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Diffstat (limited to 'src/org/apache/http/impl/conn/AbstractPoolEntry.java')
| -rw-r--r-- | src/org/apache/http/impl/conn/AbstractPoolEntry.java | 322 |
1 files changed, 322 insertions, 0 deletions
diff --git a/src/org/apache/http/impl/conn/AbstractPoolEntry.java b/src/org/apache/http/impl/conn/AbstractPoolEntry.java new file mode 100644 index 0000000..0e7d95f --- /dev/null +++ b/src/org/apache/http/impl/conn/AbstractPoolEntry.java @@ -0,0 +1,322 @@ +/* + * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/main/java/org/apache/http/impl/conn/AbstractPoolEntry.java $ + * $Revision: 658775 $ + * $Date: 2008-05-21 10:30:45 -0700 (Wed, 21 May 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 org.apache.http.HttpHost; +import org.apache.http.params.HttpParams; +import org.apache.http.protocol.HttpContext; +import org.apache.http.conn.routing.HttpRoute; +import org.apache.http.conn.routing.RouteTracker; +import org.apache.http.conn.ClientConnectionOperator; +import org.apache.http.conn.OperatedClientConnection; + + + +/** + * A pool entry for use by connection manager implementations. + * Pool entries work in conjunction with an + * {@link AbstractClientConnAdapter adapter}. + * The adapter is handed out to applications that obtain a connection. + * The pool entry stores the underlying connection and tracks the + * {@link HttpRoute route} established. + * The adapter delegates methods for establishing the route to + * it's pool entry. + * <br/> + * If the managed connections is released or revoked, the adapter + * gets disconnected, but the pool entry still contains the + * underlying connection and the established route. + * + * @author <a href="mailto:rolandw at apache.org">Roland Weber</a> + * @author <a href="mailto:becke@u.washington.edu">Michael Becke</a> + * + * + * <!-- empty lines to avoid svn diff problems --> + * @version $Revision: 658775 $ + * + * @since 4.0 + */ +public abstract class AbstractPoolEntry { + + /** The connection operator. */ + protected final ClientConnectionOperator connOperator; + + /** The underlying connection being pooled or used. */ + protected final OperatedClientConnection connection; + + /** The route for which this entry gets allocated. */ + //@@@ currently accessed from connection manager(s) as attribute + //@@@ avoid that, derived classes should decide whether update is allowed + //@@@ SCCM: yes, TSCCM: no + protected volatile HttpRoute route; + + /** Connection state object */ + protected volatile Object state; + + /** The tracked route, or <code>null</code> before tracking starts. */ + protected volatile RouteTracker tracker; + + + /** + * Creates a new pool entry. + * + * @param connOperator the Connection Operator for this entry + * @param route the planned route for the connection, + * or <code>null</code> + */ + protected AbstractPoolEntry(ClientConnectionOperator connOperator, + HttpRoute route) { + super(); + if (connOperator == null) { + throw new IllegalArgumentException("Connection operator may not be null"); + } + this.connOperator = connOperator; + this.connection = connOperator.createConnection(); + this.route = route; + this.tracker = null; + } + + /** + * Returns the state object associated with this pool entry. + * + * @return The state object + */ + public Object getState() { + return state; + } + + /** + * Assigns a state object to this pool entry. + * + * @param state The state object + */ + public void setState(final Object state) { + this.state = state; + } + + /** + * Opens the underlying connection. + * + * @param route the route along which to open the connection + * @param context the context for opening the connection + * @param params the parameters for opening the connection + * + * @throws IOException in case of a problem + */ + public void open(HttpRoute route, + HttpContext context, HttpParams params) + throws IOException { + + if (route == null) { + throw new IllegalArgumentException + ("Route must not be null."); + } + //@@@ is context allowed to be null? depends on operator? + if (params == null) { + throw new IllegalArgumentException + ("Parameters must not be null."); + } + if ((this.tracker != null) && this.tracker.isConnected()) { + throw new IllegalStateException("Connection already open."); + } + + // - collect the arguments + // - call the operator + // - update the tracking data + // In this order, we can be sure that only a successful + // opening of the connection