FedP2P/torrent.go

2300 lines
57 KiB
Go

package torrent
import (
"bytes"
"container/heap"
"context"
"crypto/sha1"
"errors"
"fmt"
"io"
"math/rand"
"net/http"
"net/url"
"sort"
"strings"
"text/tabwriter"
"time"
"unsafe"
"github.com/RoaringBitmap/roaring"
"github.com/anacrolix/chansync"
"github.com/anacrolix/chansync/events"
"github.com/anacrolix/dht/v2"
"github.com/anacrolix/log"
"github.com/anacrolix/missinggo/perf"
"github.com/anacrolix/missinggo/pubsub"
"github.com/anacrolix/missinggo/slices"
"github.com/anacrolix/missinggo/v2"
"github.com/anacrolix/missinggo/v2/bitmap"
"github.com/anacrolix/missinggo/v2/prioritybitmap"
"github.com/anacrolix/multiless"
"github.com/anacrolix/sync"
"github.com/davecgh/go-spew/spew"
"github.com/pion/datachannel"
"github.com/anacrolix/torrent/bencode"
"github.com/anacrolix/torrent/common"
"github.com/anacrolix/torrent/metainfo"
pp "github.com/anacrolix/torrent/peer_protocol"
"github.com/anacrolix/torrent/segments"
"github.com/anacrolix/torrent/storage"
"github.com/anacrolix/torrent/tracker"
"github.com/anacrolix/torrent/webseed"
"github.com/anacrolix/torrent/webtorrent"
)
// Maintains state of torrent within a Client. Many methods should not be called before the info is
// available, see .Info and .GotInfo.
type Torrent struct {
// Torrent-level aggregate statistics. First in struct to ensure 64-bit
// alignment. See #262.
stats ConnStats
cl *Client
logger log.Logger
networkingEnabled chansync.Flag
dataDownloadDisallowed chansync.Flag
dataUploadDisallowed bool
userOnWriteChunkErr func(error)
closed chansync.SetOnce
infoHash metainfo.Hash
pieces []Piece
// Values are the piece indices that changed.
pieceStateChanges *pubsub.PubSub
// The size of chunks to request from peers over the wire. This is
// normally 16KiB by convention these days.
chunkSize pp.Integer
chunkPool sync.Pool
// Total length of the torrent in bytes. Stored because it's not O(1) to
// get this from the info dict.
length *int64
// The storage to open when the info dict becomes available.
storageOpener *storage.Client
// Storage for torrent data.
storage *storage.Torrent
// Read-locked for using storage, and write-locked for Closing.
storageLock sync.RWMutex
// TODO: Only announce stuff is used?
metainfo metainfo.MetaInfo
// The info dict. nil if we don't have it (yet).
info *metainfo.Info
fileIndex segments.Index
files *[]*File
webSeeds map[string]*Peer
// Active peer connections, running message stream loops. TODO: Make this
// open (not-closed) connections only.
conns map[*PeerConn]struct{}
maxEstablishedConns int
// Set of addrs to which we're attempting to connect. Connections are
// half-open until all handshakes are completed.
halfOpen map[string]PeerInfo
// 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 in
// the swarm.
peers prioritizedPeers
// Whether we want to know to know more peers.
wantPeersEvent missinggo.Event
// An announcer for each tracker URL.
trackerAnnouncers map[string]torrentTrackerAnnouncer
// How many times we've initiated a DHT announce. TODO: Move into stats.
numDHTAnnounces int
// Name used if the info name isn't available. Should be cleared when the
// Info does become available.
nameMu sync.RWMutex
displayName string
// The bencoded bytes of the info dict. This is actively manipulated if
// the info bytes aren't initially available, and we try to fetch them
// from peers.
metadataBytes []byte
// Each element corresponds to the 16KiB metadata pieces. If true, we have
// received that piece.
metadataCompletedChunks []bool
metadataChanged sync.Cond
// Closed when .Info is obtained.
gotMetainfoC chan struct{}
readers map[*reader]struct{}
_readerNowPieces bitmap.Bitmap
_readerReadaheadPieces bitmap.Bitmap
// A cache of pieces we need to get. Calculated from various piece and
// file priorities and completion states elsewhere.
_pendingPieces prioritybitmap.PriorityBitmap
// A cache of completed piece indices.
_completedPieces roaring.Bitmap
// Pieces that need to be hashed.
piecesQueuedForHash bitmap.Bitmap
activePieceHashes int
initialPieceCheckDisabled bool
// A pool of piece priorities []int for assignment to new connections.
// These "inclinations" are used to give connections preference for
// different pieces.
connPieceInclinationPool sync.Pool
// Count of each request across active connections.
pendingRequests pendingRequests
// Chunks we've written to since the corresponding piece was last checked.
dirtyChunks roaring.Bitmap
pex pexState
// Is On when all pieces are complete.
Complete chansync.Flag
}
func (t *Torrent) pieceAvailabilityFromPeers(i pieceIndex) (count int) {
t.iterPeers(func(peer *Peer) {
if peer.peerHasPiece(i) {
count++
}
})
return
}
func (t *Torrent) decPieceAvailability(i pieceIndex) {
if !t.haveInfo() {
return
}
p := t.piece(i)
if p.availability <= 0 {
panic(p.availability)
}
p.availability--
}
func (t *Torrent) incPieceAvailability(i pieceIndex) {
// If we don't the info, this should be reconciled when we do.
if t.haveInfo() {
p := t.piece(i)
p.availability++
}
}
func (t *Torrent) readerNowPieces() bitmap.Bitmap {
return t._readerNowPieces
}
func (t *Torrent) readerReadaheadPieces() bitmap.Bitmap {
return t._readerReadaheadPieces
}
func (t *Torrent) ignorePieceForRequests(i pieceIndex) bool {
return !t.wantPieceIndex(i)
}
func (t *Torrent) pendingPieces() *prioritybitmap.PriorityBitmap {
return &t._pendingPieces
}
// Returns a channel that is closed when the Torrent is closed.
func (t *Torrent) Closed() events.Done {
return t.closed.Done()
}
// KnownSwarm returns the known subset of the peers in the Torrent's swarm, including active,
// pending, and half-open peers.
func (t *Torrent) KnownSwarm() (ks []PeerInfo) {
// Add pending peers to the list
t.peers.Each(func(peer PeerInfo) {
ks = append(ks, peer)
})
// Add half-open peers to the list
for _, peer := range t.halfOpen {
ks = append(ks, peer)
}
// Add active peers to the list
for conn := range t.conns {
ks = append(ks, PeerInfo{
Id: conn.PeerID,
Addr: conn.RemoteAddr,
Source: conn.Discovery,
// > If the connection is encrypted, that's certainly enough to set SupportsEncryption.
// > But if we're not connected to them with an encrypted connection, I couldn't say
// > what's appropriate. We can carry forward the SupportsEncryption value as we
// > received it from trackers/DHT/PEX, or just use the encryption state for the
// > connection. It's probably easiest to do the latter for now.
// https://github.com/anacrolix/torrent/pull/188
SupportsEncryption: conn.headerEncrypted,
})
}
return
}
func (t *Torrent) setChunkSize(size pp.Integer) {
t.chunkSize = size
t.chunkPool = sync.Pool{
New: func() interface{} {
b := make([]byte, size)
return &b
},
}
}
func (t *Torrent) pieceComplete(piece pieceIndex) bool {
return t._completedPieces.Contains(bitmap.BitIndex(piece))
}
func (t *Torrent) pieceCompleteUncached(piece pieceIndex) storage.Completion {
return t.pieces[piece].Storage().Completion()
}
// There's a connection to that address already.
