StopwatchRecorder.cs

using System;
using System.Diagnostics;
using System.Collections.Generic;
using System.Linq;

namespace NG.Diagnostics
{
    /// <summary>
    /// Derives from System.Diagnostics.Stopwatch
    /// Adds the ability to stop and restart the stopwatch multiple times
    /// and record the total time elapsed, minimum & maximum time elapsed,
    /// and the average time elapsed from all calls to this stopwatch.
    /// </summary>
    public class StopwatchRecorder : Stopwatch
    {
        private List<long> capturedMilliseconds = new List<long>();
        private List<KeyValuePair<long, int>> sumCountsPairs = new List<KeyValuePair<long, int>>();
        private int bufferSize = int.MaxValue - 1;

        /// <summary>
        /// The total time recorded by this stopwatch even after restarts.
        /// </summary>
        public ulong TotalElapsedMilliseconds { get; private set; }

        /// <summary>
        /// This minimum amount of time elapsed during a run of this stopwatch.
        /// </summary>
        public long MinimumElapsedMilliseconds { get; private set; }

        /// <summary>
        /// This maximum amount of time elapsed during a run of this stopwatch.
        /// </summary>
        public long MaximumElapsedMilliseconds { get; private set; }

        /// <summary>
        /// The average time elapsed during a run of this stopwatch.
        /// </summary>
        public double AverageElapsedMilliseconds
        {
            get
            {
                ulong count = (uint)capturedMilliseconds.Count;
                double sum = 0;

                if (count > 0)
                    sum = capturedMilliseconds.Sum();

                foreach (var item in sumCountsPairs)
                {
                    ulong maxCheck = ulong.MaxValue - count;
                    if ((uint)item.Value < maxCheck)
                        count += (uint)item.Value;
                    else
                        break;
                    sum += item.Key;
                }

                if (count > 0)
                    return (sum / count);
                else
                    return 0;
            }
        }

        /// <summary>
        /// The amount of time elapsed in the last run of this stopwatch.
        /// </summary>
        public long LastElapsedMilliseconds
        {
            get
            {
                if (capturedMilliseconds.Count > 0)
                    return capturedMilliseconds.Last();
                else
                    return -1;
            }
        }


        public new void Stop()
        {
            base.Stop();

            if (MinimumElapsedMilliseconds == 0)
                MinimumElapsedMilliseconds = ElapsedMilliseconds;
            else
                MinimumElapsedMilliseconds = Math.Min(ElapsedMilliseconds, MinimumElapsedMilliseconds);

            MaximumElapsedMilliseconds = Math.Max(ElapsedMilliseconds, MaximumElapsedMilliseconds);

            if (capturedMilliseconds.Count >= bufferSize)
            {
                sumCountsPairs.Add(
                    new KeyValuePair<long, int>(
                        capturedMilliseconds.Sum(), capturedMilliseconds.Count));
                capturedMilliseconds.Clear();
            }
            capturedMilliseconds.Add(ElapsedMilliseconds);
            TotalElapsedMilliseconds += (ulong)ElapsedMilliseconds;

            Reset();
        }
    }
}