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1   /*
2    * ====================================================================
3    * Licensed to the Apache Software Foundation (ASF) under one
4    * or more contributor license agreements.  See the NOTICE file
5    * distributed with this work for additional information
6    * regarding copyright ownership.  The ASF licenses this file
7    * to you under the Apache License, Version 2.0 (the
8    * "License"); you may not use this file except in compliance
9    * with the License.  You may obtain a copy of the License at
10   *
11   *   http://www.apache.org/licenses/LICENSE-2.0
12   *
13   * Unless required by applicable law or agreed to in writing,
14   * software distributed under the License is distributed on an
15   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16   * KIND, either express or implied.  See the License for the
17   * specific language governing permissions and limitations
18   * under the License.
19   * ====================================================================
20   *
21   * This software consists of voluntary contributions made by many
22   * individuals on behalf of the Apache Software Foundation.  For more
23   * information on the Apache Software Foundation, please see
24   * <http://www.apache.org/>.
25   *
26   */
27  
28  package org.apache.hc.client5.http.async;
29  
30  import org.apache.hc.client5.http.EndpointInfo;
31  import org.apache.hc.client5.http.HttpRoute;
32  import org.apache.hc.client5.http.protocol.HttpClientContext;
33  import org.apache.hc.core5.annotation.Internal;
34  import org.apache.hc.core5.concurrent.Cancellable;
35  import org.apache.hc.core5.concurrent.FutureCallback;
36  import org.apache.hc.core5.http.nio.AsyncClientExchangeHandler;
37  import org.apache.hc.core5.util.TimeValue;
38  
39  /**
40   * Execution runtime that provides access to the underlying connection endpoint and helps
41   * manager its life cycle.
42   * <p>
43   * This interface is considered internal and generally ought not be used or accessed
44   * by custom request exec handlers.
45   * </p>
46   *
47   * @since 5.0
48   */
49  @Internal
50  public interface AsyncExecRuntime {
51  
52      /**
53       * Determines of a connection endpoint has been acquired.
54       *
55       * @return {@code true} if an endpoint has been acquired, {@code false} otherwise.
56       */
57      boolean isEndpointAcquired();
58  
59      /**
60       * Initiates operation to acquire a connection endpoint. Endpoints can leased from a pool
61       * or unconnected new endpoint can be created.
62       *
63       * @param id unique operation ID or {@code null}.
64       * @param route the connection route.
65       * @param state the expected connection state. May be {@code null} if connection
66       *              can be state-less or its state is irrelevant.
67       * @param context the execution context.
68       * @param callback the result callback.
69       * @return handle that can be used to cancel the operation.
70       */
71      Cancellable acquireEndpoint(
72              String id,
73              HttpRoute route,
74              Object state,
75              HttpClientContext context,
76              FutureCallback<AsyncExecRuntime> callback);
77  
78      /**
79       * Releases the acquired endpoint potentially making it available for re-use.
80       */
81      void releaseEndpoint();
82  
83      /**
84       * Shuts down and discards the acquired endpoint.
85       */
86      void discardEndpoint();
87  
88      /**
89       * Determines of there the endpoint is connected to the initial hop (connection target
90       * in case of a direct route or to the first proxy hop in case of a route via a proxy
91       * or multiple proxies).
92       *
93       * @return {@code true} if the endpoint is connected, {@code false} otherwise.
94       */
95      boolean isEndpointConnected();
96  
97      /**
98       * Initiates operation to connect the local endpoint to the initial hop (connection
99       * target in case of a direct route or to the first proxy hop in case of a route
100      * via a proxy or multiple proxies).
101      *
102      * @param context the execution context.
103      * @param callback the result callback.
104      * @return handle that can be used to cancel the operation.
105      */
106     Cancellable connectEndpoint(
107             HttpClientContext context,
108             FutureCallback<AsyncExecRuntime> callback);
109 
110     /**
111      * Disconnects the local endpoint from the initial hop in the connection route.
112      */
113     void disconnectEndpoint();
114 
115     /**
116      * Upgrades transport security of the active connection by using the TLS security protocol.
117      *
118      * @param context the execution context.
119      */
120     void upgradeTls(HttpClientContext context);
121 
122     /**
123      * Upgrades transport security of the active connection by using the TLS security protocol.
124      *
125      * @param context the execution context.
126      *
127      * @since 5.2
128      */
129     default void upgradeTls(HttpClientContext context,
130                             FutureCallback<AsyncExecRuntime> callback) {
131         upgradeTls(context);
132         if (callback != null) {
133             callback.completed(this);
134         }
135     }
136 
137     /**
138      * Returns information about the underlying endpoint when connected or {@code null} otherwise.
139      */
140     default EndpointInfo getEndpointInfo() {
141         return null;
142     }
143 
144     /**
145      * Validates the connection making sure it can be used to execute requests.
146      *
147      * @return {@code true} if the connection is valid, {@code false}.
148      */
149     boolean validateConnection();
150 
151     /**
152      * Initiates a message exchange using the given handler.
153      *
154      * @param id unique operation ID or {@code null}.
155      * @param exchangeHandler the client message handler.
156      * @param context the execution context.
157      */
158     Cancellable execute(
159             String id,
160             AsyncClientExchangeHandler exchangeHandler,
161             HttpClientContext context);
162 
163     /**
164      * Marks the connection as potentially re-usable for the given period of time
165      * and also marks it as stateful if the state representation is given.
166      * @param state the connection state representation or {@code null} if stateless.
167      * @param validityTime the period of time this connection is valid for.
168      */
169     void markConnectionReusable(Object state, TimeValue validityTime);
170 
171     /**
172      * Marks the connection as non re-usable.
173      */
174     void markConnectionNonReusable();
175 
176     /**
177      * Forks this runtime for parallel execution.
178      *
179      * @return another runtime with the same configuration.
180      */
181     AsyncExecRuntime fork();
182 
183 }