/**
*
* Copyright 2003-2005 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.geronimo.connector.outbound;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Arrays;
import javax.resource.ResourceException;
import javax.resource.spi.ManagedConnection;
/**
* SinglePoolConnectionInterceptor chooses a single connection from the pool. If selectOneAssumeMatch
* is true, it simply returns the selected connection.
* THIS SHOULD BE USED ONLY IF MAXIMUM SPEED IS ESSENTIAL AND YOU HAVE THOROUGLY CHECKED THAT
* MATCHING WOULD SUCCEED ON THE SELECTED CONNECTION. (i.e., read the docs on your connector
* to find out how matching works)
* If selectOneAssumeMatch is false, it checks with the ManagedConnectionFactory that the
* selected connection does match before returning it: if not it throws an exception.
*
* @version $Rev: 355877 $ $Date: 2005-12-11 03:48:27 +0100 (Sun, 11 Dec 2005) $
*/
public class SinglePoolConnectionInterceptor extends AbstractSinglePoolConnectionInterceptor {
private boolean selectOneAssumeMatch;
private PoolDeque pool;
public SinglePoolConnectionInterceptor(final ConnectionInterceptor next,
int maxSize,
int minSize,
int blockingTimeoutMilliseconds,
int idleTimeoutMinutes,
boolean selectOneAssumeMatch) {
super(next, maxSize, minSize, blockingTimeoutMilliseconds, idleTimeoutMinutes);
pool = new PoolDeque(maxSize);
this.selectOneAssumeMatch = selectOneAssumeMatch;
}
protected void internalGetConnection(ConnectionInfo connectionInfo) throws ResourceException {
synchronized (pool) {
if (destroyed) {
throw new ResourceException("ManagedConnection pool has been destroyed");
}
ManagedConnectionInfo newMCI = null;
if (pool.isEmpty()) {
next.getConnection(connectionInfo);
connectionCount++;
if (log.isTraceEnabled()) {
log.trace("Returning new connection " + connectionInfo.getManagedConnectionInfo());
}
return;
} else {
newMCI = pool.removeLast();
}
if (connectionCount < minSize) {
timer.schedule(new FillTask(connectionInfo), 10);
}
if (selectOneAssumeMatch) {
connectionInfo.setManagedConnectionInfo(newMCI);
if (log.isTraceEnabled()) {
log.trace("Returning pooled connection without checking matching " + connectionInfo.getManagedConnectionInfo());
}
return;
}
try {
ManagedConnectionInfo mci = connectionInfo.getManagedConnectionInfo();
ManagedConnection matchedMC =
newMCI
.getManagedConnectionFactory()
.matchManagedConnections(Collections.singleton(newMCI.getManagedConnection()),
mci.getSubject(),
mci.getConnectionRequestInfo());
if (matchedMC != null) {
connectionInfo.setManagedConnectionInfo(newMCI);
if (log.isTraceEnabled()) {
log.trace("Returning pooled connection " + connectionInfo.getManagedConnectionInfo());
}
return;
} else {
//matching failed.
ConnectionInfo returnCI = new ConnectionInfo();
returnCI.setManagedConnectionInfo(newMCI);
returnConnection(returnCI,
ConnectionReturnAction.RETURN_HANDLE);
throw new ResourceException("The pooling strategy does not match the MatchManagedConnections implementation. Please investigate and reconfigure this pool");
}
} catch (ResourceException e) {
//something is wrong: destroy connection, rethrow, release permit
ConnectionInfo returnCI = new ConnectionInfo();
returnCI.setManagedConnectionInfo(newMCI);
returnConnection(returnCI,
ConnectionReturnAction.DESTROY);
throw e;
}
}
}
protected void internalDestroy() {
synchronized (pool) {
while (!pool.isEmpty()) {
ManagedConnection mc = pool.removeLast().getManagedConnection();
if (mc != null) {
try {
mc.destroy();
}
catch (ResourceException re) { } // ignore
}
}
}
}
protected boolean internalReturn(ConnectionInfo connectionInfo, ConnectionReturnAction connectionReturnAction) {
ManagedConnectionInfo mci = connectionInfo.getManagedConnectionInfo();
ManagedConnection mc = mci.getManagedConnection();
try {
mc.cleanup();
} catch (ResourceException e) {
connectionReturnAction = ConnectionReturnAction.DESTROY;
}
boolean wasInPool = false;
synchronized (pool) {
// a bit redundant with returnConnection check in AbstractSinglePoolConnectionInterceptor,
// but checking here closes a small timing hole...
