downloadmanagerimpl.java

这是一个基于java编写的torrent的P2P源码

					 	// flag set true below
					 
					 dl_identity			= torrent_hash==null?torrent.getHash():torrent_hash;
	                 
	                 this.dl_identity_hashcode = new String( dl_identity ).hashCode();		 
				 }
					 
				 if ( !Arrays.equals( dl_identity, torrent.getHash())){
						 
					 torrent	= null;	// prevent this download from being used
					 
					 	// set up some kinda default else things don't work wel...
					 
					 torrent_save_location = new File( torrent_save_dir, torrentFileName );
					 
					 throw( new NoStackException( "Download identity changed - please remove and re-add the download" ));
				 }
				 
				 read_torrent_state	= null;	// no longer needed if we saved it
	
				 LocaleUtilDecoder	locale_decoder = LocaleTorrentUtil.getTorrentEncoding( torrent );
						 
				 	// if its a simple torrent and an explicit save file wasn't supplied, use
				 	// the torrent name itself
				 
				 display_name = locale_decoder.decodeString( torrent.getName());
	             
				 display_name = FileUtil.convertOSSpecificChars( display_name );
			
				 internal_name = ByteFormatter.nicePrint(torrent.getHash(),true);
	
				 	// now we know if its a simple torrent or not we can make some choices about
				 	// the save dir and file. On initial entry the save_dir will have the user-selected
				 	// save location and the save_file will be null
				 
				 File	save_dir_file	= new File( torrent_save_dir );
				 
				 // System.out.println( "before: " + torrent_save_dir + "/" + torrent_save_file );
				 
				 	// if save file is non-null then things have already been sorted out
				 
				 if ( torrent_save_file == null ){
				 		 	
				 		// make sure we're working off a canonical save dir if possible
				 	
				 	try{
				 		if ( save_dir_file.exists()){
				 			
				 			save_dir_file = save_dir_file.getCanonicalFile();
				 		}
				 	}catch( Throwable e ){
				 			
				 		Debug.printStackTrace(e);
				 	}
		
				 	if ( torrent.isSimpleTorrent()){
				 		
				 			// if target save location is a directory then we use that as the save
				 			// dir and use the torrent display name as the target. Otherwise we
				 			// use the file name
				 		
				 		if ( save_dir_file.exists()){
				 			
				 			if ( save_dir_file.isDirectory()){
				 				
				 				torrent_save_file	= display_name;
				 				
				 			}else{
				 				
				 				torrent_save_dir	= save_dir_file.getParent().toString();
				 				
				 				torrent_save_file	= save_dir_file.getName();
				 			}
				 		}else{
				 			
				 				// doesn't exist, assume it refers directly to the file
				 			
				 			if ( save_dir_file.getParent() == null ){
				 				
				 				throw( new NoStackException( "Data location '" + torrent_save_dir + "' is invalid" ));
	
				 			}
				 			
			 				torrent_save_dir	= save_dir_file.getParent().toString();
			 				
			 				torrent_save_file	= save_dir_file.getName(); 			
				 		}
				 		
				 	}else{
				 	
				 			// torrent is a folder. It is possible that the natural location
				 			// for the folder is X/Y and that in fact 'Y' already exists and
				 			// has been selected. If ths is the case the select X as the dir and Y
				 			// as the file name
				 		
				 		if ( save_dir_file.exists()){
				 			
				 			if ( !save_dir_file.isDirectory()){
				 				
				 				throw( new NoStackException( "'" + torrent_save_dir + "' is not a directory" ));
				 			}
				 			
				 			if ( save_dir_file.getName().equals( display_name )){
				 				
				 				torrent_save_dir	= save_dir_file.getParent().toString();
				 			}
				 		}
				 		
				 		torrent_save_file	= display_name;		
				 	}
				 }
	
				 torrent_save_location = new File( torrent_save_dir, torrent_save_file );
				 
				 	// final validity test must be based of potentially linked target location as file
				 	// may have been re-targetted
	
