, len(t.Pieces)), + } + for i := range t.Pieces { + slice.Pending = append(slice.Pending, t.PieceNumPendingBytes(peer_protocol.Integer(i))) + slice.Indices = append(slice.Indices, peer_protocol.Integer(i)) + } + sort.Sort(sort.Reverse(slice)) + return slice.Indices +} + +func (t *Torrent) offsetRequest(off int64) (req Request, ok bool) { + req.Index = peer_protocol.Integer(off / t.MetaInfo.PieceLength) + if req.Index < 0 || int(req.Index) >= len(t.Pieces) { + return + } + off %= t.MetaInfo.PieceLength + pieceLeft := t.PieceLength(req.Index) - peer_protocol.Integer(off) + if pieceLeft <= 0 { + return + } + req.Begin = chunkSize * (peer_protocol.Integer(off) / chunkSize) + req.Length = chunkSize + if req.Length > pieceLeft { + req.Length = pieceLeft + } + ok = true + return +} + +func (t *Torrent) WriteChunk(piece int, begin int64, data []byte) (err error) { + _, err = t.Data.WriteAt(data, int64(piece)*t.MetaInfo.PieceLength+begin) + return +} + +func (t *Torrent) bitfield() (bf []bool) { + for _, p := range t.Pieces { + bf = append(bf, p.EverHashed && len(p.PendingChunkSpecs) == 0) + } + return +} + +func (t *Torrent) pendAllChunkSpecs(index peer_protocol.Integer) { + piece := t.Pieces[index] + if piece.PendingChunkSpecs == nil { + piece.PendingChunkSpecs = make( + map[ChunkSpec]struct{}, + (t.MetaInfo.PieceLength+chunkSize-1)/chunkSize) + } + c := ChunkSpec{ + Begin: 0, + } + cs := piece.PendingChunkSpecs + for left := peer_protocol.Integer(t.PieceLength(index)); left != 0; left -= c.Length { + c.Length = left + if c.Length > chunkSize { + c.Length = chunkSize + } + cs[c] = struct{}{} + c.Begin += c.Length + } + return +} + +func (t *Torrent) requestHeat() (ret map[Request]int) { + ret = make(map[Request]int) + for _, conn := range t.Conns { + for req, _ := range conn.Requests { + ret[req]++ + } + } + return +} + +type Peer struct { + Id [20]byte + IP net.IP + Port int +} + +func (t *Torrent) PieceLength(piece peer_protocol.Integer) (len_ peer_protocol.Integer) { + if int(piece) == t.NumPieces()-1 { + len_ = peer_protocol.Integer(t.Data.Size() % t.MetaInfo.PieceLength) + } + if len_ == 0 { + len_ = peer_protocol.Integer(t.MetaInfo.PieceLength) + } + return +} + +func (t *Torrent) HashPiece(piece peer_protocol.Integer) (ps pieceSum) { + hash := PieceHash.New() + n, err := t.Data.WriteSectionTo(hash, int64(piece)*t.MetaInfo.PieceLength, t.MetaInfo.PieceLength) + if err != nil { + panic(err) + } + if peer_protocol.Integer(n) != t.PieceLength(piece) { + panic(fmt.Sprintf("hashed wrong number of bytes: expected %d; did %d; piece %d", t.PieceLength(piece), n, piece)) + } + copyHashSum(ps[:], hash.Sum(nil)) + return +} +func (t *Torrent) haveAllPieces() bool { + for _, piece := range t.Pieces { + if !piece.Complete() { + return false + } + } + return true +} + +func (me *Torrent) haveAnyPieces() bool { + for _, piece := range me.Pieces { + if piece.Complete() { + return true + } + } + return false +} + +func (t *Torrent) wantPiece(index int) bool { + p := t.Pieces[index] + return p.EverHashed && len(p.PendingChunkSpecs) != 0 +}