FedP2P/torrent.go

615 lines
14 KiB
Go

package torrent
import (
"container/heap"
"container/list"
"fmt"
"io"
"log"
"net"
"sort"
"sync"
"bitbucket.org/anacrolix/go.torrent/util"
"bitbucket.org/anacrolix/go.torrent/mmap_span"
pp "bitbucket.org/anacrolix/go.torrent/peer_protocol"
"bitbucket.org/anacrolix/go.torrent/tracker"
"github.com/anacrolix/libtorgo/bencode"
"github.com/anacrolix/libtorgo/metainfo"
)
func (t *torrent) PieceNumPendingBytes(index pp.Integer) (count pp.Integer) {
pendingChunks := t.Pieces[index].PendingChunkSpecs
count = pp.Integer(len(pendingChunks)) * chunkSize
_lastChunkSpec := lastChunkSpec(t.PieceLength(index))
if _lastChunkSpec.Length != chunkSize {
if _, ok := pendingChunks[_lastChunkSpec]; ok {
count += _lastChunkSpec.Length - chunkSize
}
}
return
}
type pieceBytesLeft struct {
Piece, BytesLeft int
}
type torrentPiece struct {
piece
bytesLeftElement *list.Element
}
type peersKey struct {
IPBytes string
Port int
}
type torrent struct {
stateMu sync.Mutex
closing chan struct{}
// Closed when no more network activity is desired. This includes
// announcing, and communicating with peers.
ceasingNetworking chan struct{}
InfoHash InfoHash
Pieces []*torrentPiece
IncompletePiecesByBytesLeft *OrderedList
length int64
// Prevent mutations to Data memory maps while in use as they're not safe.
dataLock sync.RWMutex
Data mmap_span.MMapSpan
Info *MetaInfo
// Active peer connections.
Conns []*connection
// Set of addrs to which we're attempting to connect.
HalfOpen map[string]struct{}
// Reserve of peers to connect to. A peer can be both here and in the
// active connections if were told about the peer after connecting with
// them. That encourages us to reconnect to peers that are well known.
Peers map[peersKey]Peer
wantPeers sync.Cond
// BEP 12 Multitracker Metadata Extension. The tracker.Client instances
// mirror their respective URLs from the announce-list key.
Trackers [][]tracker.Client
DisplayName string
MetaData []byte
metadataHave []bool
gotMetainfo chan *metainfo.MetaInfo
GotMetainfo <-chan *metainfo.MetaInfo
}
func (t *torrent) addrActive(addr string) bool {
if _, ok := t.HalfOpen[addr]; ok {
return true
}
for _, c := range t.Conns {
if c.Socket.RemoteAddr().String() == addr {
return true
}
}
return false
}
func (t *torrent) worstConnsHeap() (wcs *worstConns) {
wcs = &worstConns{
c: append([]*connection{}, t.Conns...),
t: t,
}
heap.Init(wcs)
return
}
func (t *torrent) CeaseNetworking() {
t.stateMu.Lock()
defer t.stateMu.Unlock()
select {
case <-t.ceasingNetworking:
return
default:
}
close(t.ceasingNetworking)
for _, c := range t.Conns {
c.Close()
}
}
func (t *torrent) assertIncompletePiecesByBytesLeftOrdering() {
allIndexes := make(map[int]struct{}, t.NumPieces())
for i := 0; i < t.NumPieces(); i++ {
allIndexes[i] = struct{}{}
}
var lastBytesLeft int
for e := t.IncompletePiecesByBytesLeft.Front(); e != nil; e = e.Next() {
i := e.Value.(int)
if _, ok := allIndexes[i]; !ok {
panic("duplicate entry")
}
delete(allIndexes, i)
if t.Pieces[i].Complete() {
panic("complete piece")
}
