1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18 package org.apache.river.norm;
19
20 import java.util.HashMap;
21 import java.util.Map;
22
23 import net.jini.core.lease.Lease;
24
25 /**
26 * Maps client leases to the wrapper objects that we use internally.
27 * <p>
28 * Internally we keep two tables of client leases, one mapping client
29 * leases to client lease wrappers, the other a list of client lease
30 * wrappers whose leases could not be unpacked (aka "deformed wrappers")
31 * when they were added (and thus could not be put in the map). This
32 * bifurcation is not exposed to the client.
33 * <p>
34 * Unless otherwise noted the methods of this class are not thread safe.
35 *
36 * @author Sun Microsystems, Inc.
37 */
38 class LeaseTable {
39 /**
40 * The list we store deformed wrappers in.
41 */
42 final private DeformedLeaseList deformedLeases = new DeformedLeaseList();
43
44 /**
45 * The map we use to map client leases to wrappers.
46 */
47 final private Map leaseTable = new HashMap();
48
49 /**
50 * Find the client lease wrapper associated with the passed lease.
51 *
52 * @param clientLease the lease we need the wrapper for
53 * @return the wrapper associated with the passed lease, or
54 * <code>null</code> if we don't know about this lease
55 */
56 ClientLeaseWrapper get(Lease clientLease) {
57 final ClientLeaseWrapper clw =
58 (ClientLeaseWrapper) leaseTable.get(clientLease);
59 if (clw == null) {
60 /*
61 * Could it be that this was a lease that could not be
62 * recovered? Check the deformed list.
63 */
64 return deformedLeases.query(clientLease, leaseTable);
65 } else {
66 return clw;
67 }
68 }
69
70 /**
71 * Add a mapping from lease wrapper to client lease. Gets client
72 * lease from wrapper.
73 *
74 * @param clw client lease wrapper, and client lease to add to
75 * table
76 */
77 void put(ClientLeaseWrapper clw) {
78 if (clw.isDeformed()) {
79 deformedLeases.add(clw);
80 } else {
81 leaseTable.put(clw.getClientLease(), clw);
82 }
83 }
84
85 /**
86 * Remove a lease from the table.
87 *
88 * @param clw client lease wrapper for the lease we want to
89 * remove
90 */
91 void remove(ClientLeaseWrapper clw) {
92 if (!clw.isDeformed()) {
93 /*
94 * Not deformed, we need to remove both the client lease and
95 * the wrapper from the leaseTable.
96 */
97 leaseTable.remove(clw.getClientLease());
98 } else {
99 /* Deformed, we need to remove the lease from the deformed
100 * list.
101 */
102 deformedLeases.remove(clw);
103 }
104 }
105 }