/Main/src/Samples/v0.2/PerfCounter/Filters.cs

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;



namespace PerfCounterChart

{

	public class MaxSizeFilter : IFilter<PerformanceInfo>

	{

		TimeSpan length = TimeSpan.FromSeconds(10);

		public IList<PerformanceInfo> Filter(IList<PerformanceInfo> c)

		{

			if (c.Count == 0)

				return new List<PerformanceInfo>();



			DateTime end = c[c.Count - 1].Time;



			int startIndex = 0;

			for (int i = 0; i < c.Count; i++)

			{

				if (end - c[i].Time <= length)

				{

					startIndex = i;

					break;

				}

			}



			List<PerformanceInfo> res = new List<PerformanceInfo>(c.Count - startIndex);

			for (int i = startIndex; i < c.Count; i++)

			{

				res.Add(c[i]);

			}

			return res;

		}



	}



	public class FilterChain : IFilter<PerformanceInfo>

	{

		private readonly IFilter<PerformanceInfo>[] filters;

		public FilterChain(params IFilter<PerformanceInfo>[] filters)

		{

			this.filters = filters;

		}



		#region IFilter<PerformanceInfo> Members



		public IList<PerformanceInfo> Filter(IList<PerformanceInfo> c)

		{

			foreach (var filter in filters)

			{

				c = filter.Filter(c);

			}

			return c;

		}



		#endregion

	}



	public class AverageFilter : IFilter<PerformanceInfo>

	{

		private int number = 2;

		public int Number

		{

			get { return number; }

			set { number = value; }

		}



		public IList<PerformanceInfo> Filter(IList<PerformanceInfo> c)

		{

			int num = number - 1;

			if (c.Count - num <= 0)

				return c;



			List<PerformanceInfo> res = new List<PerformanceInfo>(c.Count - num);

			for (int i = 0; i < c.Count - num; i++)

			{

				double doubleSum = 0;

				long ticksSum = 0;

				for (int j = i; j < i + number; j++)

				{

					doubleSum += c[j].Value;

					ticksSum += c[j].Time.Ticks / number;

				}

				doubleSum /= number;

				res.Add(new PerformanceInfo { Time = new DateTime(ticksSum), Value = doubleSum });

			}

			return res;

		}

	}

}