if (destroyed) {
try {
mc.destroy();
}
catch (ResourceException re) { } // ignore
return pool.remove(mci);
}
if (shrinkLater > 0) {
//nothing can get in the pool while shrinkLater > 0, so wasInPool is false here.
connectionReturnAction = ConnectionReturnAction.DESTROY;
shrinkLater--;
} else if (connectionReturnAction == ConnectionReturnAction.RETURN_HANDLE) {
mci.setLastUsed(System.currentTimeMillis());
pool.add(mci);
return wasInPool;
} else {
wasInPool = pool.remove(mci);
}
}
//we must destroy connection.
next.returnConnection(connectionInfo, connectionReturnAction);
connectionCount--;
return wasInPool;
}
public int getPartitionMaxSize() {
return pool.capacity();
}
protected void transferConnections(int maxSize, int shrinkNow) {
//1st example: copy 0 (none)
//2nd example: copy 10 (all)
PoolDeque oldPool = pool;
pool = new PoolDeque(maxSize);
//since we have replaced pool already, pool.remove will be very fast:-)
for (int i = 0; i < shrinkNow; i++) {
ConnectionInfo killInfo = new ConnectionInfo(oldPool.peek(i));
internalReturn(killInfo, ConnectionReturnAction.DESTROY);
}
for (int i = shrinkNow; i < connectionCount; i++) {
pool.add(oldPool.peek(i));
}
}
public int getIdleConnectionCount() {
return pool.currentSize();
}
protected void getExpiredManagedConnectionInfos(long threshold, ArrayList killList) {
synchronized (pool) {
for (int i = 0; i < pool.currentSize(); i++) {
ManagedConnectionInfo mci = pool.peek(i);
if (mci.getLastUsed() < threshold) {
killList.add(mci);
}
}
}
}
protected boolean addToPool(ManagedConnectionInfo mci) {
boolean added;
synchronized (pool) {
connectionCount++;
added = getPartitionMaxSize() > getIdleConnectionCount();
if (added) {
pool.add(mci);
}
}
return added;
}
static class PoolDeque {
private final ManagedConnectionInfo[] deque;
private final int first = 0;
private int last = -1;
public PoolDeque(int size) {
deque = new ManagedConnectionInfo[size];
}
//internal
public boolean isEmpty() {
return first > last;
}
//internal
public void add(ManagedConnectionInfo mci) {
if (last == deque.length - 1) {
throw new IllegalStateException("deque is full: contents: " + Arrays.asList(deque));
}
deque[++last] = mci;
}
//internal
public ManagedConnectionInfo peek(int i) {
if (i < first || i > last) {
throw new IllegalStateException("index is out of current range");
}
return deque[i];
}
//internal
public ManagedConnectionInfo removeLast() {
if (isEmpty()) {
throw new IllegalStateException("deque is empty");
}
return deque[last--];
}
//internal
public boolean remove(ManagedConnectionInfo mci) {
for (int i = first; i <= last; i++) {
if (deque[i] == mci) {
for (int j = i + 1; j <= last; j++) {
deque[j - 1] = deque[j];
}
last--;
return true;
}
}
return false;
}
//internal
public int capacity() {
return deque.length;
}
//internal
public int currentSize() {
return last - first + 1;
}
}
}