yacy_search_server/source/de/anomic/server/serverProfiling.java

// serverProfiling.java
// (C) 2007 by Michael Peter Christen; mc@yacy.net, Frankfurt a. M., Germany
// first published 17.11.2007 on http://yacy.net
//
// This is a part of YaCy, a peer-to-peer based web search engine
//
// $LastChangedDate: 2006-04-02 22:40:07 +0200 (So, 02 Apr 2006) $
// $LastChangedRevision: 1986 $
// $LastChangedBy: orbiter $
//
// LICENSE
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

package de.anomic.server;

import java.util.Iterator;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentLinkedQueue;

import de.anomic.kelondro.util.MemoryControl;

public class serverProfiling extends Thread {
    
    private static final Map<String, ConcurrentLinkedQueue<Event>> historyMaps = new ConcurrentHashMap<String, ConcurrentLinkedQueue<Event>>();
    private static final Map<String, Long> eventAccess = new ConcurrentHashMap<String, Long>(); // value: last time when this was accessed
    private static serverProfiling systemProfiler = null;
    
    public static void startSystemProfiling() {
    	systemProfiler = new serverProfiling(1500);
    	systemProfiler.start();
    }
    
    public static void stopSystemProfiling() {
    	systemProfiler.running = false;
    }

    private final long delaytime;
    private boolean running;
    
    public serverProfiling(final long time) {
    	this.delaytime = time;
    	running = true;
    }
    
    public void run() {
    	while (running) {
    		update("memory", Long.valueOf(MemoryControl.used()), true);
    		try {
				Thread.sleep(this.delaytime);
			} catch (final InterruptedException e) {
				this.running = false;
			}
    	}
    }
    
    public static void update(final String eventName, final Object eventPayload, boolean useProtection) {
    	// get event history container
        Long lastAcc = eventAccess.get(eventName);
        if (lastAcc == null) {
            eventAccess.put(eventName, Long.valueOf(System.currentTimeMillis()));
        } else {
            long time = System.currentTimeMillis();
            if (!useProtection || time - lastAcc.longValue() > 1000) {
                eventAccess.put(eventName, Long.valueOf(time));
            } else {
                return; // protect against too heavy load
            }
        }
    	ConcurrentLinkedQueue<Event> history = historyMaps.get(eventName);
    	if (history != null) {

            // update entry
            history.add(new Event(eventPayload));
            
            // clean up too old entries
            int tp = history.size() - 30000;
            while (tp-- > 0) history.poll();
            if (history.size() % 10 == 0) { // reduce number of System.currentTimeMillis() calls
                Event e;
                final long now = System.currentTimeMillis();
                while (history.size() > 0) {
                    e = history.peek();
                    if (now - e.time < 600000) break;
                    history.poll();
                }
            }
    	} else {
    	    history = new ConcurrentLinkedQueue<Event>();

            // update entry
            history.add(new Event(eventPayload));
            
            // store map
            historyMaps.put(eventName, history);
    	}
    }
    
    public static Iterator<Event> history(final String eventName) {
    	return (historyMaps.containsKey(eventName) ? (historyMaps.get(eventName)) : new ConcurrentLinkedQueue<Event>()).iterator();
    }

    public static int countEvents(final String eventName, long time) {
        Iterator<Event> i = history(eventName);
        long now = System.currentTimeMillis();
        int count = 0;
        while (i.hasNext()) {
            if (now - i.next().time < time) count++;
        }
        return count;
    }
    
    public static class Event {
        public Object payload;
        public long time;

        public Event(final Object payload) {
            this.payload = payload;
            this.time = System.currentTimeMillis();
        }
    }

}