org.klomp.snark

Class TrackerClient

java.lang.Object

org.klomp.snark.TrackerClient

All Implemented Interfaces:

Runnable

public class TrackerClient
extends Object
implements Runnable

Handles communication with BitTorrent trackers and DHT to discover new peers.

This class manages tracker announcements and peer discovery by:

• Announcing torrent status to HTTP/HTTPS trackers
• Processing tracker responses and extracting peer information
• Managing UDP tracker communication
• Integrating with DHT for trackerless peer discovery
• Handling Peer Exchange (PEX) when available
• Managing announcement intervals and retry logic
• Processing various tracker events (started, completed, stopped)

Threading Model: The start() method creates a thread that runs one complete announcement cycle through all trackers, PEX, and DHT, then queues a new timed event and exits. This approach prevents thread accumulation while ensuring regular announcements.

The client can be restarted after halt() and handles various tracker responses including registration failures and error conditions.

Field Summary

Fields

Modifier and Type	Field and Description
static int	PORT

Constructor Summary

Constructors

Constructor and Description
TrackerClient(I2PSnarkUtil util, MetaInfo meta, String additionalTrackerURL, PeerCoordinator coordinator, Snark snark) Call start() to start it.

Method Summary

Modifier and Type	Method and Description
void	halt(boolean fast) Interrupts this Thread to stop it.
boolean	halted()
static boolean	isValidAnnounce(String ann)
void	reinitialize() Call after editing torrent
void	run() Setup the first time only, then one pass (usually) through the trackers, PEX, and DHT.
void	start()
boolean	started()
static String	urlencode(byte[] bs) Very lazy byte[] to URL encoder.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

PORT

public static final int PORT

See Also:

Constant Field Values

Constructor Detail

TrackerClient

public TrackerClient(I2PSnarkUtil util,
                     MetaInfo meta,
                     String additionalTrackerURL,
                     PeerCoordinator coordinator,
                     Snark snark)

Call start() to start it.

Parameters:

meta - null if in magnet mode

additionalTrackerURL - may be null, from the ?tr= param in magnet mode, otherwise ignored

Method Detail

halt

public void halt(boolean fast)

Interrupts this Thread to stop it.

Parameters:

fast - if true, limit the life of the unannounce threads

halted

public boolean halted()

isValidAnnounce

public static boolean isValidAnnounce(String ann)

Parameters:

ann - an announce URL, may be null, returns false if null

Returns:

true for i2p hosts only

reinitialize

public void reinitialize()

Call after editing torrent

run

public void run()

Setup the first time only, then one pass (usually) through the trackers, PEX, and DHT. This will take several seconds to several minutes.

Specified by:

run in interface Runnable

start

public void start()

started

public boolean started()

urlencode

public static String urlencode(byte[] bs)

Very lazy byte[] to URL encoder. Just encodes almost everything, even some "normal" chars. By not encoding about 1/4 of the chars, we make random data like hashes about 16% smaller.

RFC1738: 0-9a-zA-Z$-_.+!*'(), Us: 0-9a-zA-Z