connection release by stream close

git-svn-id: https://svn.apache.org/repos/asf/jakarta/httpcomponents/httpclient/trunk@508895 13f79535-47bb-0310-9956-ffa450edef68

src/examples/org/apache/http/examples/client/ClientExecuteDirect.java

@@ -47,6 +47,7 @@ import org.apache.http.protocol.RequestContent;
 import org.apache.http.protocol.RequestExpectContinue;
 import org.apache.http.protocol.RequestTargetHost;
 import org.apache.http.protocol.RequestUserAgent;
+//import org.apache.http.util.EntityUtils;
 
 import org.apache.http.conn.Scheme;
 import org.apache.http.conn.SchemeRegistry;
@@ -113,12 +114,24 @@ public class ClientExecuteDirect {
             }
             System.out.println("----------------------------------------");
 
-            //@@@ there is no entity, so we can't call close() there
+            if (rsp.getEntity() != null) {
-            //@@@ there is no need to call close() either, since the
+                // the entity is probably tied to the connection
-            //@@@ connection will have been released immediately
+                rsp.getEntity().getContent().close();
+                // If you want to see the content, use the line below
+                // _instead_ of the close() call above. The utility class
+                // will read to the end of the stream and close it,
+                // thereby releasing the underlying connection.
+                //System.out.println(EntityUtils.toString(rsp.getEntity()));
+                //@@@ in case of an exception from EntityUtils.toString,
+                //@@@ there currently is no way of releasing the connection.
+                //@@@ The stream can be obtained from the entity only once.
+            }
+            // if there is no entity, the connection is already released
 
         } finally {
             //@@@ any kind of cleanup that should be performed?
+            //@@@ if content is read instead of being ignored, this is
+            //@@@ the place for connection release in case of an error
         }
     } // main
 
@@ -187,7 +200,8 @@ public class ClientExecuteDirect {
     private final static HttpRequest createRequest(HttpHost target) {
 
         HttpRequest req = new BasicHttpRequest
-            ("OPTIONS", "*", HttpVersion.HTTP_1_1);
+            ("GET", "/", HttpVersion.HTTP_1_1);
+          //("OPTIONS", "*", HttpVersion.HTTP_1_1);
 
         req.addHeader("Host", target.getHostName());
 

src/examples/org/apache/http/examples/client/ClientExecuteProxy.java

@@ -47,6 +47,7 @@ import org.apache.http.protocol.RequestContent;
 import org.apache.http.protocol.RequestExpectContinue;
 import org.apache.http.protocol.RequestTargetHost;
 import org.apache.http.protocol.RequestUserAgent;
+//import org.apache.http.util.EntityUtils;
 
 import org.apache.http.conn.Scheme;
 import org.apache.http.conn.SchemeRegistry;
@@ -125,12 +126,24 @@ public class ClientExecuteProxy {
             }
             System.out.println("----------------------------------------");
 
-            //@@@ there is no entity, so we can't call close() there
+            if (rsp.getEntity() != null) {
-            //@@@ there is no need to call close() either, since the
+                // the entity is probably tied to the connection
-            //@@@ connection will have been released immediately
+                rsp.getEntity().getContent().close();
+                // If you want to see the content, use the line below
+                // _instead_ of the close() call above. The utility class
+                // will read to the end of the stream and close it,
+                // thereby releasing the underlying connection.
+                //System.out.println(EntityUtils.toString(rsp.getEntity()));
+                //@@@ in case of an exception from EntityUtils.toString,
+                //@@@ there currently is no way of releasing the connection.
+                //@@@ The stream can be obtained from the entity only once.
+            }
+            // if there is no entity, the connection is already released
 
         } finally {
             //@@@ any kind of cleanup that should be performed?
+            //@@@ if content is read instead of being ignored, this is
+            //@@@ the place for connection release in case of an error
         }
     } // main
 
@@ -201,7 +214,8 @@ public class ClientExecuteProxy {
     private final static HttpRequest createRequest(HttpHost target) {
 
         HttpRequest req = new BasicHttpRequest
-            ("OPTIONS", "*", HttpVersion.HTTP_1_1);
+            ("GET", "/", HttpVersion.HTTP_1_1);
+          //("OPTIONS", "*", HttpVersion.HTTP_1_1);
 
         req.addHeader("Host", target.getHostName());
 