				 File	linked_target = getSaveLocation();
				 
				 if ( !linked_target.exists()){
				 	
				 		// if this isn't a new torrent then we treat the absence of the enclosing folder
				 		// as a fatal error. This is in particular to solve a problem with the use of
				 		// externally mounted torrent data on OSX, whereby a re-start with the drive unmounted
				 		// results in the creation of a local diretory in /Volumes that subsequently stuffs
				 		// up recovery when the volume is mounted
				 	
				 		// changed this to only report the error on non-windows platforms 
				 	
				 	if ( !(new_torrent || Constants.isWindows )){
				 		
							// another exception here - if the torrent has never been started then we can
							// fairly safely continue as its in a stopped state
						
						if ( has_ever_been_started ){
				 		
							throw( new NoStackException( MessageText.getString("DownloadManager.error.datamissing") + " " + linked_target.toString()));
						}
				 	}
				 }	
				 
				 	// if this is a newly introduced torrent trash the tracker cache. We do this to
				 	// prevent, say, someone publishing a torrent with a load of invalid cache entries
				 	// in it and a bad tracker URL. This could be used as a DOS attack
	
				 if ( new_torrent ){
				 	
					download_manager_state.setLongParameter( DownloadManagerState.PARAM_DOWNLOAD_ADDED_TIME, SystemTime.getCurrentTime());
					 
				 	download_manager_state.setTrackerResponseCache( new HashMap());
				 	
				 		// also remove resume data incase someone's published a torrent with resume
				 		// data in it
				 	
				 	if ( for_seeding ){
				 		
				 		DiskManagerFactory.setTorrentResumeDataNearlyComplete(download_manager_state);
				 		
				 		// Prevent download being considered for on-completion moving - it's considered complete anyway.
				 		download_manager_state.setFlag(DownloadManagerState.FLAG_MOVE_ON_COMPLETION_DONE, true);
	
				 	}else{
				 		
				 		download_manager_state.clearResumeData();
				 	}
				 }else{
					 
			       long	add_time = download_manager_state.getLongParameter( DownloadManagerState.PARAM_DOWNLOAD_ADDED_TIME );
			        
			       if ( add_time == 0 ){
			    	  
			        		// grab an initial value from torrent file - migration only
			    	   
			        	try{
			        		add_time = new File( torrentFileName ).lastModified();
			        		
			        	}catch( Throwable e ){
			        	}
			        	
			        	if ( add_time == 0 ){
			        		
			        		add_time = SystemTime.getCurrentTime();
			        	}
			        	
			        	download_manager_state.setLongParameter( DownloadManagerState.PARAM_DOWNLOAD_ADDED_TIME, add_time );
			        }
				 }
				 
		         
				 //trackerUrl = torrent.getAnnounceURL().toString();
	         
				torrent_comment = locale_decoder.decodeString(torrent.getComment());
	         
				if ( torrent_comment == null ){
					
				   torrent_comment	= "";
				}
				
				torrent_created_by = locale_decoder.decodeString(torrent.getCreatedBy());
	         
				if ( torrent_created_by == null ){
					
					torrent_created_by	= "";
				}
				 			 
				 	// only restore the tracker response cache for non-seeds
		   
				 if ( download_manager_state.isResumeDataComplete()){
				 	
					 	// actually, can't think of a good reason not to restore the
					 	// cache for seeds, after all if the tracker's down we still want
					 	// to connect to peers to upload to
					 
					  // download_manager_state.clearTrackerResponseCache();
						
					  stats.setDownloadCompleted(1000);
				  
					  setAssumedComplete(true);
				  
				 }else{
				 					 
					 setAssumedComplete(false);
				}
			}catch( TOTorrentException e ){
			
				//Debug.printStackTrace( e );
				       		 			
				setFailed( TorrentUtils.exceptionToText( e ));
	 			
			}catch( UnsupportedEncodingException e ){
			
				Debug.printStackTrace( e );
				       					
				setFailed( MessageText.getString("DownloadManager.error.unsupportedencoding"));
				
			}catch( NoStackException e ){
				
				Debug.outNoStack( e.getMessage());
				
			}catch( Throwable e ){
				
				Debug.printStackTrace( e );
				   					
				setFailed( e );
				
