org.klomp.snark

Class Piece

java.lang.Object

org.klomp.snark.Piece

All Implemented Interfaces:

Comparable<Piece>

class Piece
extends Object
implements Comparable<Piece>

Represents a torrent piece and tracks which peers have it and are requesting it.

This class is used internally by PeerCoordinator to manage piece selection and distribution strategies. It maintains:

• The piece identifier within the torrent
• Set of peers that have this piece available
• Set of peers currently requesting this piece
• Priority level for piece selection

Pieces are sorted by priority (highest first) and then by rarity (fewest peers having it first) to optimize download performance.

Thread Safety: This class is not thread-safe. Callers must synchronize on access to most methods.

Constructor Summary

Constructors

Constructor and Description
Piece(int id)

Method Summary

Modifier and Type	Method and Description
boolean	addPeer(Peer peer) caller must synchronize
void	clear() Clear all knowledge of peers Caller must synchronize
int	compareTo(Piece op) Highest priority first, then rarest first
boolean	equals(Object o)
int	getId()
int	getPeerCount() How many peers have this piece? Caller must synchronize
int	getPriority() Gets the current priority level for this piece.
int	getRequestCount() How many peers are requesting this piece? Caller must synchronize
int	hashCode()
boolean	isDisabled() Checks if this piece is disabled (should not be downloaded).
boolean	isRequested() caller must synchronize
boolean	isRequestedBy(Peer peer) Checks if the given peer is currently requesting this piece.
boolean	removePeer(Peer peer) Caller must synchronize.
void	setDisabled() Disables this piece so it will not be downloaded.
void	setPriority(int p) Sets the priority level for this piece.
void	setRequested(Peer peer, boolean requested) Marks a peer as requesting or no longer requesting this piece.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Piece

public Piece(int id)

Method Detail

addPeer

public boolean addPeer(Peer peer)

caller must synchronize

clear

public void clear()

Clear all knowledge of peers Caller must synchronize

compareTo

public int compareTo(Piece op)

Highest priority first, then rarest first

Specified by:

compareTo in interface Comparable<Piece>

equals

public boolean equals(Object o)

Overrides:

equals in class Object

getId

public int getId()

getPeerCount

public int getPeerCount()

How many peers have this piece? Caller must synchronize

getPriority

public int getPriority()

Gets the current priority level for this piece.

Returns:

priority value (negative values indicate disabled/skipped pieces)

getRequestCount

public int getRequestCount()

How many peers are requesting this piece? Caller must synchronize

hashCode

public int hashCode()

Overrides:

hashCode in class Object

isDisabled

public boolean isDisabled()

Checks if this piece is disabled (should not be downloaded).

Returns:

true if disabled (priority < 0), false otherwise

isRequested

public boolean isRequested()

caller must synchronize

isRequestedBy

public boolean isRequestedBy(Peer peer)

Checks if the given peer is currently requesting this piece. Caller must synchronize.

Parameters:

peer - the peer to check

Returns:

true if peer is requesting, false otherwise

removePeer

public boolean removePeer(Peer peer)

Caller must synchronize.

Returns:

true if removed

setDisabled

public void setDisabled()

Disables this piece so it will not be downloaded. Sets priority to -1.

setPriority

public void setPriority(int p)

Sets the priority level for this piece.

Parameters:

p - priority value (negative to disable, 0 or positive for normal priority)

setRequested

public void setRequested(Peer peer,
                         boolean requested)

Marks a peer as requesting or no longer requesting this piece. Used to avoid deadlocks when querying each peer. Caller must synchronize.

Parameters:

peer - the peer requesting

requested - true to mark as requested, false to unmark

toString

public String toString()

Overrides:

toString in class Object