PreformanceCounterActor.cs

using Akka.Actor;
using System.Collections.Generic;

namespace Actors
{
    public class PreformanceCounterActor : ReceiveActor
    {
        private Dictionary<string, long> _counters;

        public PreformanceCounterActor()
        {
            _counters = new Dictionary<string, long>();

            Receive<string>(counterName => SetCounter(counterName));

            Receive<SetCounter>(setCounter => SetCounter(setCounter.Name));

            Receive<GetCounter>(getCounter => Sender.Tell(GetCounter(getCounter.Name)));
        }

        public void SetCounter(string counterName)
        {
            long counterValue;
            if (!_counters.TryGetValue(counterName, out counterValue))
            {
                counterValue = 0;
            }
            _counters[counterName] = ++counterValue;

        }

        public long GetCounter(string counterName)
        {
            long counterValue;
            return _counters.TryGetValue(counterName, out counterValue) ?
                counterValue:
                0;
        }
    }

    public class SetCounter
    {
        public string Name { get; private set; }

        public SetCounter(string counterName)
        {
            Name = counterName;
        }
    }

    public class GetCounter
    {
        public string Name { get; private set; }

        public GetCounter(string counterName)
        {
            Name = counterName;
        }
    }
}