Field Detail

• CHUNK_SIZE

  public static final int CHUNK_SIZE

  Chunk size for magnet metadata fetches (16 KB).

  See Also:

  Constant Field Values

Constructor Detail

• MagnetState

  public MagnetState(byte[] iHash,
                     MetaInfo meta)

  Creates a new MagnetState for the given info hash.

  Parameters:

  iHash - the 20-byte info hash

  meta - the MetaInfo if already available, or null for a new magnet download

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()

  Returns the MetaInfo for this magnet state.

  Returns:

  the MetaInfo

  Throws:

  IllegalArgumentException - if not complete

• 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()

  Returns the total metadata size in bytes.

  Returns:

  the metadata size

  Throws:

  IllegalArgumentException - if not initialized

• initialize

  public void initialize(int size)

  Initializes the magnet state with the given metadata size. Must only be called once.

  Parameters:

  size - the metadata size in bytes

  Throws:

  IllegalArgumentException - if already initialized

• 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

  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)

  Sets the MetaInfo for a completed magnet download.

  Parameters:

  meta - the completed MetaInfo