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package com.sun.grizzly.connectioncache.impl.transport;
import com.sun.grizzly.connectioncache.spi.concurrent.ConcurrentQueue;
import com.sun.grizzly.connectioncache.spi.transport.ConnectionCache;
import java.io.Closeable;
import java.util.logging.Logger ;
import java.util.logging.Level ;
public abstract class ConnectionCacheBase
implements ConnectionCache {
// A name for this instance, provided for convenience.
private final String cacheType ;
// Log to this logger if FINER is enabled.
protected final Logger logger ;
// Configuration data
// XXX we may want this data to be dynamically re-configurable
private final int highWaterMark ; // Maximum number of
// connections before we start
// closing idle connections
private final int numberToReclaim ; // How many connections to
// reclaim at once
// MUST be initialized in a subclass
protected ConcurrentQueue reclaimableConnections = null ;
protected boolean debug() {
return logger.isLoggable( Level.FINER ) ;
}
public final String getCacheType() {
return cacheType ;
}
public final int numberToReclaim() {
return numberToReclaim ;
}
public final int highWaterMark() {
return highWaterMark ;
}
// The name of this class, which is implemented in the subclass.
// I could derive this from this.getClass().getClassName(), but
// this is easier.
protected abstract String thisClassName() ;
ConnectionCacheBase( final String cacheType,
final int highWaterMark, final int numberToReclaim,
final Logger logger ) {
if (cacheType == null)
throw new IllegalArgumentException( "cacheType must not be null" ) ;
if (highWaterMark < 0)
throw new IllegalArgumentException( "highWaterMark must be non-negative" ) ;
if (numberToReclaim < 1)
throw new IllegalArgumentException( "numberToReclaim must be at least 1" ) ;
if (logger == null)
throw new IllegalArgumentException( "logger must not be null" ) ;
this.cacheType = cacheType ;
this.logger = logger ;
this.highWaterMark = highWaterMark ;
this.numberToReclaim = numberToReclaim ;
}
protected final void dprint(final String msg) {
logger.finer(thisClassName() + msg);
}
public String toString() {
return thisClassName() + "["
+ getCacheType() + "]";
}
public void dprintStatistics() {
dprint( ".stats:"
+ " idle=" + numberOfIdleConnections()
+ " reclaimable=" + numberOfReclaimableConnections()
+ " busy=" + numberOfBusyConnections()
+ " total=" + numberOfConnections()
+ " ("
+ highWaterMark() + "/"
+ numberToReclaim()
+ ")");
}
/** Reclaim some idle cached connections. Will never
* close a connection that is busy.
* @return any connections reclaimed, (yes or no)
*/
protected boolean reclaim() {
if (debug())
dprint( ".reclaim: starting" ) ;
int ctr = 0 ;
while (ctr < numberToReclaim()) {
C candidate = reclaimableConnections.poll() ;
if (candidate == null)
// If we have closed all idle connections, we must stop
// reclaiming.
break ;
if (debug())
dprint( ".reclaim: closing connection " + candidate ) ;
try {
close( candidate ) ;
} catch (RuntimeException exc) {
if (debug())
dprint( ".reclaim: caught exception on close: " + exc ) ;
throw exc ;
}
ctr++ ;
}
if (debug())
dprint( ".reclaim: reclaimed " + ctr + " connection(s)" ) ;
return ctr > 0 ;
}
}