michael@0: /*
michael@0:  * ====================================================================
michael@0:  * Licensed to the Apache Software Foundation (ASF) under one
michael@0:  * or more contributor license agreements.  See the NOTICE file
michael@0:  * distributed with this work for additional information
michael@0:  * regarding copyright ownership.  The ASF licenses this file
michael@0:  * to you under the Apache License, Version 2.0 (the
michael@0:  * "License"); you may not use this file except in compliance
michael@0:  * with the License.  You may obtain a copy of the License at
michael@0:  *
michael@0:  *   http://www.apache.org/licenses/LICENSE-2.0
michael@0:  *
michael@0:  * Unless required by applicable law or agreed to in writing,
michael@0:  * software distributed under the License is distributed on an
michael@0:  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
michael@0:  * KIND, either express or implied.  See the License for the
michael@0:  * specific language governing permissions and limitations
michael@0:  * under the License.
michael@0:  * ====================================================================
michael@0:  *
michael@0:  * This software consists of voluntary contributions made by many
michael@0:  * individuals on behalf of the Apache Software Foundation.  For more
michael@0:  * information on the Apache Software Foundation, please see
michael@0:  * <http://www.apache.org/>.
michael@0:  *
michael@0:  */
michael@0: 
michael@0: package ch.boye.httpclientandroidlib.conn.routing;
michael@0: 
michael@0: /**
michael@0:  * Provides directions on establishing a route.
michael@0:  * Implementations of this interface compare a planned route with
michael@0:  * a tracked route and indicate the next step required.
michael@0:  *
michael@0:  * @since 4.0
michael@0:  */
michael@0: public interface HttpRouteDirector {
michael@0: 
michael@0:     /** Indicates that the route can not be established at all. */
michael@0:     public final static int UNREACHABLE = -1;
michael@0: 
michael@0:     /** Indicates that the route is complete. */
michael@0:     public final static int COMPLETE = 0;
michael@0: 
michael@0:     /** Step: open connection to target. */
michael@0:     public final static int CONNECT_TARGET = 1;
michael@0: 
michael@0:     /** Step: open connection to proxy. */
michael@0:     public final static int CONNECT_PROXY = 2;
michael@0: 
michael@0:     /** Step: tunnel through proxy to target. */
michael@0:     public final static int TUNNEL_TARGET = 3;
michael@0: 
michael@0:     /** Step: tunnel through proxy to other proxy. */
michael@0:     public final static int TUNNEL_PROXY = 4;
michael@0: 
michael@0:     /** Step: layer protocol (over tunnel). */
michael@0:     public final static int LAYER_PROTOCOL = 5;
michael@0: 
michael@0: 
michael@0:     /**
michael@0:      * Provides the next step.
michael@0:      *
michael@0:      * @param plan      the planned route
michael@0:      * @param fact      the currently established route, or
michael@0:      *                  <code>null</code> if nothing is established
michael@0:      *
michael@0:      * @return  one of the constants defined in this interface, indicating
michael@0:      *          either the next step to perform, or success, or failure.
michael@0:      *          0 is for success, a negative value for failure.
michael@0:      */
michael@0:     public int nextStep(RouteInfo plan, RouteInfo fact);
michael@0: 
michael@0: }