Time the FileCache.Find operation in the BruTile library.

BruTileFileCacheTime

using BruTile;
using BruTile.Cache;
using System;
using System.Diagnostics;
using System.Threading;

namespace TimeFileCache
{
    //    == using lock/Monitor ==
    //    == 20 tiles fetched ==
    //    Average FileCache.Find time is 0.6ms
    //    Max time is 2ms
    //    Min time is 0ms
    //
    //    == 500 tiles fetched ==
    //    Average FileCache.Find time is 0.926ms
    //    Max time is 17ms
    //    Min time is 0ms
    //
    //    == Change to ReaderWriterLockSlim ==
    //    == 20 tiles fetched ==
    //    Average FileCache.Find time is 0ms
    //    Max time is 0ms
    //    Min time is 0ms
    //
    //    == 500 tiles fetched ==
    //    Average FileCache.Find time is 0.004ms
    //    Max time is 1ms
    //    Min time is 0ms
    class Program
    {
        private static long cacheTime = 0;
        private static long minTime = long.MaxValue;
        private static long maxTime = long.MinValue;
        private static object timeLock = new object();
        private static int threadCompleteCount = 0;

        static void Main(string[] args)
        {
            var cache = new FileCache(@"c:\FileCache", "png");
            int testCount = 500;

            for (int i = 0; i < testCount; i++)
            {
                cache.Add(new TileIndex(i % 10, i / 10, "1"), new byte[] { (byte)i });
            }
            for (int i = 0; i < testCount; i++)
            {
                var tileIndex = new TileIndex(i % 10, i / 10, "1");
                ThreadPool.QueueUserWorkItem(o => TimeCache(cache, tileIndex));
            }
            while (Interlocked.CompareExchange(ref threadCompleteCount, 0, testCount) != testCount)
            {
                Thread.Sleep(50);
            }
            Console.WriteLine("Average FileCache.Find time is {0}ms", (double)cacheTime / testCount);
            Console.WriteLine("Max time is {0}ms", maxTime);
            Console.WriteLine("Min time is {0}ms", minTime);
        }

        static void TimeCache(IPersistentCache<byte[]> cache, TileIndex index)
        {
            var stopwatch = Stopwatch.StartNew();
            var bytes = cache.Find(index);
            stopwatch.Stop();
            lock(timeLock)
            {
                cacheTime += stopwatch.ElapsedMilliseconds;
                minTime = Math.Min(minTime, stopwatch.ElapsedMilliseconds);
                maxTime = Math.Max(maxTime, stopwatch.ElapsedMilliseconds);
            }
            Interlocked.Increment(ref threadCompleteCount);
        }
    }
}