/*
* ====================================================================
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.http.impl.conn;
import java.io.IOException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.http.annotation.GuardedBy;
import org.apache.http.annotation.ThreadSafe;
import org.apache.http.conn.ClientConnectionManager;
import org.apache.http.conn.ClientConnectionOperator;
import org.apache.http.conn.ClientConnectionRequest;
import org.apache.http.conn.ManagedClientConnection;
import org.apache.http.conn.OperatedClientConnection;
import org.apache.http.conn.routing.HttpRoute;
import org.apache.http.conn.scheme.SchemeRegistry;
/**
* A connection manager for a single connection. This connection manager maintains only one active
* connection at a time. Even though this class is thread-safe it ought to be used by one execution
* thread only.
* <p/>
* BasicClientConnManager will make an effort to reuse the connection for subsequent requests
* with the same {@link HttpRoute route}. It will, however, close the existing connection and
* open it for the given route, if the route of the persistent connection does not match that
* of the connection request. If the connection has been already been allocated
* {@link IllegalStateException} is thrown.
* <p/>
* This connection manager implementation can be used inside a EJB container instead of
* {@link PoolingClientConnectionManager}.
*
* @since 4.2
*/
@ThreadSafe
public class BasicClientConnectionManager implements ClientConnectionManager {
private final Log log = LogFactory.getLog(getClass());
private static final AtomicLong COUNTER = new AtomicLong();
/** The message to be logged on multiple allocation. */
public final static String MISUSE_MESSAGE =
"Invalid use of BasicClientConnManager: connection still allocated.\n" +
"Make sure to release the connection before allocating another one.";
/** The schemes supported by this connection manager. */
private final SchemeRegistry schemeRegistry;
/** The operator for opening and updating connections. */
private final ClientConnectionOperator connOperator;
/** The one and only entry in this pool. */
@GuardedBy("this")
private HttpPoolEntry poolEntry;
/** The currently issued managed connection, if any. */
@GuardedBy("this")
private ManagedClientConnectionImpl conn;
/** Indicates whether this connection manager is shut down. */
@GuardedBy("this")
private volatile boolean shutdown;
/**
* Creates a new simple connection manager.
*
* @param schreg the scheme registry
*/
public BasicClientConnectionManager(final SchemeRegistry schreg) {
if (schreg == null) {
throw new IllegalArgumentException("Scheme registry may not be null");
}
this.schemeRegistry = schreg;
this.connOperator = createConnectionOperator(schreg);
}
public BasicClientConnectionManager() {
this(SchemeRegistryFactory.createDefault());
}
@Override
protected void finalize() throws Throwable {
try {
shutdown();
} finally { // Make sure we call overridden method even if shutdown barfs
super.finalize();
}
}
public SchemeRegistry getSchemeRegistry() {
return this.schemeRegistry;
}
protected ClientConnectionOperator createConnectionOperator(final SchemeRegistry schreg) {
return new DefaultClientConnectionOperator(schreg);
}
public final ClientConnectionRequest requestConnection(
final HttpRoute route,
final Object state) {
return new ClientConnectionRequest() {
public void abortRequest() {
// Nothing to abort, since requests are immediate.
}
public ManagedClientConnection getConnection(
long timeout, TimeUnit tunit) {
return BasicClientConnectionManager.this.getConnection(
route, state);
}
};
}
private void assertNotShutdown() {
if (this.shutdown) {
throw new IllegalStateException("Connection manager has been shut down");
}
}
ManagedClientConnection getConnection(final HttpRoute route, final Object state) {
if (route == null) {
throw new IllegalArgumentException("Route may not be null.");
}
assertNotShutdown();
if (this.log.isDebugEnabled()) {
this.log.debug("Get connection for route " + route);
}
synchronized (this) {
if (this.conn != null) {
throw new IllegalStateException(MISUSE_MESSAGE);
}
if (this.poolEntry != null && !this.poolEntry.getPlannedRoute().equals(route)) {
this.poolEntry.close();
this.poolEntry = null;
}
if (this.poolEntry == null) {
String id = Long.toString(COUNTER.getAndIncrement());
OperatedClientConnection conn = this.connOperator.createConnection();
this.poolEntry = new HttpPoolEntry(this.log, id, route, conn, 0, TimeUnit.MILLISECONDS);
}
long now = System.currentTimeMillis();
if (this.poolEntry.isExpired(now)) {
this.poolEntry.close();
this.poolEntry.getTracker().reset();
}
this.conn = new ManagedClientConnectionImpl(this, this.connOperator, this.poolEntry);
return this.conn;
}
}
public void releaseConnection(final ManagedClientConnection conn, long keepalive, TimeUnit tunit) {
assertNotShutdown();
if (!(conn instanceof ManagedClientConnectionImpl)) {
throw new IllegalArgumentException("Connection class mismatch, " +
"connection not obtained from this manager");
}
if (this.log.isDebugEnabled()) {
this.log.debug("Releasing connection " + conn);
}
ManagedClientConnectionImpl managedConn = (ManagedClientConnectionImpl) conn;
synchronized (managedConn) {
if (managedConn.getPoolEntry() == null) {
return; // already released
}
ClientConnectionManager manager = managedConn.getManager();
if (manager != null && manager != this) {
throw new IllegalStateException("Connection not obtained from this manager");
}
synchronized (this) {
try {
if (managedConn.isOpen() && !managedConn.isMarkedReusable()) {
try {
managedConn.shutdown();
} catch (IOException iox) {
if (this.log.isDebugEnabled()) {
this.log.debug("I/O exception shutting down released connection", iox);
}
}
}
this.poolEntry.updateExpiry(keepalive, tunit != null ? tunit : TimeUnit.MILLISECONDS);
if (this.log.isDebugEnabled()) {
String s;
if (keepalive > 0) {
s = "for " + keepalive + " " + tunit;
} else {
s = "indefinitely";
}
this.log.debug("Connection can be kept alive " + s);
}
} finally {
managedConn.detach();
this.conn = null;
if (this.poolEntry.isClosed()) {
this.poolEntry = null;
}
}
}
}
}
public void closeExpiredConnections() {
assertNotShutdown();
synchronized (this) {
long now = System.currentTimeMillis();
if (this.poolEntry != null && this.poolEntry.isExpired(now)) {
this.poolEntry.close();
this.poolEntry.getTracker().reset();
}
}
}
public void closeIdleConnections(long idletime, TimeUnit tunit) {
if (tunit == null) {
throw new IllegalArgumentException("Time unit must not be null.");
}
assertNotShutdown();
synchronized (this) {
long time = tunit.toMillis(idletime);
if (time < 0) {
time = 0;
}
long deadline = System.currentTimeMillis() - time;
if (this.poolEntry != null && this.poolEntry.getUpdated() <= deadline) {
this.poolEntry.close();
this.poolEntry.getTracker().reset();
}
}
}
public void shutdown() {
this.shutdown = true;
synchronized (this) {
try {
if (this.poolEntry != null) {
this.poolEntry.close();
}
} finally {
this.poolEntry = null;
this.conn = null;
}
}
}
}