org.klomp.snark

Class MagnetState

java.lang.Object

org.klomp.snark.MagnetState

class MagnetState
extends Object

Simple state for the download of the metainfo, shared between Peer and ExtensionHandler.

Nothing is synchronized here! Caller must synchronize on this for everything!

Reference: BEP 9

Field Summary

Fields

Modifier and Type	Field and Description
static int	CHUNK_SIZE

Constructor Summary

Constructors

Constructor and Description
MagnetState(byte[] iHash, MetaInfo meta)

Method Summary

Modifier and Type	Method and Description
int	chunkSize(int chunk) Get the size of a specific chunk.
int	chunksRemaining() Get the number of chunks remaining to be downloaded.
byte[]	getChunk(int chunk) Get the data for a specific chunk.
MetaInfo	getMetaInfo()
int	getNextRequest() Get the next chunk number to request.
int	getSize()
void	initialize(int size) Call this for a new magnet when you have the size
boolean	isComplete() Check if the magnet download is complete.
boolean	isInitialized() Check if the magnet state has been initialized.
boolean	saveChunk(int chunk, byte[] data, int off, int length) Save a chunk of data to the magnet state.
void	setMetaInfo(MetaInfo meta) Call this for a new magnet when the download is complete.

Methods inherited from class java.lang.Object

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

Field Detail

CHUNK_SIZE

public static final int CHUNK_SIZE

See Also:

Constant Field Values

Constructor Detail

MagnetState

public MagnetState(byte[] iHash,
                   MetaInfo meta)

Parameters:

meta - null for new magnet

Method Detail

chunkSize

public int chunkSize(int chunk)

Get the size of a specific chunk.

Parameters:

chunk - the chunk number

Returns:

the size of the chunk in bytes

chunksRemaining

public int chunksRemaining()

Get the number of chunks remaining to be downloaded.

Returns:

the number of chunks remaining

Throws:

IllegalArgumentException - if not initialized

getChunk

public byte[] getChunk(int chunk)

Get the data for a specific chunk.

Parameters:

chunk - the chunk number to retrieve

Returns:

the chunk data as a byte array

Throws:

IllegalArgumentException - if not complete or chunk number is invalid

getMetaInfo

public MetaInfo getMetaInfo()

Throws:

IllegalArgumentException

getNextRequest

public int getNextRequest()

Get the next chunk number to request. Uses a random selection algorithm to avoid requesting the same chunks repeatedly.

Returns:

the next chunk number to request

Throws:

IllegalArgumentException - if not initialized or complete

getSize

public int getSize()

Throws:

IllegalArgumentException

initialize

public void initialize(int size)

Call this for a new magnet when you have the size

Throws:

IllegalArgumentException

isComplete

public boolean isComplete()

Check if the magnet download is complete.

Returns:

true if complete, false otherwise

isInitialized

public boolean isInitialized()

Check if the magnet state has been initialized.

Returns:

true if initialized, false otherwise

saveChunk

public boolean saveChunk(int chunk,
                         byte[] data,
                         int off,
                         int length)
                  throws Exception

Save a chunk of data to the magnet state.

Parameters:

chunk - the chunk number to save

data - the byte array containing the chunk data

off - the offset in the data array where the chunk starts

length - the length of the chunk data

Returns:

true if this was the last piece, false otherwise

Throws:

IllegalArgumentException - if not initialized, chunk number is invalid, or length is incorrect

Exception - if there's an error building the MetaInfo

setMetaInfo

public void setMetaInfo(MetaInfo meta)

Call this for a new magnet when the download is complete.

Throws:

IllegalArgumentException