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java.lang.Object
   |
   +----edu.utah.janos.antsr.core.Xdr

Summary

public final class  Xdr
     extends java.lang.Object
{
          // Fields 11
     public static final int BOOLEAN;
     public static final int BYTE;
     public static final int INT;
     public static final int LONG;
     public static final int SHORT;
     public static final int TYPEID;
     private byte[] buf;
     private int index;
     private int len;
     private int offset;
     private Xdr parent;

          // Constructors 8
     public Xdr(byte[]);
     public Xdr(byte[], int);
     public Xdr(byte[], int, int) throws IndexOutOfBoundsException;
     public Xdr(ByteArray, int);
     public Xdr(ByteArray, int, int) throws IndexOutOfBoundsException;
     Xdr(Xdr, int);
     Xdr(Xdr, int, int) throws IndexOutOfBoundsException;
     public Xdr(int);

          // Methods 25
     public static final int BYTEARRAY(ByteArray);
     public static final int STRING(String);

     public final boolean BOOLEAN();
     public final byte BYTE();
     public final ByteArray BYTEARRAY();
     public final void BYTES(byte[], int, int);
     public final int INT();
     public final long LONG();
     public final void PUT(boolean);
     public final void PUT(byte);
     public final void PUT(byte[], int, int);
     public final void PUT(ByteArray);
     public final void PUT(TypeID);
     public final void PUT(int);
     public final void PUT(String);
     public final void PUT(long);
     public final void PUT(short);
     public final short SHORT();
     public final String STRING();
     public final TypeID TYPEID();
     byte[] getBytes();
     int index();
     public final int length();
     Xdr reset();
     public final void skip(int);
}

An Xdr instance encapsulates an external, byte-oriented data structure (an "External Data Representation".) Xdr's can include Strings, byte arrays, booleans, bytes, shorts, ints, longs, TypeIDs. Elements must encoded/decoded serially to/from the Xdr.

Xdr's may be hierarchical. That is an xdr may subdivide its buffer space into child buffers.

Xdr's will allocate a byte[] when constructed, or alternatively they can use a given byte[], a ByteArray, another Xdr (parenting), or a Core Buffer.

These methods are declared final so that they can be inlined with optimization.

Author:

David Wetherall

Cross Reference

Returned By:

Many

   public static final int BOOLEAN

The length of a boolean in an xdr.

   public static final int BYTE

The length of a byte in an xdr.

   public static final int SHORT

The length of a short in an xdr.

   public static final int INT

The length of a int in an xdr.

   public static final int LONG

The length of a long in an xdr.

   public static final int TYPEID

The length of a typeid in an xdr.

   private byte[] buf

The byte array encoding. XXX final?

   private int offset

Base offset in the buf. The "start" of the xdr encoding. XXX final?

   private int len

Internal buffer length. XXX final?

   private int index

Current index in the encoding. Serializing and deserialzing automatically increment this offset.

   private Xdr parent

A parent xdr. A parent can subdivide is xdr buffer among child Xdrs. XXX final?

Constructors

· Xdr

Summary  |  Top

   public Xdr(int len) 

Create a new xdr with a buffer of len bytes for encoding.

Parameter	Description
len	the size of the buffer to create.

   public Xdr(byte[] buf) 

Create a new xdr using the given buffer. Does NOT copy the given buf.

XXX probably shouldn't be public.

Parameter	Description
buf	the buffer to use.

   public Xdr(ByteArray buf, 
              int offset) 

Create a new xdr using the buffer in the given ByteArray.

Parameter	Description
buf	the ByteArray to steal the byte[] from
offset	offset to start at in the ByteArray

   public Xdr(ByteArray buf, 
              int offset, 
              int len)  throws IndexOutOfBoundsException

Create a new xdr using the buffer in the given ByteArray.

Parameter	Description
buf	the ByteArray to steal the byte[] from
offset	offset to start at in the ByteArray
len	length of ByteArray to use

   public Xdr(byte[] buf, 
              int offset) 

Create a new xdr using the given portion of the given buffer.

Parameter	Description
buf	the buffer to use.
offset	only encode in the portion of the buffer starting at offset.

   public Xdr(byte[] buf, 
              int offset, 
              int len)  throws IndexOutOfBoundsException

Create a new xdr using the given portion of the given buffer.

Parameter	Description
buf	the buffer to use.
offset	only encode in the portion of the buffer starting at offset.
len	only encode using len bytes of the buffer.

   Xdr(Xdr parent, 
       int offset) 

Package-only constructor for creating an xdr as a subsequence of a parent xdr. New xdr will manage remainder of parent xdr's buffer.

Parameter	Description
parent	Xdr to steal buffer space from.
offset	Offset in parent buffer to start.

   Xdr(Xdr parent, 
       int offset, 
       int len)  throws IndexOutOfBoundsException

Package-only constructor for creating an xdr as a subsequence of a parent xdr. New xdr will manage only the given portion of parent's buffer.

Parameter	Description
parent	Xdr to steal buffer space from.
offset	Offset in parent buffer to start.
len	Length of the buffer to manage.

   Xdr reset() 

Reset an xdr stream.

Package-access only.

Returns:

For convenience, return Xdr stream that was reset.

   int index() 

Return the current index in the xdr.

   public static final int STRING(String x) 

Return the number of bytes required t encode x in the xdr. Does not actually encode the string. Handles null strings just fine.

The string had best be less than 256 characters long.

The string had best be in ASCII. (Or some other one-to-one encoding of characters into bytes.)

Parameter	Description
x	the string to check

Returns:

the number of bytes required in the xdr

   public static final int BYTEARRAY(ByteArray x) 

Return the number of bytes required to encode a ByteArray in the xdr. Does not actually encode the ByteArray. Handles null just fine.

The ByteArray must be less than 65,535 bytes.

Parameter	Description
x	the ByteArray to check

Returns:

the number of bytes required in the xdr.

   public final int length() 

Return the size of the buffer used by this xdr.

Returns:

the size of the buffer used by this xdr.

   public final void PUT(boolean x) 

Encode the given boolean into this xdr. There must be sufficient space in this xdr preallocated.

   public final void PUT(byte x) 

   public final void PUT(short x) 

   public final void PUT(int x) 

   public final void PUT(long x) 

   public final void PUT(TypeID t) 

   public final void PUT(String x) 

   public final void PUT(ByteArray x) 

   public final void PUT(byte[] x, 
                         int start, 
                         int length) 

   public final boolean BOOLEAN() 

   public final byte BYTE() 

   public final short SHORT() 

   public final int INT() 

   public final long LONG() 

   public final TypeID TYPEID() 

   public final String STRING() 

   public final ByteArray BYTEARRAY() 

   public final void BYTES(byte[] x, 
                           int start, 
                           int length) 

   public final void skip(int count) 

   byte[] getBytes() 

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