bytesLeft := int(t.PieceNumPendingBytes(pp.Integer(i)))
if bytesLeft < lastBytesLeft {
panic("ordering broken")
}
lastBytesLeft = bytesLeft
}
for i := range allIndexes {
if !t.Pieces[i].Complete() {
panic("leaked incomplete piece")
}
}
}
func (t *torrent) AddPeers(pp []Peer) {
for _, p := range pp {
t.Peers[peersKey{string(p.IP), p.Port}] = p
}
}
func (t *torrent) InvalidateMetadata() {
t.MetaData = nil
t.metadataHave = nil
t.Info = nil
}
func (t *torrent) SaveMetadataPiece(index int, data []byte) {
if t.haveInfo() {
return
}
if index >= len(t.metadataHave) {
log.Printf("%s: ignoring metadata piece %d", t, index)
return
}
copy(t.MetaData[(1<<14)*index:], data)
t.metadataHave[index] = true
}
func (t *torrent) MetadataPieceCount() int {
return (len(t.MetaData) + (1 << 14) - 1) / (1 << 14)
}
func (t *torrent) HaveMetadataPiece(piece int) bool {
if t.haveInfo() {
return (1<<14)*piece < len(t.MetaData)
} else {
return piece < len(t.metadataHave) && t.metadataHave[piece]
}
}
func (t *torrent) metadataSizeKnown() bool {
return t.MetaData != nil
}
func (t *torrent) metadataSize() int {
return len(t.MetaData)
}
func infoPieceHashes(info *metainfo.Info) (ret []string) {
for i := 0; i < len(info.Pieces); i += 20 {
ret = append(ret, string(info.Pieces[i:i+20]))
}
return
}
// Called when metadata for a torrent becomes available.
func (t *torrent) setMetadata(md metainfo.Info, dataDir string, infoBytes []byte) (err error) {
t.Info = newMetaInfo(&md)
t.MetaData = infoBytes
t.metadataHave = nil
t.Data, err = mmapTorrentData(&md, dataDir)
if err != nil {
return
}
t.length = t.Data.Size()
t.IncompletePiecesByBytesLeft = NewList(func(a, b interface{}) bool {
apb := t.PieceNumPendingBytes(pp.Integer(a.(int)))
bpb := t.PieceNumPendingBytes(pp.Integer(b.(int)))
if apb < bpb {
return true
}
if apb > bpb {
return false
}
return a.(int) < b.(int)
})
for index, hash := range infoPieceHashes(&md) {
piece := &torrentPiece{}
util.CopyExact(piece.Hash[:], hash)
t.Pieces = append(t.Pieces, piece)
piece.bytesLeftElement = t.IncompletePiecesByBytesLeft.Insert(index)
t.pendAllChunkSpecs(pp.Integer(index))
}
t.assertIncompletePiecesByBytesLeftOrdering()
for _, conn := range t.Conns {
if err := conn.setNumPieces(t.NumPieces()); err != nil {
log.Printf("closing connection: %s", err)
conn.Close()
}
}
return
}
func (t *torrent) HaveAllMetadataPieces() bool {
if t.haveInfo() {
return true
}
if t.metadataHave == nil {
return false
}
for _, have := range t.metadataHave {
if !have {
return false
}
}
return true
}
func (t *torrent) SetMetadataSize(bytes int64) {
if t.MetaData != nil {
return
}
t.MetaData = make([]byte, bytes)
t.metadataHave = make([]bool, (bytes+(1<<14)-1)/(1<<14))
}
func (t *torrent) Name() string {
if !t.haveInfo() {
return t.DisplayName
}
return t.Info.Name
}
func (t *torrent) pieceStatusChar(index int) byte {
p := t.Pieces[index]
switch {
case p.Complete():
return 'C'
case p.QueuedForHash:
return 'Q'
case p.Hashing:
return 'H'
case !p.EverHashed:
return '?'
case t.PiecePartiallyDownloaded(index):
return 'P'
default:
return '.'