func (t *Torrent) addrActive(addr string) bool {
if _, ok := t.halfOpen[addr]; ok {
return true
}
for c := range t.conns {
ra := c.RemoteAddr
if ra.String() == addr {
return true
}
}
return false
}
func (t *Torrent) appendUnclosedConns(ret []*PeerConn) []*PeerConn {
for c := range t.conns {
if !c.closed.IsSet() {
ret = append(ret, c)
}
}
return ret
}
func (t *Torrent) addPeer(p PeerInfo) (added bool) {
cl := t.cl
torrent.Add(fmt.Sprintf("peers added by source %q", p.Source), 1)
if t.closed.IsSet() {
return false
}
if ipAddr, ok := tryIpPortFromNetAddr(p.Addr); ok {
if cl.badPeerIPPort(ipAddr.IP, ipAddr.Port) {
torrent.Add("peers not added because of bad addr", 1)
// cl.logger.Printf("peers not added because of bad addr: %v", p)
return false
}
}
if replaced, ok := t.peers.AddReturningReplacedPeer(p); ok {
torrent.Add("peers replaced", 1)
if !replaced.equal(p) {
t.logger.WithDefaultLevel(log.Debug).Printf("added %v replacing %v", p, replaced)
added = true
}
} else {
added = true
}
t.openNewConns()
for t.peers.Len() > cl.config.TorrentPeersHighWater {
_, ok := t.peers.DeleteMin()
if ok {
torrent.Add("excess reserve peers discarded", 1)
}
}
return
}
func (t *Torrent) invalidateMetadata() {
for i := 0; i < len(t.metadataCompletedChunks); i++ {
t.metadataCompletedChunks[i] = false
}
t.nameMu.Lock()
t.gotMetainfoC = make(chan struct{})
t.info = nil
t.nameMu.Unlock()
}
func (t *Torrent) saveMetadataPiece(index int, data []byte) {
if t.haveInfo() {
return
}
if index >= len(t.metadataCompletedChunks) {
t.logger.Printf("%s: ignoring metadata piece %d", t, index)
return
}
copy(t.metadataBytes[(1<<14)*index:], data)
t.metadataCompletedChunks[index] = true
}
func (t *Torrent) metadataPieceCount() int {
return (len(t.metadataBytes) + (1 << 14) - 1) / (1 << 14)
}
func (t *Torrent) haveMetadataPiece(piece int) bool {
if t.haveInfo() {
return (1<<14)*piece < len(t.metadataBytes)
} else {
return piece < len(t.metadataCompletedChunks) && t.metadataCompletedChunks[piece]
}
}
func (t *Torrent) metadataSize() int {
return len(t.metadataBytes)
}
func infoPieceHashes(info *metainfo.Info) (ret [][]byte) {
for i := 0; i < len(info.Pieces); i += sha1.Size {
ret = append(ret, info.Pieces[i:i+sha1.Size])
}
return
}
func (t *Torrent) makePieces() {
hashes := infoPieceHashes(t.info)
t.pieces = make([]Piece, len(hashes))
for i, hash := range hashes {
piece := &t.pieces[i]
piece.t = t
piece.index = pieceIndex(i)
piece.noPendingWrites.L = &piece.pendingWritesMutex
piece.hash = (*metainfo.Hash)(unsafe.Pointer(&hash[0]))
files := *t.files
beginFile := pieceFirstFileIndex(piece.torrentBeginOffset(), files)
endFile := pieceEndFileIndex(piece.torrentEndOffset(), files)
piece.files = files[beginFile:endFile]
}
}
// Returns the index of the first file containing the piece. files must be
// ordered by offset.
func pieceFirstFileIndex(pieceOffset int64, files []*File) int {
for i, f := range files {
if f.offset+f.length > pieceOffset {
return i
}
}
return 0
}
// Returns the index after the last file containing the piece. files must be
// ordered by offset.
func pieceEndFileIndex(pieceEndOffset int64, files []*File) int {
for i, f := range files {
if f.offset+f.length >= pieceEndOffset {
return i + 1
}
}
return 0
}
func (t *Torrent) cacheLength() {
var l int64
for _, f := range t.info.UpvertedFiles() {
l += f.Length
}
t.length = &l
}
// TODO: This shouldn't fail for storage reasons. Instead we should handle storage failure
// separately.
func (t *Torrent) setInfo(info *metainfo.Info) error {
if err := validateInfo(info); err != nil {
return fmt.Errorf("bad info: %s", err)
}
if t.storageOpener != nil {
var err error
t.storage, err = t.storageOpener.OpenTorrent(info, t.infoHash)
if err != nil {
return fmt.Errorf("error opening torrent storage: %s", err)
}
}
t.nameMu.Lock()
t.info = info
t.nameMu.Unlock()
t.updateComplete()
t.fileIndex = segments.NewIndex(common.LengthIterFromUpvertedFiles(info.UpvertedFiles()))
t.displayName = "" // Save a few bytes lol.
t.initFiles()
t.cacheLength()
t.makePieces()
return nil
}
// This seems to be all the follow-up tasks after info is set, that can't fail.
func (t *Torrent) onSetInfo() {
for i := range t.pieces {
p := &t.pieces[i]
// Need to add availability before updating piece completion, as that may result in conns
// being dropped.
if p.availability != 0 {
panic(p.availability)
}
p.availability = int64(t.pieceAvailabilityFromPeers(i))
t.updatePieceCompletion(pieceIndex(i))
if !t.initialPieceCheckDisabled && !p.storageCompletionOk {
// t.logger.Printf("piece %s completion unknown, queueing check", p)
t.queuePieceCheck(pieceIndex(i))
}
}
t.cl.event.Broadcast()
close(t.gotMetainfoC)
t.updateWantPeersEvent()
t.pendingRequests.Init(t.numRequests())
t.tryCreateMorePieceHashers()
t.iterPeers(func(p *Peer) {
p.onGotInfo(t.info)
p.updateRequests("onSetInfo")
})
}
// Called when metadata for a torrent becomes available.
func (t *Torrent) setInfoBytesLocked(b []byte) error {
if metainfo.HashBytes(b) != t.infoHash {
return errors.New("info bytes have wrong hash")
}
var info metainfo.Info
if err := bencode.Unmarshal(b, &info); err != nil {
return fmt.Errorf("error unmarshalling info bytes: %s", err)
}
t.metadataBytes = b
t.metadataCompletedChunks = nil
if t.info != nil {
return nil
}
if err := t.setInfo(&info); err != nil {
return err
}
t.onSetInfo()
return nil
}
func (t *Torrent) haveAllMetadataPieces() bool {
if t.haveInfo() {
return true
}
if t.metadataCompletedChunks == nil {
return false
}
for _, have := range t.metadataCompletedChunks {
if !have {
return false
}
}
return true
}
// TODO: Propagate errors to disconnect peer.
func (t *Torrent) setMetadataSize(size int) (err error) {
if t.haveInfo() {
// We already know the correct metadata size.
return
}
if uint32(size) > maxMetadataSize {
return errors.New("bad size")
}
if len(t.metadataBytes) == size {
return
}
t.metadataBytes = make([]byte, size)
t.metadataCompletedChunks = make([]bool, (size+(1<<14)-1)/(1<<14))
t.metadataChanged.Broadcast()
for c := range t.conns {
c.requestPendingMetadata()
}
return
}
// The current working name for the torrent. Either the name in the info dict,
// or a display name given such as by the dn value in a magnet link, or "".
func (t *Torrent) name() string {
t.nameMu.RLock()
defer t.nameMu.RUnlock()
if t.haveInfo() {
return t.info.Name
}
if t.displayName != "" {
return t.displayName
}
return "infohash:" + t.infoHash.HexString()
}
func (t *Torrent) pieceState(index pieceIndex) (ret PieceState) {
p := &t.pieces[index]
ret.Priority = t.piecePriority(index)
ret.Completion = p.completion()
ret.QueuedForHash = p.queuedForHash()
ret.Hashing = p.hashing
ret.Checking = ret.QueuedForHash || ret.Hashing
ret.Marking = p.marking
if !ret.Complete && t.piecePartiallyDownloaded(index) {
ret.Partial = true
}
return
}
func (t *Torrent) metadataPieceSize(piece int) int {
return metadataPieceSize(len(t.metadataBytes), piece)
}
func (t *Torrent) newMetadataExtensionMessage(c *PeerConn, msgType pp.ExtendedMetadataRequestMsgType, piece int, data []byte) pp.Message {
return pp.Message{
Type: pp.Extended,
ExtendedID: c.PeerExtensionIDs[pp.ExtensionNameMetadata],
ExtendedPayload: append(bencode.MustMarshal(pp.ExtendedMetadataRequestMsg{
Piece: piece,
TotalSize: len(t.metadataBytes),
Type: msgType,
}), data...),
}
}
type pieceAvailabilityRun struct {
count pieceIndex
availability int64
}
func (me pieceAvailabilityRun) String() string {
return fmt.Sprintf("%v(%v)", me.count, me.availability)
}
func (t *Torrent) pieceAvailabilityRuns() (ret []pieceAvailabilityRun) {
rle := missinggo.NewRunLengthEncoder(func(el interface{}, count uint64) {
ret = append(ret, pieceAvailabilityRun{availability: el.(int64), count: int(count)})
})
for i := range t.pieces {
rle.Append(t.pieces[i].availability, 1)
}
rle.Flush()
return
}
func (t *Torrent) pieceStateRuns() (ret PieceStateRuns) {
rle := missinggo.NewRunLengthEncoder(func(el interface{}, count uint64) {
ret = append(ret, PieceStateRun{
PieceState: el.(PieceState),
Length: int(count),
})
})
for index := range t.pieces {
rle.Append(t.pieceState(pieceIndex(index)), 1)
}
rle.Flush()
return
}
// Produces a small string representing a PieceStateRun.
