ajp13packet.java

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    }

    /** 
     * Copy a chunk of bytes into the packet, starting at the current
     * write position.  The chunk of bytes is encoded with the length
     * in two bytes first, then the data itself, and finally a
     * terminating \0 (which is <B>not</B> included in the encoded
     * length).
     *
     * @param b The array from which to copy bytes.
     * @param off The offset into the array at which to start copying
     * @param numBytes The number of bytes to copy.  
     */
    public void appendBytes( byte b[], int off, int numBytes ) {
        appendInt( numBytes );
        if( pos + numBytes >= buff.length ) {
            if (log.isDebugEnabled())
                log.debug("Buffer overflow " + buff.length + " " + pos + " " + numBytes );
        }
        System.arraycopy( b, off, buff, pos, numBytes);
        buff[pos + numBytes] = 0; // Terminating \0
        pos += numBytes + 1;
    }

        /**
     * Write a 32 bits integer at an arbitrary position in the packet, but don't
     * change the write position.
     *
     * @param bpos The 0-indexed position within the buffer at which to
     * write the integer (where 0 is the beginning of the header).
     * @param val The integer to write.
     */
    private void setLongInt( int bPos, int val ) {
        buff[bPos]   = (byte) ((val >>>  24) & 0xFF);
        buff[bPos+1] = (byte) ((val >>>  16) & 0xFF);
        buff[bPos+2] = (byte) ((val >>>   8) & 0xFF);
        buff[bPos+3] = (byte) (val & 0xFF);
    }

    public void appendLongInt( int val ) {
        setLongInt( pos, val );
        pos += 4;
    }

    /**
     * Copy a chunk of bytes into the packet, starting at the current
     * write position.  The chunk of bytes IS NOT ENCODED with ANY length
     * header.
     *
     * @param b The array from which to copy bytes.
     * @param off The offset into the array at which to start copying
     * @param numBytes The number of bytes to copy.
     */
    public void appendXBytes(byte[] b, int off, int numBytes) {
        if( pos + numBytes > buff.length ) {
            if (log.isDebugEnabled())
                log.debug("appendXBytes - Buffer overflow " + buff.length + " " + pos + " " + numBytes );
        }
        System.arraycopy( b, off, buff, pos, numBytes);
        pos += numBytes;
    }
	
    
    // ============ Data Reading Methods ===================

    /**
     * Read an integer from packet, and advance the read position past
     * it.  Integers are encoded as two unsigned bytes with the
     * high-order byte first, and, as far as I can tell, in
     * little-endian order within each byte.  
     */
    public int getInt() {
        int result = peekInt();
        pos += 2;
        return result;
    }

    /**
     * Read an integer from the packet, but don't advance the read
     * position past it.  
     */
    public int peekInt() {
        int b1 = buff[pos] & 0xFF;  // No swap, Java order
        int b2 = buff[pos + 1] & 0xFF;

        return  (b1<<8) + b2;
    }

    public byte getByte() {
        byte res = buff[pos];
        pos++;
        return res;
    }

    public byte peekByte() {
        return buff[pos];
    }

    public boolean getBool() {
        return (getByte() == (byte) 1);
    }

    public void getMessageBytes(MessageBytes mb) {
        int length = getInt();
        if( (length == 0xFFFF) || (length == -1) ) {
            mb.setString( null );
            return;
        }
        mb.setBytes( buff, pos, length );
        pos += length;
        pos++; // Skip the terminating \0
    }
    
    public MessageBytes addHeader(MimeHeaders headers) {
        int length = getInt();
        if( (length == 0xFFFF) || (length == -1) ) {
            return null;
        }
        MessageBytes vMB=headers.addValue( buff, pos, length );
        pos += length;
        pos++; // Skip the terminating \0
	    
