configentry.java

與 unix 上相似的syslog daemon, 沒有 log4j 複雜

package com.ice.syslogd;

import java.util.*;

import com.ice.syslog.SyslogDefs;


public class
ConfigEntry
	{
	public static final String		RCS_ID = "$Id: ConfigEntry.java,v 1.2 1998/07/29 02:15:09 time Exp $";
	public static final String		RCS_REV = "$Revision: 1.2 $";
	public static final String		RCS_NAME = "$Name:  $";

	private static final int[] repeatBackoff =
		{ 15, 30, 60, 180, 600, 3600 };

	private boolean			hasMatch;
	private boolean			notMatch;
	private SyslogMatch		matcher;
	private SyslogAction	action;

	private int[]			facilities;

	private String[]		parameters;

	private int				backOffIdx;
	private int				repeatCount;
	private Date			repeatTimeout;

	private Date			prevTime;
	private SyslogMessage	prevMsg;


	public
	ConfigEntry()
		{
		this.matcher = null;
		this.hasMatch = false;
		this.notMatch = false;
		
		this.facilities =
			new int[ SyslogDefs.LOG_NFACILITIES ];

		this.action = null;
		this.parameters = null;

		this.backOffIdx = 0;
		this.repeatCount = 0;
		this.prevTime = null;
		this.prevMsg = null;
		}

	public void
	setAction( SyslogAction action )
		{
		this.action = action;
		}

	public boolean
	afterRepeatTimeout( Date now )
		{
		return now.after( this.repeatTimeout );
		}

	public Date
	getRepeatTimeout( Date now )
		{
		return this.repeatTimeout;
		}

	public void
	setFacilityLevel( int facility, int level )
		{
		this.facilities[ facility ] = level;
		}

	public void
	setMatchExpr( String expr )
		{
		this.hasMatch = true;
		this.notMatch = false;
		if ( expr.startsWith( "!" ) )
			{
			this.notMatch = true;
			expr = expr.substring(1);
			}

		this.matcher = new SyslogMatch();

		try { this.matcher.compile( expr ); }
		catch ( MatchCompileException ex )
			{
			this.matcher = null;
			this.hasMatch = false;
			this.notMatch = false;
			}
		}

	private boolean
	matchMessage( String message )
		{
		boolean result = false;

		if ( this.hasMatch && this.matcher != null )
			{
			result = this.matcher.matchMessage( message );
			if ( this.notMatch )
				{
				result = ! result;
				}
			}

		return result;
		}

	public void
	openAction()
		{
		if ( this.action != null )
			{
			this.action.openAction();
			}
		}

	public void
	closeAction()
		{
		if ( this.action != null )
			{
			this.action.closeAction();
			}
		}

	public void
	registerActionDisplay( String name, SyslogDisplayInterface display )
		{
		if ( this.action != null )
			{
			this.action.registerActionDisplay( name, display );
			}
		}

	private SyslogMessage
	createRepeatMsg( SyslogMessage logMsg, Date now )
		{
		SyslogMessage repeatMsg =
			(SyslogMessage)logMsg.clone();

		long repSecs =
			( now.getTime()
				- this.prevTime.getTime() )
					/ 1000;

		repeatMsg.isRepeat = true;
		repeatMsg.matchVars = null;
		repeatMsg.message =
			"msg repeated " + this.repeatCount
			+ " times in " + repSecs + " seconds.";

		return repeatMsg;
		}
	
	public void
	incrementBackOff()
		{
		if ( ConfigEntry.repeatBackoff.length
				> ( this.backOffIdx + 1 ) )
			{
			this.backOffIdx++;
			}
		}

	public void
	computeRepeatTimer( Date now )
		{
		Calendar cal = Calendar.getInstance();

		cal.setTime( now );
		cal.add
			( Calendar.SECOND,
				this.repeatBackoff[ this.backOffIdx ] );
		
		this.repeatTimeout = cal.getTime();
		}
 
	public synchronized void
	checkRepeatTimeout( Date now )
		{
		if ( this.prevMsg != null
				&& this.repeatCount > 0 )
			{
			if ( now.after( this.repeatTimeout ) )
				{
				SyslogMessage repeatMsg;

				if ( this.repeatCount == 1 )
					repeatMsg = this.prevMsg;
				else
					repeatMsg =
						this.createRepeatMsg( this.prevMsg, now );

				this.invokeMessageAction( repeatMsg );

				this.prevMsg = null;
				this.repeatCount = 0;
				this.backOffIdx = 0;
				}
			}
		}

	/*
	 *
	 * @return True, if the message should be processed.
	 *         otherwise, False, indicating a repeat.
	 */

	public synchronized boolean
	checkForRepeats( SyslogMessage logMsg )
		{
		boolean result = true;
		boolean newMsg = true;
		Date	now = new Date();
		SyslogMessage repeatMsg = null;

		if ( this.prevMsg != null
				&& this.prevMsg.message.length()
					== logMsg.message.length()
				&& this.prevMsg.hostName.equals( logMsg.hostName )
				&& this.prevMsg.message.equals( logMsg.message ) )
			{
			result = false;
			newMsg = false;

			if ( this.repeatCount > 0 )
				{
				this.repeatCount++;
				if ( now.after( this.repeatTimeout ) )
					{
					result = true;
					
					repeatMsg = this.createRepeatMsg( logMsg, now );

					this.invokeMessageAction( repeatMsg );

					this.computeRepeatTimer( now );

					this.incrementBackOff();
					
					this.prevTime = now;
					this.repeatCount = 0;
					}
				}
			else
				{
				this.repeatCount++;
				this.computeRepeatTimer( now );
				}
			}

		if ( newMsg )
			{
			if ( this.repeatCount > 0 )
				{
				repeatMsg = this.createRepeatMsg( logMsg, now );
				this.invokeMessageAction( repeatMsg );
				}

			this.backOffIdx = 0;
			this.prevTime = now;
			this.repeatCount = 0;
			}

		this.prevMsg = logMsg;

		return result;
		}

	public void
	invokeMessageAction( SyslogMessage logMsg )
		{
		if ( this.action.isThreaded() )
			{
			ActionThread thread =
				new ActionThread( this.action, logMsg );

			thread.start();
			}
		else
			{
			this.action.processMessage( logMsg );
			}
		}

	public void
	processMessage( SyslogMessage logMsg )
		{
		boolean		processIt = true;

		if ( facilities[ logMsg.facility ] >= logMsg.priority
				&& this.action != null && this.action.isOpen() )
			{
			if ( this.hasMatch )
				{
				processIt = this.matchMessage( logMsg.message );
				}

			if ( processIt )
				{
				if ( this.checkForRepeats( logMsg ) )
					{
					logMsg.matchVars = null;
					if ( this.hasMatch && ! this.notMatch )
						{
						logMsg.matchVars =
							this.matcher.getMatchVariables();
						}

					this.invokeMessageAction( logMsg );
					}
				}
			}
		}

	}