src/java/org/apache/http/conn/BasicEofSensorWatcher.java

@@ -0,0 +1,122 @@
+/*
+ * $HeadURL$
+ * $Revision $
+ * $Date$
+ *
+ * ====================================================================
+ *
+ *  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.conn;
+
+import java.io.InputStream;
+import java.io.IOException;
+
+
+/**
+ * Basic implementation of {@link EofSensorWatcher EofSensorWatcher}.
+ * The underlying connection is released on close or EOF.
+ *
+ * @author <a href="mailto:rolandw at apache.org">Roland Weber</a>
+ *
+ *
+ * <!-- empty lines to avoid svn diff problems -->
+ * @version $Revision$
+ *
+ * @since 4.0
+ */
+public class BasicEofSensorWatcher implements EofSensorWatcher {
+
+
+    /** The connection to auto-release. */
+    protected ManagedClientConnection managedConn;
+
+    /** The connection manager to release to. */
+    protected ClientConnectionManager connManager;
+
+    /** Whether to keep the connection alive. */
+    protected boolean attemptReuse;
+
+
+
+    /**
+     * Creates a new watcher for auto-releasing a connection.
+     *
+     * @param conn      the connection to auto-release
+     * @param mgr       the connection manager to release to
+     * @param reuse     whether the connection should be re-used
+     */
+    public BasicEofSensorWatcher(ManagedClientConnection conn,
+                                 ClientConnectionManager mgr,
+                                 boolean reuse) {
+        if (conn == null)
+            throw new IllegalArgumentException
+                ("Connection may not be null.");
+        if (mgr == null)
+            throw new IllegalArgumentException
+                ("Connection manager may not be null.");
+
+        managedConn = conn;
+        //@@@ put a release method in the connection interface?
+        connManager = mgr;
+        attemptReuse = reuse;
+    }
+
+
+    // non-javadoc, see interface EofSensorWatcher
+    public boolean eofDetected(InputStream wrapped)
+        throws IOException {
+
+        try {
+            if (attemptReuse) {
+                // there may be some cleanup required, such as
+                // reading trailers after the response body:
+                wrapped.close();
+                managedConn.markReusable();
+            }
+        } finally {
+            connManager.releaseConnection(managedConn);
+        }
+        return false;
+    }
+
+
+    // non-javadoc, see interface EofSensorWatcher
+    public boolean streamClosed(InputStream wrapped)
+        throws IOException {
+
+        try {
+            if (attemptReuse) {
+                // this assumes that closing the stream will
+                // consume the remainder of the response body:
+                wrapped.close();
+                managedConn.markReusable();
+            }
+        } finally {
+            connManager.releaseConnection(managedConn);
+        }
+        return false;
+    }
+
+} // class BasicEofSensorWatcher

src/java/org/apache/http/impl/client/DefaultClientRequestDirector.java

@@ -37,6 +37,8 @@ import org.apache.http.HttpVersion;
 import org.apache.http.HttpRequest;
 import org.apache.http.HttpResponse;
 import org.apache.http.HttpException;
+import org.apache.http.HttpEntity;
+import org.apache.http.entity.BasicHttpEntity;
 import org.apache.http.message.BasicHttpRequest;
 import org.apache.http.params.HttpParams;
 import org.apache.http.protocol.HttpContext;
@@ -45,6 +47,9 @@ import org.apache.http.conn.HttpRoute;
 import org.apache.http.conn.RouteDirector;
 import org.apache.http.conn.ClientConnectionManager;
 import org.apache.http.conn.ManagedClientConnection;
+import org.apache.http.conn.EofSensorInputStream;
+import org.apache.http.conn.EofSensorWatcher;
+import org.apache.http.conn.BasicEofSensorWatcher;
 import org.apache.http.client.RoutedRequest;
 import org.apache.http.client.ClientRequestDirector;
 
@@ -407,6 +412,25 @@ public class DefaultClientRequestDirector
                 managedConn = null;
                 mcc.markReusable();
                 connManager.releaseConnection(mcc);
+            } else {
+                HttpEntity entity = response.getEntity();
+                if (!(entity instanceof BasicHttpEntity)) {
+                    //@@@ fall back to an entity wrapper in this case?
+                    managedConn = null;
+                    connManager.releaseConnection(mcc);
+                    throw new IllegalStateException
+                        ("Unsupported entity type: " +
+                         entity.getClass().getName());
+                }
+                // install an auto-release handler
+                BasicHttpEntity bhe = (BasicHttpEntity) entity;
+                //@@@ evaluate connection re-use strategy
+                boolean reuse = false;
+                BasicEofSensorWatcher esw = new BasicEofSensorWatcher
+                    (mcc, connManager, reuse);
+                EofSensorInputStream esis = new EofSensorInputStream
+                    (bhe.getContent(), esw);
+                bhe.setContent(esis);
             }
         } else {
             // we got here as the result of an exception

src/java/org/apache/http/impl/client/DefaultHttpClient.java

@@ -123,14 +123,13 @@ public class DefaultHttpClient extends AbstractHttpClient {
 
         ClientRequestDirector director = createDirector(context);
         HttpResponse          response = director.execute(roureq, context);
+        // If the response depends on the connection, the director
+        // will have set up an auto-release input stream.
+        //@@@ or move that logic here into the client?
 
         //@@@ "finalize" response, to allow for buffering of entities?
         //@@@ here or in director?
 
-        System.out.println("@@@ what about "+director.getConnection()+"?");
-        //@@@ return a "connected response" with a release() callback?
-        //@@@ use a special response entity to implement the release()?
-
         return response;
 
     } // execute