			}finally{
				
				 dl_identity_obtained	= true;			 
			}
			
			if ( download_manager_state == null ){
			
				read_torrent_state = 
					new Object[]{ 	
						torrent_save_dir, torrent_save_file, torrent_hash,
						new Boolean(new_torrent), new Boolean( for_seeding ), new Boolean( has_ever_been_started ),
						new Integer( initial_state )
					};
	
					// torrent's stuffed - create a dummy "null object" to simplify use
					// by other code
				
				download_manager_state	= DownloadManagerStateImpl.getDownloadState( this );
				
					// make up something vaguely sensible for save location
				
				if ( torrent_save_file == null ){
					
					torrent_save_location = new File( torrent_save_dir );
					
				}else{
					
					torrent_save_location = new File( torrent_save_dir, torrent_save_file );
				}
				
			}else{
				
				
					// make up something vaguely sensible for save location if we haven't got one
			
				if ( torrent_save_file == null ){
				
					torrent_save_location = new File( torrent_save_dir );
				}
				
					// make sure we know what networks to use for this download
				
				if ( download_manager_state.getNetworks().length == 0 ){
					
					String[] networks = AENetworkClassifier.getNetworks( torrent, display_name );
					
					download_manager_state.setNetworks( networks );
				}
				
				if ( download_manager_state.getPeerSources().length == 0 ){
					
					String[] ps = PEPeerSource.getPeerSources();
					
					download_manager_state.setPeerSources( ps );
				}
			}			
		}finally{
			
			if ( torrent_save_location != null ){
				
				try{
					torrent_save_location = torrent_save_location.getCanonicalFile();
					
				}catch( Throwable e ){
					
					torrent_save_location = torrent_save_location.getAbsoluteFile();
				}
			}
			
				// must be after torrent read, so that any listeners have a TOTorrent
				// not that if things have failed above this method won't override a failed
				// state with the initial one
			
			controller.setInitialState( initial_state );
		}
	}

	protected void
	readTorrent()
	{
		if ( read_torrent_state == null ){
			
			return;
		}
		
		readTorrent(
				(String)read_torrent_state[0],
				(String)read_torrent_state[1],
				(byte[])read_torrent_state[2],
				((Boolean)read_torrent_state[3]).booleanValue(),
				((Boolean)read_torrent_state[4]).booleanValue(),
				((Boolean)read_torrent_state[5]).booleanValue(),
				((Integer)read_torrent_state[6]).intValue());

	}
	
	protected void
	readParameters()
	{
		max_connections							= getDownloadState().getIntParameter( DownloadManagerState.PARAM_MAX_PEERS );
		max_connections_when_seeding_enabled	= getDownloadState().getBooleanParameter( DownloadManagerState.PARAM_MAX_PEERS_WHEN_SEEDING_ENABLED );
		max_connections_when_seeding			= getDownloadState().getIntParameter( DownloadManagerState.PARAM_MAX_PEERS_WHEN_SEEDING );
		max_seed_connections					= getDownloadState().getIntParameter( DownloadManagerState.PARAM_MAX_SEEDS );
		max_uploads						 		= getDownloadState().getIntParameter( DownloadManagerState.PARAM_MAX_UPLOADS );
		max_uploads_when_seeding_enabled 		= getDownloadState().getBooleanParameter( DownloadManagerState.PARAM_MAX_UPLOADS_WHEN_SEEDING_ENABLED );
		max_uploads_when_seeding 				= getDownloadState().getIntParameter( DownloadManagerState.PARAM_MAX_UPLOADS_WHEN_SEEDING );
		max_upload_when_busy_bps				= getDownloadState().getIntParameter( DownloadManagerState.PARAM_MAX_UPLOAD_WHEN_BUSY ) * 1024;

		max_uploads = Math.max( max_uploads, DownloadManagerState.MIN_MAX_UPLOADS );
		max_uploads_when_seeding = Math.max( max_uploads_when_seeding, DownloadManagerState.MIN_MAX_UPLOADS );
	}
	
	protected int
	getMaxConnections()
	{
		return( max_connections );
	}
	
	protected int
	getMaxConnectionsWhenSeeding()
	{
		return( max_connections_when_seeding );
	}
	
