/*
* $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/main/java/org/apache/http/impl/conn/AbstractClientConnAdapter.java $
* $Revision: 672969 $
* $Date: 2008-06-30 18:09:50 -0700 (Mon, 30 Jun 2008) $
*
* ====================================================================
*
* 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.io.InterruptedIOException;
import java.net.InetAddress;
import java.net.Socket;
import java.util.concurrent.TimeUnit;
import javax.net.ssl.SSLSocket;
import javax.net.ssl.SSLSession;
import org.apache.http.HttpException;
import org.apache.http.HttpRequest;
import org.apache.http.HttpEntityEnclosingRequest;
import org.apache.http.HttpResponse;
import org.apache.http.HttpConnectionMetrics;
import org.apache.http.conn.OperatedClientConnection;
import org.apache.http.conn.ManagedClientConnection;
import org.apache.http.conn.ClientConnectionManager;
/**
* Abstract adapter from {@link OperatedClientConnection operated} to
* {@link ManagedClientConnection managed} client connections.
* Read and write methods are delegated to the wrapped connection.
* Operations affecting the connection state have to be implemented
* by derived classes. Operations for querying the connection state
* are delegated to the wrapped connection if there is one, or
* return a default value if there is none.
* <br/>
* This adapter tracks the checkpoints for reusable communication states,
* as indicated by {@link #markReusable markReusable} and queried by
* {@link #isMarkedReusable isMarkedReusable}.
* All send and receive operations will automatically clear the mark.
* <br/>
* Connection release calls are delegated to the connection manager,
* if there is one. {@link #abortConnection abortConnection} will
* clear the reusability mark first. The connection manager is
* expected to tolerate multiple calls to the release method.
*
* @author <a href="mailto:rolandw at apache.org">Roland Weber</a>
*
*
* <!-- empty lines to avoid svn diff problems -->
* @version $Revision: 672969 $ $Date: 2008-06-30 18:09:50 -0700 (Mon, 30 Jun 2008) $
*
* @since 4.0
*/
public abstract class AbstractClientConnAdapter
implements ManagedClientConnection {
/** Thread that requested this connection. */
private final Thread executionThread;
/**
* The connection manager, if any.
* This attribute MUST NOT be final, so the adapter can be detached
* from the connection manager without keeping a hard reference there.
*/
private volatile ClientConnectionManager connManager;
/** The wrapped connection. */
private volatile OperatedClientConnection wrappedConnection;
/** The reusability marker. */
private volatile boolean markedReusable;
/** True if the connection has been aborted. */
private volatile boolean aborted;
/** The duration this is valid for while idle (in ms). */
private volatile long duration;
/**
* Creates a new connection adapter.
* The adapter is initially <i>not</i>
* {@link #isMarkedReusable marked} as reusable.
*
* @param mgr the connection manager, or <code>null</code>
* @param conn the connection to wrap, or <code>null</code>
*/
protected AbstractClientConnAdapter(ClientConnectionManager mgr,
OperatedClientConnection conn) {
super();
executionThread = Thread.currentThread();
connManager = mgr;
wrappedConnection = conn;
markedReusable = false;
aborted = false;
duration = Long.MAX_VALUE;
} // <constructor>
/**
* Detaches this adapter from the wrapped connection.
* This adapter becomes useless.
*/
protected void detach() {
wrappedConnection = null;
connManager = null; // base class attribute
duration = Long.MAX_VALUE;
}
protected OperatedClientConnection getWrappedConnection() {
return wrappedConnection;
}
protected ClientConnectionManager getManager() {
return connManager;
}
/**
* Asserts that the connection has not been aborted.
*
* @throws InterruptedIOException if the connection has been aborted
*/
protected final void assertNotAborted() throws InterruptedIOException {
if (aborted) {
throw new InterruptedIOException("Connection has been shut down.");
}
}
/**
* Asserts that there is a wrapped connection to delegate to.