}
}
func (t *torrent) metadataPieceSize(piece int) int {
return metadataPieceSize(len(t.MetaData), piece)
}
func (t *torrent) NewMetadataExtensionMessage(c *connection, msgType int, piece int, data []byte) pp.Message {
d := map[string]int{
"msg_type": msgType,
"piece": piece,
}
if data != nil {
d["total_size"] = len(t.MetaData)
}
p, err := bencode.Marshal(d)
if err != nil {
panic(err)
}
return pp.Message{
Type: pp.Extended,
ExtendedID: byte(c.PeerExtensionIDs["ut_metadata"]),
ExtendedPayload: append(p, data...),
}
}
func (t *torrent) WriteStatus(w io.Writer) {
fmt.Fprintf(w, "Infohash: %x\n", t.InfoHash)
fmt.Fprintf(w, "Piece length: %s\n", func() string {
if t.haveInfo() {
return fmt.Sprint(t.UsualPieceSize())
} else {
return "?"
}
}())
fmt.Fprint(w, "Pieces:")
for index := range t.Pieces {
if index%100 == 0 {
fmt.Fprintln(w)
}
fmt.Fprintf(w, "%c", t.pieceStatusChar(index))
}
fmt.Fprintln(w)
fmt.Fprintf(w, "Trackers: ")
for _, tier := range t.Trackers {
for _, tr := range tier {
fmt.Fprintf(w, "%q ", tr.String())
}
}
fmt.Fprintf(w, "\n")
fmt.Fprintf(w, "Pending peers: %d\n", len(t.Peers))
fmt.Fprintf(w, "Half open: %d\n", len(t.HalfOpen))
fmt.Fprintf(w, "Active peers: %d\n", len(t.Conns))
sort.Sort(&worstConns{
c: t.Conns,
t: t,
})
for _, c := range t.Conns {
c.WriteStatus(w)
}
}
func (t *torrent) String() string {
return t.Name()
}
func (t *torrent) haveInfo() bool {
return t.Info != nil
}
func (t *torrent) BytesLeft() (left int64) {
if !t.haveInfo() {
return -1
}
for i := pp.Integer(0); i < pp.Integer(t.NumPieces()); i++ {
left += int64(t.PieceNumPendingBytes(i))
}
return
}
func (t *torrent) PiecePartiallyDownloaded(index int) bool {
return t.PieceNumPendingBytes(pp.Integer(index)) != t.PieceLength(pp.Integer(index))
}
func NumChunksForPiece(chunkSize int, pieceSize int) int {
return (pieceSize + chunkSize - 1) / chunkSize
}
func (t *torrent) ChunkCount() (num int) {
num += (t.NumPieces() - 1) * NumChunksForPiece(chunkSize, int(t.PieceLength(0)))
num += NumChunksForPiece(chunkSize, int(t.PieceLength(pp.Integer(t.NumPieces()-1))))
return
}
func (t *torrent) UsualPieceSize() int {
return int(t.Info.PieceLength)
}
func (t *torrent) LastPieceSize() int {
return int(t.PieceLength(pp.Integer(t.NumPieces() - 1)))
}
func (t *torrent) NumPieces() int {
return len(t.Info.Pieces) / 20
}
func (t *torrent) NumPiecesCompleted() (num int) {
for _, p := range t.Pieces {
if p.Complete() {
num++
}
}
return
}
func (t *torrent) Length() int64 {
if t.Data == nil {
// Possibly the length might be available before the data is mmapped,
// I defer this decision to such a need arising.
panic("torrent length not known?")
}
return t.length
}
func (t *torrent) isClosed() bool {
select {
case <-t.closing:
return true
default:
return false
}
}
func (t *torrent) Close() (err error) {
if t.isClosed() {
return
}
t.CeaseNetworking()
close(t.closing)
t.dataLock.Lock()
t.Data.Close()
t.Data = nil
t.dataLock.Unlock()
for _, conn := range t.Conns {
conn.Close()
}
return
}
// 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)
left := torrentLength - int64(r.Index)*pieceSize - int64(r.Begin)
if chunkSize < left {
r.Length = pp.Integer(chunkSize)
} else {
r.Length = pp.Integer(left)
}
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 (t *torrent) requestOffset(r request) int64 {
return torrentRequestOffset(t.Length(), int64(t.UsualPieceSize()), r)
}
// Return the request that would include the given offset into the torrent data.
