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java.lang.Object
   |
   +----edu.utah.janos.nodeos.DemultiplexKey

Summary

public abstract class  DemultiplexKey
     extends java.lang.Object
{
          // Fields 1
     private final int length;

          // Constructors 1
     public DemultiplexKey(int);

          // Methods 5
     protected static final int compareByte(byte[], int, int, int, byte);
     protected static final int compareSlice(byte[], int, int, int, byte[]);

     protected final int length();
     public abstract int matches(byte[], int, int);
     public String toString();
}

A key for matching incoming packets.

Author:

Janos Ministry of Development

Cross Reference

Extended By:

ANEPDemultiplexKey, DemultiplexKeyTester.TestKey, SimpleDemultiplexKey

   private final int length

"length" of this filter for sorting the filters (longest first..)

Constructors

· DemultiplexKey

Summary  |  Top

   public DemultiplexKey(int length) 

   protected final int length() 

   protected static final int compareByte(byte[] packetBuf, 
                                          int packetOffset, 
                                          int packetLength, 
                                          int offset, 
                                          byte val) 

See if the offset'th byte of the packet is val. The packet is defined as the sub-array of packetBuf from packetOffset to packetOffset + packetLength.

Returns:

0 if it failed to match; offset+1 if it did match.

   protected static final int compareSlice(byte[] packetBuf, 
                                           int packetOffset, 
                                           int packetLength, 
                                           int offset, 
                                           byte[] slice) 

Comparse the slice of bytes at offset'th byte of the packet against the given slice. The packet is defined as the sub-array of packetBuf from packetOffset to packetOffset + packetLength.

Returns:

offset + slice.length if they match, otherwise returns zero.

   public abstract int matches(byte[] data, 
                               int packetOffset, 
                               int packetLength) 

XXX this is not supposed to be public. It is currently public so that it may be overridden to supply more interesting packet demultiplexing matchers (e.g., in ANTSR). Check if the given packet matches this filter. Return 0 if it does not, or a non-zero integer value to pass to the receive function.

   public String toString() 

Overrides:

toString in class Object

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