From 8c0955321a5f0d4de21ceb9b98b4e329e1b56200 Mon Sep 17 00:00:00 2001
From: Justin Clarke Casey
Date: Mon, 24 Mar 2008 18:21:06 +0000
Subject: * Refactor: Genericise request limit strategies and move to
OpenSim.Framework.Communications.Limit
---
.../Communications/Limit/IRequestLimitStrategy.cs | 68 +++++++++++++
.../Communications/Limit/RepeatLimitStrategy.cs | 113 +++++++++++++++++++++
2 files changed, 181 insertions(+)
create mode 100644 OpenSim/Framework/Communications/Limit/IRequestLimitStrategy.cs
create mode 100644 OpenSim/Framework/Communications/Limit/RepeatLimitStrategy.cs
(limited to 'OpenSim/Framework')
diff --git a/OpenSim/Framework/Communications/Limit/IRequestLimitStrategy.cs b/OpenSim/Framework/Communications/Limit/IRequestLimitStrategy.cs
new file mode 100644
index 0000000..ded9ffc
--- /dev/null
+++ b/OpenSim/Framework/Communications/Limit/IRequestLimitStrategy.cs
@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) Contributors, http://opensimulator.org/
+ * See CONTRIBUTORS.TXT for a full list of copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of the OpenSim Project nor the
+ * names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+using System;
+
+namespace OpenSim.Framework.Communications.Limit
+{
+ ///
+ /// Interface for strategies that can limit requests from the client. Currently only used in the
+ /// texture modules to deal with repeated requests for certain textures. However, limiting strategies
+ /// could be used with other requests.
+ ///
+ public interface IRequestLimitStrategy
+ {
+ ///
+ /// Should the request be allowed? If the id is not monitored, then the request is always allowed.
+ /// Otherwise, the strategy criteria will be applied.
+ ///
+ ///
+ ///
+ bool AllowRequest(TId id);
+
+ ///
+ /// Has the request been refused just once?
+ ///
+ /// False if the request has not yet been refused, or if the request has been refused more
+ /// than once.
+ bool IsFirstRefusal(TId id);
+
+ ///
+ /// Start monitoring for future AllowRequest calls. If the id is already monitored, then monitoring
+ /// continues.
+ ///
+ ///
+ void MonitorRequests(TId id);
+
+ ///
+ /// Is the id being monitored?
+ ///
+ ///
+ ///
+ bool IsMonitoringRequests(TId id);
+ }
+}
diff --git a/OpenSim/Framework/Communications/Limit/RepeatLimitStrategy.cs b/OpenSim/Framework/Communications/Limit/RepeatLimitStrategy.cs
new file mode 100644
index 0000000..6dd0fa1
--- /dev/null
+++ b/OpenSim/Framework/Communications/Limit/RepeatLimitStrategy.cs
@@ -0,0 +1,113 @@
+/*
+ * Copyright (c) Contributors, http://opensimulator.org/
+ * See CONTRIBUTORS.TXT for a full list of copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of the OpenSim Project nor the
+ * names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+namespace OpenSim.Framework.Communications.Limit
+{
+ ///
+ /// Limit requests by discarding them after they've been repeated a certain number of times.
+ ///
+ public class RepeatLimitStrategy : IRequestLimitStrategy
+ {
+ private static readonly log4net.ILog m_log
+ = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
+
+ ///
+ /// Record each asset request that we're notified about.
+ ///
+ private readonly Dictionary requestCounts = new Dictionary();
+
+ ///
+ /// The maximum number of requests that can be made before we drop subsequent requests.
+ ///
+ private readonly int m_maxRequests;
+ public int MaxRequests
+ {
+ get { return m_maxRequests; }
+ }
+
+ ///
+ /// The maximum number of requests that may be served before all further
+ /// requests are dropped.
+ public RepeatLimitStrategy(int maxRequests)
+ {
+ m_maxRequests = maxRequests;
+ }
+
+ ///
+ ///
+ ///
+ public bool AllowRequest(TId id)
+ {
+ if (requestCounts.ContainsKey(id))
+ {
+ requestCounts[id] += 1;
+
+ if (requestCounts[id] > m_maxRequests)
+ {
+ return false;
+ }
+ }
+
+ return true;
+ }
+
+ ///
+ ///
+ ///
+ public bool IsFirstRefusal(TId id)
+ {
+ if (m_maxRequests + 1 == requestCounts[id])
+ {
+ return true;
+ }
+
+ return false;
+ }
+
+ ///
+ ///
+ ///
+ public void MonitorRequests(TId id)
+ {
+ if (!IsMonitoringRequests(id))
+ {
+ requestCounts.Add(id, 1);
+ }
+ }
+
+ ///
+ ///
+ ///
+ public bool IsMonitoringRequests(TId id)
+ {
+ return requestCounts.ContainsKey(id);
+ }
+ }
+}
--
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