/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.jk.core;
import java.io.IOException;
import org.apache.tomcat.util.buf.ByteChunk;
import org.apache.tomcat.util.buf.MessageBytes;
/**
* A single packet for communication between the web server and the
* container.
*
* In a more generic sense, it's the event that drives the processing chain.
* XXX Use Event, make Msg a particular case.
*
* @author Henri Gomez [hgomez@apache.org]
* @author Dan Milstein [danmil@shore.net]
* @author Keith Wannamaker [Keith@Wannamaker.org]
* @author Kevin Seguin
* @author Costin Manolache
*/
public abstract class Msg {
/**
* Prepare this packet for accumulating a message from the container to
* the web server. Set the write position to just after the header
* (but leave the length unwritten, because it is as yet unknown).
*/
public abstract void reset();
/**
* For a packet to be sent to the web server, finish the process of
* accumulating data and write the length of the data payload into
* the header.
*/
public abstract void end();
public abstract void appendInt( int val );
public abstract void appendByte( int val );
public abstract void appendLongInt( int val );
/**
*/
public abstract void appendBytes(MessageBytes mb) throws IOException;
public abstract void appendByteChunk(ByteChunk bc) throws IOException;
/**
* 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 abstract void appendBytes( byte b[], int off, int numBytes );
/**
* 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 abstract int getInt();
public abstract int peekInt();
public abstract byte getByte();
public abstract byte peekByte();
public abstract void getBytes(MessageBytes mb);
/**
* 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 abstract int getBytes(byte dest[]);
/**
* 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 abstract int getLongInt();
public abstract int getHeaderLength();
public abstract int processHeader();
public abstract byte[] getBuffer();
public abstract int getLen();
public abstract void dump(String msg);
/* -------------------- Utilities -------------------- */
// XXX Move to util package
public static String hexLine( byte buf[], int start, int len ) {
StringBuffer sb=new StringBuffer();
for( int i=start; i< start+16 ; i++ ) {
if( i < len + 4)
sb.append( hex( buf[i] ) + " ");
else
sb.append( " " );
}
sb.append(" | ");
for( int i=start; i < start+16 && i < len + 4; i++ ) {
if( ! Character.isISOControl( (char)buf[i] ))
sb.append( new Character((char)buf[i]) );
else
sb.append( "." );
}
return sb.toString();
}
private static 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 );
}
}