func (t *torrent) offsetRequest(off int64) (req request, ok bool) {
return torrentOffsetRequest(t.Length(), t.Info.PieceLength, chunkSize, off)
}
func (t *torrent) WriteChunk(piece int, begin int64, data []byte) (err error) {
_, err = t.Data.WriteAt(data, int64(piece)*t.Info.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) pieceChunks(piece int) (css []chunkSpec) {
css = make([]chunkSpec, 0, (t.PieceLength(pp.Integer(piece))+chunkSize-1)/chunkSize)
var cs chunkSpec
for left := t.PieceLength(pp.Integer(piece)); left != 0; left -= cs.Length {
cs.Length = left
if cs.Length > chunkSize {
cs.Length = chunkSize
}
css = append(css, cs)
cs.Begin += cs.Length
}
return
}
func (t *torrent) pendAllChunkSpecs(index pp.Integer) {
piece := t.Pieces[index]
if piece.PendingChunkSpecs == nil {
piece.PendingChunkSpecs = make(
map[chunkSpec]struct{},
(t.PieceLength(index)+chunkSize-1)/chunkSize)
}
pcss := piece.PendingChunkSpecs
for _, cs := range t.pieceChunks(int(index)) {
pcss[cs] = struct{}{}
}
t.IncompletePiecesByBytesLeft.ValueChanged(piece.bytesLeftElement)
return
}
func (t *torrent) PieceBytesLeftChanged(index int) {
p := t.Pieces[index]
if p.Complete() {
t.IncompletePiecesByBytesLeft.Remove(p.bytesLeftElement)
} else {
t.IncompletePiecesByBytesLeft.ValueChanged(p.bytesLeftElement)
}
}
type Peer struct {
Id [20]byte
IP net.IP
Port int
Source peerSource
}
func (t *torrent) PieceLength(piece pp.Integer) (len_ pp.Integer) {
if int(piece) == t.NumPieces()-1 {
len_ = pp.Integer(t.Length() % t.Info.PieceLength)
}
if len_ == 0 {
len_ = pp.Integer(t.Info.PieceLength)
}
return
}
func (t *torrent) HashPiece(piece pp.Integer) (ps pieceSum) {
hash := pieceHash.New()
t.dataLock.RLock()
n, err := t.Data.WriteSectionTo(hash, int64(piece)*t.Info.PieceLength, t.Info.PieceLength)
t.dataLock.RUnlock()
if err != nil {
panic(err)
}
if pp.Integer(n) != t.PieceLength(piece) {
// log.Print(t.Info)
panic(fmt.Sprintf("hashed wrong number of bytes: expected %d; did %d; piece %d", t.PieceLength(piece), n, piece))
}
util.CopyExact(ps[:], hash.Sum(nil))
return
}
func (t *torrent) haveAllPieces() bool {
if !t.haveInfo() {
return false
}
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) havePiece(index int) bool {
return t.haveInfo() && t.Pieces[index].Complete()
}
func (t *torrent) haveChunk(r request) bool {
p := t.Pieces[r.Index]
if !p.EverHashed {
return false
}
_, ok := p.PendingChunkSpecs[r.chunkSpec]
return !ok
}
func (t *torrent) wantChunk(r request) bool {
if !t.wantPiece(int(r.Index)) {
return false
}
_, ok := t.Pieces[r.Index].PendingChunkSpecs[r.chunkSpec]
return ok
}
func (t *torrent) wantPiece(index int) bool {
if !t.haveInfo() {
return false
}
p := t.Pieces[index]
return p.EverHashed && len(p.PendingChunkSpecs) != 0
}
func (t *torrent) connHasWantedPieces(c *connection) bool {
for p := range t.Pieces {
if t.wantPiece(p) && c.PeerHasPiece(pp.Integer(p)) {
return true
}
}
return false
}
func (t *torrent) extentPieces(off, _len int64) (pieces []int) {
for i := off / int64(t.UsualPieceSize()); i*int64(t.UsualPieceSize()) < off+_len; i++ {
pieces = append(pieces, int(i))
}
return
}