/*
* (non-Javadoc)
*
* @see ch.elexis.data.cache.IPersistentObjectCache#stat()
*/
public void stat() {
long total = hits + misses + removed + expired;
if (total != 0) {
StringBuilder sb = new StringBuilder();
sb.append("--------- cache statistics ------\n")
.append("Total read:\t")
.append(total)
.append("\n")
.append("cache hits:\t")
.append(hits)
.append(" (")
.append(hits * 100 / total)
.append("%)\n")
.append("object expired:\t")
.append(expired)
.append(" (")
.append(expired * 100 / total)
.append("%)\n")
.append("cache missed:\t")
.append(misses)
.append(" (")
.append(misses * 100 / total)
.append("%)\n")
.append("object removed:\t")
.append(removed)
.append(" (")
.append(removed * 100 / total)
.append("%)\n")
.append("Object inserts:\t")
.append(inserts)
.append("\n");
log.log(sb.toString(), Log.INFOS);
}
}
/**
* Heartbeat (wieder) laufen lassen.
*
* @param immediately true: Sofort einen ersten beat losschicken, false: im normalen Rhythmus
* bleiben.
*/
public void resume(boolean immediately) {
isSuspended = false;
log.log("resume", Log.DEBUGMSG); // $NON-NLS-1$
if (immediately) {
theBeat.run();
}
}
/**
* A Cache with soft references and optional expiring items The cache keeps count on numbes of items
* that are added, removed or expired and can display its statistic
*
* @author Gerry
*/
@SuppressWarnings("unchecked")
public class SoftCache<K> implements IPersistentObjectCache<K> {
private static boolean enabled = true;
protected Map<K, CacheEntry> cache;
protected long hits, misses, removed, inserts, expired;
protected Log log = Log.get("SoftCache");
public SoftCache() {
// must be thread-safe
cache = Collections.synchronizedMap(new HashMap<K, CacheEntry>());
}
public SoftCache(final int num, final float load) {
cache = Collections.synchronizedMap(new HashMap<K, CacheEntry>(num, load));
}
public SoftCache(final int num) {
cache = Collections.synchronizedMap(new HashMap<K, CacheEntry>(num));
}
/*
* (non-Javadoc)
*
* @see ch.elexis.data.cache.IPersistentObjectCache#put(K, java.lang.Object, int)
*/
public void put(final K key, final Object object, final int timeToCacheInSeconds) {
if (enabled) {
cache.put(key, new CacheEntry(object, timeToCacheInSeconds));
inserts++;
}
}
/*
* (non-Javadoc)
*
* @see ch.elexis.data.cache.IPersistentObjectCache#get(K)
*/
public Object get(final K key) {
if (!enabled) {
return null;
}
synchronized (cache) {
CacheEntry ref = cache.get(key);
if (ref == null) {
misses++;
return null;
}
Object ret = ref.get();
if (ret == null) {
remove(key);
return null;
} else {
hits++;
return ret;
}
}
}
/*
* (non-Javadoc)
*
* @see ch.elexis.data.cache.IPersistentObjectCache#remove(K)
*/
public void remove(final K key) {
synchronized (cache) {
cache.remove(key);
removed++;
}
}
/*
* (non-Javadoc)
*
* @see ch.elexis.data.cache.IPersistentObjectCache#clear()
*/
public void clear() {
synchronized (cache) {
purge();
cache.clear();
}
}
/*
* (non-Javadoc)
*
* @see ch.elexis.data.cache.IPersistentObjectCache#stat()
*/
public void stat() {
long total = hits + misses + removed + expired;
if (total != 0) {
StringBuilder sb = new StringBuilder();
sb.append("--------- cache statistics ------\n")
.append("Total read:\t")
.append(total)
.append("\n")
.append("cache hits:\t")
.append(hits)
.append(" (")
.append(hits * 100 / total)
.append("%)\n")
.append("object expired:\t")
.append(expired)
.append(" (")
.append(expired * 100 / total)
.append("%)\n")
.append("cache missed:\t")
.append(misses)
.append(" (")
.append(misses * 100 / total)
.append("%)\n")
.append("object removed:\t")
.append(removed)
.append(" (")
.append(removed * 100 / total)
.append("%)\n")
.append("Object inserts:\t")
.append(inserts)
.append("\n");
log.log(sb.toString(), Log.INFOS);
}
}
/*
* (non-Javadoc)
*
* @see ch.elexis.data.cache.IPersistentObjectCache#purge()
*/
public void purge() {