will be tracked. + + //@@@ verify route against planned route? + + this.tracker = new RouteTracker(route); + final HttpHost proxy = route.getProxyHost(); + + connOperator.openConnection + (this.connection, + (proxy != null) ? proxy : route.getTargetHost(), + route.getLocalAddress(), + context, params); + + RouteTracker localTracker = tracker; // capture volatile + + // If this tracker was reset while connecting, + // fail early. + if (localTracker == null) { + throw new IOException("Request aborted"); + } + + if (proxy == null) { + localTracker.connectTarget(this.connection.isSecure()); + } else { + localTracker.connectProxy(proxy, this.connection.isSecure()); + } + + } // open + + + /** + * Tracks tunnelling of the connection to the target. + * The tunnel has to be established outside by sending a CONNECT + * request to the (last) proxy. + * + * @param secure <code>true</code> if the tunnel should be + * considered secure, <code>false</code> otherwise + * @param params the parameters for tunnelling the connection + * + * @throws IOException in case of a problem + */ + public void tunnelTarget(boolean secure, HttpParams params) + throws IOException { + + if (params == null) { + throw new IllegalArgumentException + ("Parameters must not be null."); + } + + //@@@ check for proxy in planned route? + if ((this.tracker == null) || !this.tracker.isConnected()) { + throw new IllegalStateException("Connection not open."); + } + if (this.tracker.isTunnelled()) { + throw new IllegalStateException + ("Connection is already tunnelled."); + } + + // LOG.debug? + + this.connection.update(null, tracker.getTargetHost(), + secure, params); + this.tracker.tunnelTarget(secure); + + } // tunnelTarget + + + /** + * Tracks tunnelling of the connection to a chained proxy. + * The tunnel has to be established outside by sending a CONNECT + * request to the previous proxy. + * + * @param next the proxy to which the tunnel was established. + * See {@link org.apache.http.conn.ManagedClientConnection#tunnelProxy + * ManagedClientConnection.tunnelProxy} + * for details. + * @param secure <code>true</code> if the tunnel should be + * considered secure, <code>false</code> otherwise + * @param params the parameters for tunnelling the connection + * + * @throws IOException in case of a problem + */ + public void tunnelProxy(HttpHost next, boolean secure, HttpParams params) + throws IOException { + + if (next == null) { + throw new IllegalArgumentException + ("Next proxy must not be null."); + } + if (params == null) { + throw new IllegalArgumentException + ("Parameters must not be null."); + } + + //@@@ check for proxy in planned route? + if ((this.tracker == null) || !this.tracker.isConnected()) { + throw new IllegalStateException("Connection not open."); + } + + // LOG.debug? + + this.connection.update(null, next, secure, params); + this.tracker.tunnelProxy(next, secure); + + } // tunnelProxy + + + /** + * Layers a protocol on top of an established tunnel. + * + * @param context the context for layering + * @param params the parameters for layering + * + * @throws IOException in case of a problem + */ + public void layerProtocol(HttpContext context, HttpParams params) + throws IOException { + + //@@@ is context allowed to be null? depends on operator? + if (params == null) { + throw new IllegalArgumentException + ("Parameters must not be null."); + } + + if ((this.tracker == null) || !this.tracker.isConnected()) { + throw new IllegalStateException("Connection not open."); + } + if (!this.tracker.isTunnelled()) { + //@@@ allow this? + throw new IllegalStateException + ("Protocol layering without a tunnel not supported."); + } + if (this.tracker.isLayered()) { + throw new IllegalStateException + ("Multiple protocol layering not supported."); + } + + // - collect the arguments + // - call the operator + // - update the tracking data + // In this order, we can be sure that only a successful + // layering on top of the connection will be tracked. + + final HttpHost target = tracker.getTargetHost(); + + connOperator.updateSecureConnection(this.connection, target, + context, params); + + this.tracker.layerProtocol(this.connection.isSecure()); + + } // layerProtocol + + + /** + * Shuts down the entry. + * + * If {@link #open(HttpRoute, HttpContext, HttpParams)} is in progress, + * this will cause that open to possibly throw an {@link IOException}. + */ + protected void shutdownEntry() { + tracker = null; + } + + +} // class AbstractPoolEntry + |