func (psr PieceStateRun) String() (ret string) {
ret = fmt.Sprintf("%d", psr.Length)
ret += func() string {
switch psr.Priority {
case PiecePriorityNext:
return "N"
case PiecePriorityNormal:
return "."
case PiecePriorityReadahead:
return "R"
case PiecePriorityNow:
return "!"
case PiecePriorityHigh:
return "H"
default:
return ""
}
}()
if psr.Hashing {
ret += "H"
}
if psr.QueuedForHash {
ret += "Q"
}
if psr.Marking {
ret += "M"
}
if psr.Partial {
ret += "P"
}
if psr.Complete {
ret += "C"
}
if !psr.Ok {
ret += "?"
}
return
}
func (t *Torrent) writeStatus(w io.Writer) {
fmt.Fprintf(w, "Infohash: %s\n", t.infoHash.HexString())
fmt.Fprintf(w, "Metadata length: %d\n", t.metadataSize())
if !t.haveInfo() {
fmt.Fprintf(w, "Metadata have: ")
for _, h := range t.metadataCompletedChunks {
fmt.Fprintf(w, "%c", func() rune {
if h {
return 'H'
} else {
return '.'
}
}())
}
fmt.Fprintln(w)
}
fmt.Fprintf(w, "Piece length: %s\n",
func() string {
if t.haveInfo() {
return fmt.Sprintf("%v (%v chunks)",
t.usualPieceSize(),
float64(t.usualPieceSize())/float64(t.chunkSize))
} else {
return "no info"
}
}(),
)
if t.info != nil {
fmt.Fprintf(w, "Num Pieces: %d (%d completed)\n", t.numPieces(), t.numPiecesCompleted())
fmt.Fprintf(w, "Piece States: %s\n", t.pieceStateRuns())
fmt.Fprintf(w, "Piece availability: %v\n", strings.Join(func() (ret []string) {
for _, run := range t.pieceAvailabilityRuns() {
ret = append(ret, run.String())
}
return
}(), " "))
}
fmt.Fprintf(w, "Reader Pieces:")
t.forReaderOffsetPieces(func(begin, end pieceIndex) (again bool) {
fmt.Fprintf(w, " %d:%d", begin, end)
return true
})
fmt.Fprintln(w)
fmt.Fprintf(w, "Enabled trackers:\n")
func() {
tw := tabwriter.NewWriter(w, 0, 0, 2, ' ', 0)
fmt.Fprintf(tw, " URL\tExtra\n")
for _, ta := range slices.Sort(slices.FromMapElems(t.trackerAnnouncers), func(l, r torrentTrackerAnnouncer) bool {
lu := l.URL()
ru := r.URL()
var luns, runs url.URL = *lu, *ru
luns.Scheme = ""
runs.Scheme = ""
var ml missinggo.MultiLess
ml.StrictNext(luns.String() == runs.String(), luns.String() < runs.String())
ml.StrictNext(lu.String() == ru.String(), lu.String() < ru.String())
return ml.Less()
}).([]torrentTrackerAnnouncer) {
fmt.Fprintf(tw, " %q\t%v\n", ta.URL(), ta.statusLine())
}
tw.Flush()
}()
fmt.Fprintf(w, "DHT Announces: %d\n", t.numDHTAnnounces)
spew.NewDefaultConfig()
spew.Fdump(w, t.statsLocked())
peers := t.peersAsSlice()
sort.Slice(peers, func(_i, _j int) bool {
i := peers[_i]
j := peers[_j]
if less, ok := multiless.New().EagerSameLess(
i.downloadRate() == j.downloadRate(), i.downloadRate() < j.downloadRate(),
).LessOk(); ok {
return less
}
return worseConn(i, j)
})
for i, c := range peers {
fmt.Fprintf(w, "%2d. ", i+1)
c.writeStatus(w, t)
}
}
func (t *Torrent) haveInfo() bool {
return t.info != nil
}
// Returns a run-time generated MetaInfo that includes the info bytes and
// announce-list as currently known to the client.
func (t *Torrent) newMetaInfo() metainfo.MetaInfo {
return metainfo.MetaInfo{
CreationDate: time.Now().Unix(),
Comment: "dynamic metainfo from client",
CreatedBy: "go.torrent",
AnnounceList: t.metainfo.UpvertedAnnounceList().Clone(),
InfoBytes: func() []byte {
if t.haveInfo() {
return t.metadataBytes
} else {
return nil
}
}(),
UrlList: func() []string {
ret := make([]string, 0, len(t.webSeeds))
for url := range t.webSeeds {
ret = append(ret, url)
}
return ret
}(),
}
}
// Get bytes left
func (t *Torrent) BytesMissing() (n int64) {
t.cl.rLock()
n = t.bytesMissingLocked()
t.cl.rUnlock()
return
}
func (t *Torrent) bytesMissingLocked() int64 {
return t.bytesLeft()
}
func iterFlipped(b *roaring.Bitmap, end uint64, cb func(uint32) bool) {
roaring.Flip(b, 0, end).Iterate(cb)
}
func (t *Torrent) bytesLeft() (left int64) {
iterFlipped(&t._completedPieces, uint64(t.numPieces()), func(x uint32) bool {
p := t.piece(pieceIndex(x))
left += int64(p.length() - p.numDirtyBytes())
return true
})
return
}
// Bytes left to give in tracker announces.
func (t *Torrent) bytesLeftAnnounce() int64 {
if t.haveInfo() {
return t.bytesLeft()
} else {
return -1
}
}
func (t *Torrent) piecePartiallyDownloaded(piece pieceIndex) bool {
if t.pieceComplete(piece) {
return false
}
if t.pieceAllDirty(piece) {
return false
}
return t.pieces[piece].hasDirtyChunks()
}
func (t *Torrent) usualPieceSize() int {
return int(t.info.PieceLength)
}
func (t *Torrent) numPieces() pieceIndex {
return pieceIndex(t.info.NumPieces())
}
func (t *Torrent) numPiecesCompleted() (num pieceIndex) {
return pieceIndex(t._completedPieces.GetCardinality())
}
func (t *Torrent) close(wg *sync.WaitGroup) (err error) {
t.closed.Set()
if t.storage != nil {
wg.Add(1)
go func() {
defer wg.Done()
t.storageLock.Lock()
defer t.storageLock.Unlock()
if f := t.storage.Close; f != nil {
err1 := f()
if err1 != nil {
t.logger.WithDefaultLevel(log.Warning).Printf("error closing storage: %v", err1)
}
}
}()
}
t.iterPeers(func(p *Peer) {
p.close()
})
t.pex.Reset()
t.cl.event.Broadcast()
t.pieceStateChanges.Close()
t.updateWantPeersEvent()
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. Returns !ok if
// there is no such request.
