Create Data Pool using Concurrent Queue

      

Scenario:

Create Data Pool of numbers using Concurrent Queue.

Solution:

C# ConcurrentQueue is a thread-safe collection class. It is introduced in .NET 4.0 with other concurrent collection classes. It provides a thread-safe First-In-First-Out (FIFO) data structure. ConcurrentQueue exists in System.Collections.Concurrent namespace. ConcurrentQueue is a wrapper around generic Queue class

using System.Collections.Concurrent;

namespace TestProject
{
    public class PoolNextData
    {
        private readonly Dictionary<string, ConcurrentQueue<long>> _dataPool;
        private int _poolLength;

        public PoolNextData()
        {
            _dataPool = new Dictionary<string, ConcurrentQueue<long>>();
        }

        private long[] GetNextData(ConcurrentQueue<long> pool, string kind, int noOfRecords)
        {
            var result = new List<long>();

            for (var i = 0; i < noOfRecords; i++)
            {
                long data;
                if (!pool.TryDequeue(out data))
                {
                    break;
                }

                result.Add(data);
            }

            //not enough available, put it back
            if (result.Count < noOfRecords)
            {
                FillPool(pool, kind, noOfRecords - result.Count + _poolLength);

                result.ForEach(pool.Enqueue);
            }
            else
            {
                Task.Factory.StartNew(() => FillPool(pool, kind, noOfRecords));
            }

            return result.ToArray();
        }
        private void FillPool(ConcurrentQueue<long> pool, string kind, int noOfRecords)
        {
            //Get next numbers list from DB

            var nos = new List<long>();
            nos.ForEach(pool.Enqueue);
        }

        private ConcurrentQueue<long> GetPool(string kind)
        {
            var result = new ConcurrentQueue<long>();
            _dataPool.Add(kind, result);

            return result;
        }
    }
}