abstractdebuggercommand.java

Python Development Environment (Python IDE plugin for Eclipse). Features editor, code completion, re

/*
 * Author: atotic
 * Created on Mar 23, 2004
 * License: Common Public License v1.0
 */
package org.python.pydev.debug.model.remote;

import org.eclipse.core.runtime.IStatus;
import org.python.pydev.debug.core.PydevDebugPlugin;

/**
 * Superclass of all debugger commands.
 * 
 * Debugger commands know how to interact with pydevd.py.
 * See pydevd.py for protocol information.
 * 
 * Command lifecycle:
 *  cmd = new Command() // creation
 *  cmd.getSequence()	// get the sequence number of the command
 *  cmd.getOutgoing()	// asks command for outgoing message
 *  cmd.aboutToSend()	// called right before we go on wire
 * 						// by default, if command needs response
 * 						// it gets posted to in the response queue
 * 	if (cmd.needsResponse())
 * 		post the command to response queue, otherwise we are done
 *  when response arrives:
 *  if response is an error
 * 		cmd.processResponse()
 * 	else
 * 		cmd.processErrorResponse()
 * 
 */
public abstract class AbstractDebuggerCommand {
	
	static public final int CMD_RUN = 101;
	static public final int CMD_LIST_THREADS = 102;
	static public final int CMD_THREAD_CREATED = 103;
	static public final int CMD_THREAD_KILL = 104;
	static public final int CMD_THREAD_SUSPEND = 105;
	static public final int CMD_THREAD_RUN = 106;
	static public final int CMD_STEP_INTO = 107;
	static public final int CMD_STEP_OVER = 108;
	static public final int CMD_STEP_RETURN = 109;
	static public final int CMD_GET_VARIABLE = 110;
	static public final int CMD_SET_BREAK = 111;
	static public final int CMD_REMOVE_BREAK = 112;
	static public final int CMD_EVALUATE_EXPRESSION = 113;
	static public final int CMD_GET_FRAME = 114;
	static public final int CMD_EXEC_EXPRESSION = 115;
	static public final int CMD_WRITE_TO_CONSOLE = 116;
	static public final int CMD_CHANGE_VARIABLE = 117;
	static public final int CMD_ERROR = 901;
	static public final int CMD_VERSION = 501;
	static public final int CMD_RETURN = 502;
	
	protected AbstractRemoteDebugger debugger;
	protected ICommandResponseListener responseListener;
	int sequence;
	
	public AbstractDebuggerCommand(AbstractRemoteDebugger debugger) {
		this.debugger = debugger;
		this.responseListener = null;
		sequence = debugger.getNextSequence();
	}

	public void setCompletionListener(ICommandResponseListener listener) {
		this.responseListener = listener;
	}
	
	/**
	 * @return outgoing message
	 */
	public abstract String getOutgoing();
	
	/**
	 * Notification right before the command is sent.
	 * If subclassed, call super()
	 */
	public void aboutToSend() {
		// if we need a response, put me on the waiting queue
		if (needResponse()){
			debugger.addToResponseQueue(this);
        }
	}

	/**
	 * Does this command require a response?
     * 
     * This is meant to be overriden by subclasses if they need a response.
	 */
	public boolean needResponse() {
		return false;
	}
	
	/**
	 * returns Sequence # 
	 */
	public final int getSequence() {
		return sequence;
	}
	
	/**
	 * Called when command completes, if needResponse was true
	 */
	public final void processResponse(int cmdCode, String payload) {
		if (cmdCode / 100  == 9){
			processErrorResponse(cmdCode, payload);	
        }else{
			processOKResponse(cmdCode, payload);
        }
		
        if (responseListener != null){
			responseListener.commandComplete(this);
        }
	}
	
	/**
	 * notification of the response to the command.
	 * You'll get either processResponse or processErrorResponse
	 */
	public void processOKResponse(int cmdCode, String payload) {
		PydevDebugPlugin.log(IStatus.ERROR, "Debugger command ignored response " + getClass().toString() + payload, null);
	}
	
	/**
	 * notification of the response to the command.
	 * You'll get either processResponse or processErrorResponse
	 */
	public void processErrorResponse(int cmdCode, String payload) {
		PydevDebugPlugin.log(IStatus.ERROR, "Debugger command ignored error response " + getClass().toString() + payload, null);
	}
	
	public static String makeCommand(int code, int sequence, String payload) {
		StringBuffer s = new StringBuffer();
		s.append(code);
		s.append("\t");
		s.append(sequence);
		s.append("\t");
		s.append(payload);
		return s.toString();
	}
}