        return vMB;
    }
	
    /**
     * Read a String from the packet, and advance the read position
     * past it.  See appendString for details on string encoding.
     **/
    public String getString() throws java.io.UnsupportedEncodingException {
        int length = getInt();
        if( (length == 0xFFFF) || (length == -1) ) {
            if (log.isDebugEnabled())
                log.debug("null string " + length);
            return null;
        }
        String s = new String(buff, pos, length, encoding);

        pos += length;
        pos++; // Skip the terminating \0
        return s;
    }

    /**
     * Copy a chunk of bytes from the packet into an array and advance
     * the read position past the chunk.  See appendBytes() for details
     * on the encoding.
     *
     * @return The number of bytes copied.
     */
    public int getBytes(byte dest[]) {
        int length = getInt();
        if( length > buff.length ) {
            // XXX Should be if(pos + length > buff.legth)?
            if (log.isDebugEnabled())
                log.debug("XXX Assert failed, buff too small ");
        }
	
        if( (length == 0xFFFF) || (length == -1) ) {
            if (log.isDebugEnabled())
                log.debug("null string " + length);
            return 0;
        }

        System.arraycopy( buff, pos,  dest, 0, length );
        pos += length;
        pos++; // Skip terminating \0  XXX I believe this is wrong but harmless
        return length;
    }

        /**
     * Read a 32 bits integer from packet, and advance the read position past
     * it.  Integers are encoded as four unsigned bytes with the
     * high-order byte first, and, as far as I can tell, in
     * little-endian order within each byte.
     */
    public int getLongInt() {
        int result = peekLongInt();
        pos += 4;
        return result;
    }

    /**
     * Copy a chunk of bytes from the packet into an array and advance
     * the read position past the chunk.  See appendXBytes() for details
     * on the encoding.
     *
     * @return The number of bytes copied.
     */
    public int getXBytes(byte[] dest, int length) {
        if( length > buff.length ) {
        // XXX Should be if(pos + length > buff.legth)?
            if (log.isDebugEnabled())
                log.debug("XXX Assert failed, buff too small ");
        }

        System.arraycopy( buff, pos,  dest, 0, length );
        pos += length;
        return length;
    }

    /**
     * Read a 32 bits integer from the packet, but don't advance the read
     * position past it.
     */
    public int peekLongInt() {
        int b1 = buff[pos] & 0xFF;  // No swap, Java order
        b1 <<= 8;
        b1 |= (buff[pos + 1] & 0xFF);
        b1 <<= 8;
        b1 |= (buff[pos + 2] & 0xFF);
        b1 <<=8;
        b1 |= (buff[pos + 3] & 0xFF);
        return  b1;
    }

    // ============== Debugging code =========================
    private String hex( int x ) {
        //	    if( x < 0) x=256 + x;
        String h=Integer.toHexString( x );
        if( h.length() == 1 ) h = "0" + h;
        return h.substring( h.length() - 2 );
    }

    private void hexLine( int start ) {
	int pkgEnd = len + 4;
	if( pkgEnd > buff.length )
	    pkgEnd = buff.length;
        for( int i=start; i< start+16 ; i++ ) {
            if( i < pkgEnd) {
                if (log.isDebugEnabled())
                    log.debug( hex( buff[i] ) + " ");
            } else {
                if (log.isDebugEnabled()) 
                    log.debug( "   " );
            }
        }
        if (log.isDebugEnabled()) 
            log.debug(" | ");
        for( int i=start; i < start+16 && i < pkgEnd; i++ ) {
            if( Character.isLetterOrDigit( (char)buff[i] )) {
                if (log.isDebugEnabled()) 
                    log.debug( new Character((char)buff[i]) );
            } else {
                if (log.isDebugEnabled()) 
                    log.debug( "." );
            }
        }
    }
    
    public void dump(String msg) {
        if (log.isDebugEnabled())
            log.debug( msg + ": " + buff + " " + pos +"/" + (len + 4));

        for( int j=0; j < len + 4; j+=16 )
            hexLine( j );

    }
}