func (t *Torrent) offsetRequest(off int64) (req Request, ok bool) {
return torrentOffsetRequest(*t.length, t.info.PieceLength, int64(t.chunkSize), off)
}
func (t *Torrent) writeChunk(piece int, begin int64, data []byte) (err error) {
defer perf.ScopeTimerErr(&err)()
n, err := t.pieces[piece].Storage().WriteAt(data, begin)
if err == nil && n != len(data) {
err = io.ErrShortWrite
}
return err
}
func (t *Torrent) bitfield() (bf []bool) {
bf = make([]bool, t.numPieces())
t._completedPieces.Iterate(func(piece uint32) (again bool) {
bf[piece] = true
return true
})
return
}
func (t *Torrent) pieceNumChunks(piece pieceIndex) chunkIndexType {
return chunkIndexType((t.pieceLength(piece) + t.chunkSize - 1) / t.chunkSize)
}
func (t *Torrent) chunksPerRegularPiece() uint32 {
return uint32((pp.Integer(t.usualPieceSize()) + t.chunkSize - 1) / t.chunkSize)
}
func (t *Torrent) numRequests() RequestIndex {
if t.numPieces() == 0 {
return 0
}
return uint32(t.numPieces()-1)*t.chunksPerRegularPiece() + t.pieceNumChunks(t.numPieces()-1)
}
func (t *Torrent) pendAllChunkSpecs(pieceIndex pieceIndex) {
t.dirtyChunks.RemoveRange(
uint64(t.pieceRequestIndexOffset(pieceIndex)),
uint64(t.pieceRequestIndexOffset(pieceIndex+1)))
}
func (t *Torrent) pieceLength(piece pieceIndex) pp.Integer {
if t.info.PieceLength == 0 {
// There will be no variance amongst pieces. Only pain.
return 0
}
if piece == t.numPieces()-1 {
ret := pp.Integer(*t.length % t.info.PieceLength)
if ret != 0 {
return ret
}
}
return pp.Integer(t.info.PieceLength)
}
func (t *Torrent) hashPiece(piece pieceIndex) (ret metainfo.Hash, err error) {
p := t.piece(piece)
p.waitNoPendingWrites()
storagePiece := t.pieces[piece].Storage()
//Does the backend want to do its own hashing?
if i, ok := storagePiece.PieceImpl.(storage.SelfHashing); ok {
var sum metainfo.Hash
//log.Printf("A piece decided to self-hash: %d", piece)
sum, err = i.SelfHash()
missinggo.CopyExact(&ret, sum)
return
}
hash := pieceHash.New()
const logPieceContents = false
if logPieceContents {
var examineBuf bytes.Buffer
_, err = storagePiece.WriteTo(io.MultiWriter(hash, &examineBuf))
log.Printf("hashed %q with copy err %v", examineBuf.Bytes(), err)
} else {
_, err = storagePiece.WriteTo(hash)
}
missinggo.CopyExact(&ret, hash.Sum(nil))
return
}
func (t *Torrent) haveAnyPieces() bool {
return t._completedPieces.GetCardinality() != 0
}
func (t *Torrent) haveAllPieces() bool {
if !t.haveInfo() {
return false
}
return t._completedPieces.GetCardinality() == bitmap.BitRange(t.numPieces())
}
func (t *Torrent) havePiece(index pieceIndex) bool {
return t.haveInfo() && t.pieceComplete(index)
}
func (t *Torrent) maybeDropMutuallyCompletePeer(
// I'm not sure about taking peer here, not all peer implementations actually drop. Maybe that's
// okay?
p *Peer,
) {
if !t.cl.config.DropMutuallyCompletePeers {
return
}
if !t.haveAllPieces() {
return
}
if all, known := p.peerHasAllPieces(); !(known && all) {
return
}
if p.useful() {
return
}
t.logger.WithDefaultLevel(log.Debug).Printf("dropping %v, which is mutually complete", p)
p.drop()
}
func (t *Torrent) haveChunk(r Request) (ret bool) {
// defer func() {
// log.Println("have chunk", r, ret)
// }()
if !t.haveInfo() {
return false
}
if t.pieceComplete(pieceIndex(r.Index)) {
return true
}
p := &t.pieces[r.Index]
return !p.pendingChunk(r.ChunkSpec, t.chunkSize)
}
func chunkIndexFromChunkSpec(cs ChunkSpec, chunkSize pp.Integer) chunkIndexType {
return chunkIndexType(cs.Begin / chunkSize)
}
func (t *Torrent) wantPieceIndex(index pieceIndex) bool {
// TODO: Are these overly conservative, should we be guarding this here?
{
if !t.haveInfo() {
return false
}
if index < 0 || index >= t.numPieces() {
return false
}
}
p := &t.pieces[index]
if p.queuedForHash() {
return false
}
if p.hashing {
return false
}
if t.pieceComplete(index) {
return false
}
if t._pendingPieces.Contains(int(index)) {
return true
}
// t.logger.Printf("piece %d not pending", index)
return !t.forReaderOffsetPieces(func(begin, end pieceIndex) bool {
return index < begin || index >= end
})
}
// A pool of []*PeerConn, to reduce allocations in functions that need to index or sort Torrent
// conns (which is a map).
var peerConnSlices sync.Pool
// The worst connection is one that hasn't been sent, or sent anything useful for the longest. A bad
// connection is one that usually sends us unwanted pieces, or has been in the worse half of the
// established connections for more than a minute. This is O(n log n). If there was a way to not
// consider the position of a conn relative to the total number, it could be reduced to O(n).
func (t *Torrent) worstBadConn() (ret *PeerConn) {
var sl []*PeerConn
getInterface := peerConnSlices.Get()
if getInterface == nil {
sl = make([]*PeerConn, 0, len(t.conns))
} else {
sl = getInterface.([]*PeerConn)[:0]
}
sl = t.appendUnclosedConns(sl)
defer peerConnSlices.Put(sl)
wcs := worseConnSlice{sl}
heap.Init(&wcs)
for wcs.Len() != 0 {
c := heap.Pop(&wcs).(*PeerConn)
if c._stats.ChunksReadWasted.Int64() >= 6 && c._stats.ChunksReadWasted.Int64() > c._stats.ChunksReadUseful.Int64() {
return c
}
// If the connection is in the worst half of the established
// connection quota and is older than a minute.
if wcs.Len() >= (t.maxEstablishedConns+1)/2 {
// Give connections 1 minute to prove themselves.
if time.Since(c.completedHandshake) > time.Minute {
return c
}
}
}
return nil
}
type PieceStateChange struct {
Index int
PieceState
}
func (t *Torrent) publishPieceChange(piece pieceIndex) {
t.cl._mu.Defer(func() {
cur := t.pieceState(piece)
p := &t.pieces[piece]
if cur != p.publicPieceState {
p.publicPieceState = cur
t.pieceStateChanges.Publish(PieceStateChange{
int(piece),
cur,
})
}
})
}
func (t *Torrent) pieceNumPendingChunks(piece pieceIndex) pp.Integer {
if t.pieceComplete(piece) {
return 0
}
return pp.Integer(t.pieceNumChunks(piece) - t.pieces[piece].numDirtyChunks())
}
func (t *Torrent) pieceAllDirty(piece pieceIndex) bool {
return t.pieces[piece].allChunksDirty()
}
func (t *Torrent) readersChanged() {
t.updateReaderPieces()
t.updateAllPiecePriorities("Torrent.readersChanged")
}
func (t *Torrent) updateReaderPieces() {
t._readerNowPieces, t._readerReadaheadPieces = t.readerPiecePriorities()
}
func (t *Torrent) readerPosChanged(from, to pieceRange) {
if from == to {
return
}
t.updateReaderPieces()
// Order the ranges, high and low.
l, h := from, to
if l.begin > h.begin {
l, h = h, l
}
if l.end < h.begin {
// Two distinct ranges.
t.updatePiecePriorities(l.begin, l.end, "Torrent.readerPosChanged")
t.updatePiecePriorities(h.begin, h.end, "Torrent.readerPosChanged")
} else {
// Ranges overlap.
end := l.end
if h.end > end {
end = h.end
}
t.updatePiecePriorities(l.begin, end, "Torrent.readerPosChanged")
}
}
func (t *Torrent) maybeNewConns() {
// Tickle the accept routine.
t.cl.event.Broadcast()
t.openNewConns()
}
func (t *Torrent) piecePriorityChanged(piece pieceIndex, reason string) {
if t._pendingPieces.Contains(piece) {
t.iterPeers(func(c *Peer) {
c.updateRequests(reason)
})
}
t.maybeNewConns()
t.publishPieceChange(piece)
}
func (t *Torrent) updatePiecePriority(piece pieceIndex, reason string) {
p := &t.pieces[piece]
newPrio := p.uncachedPriority()
// t.logger.Printf("torrent %p: piece %d: uncached priority: %v", t, piece, newPrio)
if newPrio == PiecePriorityNone {
if !t._pendingPieces.Remove(int(piece)) {
return
}
} else {
if !t._pendingPieces.Set(int(piece), newPrio.BitmapPriority()) {
return
}
}
t.piecePriorityChanged(piece, reason)
}
func (t *Torrent) updateAllPiecePriorities(reason string) {
t.updatePiecePriorities(0, t.numPieces(), reason)
}
// Update all piece priorities in one hit. This function should have the same
// output as updatePiecePriority, but across all pieces.
