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 package org.apache.hc.core5.pool;
28
29 import java.util.concurrent.Future;
30
31 import org.apache.hc.core5.concurrent.FutureCallback;
32 import org.apache.hc.core5.io.ModalCloseable;
33 import org.apache.hc.core5.util.Timeout;
34
35 /**
36 * {@code ConnPool} represents a shared pool connections can be leased from
37 * and released back to.
38 *
39 * @param <T> the route type that represents the opposite endpoint of a pooled
40 * connection.
41 * @param <C> the type of pooled connections.
42 * @since 4.2
43 */
44 public interface ConnPool<T, C extends ModalCloseable> {
45
46 /**
47 * Attempts to lease a connection for the given route and with the given
48 * state from the pool.
49 * <p>
50 * Please note the connection request can get automatically cancelled by the pool
51 * in case of a request timeout.
52 *
53 * @param route route of the connection.
54 * @param state arbitrary object that represents a particular state
55 * (usually a security principal or a unique token identifying
56 * the user whose credentials have been used while establishing the connection).
57 * May be {@code null}.
58 * @param requestTimeout request timeout. In case of a timeout the request
59 * can get automatically cancelled by the pool.
60 * @param callback operation completion callback.
61 *
62 * @return future for a leased pool entry.
63 */
64 Future<PoolEntry<T, C>> lease(T route, Object state, Timeout requestTimeout, FutureCallback<PoolEntry<T, C>> callback);
65
66 /**
67 * Releases the pool entry back to the pool.
68 *
69 * @param entry pool entry leased from the pool
70 * @param reusable flag indicating whether or not the released connection
71 * is in a consistent state and is safe for further use.
72 */
73 void release(PoolEntry<T, C> entry, boolean reusable);
74
75 }