	protected boolean
	isMaxConnectionsWhenSeedingEnabled()
	{
		return( max_connections_when_seeding_enabled );
	}
	
	protected int
	getMaxSeedConnections()
	{
		return( max_seed_connections );
	}
	
	protected boolean
	isMaxUploadsWhenSeedingEnabled()
	{
		return( max_uploads_when_seeding_enabled );
	}
	
	protected int
	getMaxUploadsWhenSeeding()
	{
		return( max_uploads_when_seeding );
	}
	
	public int
	getMaxUploads()
	{
		return( max_uploads );
	}
	
	public void
	setMaxUploads(
		int	max )
	{
		download_manager_state.setIntParameter( DownloadManagerState.PARAM_MAX_UPLOADS, max );
	}
	
	public int
	getEffectiveMaxUploads()
	{
		if ( isMaxUploadsWhenSeedingEnabled() && getState() == DownloadManager.STATE_SEEDING ){
			
			return( getMaxUploadsWhenSeeding());
			
		}else{
			
			return( max_uploads );
		}
	}
	
	public int
	getEffectiveUploadRateLimitBytesPerSecond()
	{
		int	local_max_bps	= stats.getUploadRateLimitBytesPerSecond();
		int	rate			= local_max_bps;
		
		if ( max_upload_when_busy_bps != 0 ){
			
			long	now = SystemTime.getCurrentTime();
			
			if ( now < last_upload_when_busy_update || now - last_upload_when_busy_update > 5000 ){
				
				last_upload_when_busy_update	= now;
				
					// might need to impose the limit
				
				String key = TransferSpeedValidator.getActiveUploadParameter( globalManager );
				
				int	global_limit_bps = COConfigurationManager.getIntParameter( key )*1024;
								
				if ( global_limit_bps > 0 && max_upload_when_busy_bps < global_limit_bps ){
				
						// we have a global limit and a valid busy limit
				
					local_max_bps = local_max_bps==0?global_limit_bps:local_max_bps;

					GlobalManagerStats gm_stats = globalManager.getStats();
	
					int	actual = gm_stats.getDataSendRateNoLAN() + gm_stats.getProtocolSendRateNoLAN();
				
					int	move_by = ( local_max_bps - max_upload_when_busy_bps ) / 10;
					
					if ( move_by < 1024 ){
						
						move_by = 1024;
					}
					
					if ( global_limit_bps - actual <= 2*1024 ){
				
							// close enough to impose the busy limit downwards
						
						
						if ( current_upload_when_busy_bps == 0 ){
							
							current_upload_when_busy_bps = local_max_bps;
						}
						
						int	prev_upload_when_busy_bps = current_upload_when_busy_bps;
						
						current_upload_when_busy_bps -= move_by;
						
						if ( current_upload_when_busy_bps < max_upload_when_busy_bps ){
							
							current_upload_when_busy_bps = max_upload_when_busy_bps;
						}
						
						if ( current_upload_when_busy_bps < prev_upload_when_busy_bps ){
							
							last_upload_when_busy_dec_time = now;
						}
					}else{
						
							// not hitting limit, increase
						
						if ( current_upload_when_busy_bps != 0 ){
							
								// only try increment if sufficient time passed
							
							if ( 	upload_when_busy_min_secs == 0 ||
									now < last_upload_when_busy_dec_time ||
									now - last_upload_when_busy_dec_time >=  upload_when_busy_min_secs*1000 ){
									
								current_upload_when_busy_bps += move_by;
								
								if ( current_upload_when_busy_bps >= local_max_bps ){
									
									current_upload_when_busy_bps	= 0;
								}
							}
						}
					}
					
					if ( current_upload_when_busy_bps > 0 ){
						
						rate = current_upload_when_busy_bps;
					}
				}else{
					
					current_upload_when_busy_bps = 0;
				}
			}else{
				
				if ( current_upload_when_busy_bps > 0 ){
				
					rate = current_upload_when_busy_bps;
				}
			}
		}
		
		return( rate );
	}
	
	protected void
	setFileLinks()
	{
			// invalidate the cache info in case its now wrong