func (t *Torrent) updatePiecePriorities(begin, end pieceIndex, reason string) {
for i := begin; i < end; i++ {
t.updatePiecePriority(i, reason)
}
}
// Returns the range of pieces [begin, end) that contains the extent of bytes.
func (t *Torrent) byteRegionPieces(off, size int64) (begin, end pieceIndex) {
if off >= *t.length {
return
}
if off < 0 {
size += off
off = 0
}
if size <= 0 {
return
}
begin = pieceIndex(off / t.info.PieceLength)
end = pieceIndex((off + size + t.info.PieceLength - 1) / t.info.PieceLength)
if end > pieceIndex(t.info.NumPieces()) {
end = pieceIndex(t.info.NumPieces())
}
return
}
// Returns true if all iterations complete without breaking. Returns the read regions for all
// readers. The reader regions should not be merged as some callers depend on this method to
// enumerate readers.
func (t *Torrent) forReaderOffsetPieces(f func(begin, end pieceIndex) (more bool)) (all bool) {
for r := range t.readers {
p := r.pieces
if p.begin >= p.end {
continue
}
if !f(p.begin, p.end) {
return false
}
}
return true
}
func (t *Torrent) piecePriority(piece pieceIndex) piecePriority {
prio, ok := t._pendingPieces.GetPriority(piece)
if !ok {
return PiecePriorityNone
}
if prio > 0 {
panic(prio)
}
ret := piecePriority(-prio)
if ret == PiecePriorityNone {
panic(piece)
}
return ret
}
func (t *Torrent) pendRequest(req RequestIndex) {
t.piece(int(req / t.chunksPerRegularPiece())).pendChunkIndex(req % t.chunksPerRegularPiece())
}
func (t *Torrent) pieceCompletionChanged(piece pieceIndex, reason string) {
t.cl.event.Broadcast()
if t.pieceComplete(piece) {
t.onPieceCompleted(piece)
} else {
t.onIncompletePiece(piece)
}
t.updatePiecePriority(piece, reason)
}
func (t *Torrent) numReceivedConns() (ret int) {
for c := range t.conns {
if c.Discovery == PeerSourceIncoming {
ret++
}
}
return
}
func (t *Torrent) maxHalfOpen() int {
// Note that if we somehow exceed the maximum established conns, we want
// the negative value to have an effect.
establishedHeadroom := int64(t.maxEstablishedConns - len(t.conns))
extraIncoming := int64(t.numReceivedConns() - t.maxEstablishedConns/2)
// We want to allow some experimentation with new peers, and to try to
// upset an oversupply of received connections.
return int(min(max(5, extraIncoming)+establishedHeadroom, int64(t.cl.config.HalfOpenConnsPerTorrent)))
}
func (t *Torrent) openNewConns() (initiated int) {
defer t.updateWantPeersEvent()
for t.peers.Len() != 0 {
if !t.wantConns() {
return
}
if len(t.halfOpen) >= t.maxHalfOpen() {
return
}
if len(t.cl.dialers) == 0 {
return
}
if t.cl.numHalfOpen >= t.cl.config.TotalHalfOpenConns {
return
}
p := t.peers.PopMax()
t.initiateConn(p)
initiated++
}
return
}
func (t *Torrent) getConnPieceInclination() []int {
_ret := t.connPieceInclinationPool.Get()
if _ret == nil {
pieceInclinationsNew.Add(1)
return rand.Perm(int(t.numPieces()))
}
pieceInclinationsReused.Add(1)
return *_ret.(*[]int)
}
func (t *Torrent) putPieceInclination(pi []int) {
t.connPieceInclinationPool.Put(&pi)
pieceInclinationsPut.Add(1)
}
func (t *Torrent) updatePieceCompletion(piece pieceIndex) bool {
p := t.piece(piece)
uncached := t.pieceCompleteUncached(piece)
cached := p.completion()
changed := cached != uncached
complete := uncached.Complete
p.storageCompletionOk = uncached.Ok
x := uint32(piece)
if complete {
t._completedPieces.Add(x)
} else {
t._completedPieces.Remove(x)
}
t.updateComplete()
if complete && len(p.dirtiers) != 0 {
t.logger.Printf("marked piece %v complete but still has dirtiers", piece)
}
if changed {
log.Fstr("piece %d completion changed: %+v -> %+v", piece, cached, uncached).SetLevel(log.Debug).Log(t.logger)
t.pieceCompletionChanged(piece, "Torrent.updatePieceCompletion")
}
return changed
}
// Non-blocking read. Client lock is not required.
func (t *Torrent) readAt(b []byte, off int64) (n int, err error) {
for len(b) != 0 {
p := &t.pieces[off/t.info.PieceLength]
p.waitNoPendingWrites()
var n1 int
n1, err = p.Storage().ReadAt(b, off-p.Info().Offset())
if n1 == 0 {
break
}
off += int64(n1)
n += n1
b = b[n1:]
}
return
}
// Returns an error if the metadata was completed, but couldn't be set for some reason. Blame it on
// the last peer to contribute. TODO: Actually we shouldn't blame peers for failure to open storage
// etc. Also we should probably cached metadata pieces per-Peer, to isolate failure appropriately.
func (t *Torrent) maybeCompleteMetadata() error {
if t.haveInfo() {
// Nothing to do.
return nil
}
if !t.haveAllMetadataPieces() {
// Don't have enough metadata pieces.
return nil
}
err := t.setInfoBytesLocked(t.metadataBytes)
if err != nil {
t.invalidateMetadata()
return fmt.Errorf("error setting info bytes: %s", err)
}
if t.cl.config.Debug {
t.logger.Printf("%s: got metadata from peers", t)
}
return nil
}
func (t *Torrent) readerPiecePriorities() (now, readahead bitmap.Bitmap) {
t.forReaderOffsetPieces(func(begin, end pieceIndex) bool {
if end > begin {
now.Add(bitmap.BitIndex(begin))
readahead.AddRange(bitmap.BitRange(begin)+1, bitmap.BitRange(end))
}
return true
})
return
}
func (t *Torrent) needData() bool {
if t.closed.IsSet() {
return false
}
if !t.haveInfo() {
return true
}
return t._pendingPieces.Len() != 0
}
func appendMissingStrings(old, new []string) (ret []string) {
ret = old
new:
for _, n := range new {
for _, o := range old {
if o == n {
continue new
}
}
ret = append(ret, n)
}
return
}
func appendMissingTrackerTiers(existing [][]string, minNumTiers int) (ret [][]string) {
ret = existing
for minNumTiers > len(ret) {
ret = append(ret, nil)
}
return
}
func (t *Torrent) addTrackers(announceList [][]string) {
fullAnnounceList := &t.metainfo.AnnounceList
t.metainfo.AnnounceList = appendMissingTrackerTiers(*fullAnnounceList, len(announceList))
for tierIndex, trackerURLs := range announceList {
(*fullAnnounceList)[tierIndex] = appendMissingStrings((*fullAnnounceList)[tierIndex], trackerURLs)
}
t.startMissingTrackerScrapers()
t.updateWantPeersEvent()
}
// Don't call this before the info is available.
func (t *Torrent) bytesCompleted() int64 {
if !t.haveInfo() {
return 0
}
return *t.length - t.bytesLeft()
}
func (t *Torrent) SetInfoBytes(b []byte) (err error) {
t.cl.lock()
defer t.cl.unlock()
return t.setInfoBytesLocked(b)
}
// Returns true if connection is removed from torrent.Conns.
func (t *Torrent) deletePeerConn(c *PeerConn) (ret bool) {
if !c.closed.IsSet() {
panic("connection is not closed")
// There are behaviours prevented by the closed state that will fail
// if the connection has been deleted.