synchronized (cache) {
Iterator<Entry<K, CacheEntry>> it = cache.entrySet().iterator();
long freeBefore = Runtime.getRuntime().freeMemory();
while (it.hasNext()) {
Entry<K, CacheEntry> e = it.next();
CacheEntry ce = e.getValue();
ce.expires = 0;
ce.get();
it.remove();
}
if (Hub.plugin.DEBUGMODE) {
long freeAfter = Runtime.getRuntime().freeMemory();
StringBuilder sb = new StringBuilder();
sb.append("Cache purge: Free memore before: ")
.append(freeBefore)
.append(", free memory after: ")
.append(freeAfter)
.append("\n");
Hub.log.log(sb.toString(), Log.INFOS);
}
}
}
/*
* (non-Javadoc)
*
* @see ch.elexis.data.cache.IPersistentObjectCache#reset()
*/
public synchronized void reset() {
purge();
cache.clear();
}
public class CacheEntry extends SoftReference {
long expires;
public CacheEntry(final Object obj, final int timeInSeconds) {
super(obj);
expires = System.currentTimeMillis() + timeInSeconds * 1000;
}
@Override
public synchronized Object get() {
Object ret = super.get();
if (System.currentTimeMillis() > expires) {
expired++;
super.clear();
ret = null;
}
return ret;
}
}
}
/** Heartbeat aussetzen (geht im Hintergrund weiter, wird aber nicht mehr weitergeleitet) */
public void suspend() {
log.log("suspending", Log.DEBUGMSG); // $NON-NLS-1$
isSuspended = true;
}
/**
* Heartbeat is an event source, that fires events at user-definable intervals to all
* HeartListeners. All actions that must be repeated regularly should be registered as
* HeartListener. They will all be called at about the specified rate, but not in a guaranteed
* particular order and not necessarily at exactly identical intervals.
*
* <p>Heartbeat löst das Pinger-Konzept ab. Der Heartbeat ist ein Singleton, das alle
* Hub.localCfg.get(heartbeatrate,30) Sekunden einen Event feuert. Wer reglmässige Aktionen
* durchführen will, kann sich als HeartbeatListener registrieren. Dieses Konzept hat gegenüber
* individuellen update-Threads den Vorteil, dass die Netzwerk- und Datenbankbelastung, sowie die
* Zahl der gleichzeitig laufenden Threads limitiert wird. Der Heartbeat sorgt dafür, dass die
* listener der Reihe nach (aber ncht in einer definierten Reihenfolge) aufgerufen werden.
*
* <p>The client registering a listener can define the frequency, whether the listener should be
* called at every single heart beat or at a lower frequency.
*
* @author gerry
*/
public class Heartbeat {
/** Registering a listener using FREQUENCY_HIGH, it is called at every single heartbeat. */
public static final int FREQUENCY_HIGH = 1;
/** Registering a listener using FREQUENCY_MEDIUM, it is called at every 4th heartbeat. */
public static final int FREQUENCY_MEDIUM = 2;
/** Registering a listener using FREQUENCY_LOW, it is called at every 16th heartbeat. */
public static final int FREQUENCY_LOW = 3;
private beat theBeat;
private Timer pacer;
private boolean isSuspended;
private static Heartbeat theHeartbeat;
private CopyOnWriteArrayList<HeartListener> highFrequencyListeners;
private CopyOnWriteArrayList<HeartListener> mediumFrequencyListeners;
private CopyOnWriteArrayList<HeartListener> lowFrequencyListeners;
private static Log log = Log.get("Heartbeat"); // $NON-NLS-1$
private Heartbeat() {
theBeat = new beat();
highFrequencyListeners = new CopyOnWriteArrayList<HeartListener>();
mediumFrequencyListeners = new CopyOnWriteArrayList<HeartListener>();
lowFrequencyListeners = new CopyOnWriteArrayList<HeartListener>();
pacer = new Timer(true);
int interval = Hub.localCfg.get(PreferenceConstants.ABL_HEARTRATE, 30); // $NON-NLS-1$
isSuspended = true;
pacer.schedule(theBeat, 0, interval * 1000L);
}
/**
* Das Singleton holen
*
* @return den Heartbeat der Anwendung
*/
public static Heartbeat getInstance() {
if (theHeartbeat == null) {
theHeartbeat = new Heartbeat();
}
return theHeartbeat;
}
/**
* Heartbeat (wieder) laufen lassen.
