LogException in Interval Class

Program.cs

//        The MIT License(MIT)

//Copyright(c) 2016 alex-doe

//Permission is hereby granted, free of charge, to any person obtaining a copy
//of this software and associated documentation files(the "Software"), to deal
//in the Software without restriction, including without limitation the rights
//to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//copies of the Software, and to permit persons to whom the Software is
//furnished to do so, subject to the following conditions:

//The above copyright notice and this permission notice shall be included in all
//copies or substantial portions of the Software.

//THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
//AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
//SOFTWARE.

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading;

namespace TestExceptionClass {
    class Program {
        static void Main(string[] args) {
            var exceptionInTimeHandler = new ExceptionInTimeHandler(TimeSpan.FromSeconds(60));
            DateTime starttime = DateTime.UtcNow;
            while (true) {
                try {
                    //throw every cycle
                    DirectoryInfo info = new DirectoryInfo("E:\\Temp");
                    info.GetFiles();
                } catch (Exception ex) {
                    exceptionInTimeHandler.LogException(ex);
                }

                try {
                    //throw every 4 seconds
                    if (starttime.AddSeconds(4) <= DateTime.UtcNow) {
                        var infoexalle2 = new DirectoryInfo("C:\\Tempasdfasdf");
                        infoexalle2.GetFiles();
                    }
                } catch (Exception ex) {
                    exceptionInTimeHandler.LogException(ex);
                }

                try {
                    //throw every 7 seconds
                    if (starttime.AddSeconds(7) <= DateTime.UtcNow) {
                        throw new NotImplementedException("Test impl ex 1");
                    }
                } catch (Exception ex) {
                    exceptionInTimeHandler.LogException(ex);
                }

                Thread.Sleep(TimeSpan.FromSeconds(2));
            }
        }
    }

    public class ExceptionInTimeHandler {
        private readonly List<TimedExceptionEntry> _exceptionEntries;
        private readonly TimeSpan _logInterval;

        public ExceptionInTimeHandler(TimeSpan logInterval) {
            _logInterval = logInterval;
            _exceptionEntries = new List<TimedExceptionEntry>();
        }

        public void LogException(Exception ex) {
            //todo optimize compare
            if (_exceptionEntries.Any(e => e.Exception.StackTrace == ex.StackTrace) &&
                _exceptionEntries.Any(e => e.Exception.Message == ex.Message)) {
                var exception = _exceptionEntries.Single(e => e.Exception.StackTrace == ex.StackTrace && e.Exception.Message == ex.Message);
                if (exception.LastLogTime.Add(_logInterval) > DateTime.UtcNow) return;
                exception.LastLogTime = DateTime.UtcNow;
            } else {
                _exceptionEntries.Add(new TimedExceptionEntry(ex));
            }
            Logger.Instance.LogFormat(ex.ToString());
        }

        private class TimedExceptionEntry {
            public Exception Exception { get; set; }
            public DateTime LastLogTime { get; set; }

            public TimedExceptionEntry(Exception exception) {
                Exception = exception;
                LastLogTime = DateTime.UtcNow;
            }
        }
    }

    //fake logger
    public class Logger {
        private static Logger _logger;
        public static Logger Instance => _logger ?? (_logger = new Logger());

        public void LogFormat(string text) {
            Console.WriteLine(text);
        }
    }
}