}
_, ret = t.conns[c]
delete(t.conns, c)
// Avoid adding a drop event more than once. Probably we should track whether we've generated
// the drop event against the PexConnState instead.
if ret {
if !t.cl.config.DisablePEX {
t.pex.Drop(c)
}
}
torrent.Add("deleted connections", 1)
c.deleteAllRequests()
if t.numActivePeers() == 0 && t.haveInfo() {
t.assertNoPendingRequests()
}
return
}
func (t *Torrent) decPeerPieceAvailability(p *Peer) {
if !t.haveInfo() {
return
}
p.newPeerPieces().Iterate(func(i uint32) bool {
p.t.decPieceAvailability(pieceIndex(i))
return true
})
}
func (t *Torrent) numActivePeers() (num int) {
t.iterPeers(func(*Peer) {
num++
})
return
}
func (t *Torrent) assertNoPendingRequests() {
t.pendingRequests.AssertEmpty()
}
func (t *Torrent) dropConnection(c *PeerConn) {
t.cl.event.Broadcast()
c.close()
if t.deletePeerConn(c) {
t.openNewConns()
}
}
func (t *Torrent) wantPeers() bool {
if t.closed.IsSet() {
return false
}
if t.peers.Len() > t.cl.config.TorrentPeersLowWater {
return false
}
return t.needData() || t.seeding()
}
func (t *Torrent) updateWantPeersEvent() {
if t.wantPeers() {
t.wantPeersEvent.Set()
} else {
t.wantPeersEvent.Clear()
}
}
// Returns whether the client should make effort to seed the torrent.
func (t *Torrent) seeding() bool {
cl := t.cl
if t.closed.IsSet() {
return false
}
if t.dataUploadDisallowed {
return false
}
if cl.config.NoUpload {
return false
}
if !cl.config.Seed {
return false
}
if cl.config.DisableAggressiveUpload && t.needData() {
return false
}
return true
}
func (t *Torrent) onWebRtcConn(
c datachannel.ReadWriteCloser,
dcc webtorrent.DataChannelContext,
) {
defer c.Close()
pc, err := t.cl.initiateProtocolHandshakes(
context.Background(),
webrtcNetConn{c, dcc},
t,
dcc.LocalOffered,
false,
webrtcNetAddr{dcc.Remote},
webrtcNetwork,
fmt.Sprintf("webrtc offer_id %x", dcc.OfferId),
)
if err != nil {
t.logger.WithDefaultLevel(log.Error).Printf("error in handshaking webrtc connection: %v", err)
return
}
if dcc.LocalOffered {
pc.Discovery = PeerSourceTracker
} else {
pc.Discovery = PeerSourceIncoming
}
t.cl.lock()
defer t.cl.unlock()
err = t.cl.runHandshookConn(pc, t)
if err != nil {
t.logger.WithDefaultLevel(log.Critical).Printf("error running handshook webrtc conn: %v", err)
}
}
func (t *Torrent) logRunHandshookConn(pc *PeerConn, logAll bool, level log.Level) {
err := t.cl.runHandshookConn(pc, t)
if err != nil || logAll {
t.logger.WithDefaultLevel(level).Printf("error running handshook conn: %v", err)
}
}
func (t *Torrent) runHandshookConnLoggingErr(pc *PeerConn) {
t.logRunHandshookConn(pc, false, log.Warning)
}
func (t *Torrent) startWebsocketAnnouncer(u url.URL) torrentTrackerAnnouncer {
wtc, release := t.cl.websocketTrackers.Get(u.String())
go func() {
<-t.closed.Done()
release()
}()
wst := websocketTrackerStatus{u, wtc}
go func() {
err := wtc.Announce(tracker.Started, t.infoHash)
if err != nil {
t.logger.WithDefaultLevel(log.Warning).Printf(
"error in initial announce to %q: %v",
u.String(), err,
)
}
}()
return wst
}
func (t *Torrent) startScrapingTracker(_url string) {
if _url == "" {
return
}
u, err := url.Parse(_url)
if err != nil {
// URLs with a leading '*' appear to be a uTorrent convention to
// disable trackers.
if _url[0] != '*' {
log.Str("error parsing tracker url").AddValues("url", _url).Log(t.logger)
}
return
}
if u.Scheme == "udp" {
u.Scheme = "udp4"
t.startScrapingTracker(u.String())
u.Scheme = "udp6"
t.startScrapingTracker(u.String())
return
}
if _, ok := t.trackerAnnouncers[_url]; ok {
return
}
sl := func() torrentTrackerAnnouncer {
switch u.Scheme {
case "ws", "wss":
if t.cl.config.DisableWebtorrent {
return nil
}
return t.startWebsocketAnnouncer(*u)
case "udp4":
if t.cl.config.DisableIPv4Peers || t.cl.config.DisableIPv4 {
return nil
}
case "udp6":
if t.cl.config.DisableIPv6 {
return nil
}
}
newAnnouncer := &trackerScraper{
u: *u,
t: t,
}
go newAnnouncer.Run()
return newAnnouncer
}()
if sl == nil {
return
}
if t.trackerAnnouncers == nil {
t.trackerAnnouncers = make(map[string]torrentTrackerAnnouncer)
}
t.trackerAnnouncers[_url] = sl
}
// Adds and starts tracker scrapers for tracker URLs that aren't already
// running.
func (t *Torrent) startMissingTrackerScrapers() {
if t.cl.config.DisableTrackers {
return
}
t.startScrapingTracker(t.metainfo.Announce)
for _, tier := range t.metainfo.AnnounceList {
for _, url := range tier {
t.startScrapingTracker(url)
}
}
}
// Returns an AnnounceRequest with fields filled out to defaults and current
// values.
func (t *Torrent) announceRequest(event tracker.AnnounceEvent) tracker.AnnounceRequest {
// Note that IPAddress is not set. It's set for UDP inside the tracker code, since it's
// dependent on the network in use.
return tracker.AnnounceRequest{
Event: event,
NumWant: func() int32 {
if t.wantPeers() && len(t.cl.dialers) > 0 {
return -1
} else {
return 0
}
}(),
Port: uint16(t.cl.incomingPeerPort()),
PeerId: t.cl.peerID,
InfoHash: t.infoHash,
Key: t.cl.announceKey(),
// The following are vaguely described in BEP 3.
Left: t.bytesLeftAnnounce(),
Uploaded: t.stats.BytesWrittenData.Int64(),
// There's no mention of wasted or unwanted download in the BEP.
Downloaded: t.stats.BytesReadUsefulData.Int64(),
}
}
// Adds peers revealed in an announce until the announce ends, or we have
// enough peers.
func (t *Torrent) consumeDhtAnnouncePeers(pvs <-chan dht.PeersValues) {
cl := t.cl
for v := range pvs {
cl.lock()
added := 0
for _, cp := range v.Peers {
if cp.Port == 0 {
// Can't do anything with this.
continue
}
if t.addPeer(PeerInfo{
Addr: ipPortAddr{cp.IP, cp.Port},
Source: PeerSourceDhtGetPeers,
}) {
added++
}
}
cl.unlock()
// if added != 0 {
// log.Printf("added %v peers from dht for %v", added, t.InfoHash().HexString())
// }
}
}
// Announce using the provided DHT server. Peers are consumed automatically. done is closed when the
// announce ends. stop will force the announce to end.
func (t *Torrent) AnnounceToDht(s DhtServer) (done <-chan struct{}, stop func(), err error) {
ps, err := s.Announce(t.infoHash, t.cl.incomingPeerPort(), true)
if err != nil {
return
}
_done := make(chan struct{})
done = _done
stop = ps.Close
go func() {
t.consumeDhtAnnouncePeers(ps.Peers())
close(_done)
}()
return
}
func (t *Torrent) timeboxedAnnounceToDht(s DhtServer) error {
_, stop, err := t.AnnounceToDht(s)
if err != nil {
return err
}
select {
case <-t.closed.Done():
case <-time.After(5 * time.Minute):
}
stop()
return nil
}
func (t *Torrent) dhtAnnouncer(s DhtServer) {
cl := t.cl
cl.lock()
defer cl.unlock()
for {
for {
if t.closed.IsSet() {
return
}
if !t.wantPeers() {
goto wait
}
// TODO: Determine if there's a listener on the port we're announcing.
if len(cl.dialers) == 0 && len(cl.listeners) == 0 {
goto wait
}
break
wait:
cl.event.Wait()
}
func() {
t.numDHTAnnounces++
cl.unlock()
defer cl.lock()
err := t.timeboxedAnnounceToDht(s)
if err != nil {
t.logger.WithDefaultLevel(log.Warning).Printf("error announcing %q to DHT: %s", t, err)
}
}()
}
}
func (t *Torrent) addPeers(peers []PeerInfo) (added int) {
for _, p := range peers {
if t.addPeer(p) {
added++
}
}
return
}
// The returned TorrentStats may require alignment in memory. See
// https://github.com/anacrolix/torrent/issues/383.
