File	Doc	Category	Size	Date	Package
DiskManagerPieceImpl.java	API Doc	Azureus 3.0.3.4	9620	Fri Jul 20 09:13:22 BST 2007	org.gudy.azureus2.core3.disk.impl

DiskManagerPieceImpl

• java.lang.Object

Fields Summary
private static final byte	PIECE_STATUS_NEEDED
private static final byte	PIECE_STATUS_WRITTEN
private static final byte	PIECE_STATUS_CHECKING
private static final byte	PIECE_STATUS_MASK_DOWNLOADABLE
private static final byte	PIECE_STATUS_MASK_NEEDS_CHECK
private final DiskManagerHelper	diskManager
private final int	pieceNumber
private final short	nbBlocks the number of blocks in this piece: can be short as this gives up to .5GB piece sizes with 16K blocks
protected volatile boolean[]	written
private byte	statusFlags
private short	read_count it's *very* important to accurately maintain the "done" state of a piece. Currently the statusFlags are updated in a non-thread-safe manner so a 'done' field is maintained seperatly. Synchronizing access to statusFlags or done would cause a tremendous performance hit.
private boolean	done

Constructors Summary
public DiskManagerPieceImpl(DiskManagerHelper _disk_manager, int pieceIndex, int length) diskManager =_disk_manager; pieceNumber = pieceIndex; nbBlocks =(short)((length +DiskManager.BLOCK_SIZE -1) /DiskManager.BLOCK_SIZE); statusFlags = PIECE_STATUS_NEEDED;

Methods Summary
public boolean	calcDone() return done;
public boolean	calcNeeded() boolean filesNeeded =false; final DMPieceList pieceList =diskManager.getPieceList(pieceNumber); for (int i =0; i <pieceList.size(); i++) { final DiskManagerFileInfoImpl file =pieceList.get(i).getFile(); final long fileLength =file.getLength(); filesNeeded |=fileLength >0 &&file.getDownloaded() <fileLength &&!file.isSkipped(); } if (filesNeeded) { statusFlags |=PIECE_STATUS_NEEDED; return true; } statusFlags &=~PIECE_STATUS_NEEDED; return false;
public void	clearNeeded() statusFlags &=~PIECE_STATUS_NEEDED;
public int	getBlockSize(int blockNumber) if ( blockNumber == nbBlocks -1 ){ int len = getLength() % DiskManager.BLOCK_SIZE; if ( len != 0 ){ return( len ); } } return DiskManager.BLOCK_SIZE;
public int	getLength() return int number of bytes in the piece return( diskManager.getPieceLength( pieceNumber ));
public DiskManager	getManager() return diskManager;
public int	getNbBlocks() return nbBlocks;
public int	getNbWritten() if (done) return nbBlocks; final boolean[] writtenRef =written; if (writtenRef ==null) return 0; int res =0; for (int i =0; i <nbBlocks; i++ ) { if (writtenRef[i]) res++; } return res;
public int	getPieceNumber() return pieceNumber;
public short	getReadCount() return( read_count );
public java.lang.String	getString() String text = ""; text += ( isNeeded()?"needed,":"" ); text += ( isDone()?"done,":"" ); if ( !isDone()){ text += ( isDownloadable()?"downable,":"" ); text += ( isWritten()?"written":("written " + getNbWritten())) + ","; text += ( isChecking()?"checking":"" ); } if ( text.endsWith(",")){ text = text.substring(0,text.length()-1); } return( text );
public boolean[]	getWritten() written[] can be null, in which case if the piece is Done, all blocks are complete otherwise no blocks are complete return written;
public boolean	isChecking() return (statusFlags &PIECE_STATUS_CHECKING) !=0;
public boolean	isDone() return done;
public boolean	isDownloadable() return !done &&(statusFlags &PIECE_STATUS_MASK_DOWNLOADABLE) == PIECE_STATUS_NEEDED;
public boolean	isInteresting() return true if the piece is Needed and not Done return !done &&(statusFlags &PIECE_STATUS_NEEDED) != 0;
public boolean	isNeeded() return (statusFlags &PIECE_STATUS_NEEDED) !=0;
public boolean	isNeedsCheck() return !done &&(statusFlags &PIECE_STATUS_MASK_NEEDS_CHECK) ==PIECE_STATUS_WRITTEN;
public boolean	isSkipped() final DMPieceList pieceList =diskManager.getPieceList(pieceNumber); for (int i =0; i <pieceList.size(); i++){ if ( !pieceList.get(i).getFile().isSkipped()){ return( false ); } } return( true );
public boolean	isWritten() return (statusFlags &PIECE_STATUS_WRITTEN) !=0;
public boolean	isWritten(int blockNumber) if (done) return true; final boolean[] writtenRef =written; if (writtenRef ==null) return false; return writtenRef[blockNumber];
public void	reDownloadBlock(int blockNumber) final boolean[] written_ref = written; if (written_ref !=null) { written_ref[blockNumber] =false; setDownloadable(); }
public void	reset() setDownloadable(); written =null;
public void	setChecking() statusFlags |=PIECE_STATUS_CHECKING;
public void	setDone(boolean b) // we delegate this operation to the disk manager so it can synchronise the activity if (b !=done) { diskManager.setPieceDone(this, b); }
public void	setDoneSupport(boolean b) this is ONLY used by the disk manager to update the done state while synchronized i.e. don't use it else where! param b done =b; if (done) written =null;
public void	setDownloadable() setDone(false); statusFlags &=~(PIECE_STATUS_MASK_DOWNLOADABLE); calcNeeded(); // Needed wouldn't have been calced before if couldn't download more
public void	setNeeded() statusFlags |=PIECE_STATUS_NEEDED;
public void	setNeeded(boolean b) if (b) statusFlags |=PIECE_STATUS_NEEDED; else statusFlags &=~PIECE_STATUS_NEEDED;
public void	setReadCount(short c) read_count = c;
public void	setWritten(int blockNumber) if (written ==null) written =new boolean[nbBlocks]; final boolean[] written_ref =written; written_ref[blockNumber] =true; for (int i =0; i <nbBlocks; i++) { if (!written_ref[i]) return; } statusFlags |=PIECE_STATUS_WRITTEN;