*
* @param immediately true: Sofort einen ersten beat losschicken, false: im normalen Rhythmus
* bleiben.
*/
public void resume(boolean immediately) {
isSuspended = false;
log.log("resume", Log.DEBUGMSG); // $NON-NLS-1$
if (immediately) {
theBeat.run();
}
}
/** Heartbeat aussetzen (geht im Hintergrund weiter, wird aber nicht mehr weitergeleitet) */
public void suspend() {
log.log("suspending", Log.DEBUGMSG); // $NON-NLS-1$
isSuspended = true;
}
/** Heartbeat stoppen (kann dann nicht mehr gestartet werden) */
public void stop() {
log.log("stopping", Log.DEBUGMSG); // $NON-NLS-1$
pacer.cancel();
}
/**
* Einen Listener registrieren. Achtung: Muss unbedingt mit removeListener deregistriert werden
* Calls addListener(listen, FREQUENCY_HIGH)
*
* @param listen der Listener
*/
public void addListener(HeartListener listen) {
addListener(listen, FREQUENCY_HIGH);
}
/**
* Add listener using the specified frequency. Must be de-regsitered again using removeListener
*
* @param listener
* @param frequency the frequency to call this listener. One of FREQUENCY_HIGH, FREQUENCY_MEDIUM,
* FREQUENCY_LOW
*/
public void addListener(HeartListener listen, int frequency) {
if (!highFrequencyListeners.contains(listen)
&& !mediumFrequencyListeners.contains(listen)
&& !lowFrequencyListeners.contains(listen)) {
switch (frequency) {
case FREQUENCY_HIGH:
highFrequencyListeners.add(listen);
break;
case FREQUENCY_MEDIUM:
mediumFrequencyListeners.add(listen);
break;
case FREQUENCY_LOW:
lowFrequencyListeners.add(listen);
break;
}
}
}
/**
* Einen Listener wieder austragen
*
* @param listen
*/
public void removeListener(HeartListener listen) {
// remove the listener from the three lists
// actually, it's contained in only one of them, but we don't know which one
highFrequencyListeners.remove(listen);
mediumFrequencyListeners.remove(listen);
lowFrequencyListeners.remove(listen);
}
/**
* we beat asynchronously, because most listeners will update their views
*
* @author Gerry
*/
private class beat extends TimerTask {
private static final int FREQUENCY_HIGH_MULTIPLIER = 1;
private static final int FREQUENCY_MEDIUM_MULTIPLIER = 4;
private static final int FREQUENCY_LOW_MULTIPLIER = 16;
// multiplier for resetting counter after each round
private static final int RESET_MULTIPLIER = FREQUENCY_LOW_MULTIPLIER;
private int counter = 0;
@Override
public void run() {
if (!isSuspended) {
Desk.getDisplay()
.asyncExec(
new Runnable() {
public void run() {
// low frequency
if (counter % FREQUENCY_LOW_MULTIPLIER == 0) {
log.log("Heartbeat low", Log.DEBUGMSG); // $NON-NLS-1$
for (HeartListener l : lowFrequencyListeners) {
l.heartbeat();
}
}
// medium frequency
if (counter % FREQUENCY_MEDIUM_MULTIPLIER == 0) {
log.log("Heartbeat medium", Log.DEBUGMSG); // $NON-NLS-1$
for (HeartListener l : mediumFrequencyListeners) {
l.heartbeat();
}
}
// high frequency
if (counter % FREQUENCY_HIGH_MULTIPLIER == 0) {
log.log("Heartbeat high", Log.DEBUGMSG); // $NON-NLS-1$
for (HeartListener l : highFrequencyListeners) {
l.heartbeat();
}
}
}
});
}
counter++;
counter %= RESET_MULTIPLIER;
}
}
public interface HeartListener {
/**
* Die Methode heartbeat wird in "einigermassen" regelmässigen (aber nicht garantiert immer
* genau identischen) Abständen aufgerufen
*/
public void heartbeat();
}
}
/** Heartbeat stoppen (kann dann nicht mehr gestartet werden) */
public void stop() {
log.log("stopping", Log.DEBUGMSG); // $NON-NLS-1$
pacer.cancel();
}