func (t *Torrent) Stats() TorrentStats {
t.cl.rLock()
defer t.cl.rUnlock()
return t.statsLocked()
}
func (t *Torrent) statsLocked() (ret TorrentStats) {
ret.ActivePeers = len(t.conns)
ret.HalfOpenPeers = len(t.halfOpen)
ret.PendingPeers = t.peers.Len()
ret.TotalPeers = t.numTotalPeers()
ret.ConnectedSeeders = 0
for c := range t.conns {
if all, ok := c.peerHasAllPieces(); all && ok {
ret.ConnectedSeeders++
}
}
ret.ConnStats = t.stats.Copy()
ret.PiecesComplete = t.numPiecesCompleted()
return
}
// The total number of peers in the torrent.
func (t *Torrent) numTotalPeers() int {
peers := make(map[string]struct{})
for conn := range t.conns {
ra := conn.conn.RemoteAddr()
if ra == nil {
// It's been closed and doesn't support RemoteAddr.
continue
}
peers[ra.String()] = struct{}{}
}
for addr := range t.halfOpen {
peers[addr] = struct{}{}
}
t.peers.Each(func(peer PeerInfo) {
peers[peer.Addr.String()] = struct{}{}
})
return len(peers)
}
// Reconcile bytes transferred before connection was associated with a
// torrent.
func (t *Torrent) reconcileHandshakeStats(c *PeerConn) {
if c._stats != (ConnStats{
// Handshakes should only increment these fields:
BytesWritten: c._stats.BytesWritten,
BytesRead: c._stats.BytesRead,
}) {
panic("bad stats")
}
c.postHandshakeStats(func(cs *ConnStats) {
cs.BytesRead.Add(c._stats.BytesRead.Int64())
cs.BytesWritten.Add(c._stats.BytesWritten.Int64())
})
c.reconciledHandshakeStats = true
}
// Returns true if the connection is added.
func (t *Torrent) addPeerConn(c *PeerConn) (err error) {
defer func() {
if err == nil {
torrent.Add("added connections", 1)
}
}()
if t.closed.IsSet() {
return errors.New("torrent closed")
}
for c0 := range t.conns {
if c.PeerID != c0.PeerID {
continue
}
if !t.cl.config.DropDuplicatePeerIds {
continue
}
if left, ok := c.hasPreferredNetworkOver(c0); ok && left {
c0.close()
t.deletePeerConn(c0)
} else {
return errors.New("existing connection preferred")
}
}
if len(t.conns) >= t.maxEstablishedConns {
c := t.worstBadConn()
if c == nil {
return errors.New("don't want conns")
}
c.close()
t.deletePeerConn(c)
}
if len(t.conns) >= t.maxEstablishedConns {
panic(len(t.conns))
}
t.conns[c] = struct{}{}
if !t.cl.config.DisablePEX && !c.PeerExtensionBytes.SupportsExtended() {
t.pex.Add(c) // as no further extended handshake expected
}
return nil
}
func (t *Torrent) wantConns() bool {
if !t.networkingEnabled.Bool() {
return false
}
if t.closed.IsSet() {
return false
}
if !t.seeding() && !t.needData() {
return false
}
if len(t.conns) < t.maxEstablishedConns {
return true
}
return t.worstBadConn() != nil
}
func (t *Torrent) SetMaxEstablishedConns(max int) (oldMax int) {
t.cl.lock()
defer t.cl.unlock()
oldMax = t.maxEstablishedConns
t.maxEstablishedConns = max
wcs := slices.HeapInterface(slices.FromMapKeys(t.conns), func(l, r *PeerConn) bool {
return worseConn(&l.Peer, &r.Peer)
})
for len(t.conns) > t.maxEstablishedConns && wcs.Len() > 0 {
t.dropConnection(wcs.Pop().(*PeerConn))
}
t.openNewConns()
return oldMax
}
func (t *Torrent) pieceHashed(piece pieceIndex, passed bool, hashIoErr error) {
t.logger.Log(log.Fstr("hashed piece %d (passed=%t)", piece, passed).SetLevel(log.Debug))
p := t.piece(piece)
p.numVerifies++
t.cl.event.Broadcast()
if t.closed.IsSet() {
return
}
// Don't score the first time a piece is hashed, it could be an initial check.
if p.storageCompletionOk {
if passed {
pieceHashedCorrect.Add(1)
} else {
log.Fmsg(
"piece %d failed hash: %d connections contributed", piece, len(p.dirtiers),
).AddValues(t, p).SetLevel(log.Debug).Log(t.logger)
pieceHashedNotCorrect.Add(1)
}
}
p.marking = true
t.publishPieceChange(piece)
defer func() {
p.marking = false
t.publishPieceChange(piece)
}()
if passed {
if len(p.dirtiers) != 0 {
// Don't increment stats above connection-level for every involved connection.
t.allStats((*ConnStats).incrementPiecesDirtiedGood)
}
for c := range p.dirtiers {
c._stats.incrementPiecesDirtiedGood()
}
t.clearPieceTouchers(piece)
t.cl.unlock()
err := p.Storage().MarkComplete()
if err != nil {
t.logger.Printf("%T: error marking piece complete %d: %s", t.storage, piece, err)
}
t.cl.lock()
if t.closed.IsSet() {
return
}
t.pendAllChunkSpecs(piece)
} else {
if len(p.dirtiers) != 0 && p.allChunksDirty() && hashIoErr == nil {
// Peers contributed to all the data for this piece hash failure, and the failure was
// not due to errors in the storage (such as data being dropped in a cache).
// Increment Torrent and above stats, and then specific connections.
t.allStats((*ConnStats).incrementPiecesDirtiedBad)
for c := range p.dirtiers {
// Y u do dis peer?!
c.stats().incrementPiecesDirtiedBad()
}
bannableTouchers := make([]*Peer, 0, len(p.dirtiers))
for c := range p.dirtiers {
if !c.trusted {
bannableTouchers = append(bannableTouchers, c)
}
}
t.clearPieceTouchers(piece)
slices.Sort(bannableTouchers, connLessTrusted)
if t.cl.config.Debug {
t.logger.Printf(
"bannable conns by trust for piece %d: %v",
piece,
func() (ret []connectionTrust) {
for _, c := range bannableTouchers {
ret = append(ret, c.trust())
}
return
}(),
)
}
if len(bannableTouchers) >= 1 {
c := bannableTouchers[0]
t.cl.banPeerIP(c.remoteIp())
c.drop()
}
}
t.onIncompletePiece(piece)
p.Storage().MarkNotComplete()
}
t.updatePieceCompletion(piece)
}
func (t *Torrent) cancelRequestsForPiece(piece pieceIndex) {
// TODO: Make faster
for cn := range t.conns {
cn.tickleWriter()
}
}
func (t *Torrent) onPieceCompleted(piece pieceIndex) {
t.pendAllChunkSpecs(piece)
t.cancelRequestsForPiece(piece)
t.piece(piece).readerCond.Broadcast()
for conn := range t.conns {
conn.have(piece)
t.maybeDropMutuallyCompletePeer(&conn.Peer)
}
}
// Called when a piece is found to be not complete.
func (t *Torrent) onIncompletePiece(piece pieceIndex) {
if t.pieceAllDirty(piece) {
t.pendAllChunkSpecs(piece)
}
if !t.wantPieceIndex(piece) {
// t.logger.Printf("piece %d incomplete and unwanted", piece)
return
}
// We could drop any connections that we told we have a piece that we
// don't here. But there's a test failure, and it seems clients don't care
// if you request pieces that you already claim to have. Pruning bad
// connections might just remove any connections that aren't treating us
// favourably anyway.
