clockwerk-opensim – Blame information for rev 1

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1 vero 1 /*
2 * Copyright (c) Contributors, http://opensimulator.org/
3 * See CONTRIBUTORS.TXT for a full list of copyright holders.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 * * Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * * Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * * Neither the name of the OpenSimulator Project nor the
13 * names of its contributors may be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
17 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
20 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
23 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
25 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27  
28 using System;
29 using System.Collections.Generic;
30  
31 namespace OpenSim.Framework.Communications.Limit
32 {
33 /// <summary>
34 /// Limit requests by discarding repeat attempts that occur within a given time period
35 ///
36 /// XXX Don't use this for limiting texture downloading, at least not until we better handle multiple requests
37 /// for the same texture at different resolutions.
38 /// </summary>
39 public class TimeLimitStrategy<TId> : IRequestLimitStrategy<TId>
40 {
41 /// <summary>
42 /// Record the time at which an asset request occurs.
43 /// </summary>
44 private readonly Dictionary<TId, Request> requests = new Dictionary<TId, Request>();
45  
46 /// <summary>
47 /// The minimum time period between which requests for the same data will be serviced.
48 /// </summary>
49 private readonly TimeSpan m_repeatPeriod;
50 public TimeSpan RepeatPeriod
51 {
52 get { return m_repeatPeriod; }
53 }
54  
55 /// <summary></summary>
56 /// <param name="repeatPeriod"></param>
57 public TimeLimitStrategy(TimeSpan repeatPeriod)
58 {
59 m_repeatPeriod = repeatPeriod;
60 }
61  
62 /// <summary>
63 /// <see cref="IRequestLimitStrategy"/>
64 /// </summary>
65 public bool AllowRequest(TId id)
66 {
67 if (IsMonitoringRequests(id))
68 {
69 DateTime now = DateTime.Now;
70 TimeSpan elapsed = now - requests[id].Time;
71  
72 if (elapsed < RepeatPeriod)
73 {
74 requests[id].Refusals += 1;
75 return false;
76 }
77  
78 requests[id].Time = now;
79 }
80  
81 return true;
82 }
83  
84 /// <summary>
85 /// <see cref="IRequestLimitStrategy"/>
86 /// </summary>
87 public bool IsFirstRefusal(TId id)
88 {
89 if (IsMonitoringRequests(id))
90 {
91 if (1 == requests[id].Refusals)
92 {
93 return true;
94 }
95 }
96  
97 return false;
98 }
99  
100 /// <summary>
101 /// <see cref="IRequestLimitStrategy"/>
102 /// </summary>
103 public void MonitorRequests(TId id)
104 {
105 if (!IsMonitoringRequests(id))
106 {
107 requests.Add(id, new Request(DateTime.Now));
108 }
109 }
110  
111 /// <summary>
112 /// <see cref="IRequestLimitStrategy"/>
113 /// </summary>
114 public bool IsMonitoringRequests(TId id)
115 {
116 return requests.ContainsKey(id);
117 }
118 }
119  
120 /// <summary>
121 /// Private request details.
122 /// </summary>
123 class Request
124 {
125 /// <summary>
126 /// Time of last request
127 /// </summary>
128 public DateTime Time;
129  
130 /// <summary>
131 /// Number of refusals associated with this request
132 /// </summary>
133 public int Refusals;
134  
135 public Request(DateTime time)
136 {
137 Time = time;
138 }
139 }
140 }