*
* @throws IllegalStateException if there is no wrapped connection
* or connection has been aborted
*/
protected final void assertValid(
final OperatedClientConnection wrappedConn) {
if (wrappedConn == null) {
throw new IllegalStateException("No wrapped connection.");
}
}
// non-javadoc, see interface HttpConnection
public boolean isOpen() {
OperatedClientConnection conn = getWrappedConnection();
if (conn == null)
return false;
return conn.isOpen();
}
// non-javadoc, see interface HttpConnection
public boolean isStale() {
if (aborted)
return true;
OperatedClientConnection conn = getWrappedConnection();
if (conn == null)
return true;
return conn.isStale();
}
// non-javadoc, see interface HttpConnection
public void setSocketTimeout(int timeout) {
OperatedClientConnection conn = getWrappedConnection();
assertValid(conn);
conn.setSocketTimeout(timeout);
}
// non-javadoc, see interface HttpConnection
public int getSocketTimeout() {
OperatedClientConnection conn = getWrappedConnection();
assertValid(conn);
return conn.getSocketTimeout();
}
// non-javadoc, see interface HttpConnection
public HttpConnectionMetrics getMetrics() {
OperatedClientConnection conn = getWrappedConnection();
assertValid(conn);
return conn.getMetrics();
}
// non-javadoc, see interface HttpClientConnection
public void flush()
throws IOException {
assertNotAborted();
OperatedClientConnection conn = getWrappedConnection();
assertValid(conn);
conn.flush();
}
// non-javadoc, see interface HttpClientConnection
public boolean isResponseAvailable(int timeout)
throws IOException {
assertNotAborted();
OperatedClientConnection conn = getWrappedConnection();
assertValid(conn);
return conn.isResponseAvailable(timeout);
}
// non-javadoc, see interface HttpClientConnection
public void receiveResponseEntity(HttpResponse response)
throws HttpException, IOException {
assertNotAborted();
OperatedClientConnection conn = getWrappedConnection();
assertValid(conn);
unmarkReusable();
conn.receiveResponseEntity(response);
}
// non-javadoc, see interface HttpClientConnection
public HttpResponse receiveResponseHeader()
throws HttpException, IOException {
assertNotAborted();
OperatedClientConnection conn = getWrappedConnection();
assertValid(conn);
unmarkReusable();
return conn.receiveResponseHeader();
}
// non-javadoc, see interface HttpClientConnection
public void sendRequestEntity(HttpEntityEnclosingRequest request)
throws HttpException, IOException {
assertNotAborted();
OperatedClientConnection conn = getWrappedConnection();
assertValid(conn);
unmarkReusable();
conn.sendRequestEntity(request);
}
// non-javadoc, see interface HttpClientConnection
public void sendRequestHeader(HttpRequest request)
throws HttpException, IOException {
assertNotAborted();
OperatedClientConnection conn = getWrappedConnection();
assertValid(conn);
unmarkReusable();
conn.sendRequestHeader(request);
}
// non-javadoc, see interface HttpInetConnection
public InetAddress getLocalAddress() {
OperatedClientConnection conn = getWrappedConnection();
assertValid(conn);
return conn.getLocalAddress();
}
// non-javadoc, see interface HttpInetConnection
public int getLocalPort() {
OperatedClientConnection conn = getWrappedConnection();
assertValid(conn);
return conn.getLocalPort();
}
// non-javadoc, see interface HttpInetConnection
public InetAddress getRemoteAddress() {
OperatedClientConnection conn = getWrappedConnection();
assertValid(conn);
return conn.getRemoteAddress();
}
// non-javadoc, see interface HttpInetConnection
public int getRemotePort() {
OperatedClientConnection conn = getWrappedConnection();
assertValid(conn);
return conn.getRemotePort();
}
// non-javadoc, see interface ManagedClientConnection
public boolean isSecure() {
OperatedClientConnection conn = getWrappedConnection();
assertValid(conn);
return conn.isSecure();
}
// non-javadoc, see interface ManagedClientConnection
public SSLSession getSSLSession() {
OperatedClientConnection conn = getWrappedConnection();
assertValid(conn);
if (!isOpen())
return null;
SSLSession result = null;
Socket sock = conn.getSocket();
if (sock instanceof SSLSocket) {
result = ((SSLSocket)sock).getSession();
}
return result;
}
// non-javadoc, see interface ManagedClientConnection
public void markReusable() {
markedReusable = true;
}
// non-javadoc, see interface ManagedClientConnection
public void unmarkReusable() {
markedReusable = false;
}
// non-javadoc, see interface ManagedClientConnection
public boolean isMarkedReusable() {
return markedReusable;
}
public void setIdleDuration(long duration, TimeUnit unit) {
if(duration > 0) {
this.duration = unit.toMillis(duration);
} else {
this.duration = -1;
}
}
// non-javadoc, see interface ConnectionReleaseTrigger
public void releaseConnection() {
if (connManager != null) {
connManager.releaseConnection(this, duration, TimeUnit.MILLISECONDS);
}
}
// non-javadoc, see interface ConnectionReleaseTrigger
public void abortConnection() {
if (aborted) {
return;
}
aborted = true;
unmarkReusable();
try {
shutdown();
} catch (IOException ignore) {
}
// Usually #abortConnection() is expected to be called from
// a helper thread in order to unblock the main execution thread
// blocked in an I/O operation. It may be unsafe to call
// #releaseConnection() from the helper thread, so we have to rely
// on an IOException thrown by the closed socket on the main thread
// to trigger the release of the connection back to the
// connection manager.
//
// However, if this method is called from the main execution thread
// it should be safe to release the connection immediately. Besides,
// this also helps ensure the connection gets released back to the
// manager if #abortConnection() is called from the main execution
// thread while there is no blocking I/O operation.
if (executionThread.equals(Thread.currentThread())) {
releaseConnection();
}
}
} // class AbstractClientConnAdapter