// for c := range t.conns {
// if c.sentHave(piece) {
// c.drop()
// }
// }
t.iterPeers(func(conn *Peer) {
if conn.peerHasPiece(piece) {
conn.updateRequests("piece incomplete")
}
})
}
func (t *Torrent) tryCreateMorePieceHashers() {
for !t.closed.IsSet() && t.activePieceHashes < 2 && t.tryCreatePieceHasher() {
}
}
func (t *Torrent) tryCreatePieceHasher() bool {
if t.storage == nil {
return false
}
pi, ok := t.getPieceToHash()
if !ok {
return false
}
p := t.piece(pi)
t.piecesQueuedForHash.Remove(bitmap.BitIndex(pi))
p.hashing = true
t.publishPieceChange(pi)
t.updatePiecePriority(pi, "Torrent.tryCreatePieceHasher")
t.storageLock.RLock()
t.activePieceHashes++
go t.pieceHasher(pi)
return true
}
func (t *Torrent) getPieceToHash() (ret pieceIndex, ok bool) {
t.piecesQueuedForHash.IterTyped(func(i pieceIndex) bool {
if t.piece(i).hashing {
return true
}
ret = i
ok = true
return false
})
return
}
func (t *Torrent) pieceHasher(index pieceIndex) {
p := t.piece(index)
sum, copyErr := t.hashPiece(index)
correct := sum == *p.hash
switch copyErr {
case nil, io.EOF:
default:
log.Fmsg("piece %v (%s) hash failure copy error: %v", p, p.hash.HexString(), copyErr).Log(t.logger)
}
t.storageLock.RUnlock()
t.cl.lock()
defer t.cl.unlock()
p.hashing = false
t.pieceHashed(index, correct, copyErr)
t.updatePiecePriority(index, "Torrent.pieceHasher")
t.activePieceHashes--
t.tryCreateMorePieceHashers()
}
// Return the connections that touched a piece, and clear the entries while doing it.
func (t *Torrent) clearPieceTouchers(pi pieceIndex) {
p := t.piece(pi)
for c := range p.dirtiers {
delete(c.peerTouchedPieces, pi)
delete(p.dirtiers, c)
}
}
func (t *Torrent) peersAsSlice() (ret []*Peer) {
t.iterPeers(func(p *Peer) {
ret = append(ret, p)
})
return
}
func (t *Torrent) queuePieceCheck(pieceIndex pieceIndex) {
piece := t.piece(pieceIndex)
if piece.queuedForHash() {
return
}
t.piecesQueuedForHash.Add(bitmap.BitIndex(pieceIndex))
t.publishPieceChange(pieceIndex)
t.updatePiecePriority(pieceIndex, "Torrent.queuePieceCheck")
t.tryCreateMorePieceHashers()
}
// Forces all the pieces to be re-hashed. See also Piece.VerifyData. This should not be called
// before the Info is available.
func (t *Torrent) VerifyData() {
for i := pieceIndex(0); i < t.NumPieces(); i++ {
t.Piece(i).VerifyData()
}
}
// Start the process of connecting to the given peer for the given torrent if appropriate.
func (t *Torrent) initiateConn(peer PeerInfo) {
if peer.Id == t.cl.peerID {
return
}
if t.cl.badPeerAddr(peer.Addr) && !peer.Trusted {
return
}
addr := peer.Addr
if t.addrActive(addr.String()) {
return
}
t.cl.numHalfOpen++
t.halfOpen[addr.String()] = peer
go t.cl.outgoingConnection(t, addr, peer.Source, peer.Trusted)
}
// Adds a trusted, pending peer for each of the given Client's addresses. Typically used in tests to
// quickly make one Client visible to the Torrent of another Client.
func (t *Torrent) AddClientPeer(cl *Client) int {
return t.AddPeers(func() (ps []PeerInfo) {
for _, la := range cl.ListenAddrs() {
ps = append(ps, PeerInfo{
Addr: la,
Trusted: true,
})
}
return
}())
}
// All stats that include this Torrent. Useful when we want to increment ConnStats but not for every
// connection.
func (t *Torrent) allStats(f func(*ConnStats)) {
f(&t.stats)
f(&t.cl.stats)
}
func (t *Torrent) hashingPiece(i pieceIndex) bool {
return t.pieces[i].hashing
}
func (t *Torrent) pieceQueuedForHash(i pieceIndex) bool {
return t.piecesQueuedForHash.Get(bitmap.BitIndex(i))
}
func (t *Torrent) dialTimeout() time.Duration {
return reducedDialTimeout(t.cl.config.MinDialTimeout, t.cl.config.NominalDialTimeout, t.cl.config.HalfOpenConnsPerTorrent, t.peers.Len())
}
func (t *Torrent) piece(i int) *Piece {
return &t.pieces[i]
}
func (t *Torrent) onWriteChunkErr(err error) {
if t.userOnWriteChunkErr != nil {
go t.userOnWriteChunkErr(err)
return
}
t.logger.WithDefaultLevel(log.Critical).Printf("default chunk write error handler: disabling data download")
t.disallowDataDownloadLocked()
}
func (t *Torrent) DisallowDataDownload() {
t.disallowDataDownloadLocked()
}
func (t *Torrent) disallowDataDownloadLocked() {
t.dataDownloadDisallowed.Set()
}
func (t *Torrent) AllowDataDownload() {
t.dataDownloadDisallowed.Clear()
}
// Enables uploading data, if it was disabled.
func (t *Torrent) AllowDataUpload() {
t.cl.lock()
defer t.cl.unlock()
t.dataUploadDisallowed = false
for c := range t.conns {
c.updateRequests("allow data upload")
}
}
// Disables uploading data, if it was enabled.
func (t *Torrent) DisallowDataUpload() {
t.cl.lock()
defer t.cl.unlock()
t.dataUploadDisallowed = true
for c := range t.conns {
c.updateRequests("disallow data upload")
}
}
// Sets a handler that is called if there's an error writing a chunk to local storage. By default,
// or if nil, a critical message is logged, and data download is disabled.
func (t *Torrent) SetOnWriteChunkError(f func(error)) {
t.cl.lock()
defer t.cl.unlock()
t.userOnWriteChunkErr = f
}
func (t *Torrent) iterPeers(f func(p *Peer)) {
for pc := range t.conns {
f(&pc.Peer)
}
for _, ws := range t.webSeeds {
f(ws)
}
}
func (t *Torrent) callbacks() *Callbacks {
return &t.cl.config.Callbacks
}
var WebseedHttpClient = &http.Client{
Transport: &http.Transport{
MaxConnsPerHost: 10,
},
}
func (t *Torrent) addWebSeed(url string) {
if t.cl.config.DisableWebseeds {
return
}
if _, ok := t.webSeeds[url]; ok {
return
}
const maxRequests = 10
ws := webseedPeer{
peer: Peer{
t: t,
outgoing: true,
Network: "http",
reconciledHandshakeStats: true,
// TODO: Raise this limit, and instead limit concurrent fetches.
PeerMaxRequests: 32,
RemoteAddr: remoteAddrFromUrl(url),
callbacks: t.callbacks(),
},
client: webseed.Client{
// Consider a MaxConnsPerHost in the transport for this, possibly in a global Client.
HttpClient: WebseedHttpClient,
Url: url,
},
activeRequests: make(map[Request]webseed.Request, maxRequests),
}
ws.requesterCond.L = t.cl.locker()
for i := 0; i < maxRequests; i += 1 {
go ws.requester()
}
for _, f := range t.callbacks().NewPeer {
f(&ws.peer)
}
ws.peer.logger = t.logger.WithContextValue(&ws)
ws.peer.peerImpl = &ws
if t.haveInfo() {
ws.onGotInfo(t.info)
}
t.webSeeds[url] = &ws.peer
ws.peer.onPeerHasAllPieces()
}
func (t *Torrent) peerIsActive(p *Peer) (active bool) {
t.iterPeers(func(p1 *Peer) {
if p1 == p {
active = true
}
})
return
}
func (t *Torrent) requestIndexToRequest(ri RequestIndex) Request {
index := ri / t.chunksPerRegularPiece()
return Request{
pp.Integer(index),
t.piece(int(index)).chunkIndexSpec(ri % t.chunksPerRegularPiece()),
}
}
func (t *Torrent) requestIndexFromRequest(r Request) RequestIndex {
return t.pieceRequestIndexOffset(pieceIndex(r.Index)) + uint32(r.Begin/t.chunkSize)
}
func (t *Torrent) pieceRequestIndexOffset(piece pieceIndex) RequestIndex {
return RequestIndex(piece) * t.chunksPerRegularPiece()
}
func (t *Torrent) updateComplete() {
t.Complete.SetBool(t.haveAllPieces())
}