package torrent import ( "crypto" "expvar" "time" ) const ( pieceHash = crypto.SHA1 maxRequests = 250 // Maximum pending requests we allow peers to send us. defaultChunkSize = 0x4000 // 16KiB // Updated occasionally to when there's been some changes to client // behaviour in case other clients are assuming anything of us. See also // `bep20`. extendedHandshakeClientVersion = "go.torrent dev 20150624" // Peer ID client identifier prefix. We'll update this occasionally to // reflect changes to client behaviour that other clients may depend on. // Also see `extendedHandshakeClientVersion`. bep20 = "-GT0001-" nominalDialTimeout = time.Second * 30 minDialTimeout = 5 * time.Second // Justification for set bits follows. // // Extension protocol ([5]|=0x10): // http://www.bittorrent.org/beps/bep_0010.html // // Fast Extension ([7]|=0x04): // http://bittorrent.org/beps/bep_0006.html. // Disabled until AllowedFast is implemented. // // DHT ([7]|=1): // http://www.bittorrent.org/beps/bep_0005.html defaultExtensionBytes = "\x00\x00\x00\x00\x00\x10\x00\x01" defaultEstablishedConnsPerTorrent = 80 defaultHalfOpenConnsPerTorrent = 80 torrentPeersHighWater = 200 torrentPeersLowWater = 50 // Limit how long handshake can take. This is to reduce the lingering // impact of a few bad apples. 4s loses 1% of successful handshakes that // are obtained with 60s timeout, and 5% of unsuccessful handshakes. handshakesTimeout = 20 * time.Second // These are our extended message IDs. Peers will use these values to // select which extension a message is intended for. metadataExtendedId = iota + 1 // 0 is reserved for deleting keys pexExtendedId ) // I could move a lot of these counters to their own file, but I suspect they // may be attached to a Client someday. var ( unwantedChunksReceived = expvar.NewInt("chunksReceivedUnwanted") unexpectedChunksReceived = expvar.NewInt("chunksReceivedUnexpected") chunksReceived = expvar.NewInt("chunksReceived") peersAddedBySource = expvar.NewMap("peersAddedBySource") uploadChunksPosted = expvar.NewInt("uploadChunksPosted") unexpectedCancels = expvar.NewInt("unexpectedCancels") postedCancels = expvar.NewInt("postedCancels") pieceHashedCorrect = expvar.NewInt("pieceHashedCorrect") pieceHashedNotCorrect = expvar.NewInt("pieceHashedNotCorrect") unsuccessfulDials = expvar.NewInt("dialSuccessful") successfulDials = expvar.NewInt("dialUnsuccessful") acceptUTP = expvar.NewInt("acceptUTP") acceptTCP = expvar.NewInt("acceptTCP") acceptReject = expvar.NewInt("acceptReject") peerExtensions = expvar.NewMap("peerExtensions") completedHandshakeConnectionFlags = expvar.NewMap("completedHandshakeConnectionFlags") // Count of connections to peer with same client ID. connsToSelf = expvar.NewInt("connsToSelf") // Number of completed connections to a client we're already connected with. duplicateClientConns = expvar.NewInt("duplicateClientConns") receivedMessageTypes = expvar.NewMap("receivedMessageTypes") receivedKeepalives = expvar.NewInt("receivedKeepalives") supportedExtensionMessages = expvar.NewMap("supportedExtensionMessages") postedMessageTypes = expvar.NewMap("postedMessageTypes") postedKeepalives = expvar.NewInt("postedKeepalives") // Requests received for pieces we don't have. requestsReceivedForMissingPieces = expvar.NewInt("requestsReceivedForMissingPieces") // Track the effectiveness of Torrent.connPieceInclinationPool. pieceInclinationsReused = expvar.NewInt("pieceInclinationsReused") pieceInclinationsNew = expvar.NewInt("pieceInclinationsNew") pieceInclinationsPut = expvar.NewInt("pieceInclinationsPut") fillBufferSentCancels = expvar.NewInt("fillBufferSentCancels") fillBufferSentRequests = expvar.NewInt("fillBufferSentRequests") numFillBuffers = expvar.NewInt("numFillBuffers") )