OpenSim-Test/OpenSim/Framework/Communications/Limit/RepeatLimitStrategy.cs

/*
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 *       derived from this software without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
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 */

using System;
using System.Collections.Generic;

namespace OpenSim.Framework.Communications.Limit
{
    /// <summary>
    /// Limit requests by discarding them after they've been repeated a certain number of times.
    /// </summary>    
    public class RepeatLimitStrategy<TId> : IRequestLimitStrategy<TId>
    {
        /// <summary>
        /// Record each asset request that we're notified about.
        /// </summary>
        private readonly Dictionary<TId, int> requestCounts = new Dictionary<TId, int>();
        
        /// <summary>
        /// The maximum number of requests that can be made before we drop subsequent requests.
        /// </summary>
        private readonly int m_maxRequests;
        public int MaxRequests
        {
            get { return m_maxRequests; }
        }
       
        /// <summary></summary>
        /// <param name="maxRequests">The maximum number of requests that may be served before all further
        /// requests are dropped.</param>
        public RepeatLimitStrategy(int maxRequests)
        {
            m_maxRequests = maxRequests;
        }
        
        /// <summary>
        /// <see cref="IRequestLimitStrategy"/>
        /// </summary>
        public bool AllowRequest(TId id)
        {                 
            if (requestCounts.ContainsKey(id))
            {
                requestCounts[id] += 1;
                
                if (requestCounts[id] > m_maxRequests)
                {                    
                    return false;
                }                                                         
            }
            
            return true;
        }
        
        /// <summary>
        /// <see cref="IRequestLimitStrategy"/>
        /// </summary>        
        public bool IsFirstRefusal(TId id)
        {
            if (m_maxRequests + 1 == requestCounts[id])
            {
                return true;
            }            
            
            return false;
        }
        
        /// <summary>
        /// <see cref="IRequestLimitStrategy"/>
        /// </summary>        
        public void MonitorRequests(TId id)
        {
            if (!IsMonitoringRequests(id))
            {
                requestCounts.Add(id, 1);
            }            
        }  
        
        /// <summary>
        /// <see cref="IRequestLimitStrategy"/>
        /// </summary>         
        public bool IsMonitoringRequests(TId id)
        {
            return requestCounts.ContainsKey(id);
        }
    }
}