C# How to make a ConcurrentQueue to be cleaned by the condition - linq

Question

How to make a ConcurrentQueue to be cleaned by the condition for the first elements. Eg to clear older blog posts. I came up with this idea of a ConditionConcurrentQueue:
using System;
using System.Collections.Generic;
using System.Collections.Concurrent;
using System.Threading;
public class ConditionConcurrentQueue<T> : ConcurrentQueue<T>
where T: class
{
public ConditionConcurrentQueue(Func<T, bool> condition)
: this(null, condition)
{ }
public ConditionConcurrentQueue(IEnumerable<T> items, Func<T, bool> condition)
: base(items)
{
_condition = condition;
}
private Func<T, bool> _condition;
public virtual void Enqueue(T item)
{
T removed;
bool cleaningRun = true;
int failedCnt = 0;
while (!IsEmpty && cleaningRun && failedCnt < 10)
{
if (TryPeek(out removed))
{
bool result = _condition.Invoke(removed);
if (!result)
{
if (!TryDequeue(out removed))
{
failedCnt++;
Thread.Sleep(10);
}
}
else
cleaningRun = false;
}
else
{
failedCnt++;
Thread.Sleep(10);
}
}
base.Enqueue(item);
}
}
Use this ConditionConcurrentQueue could be so:
class Blog
{
public ConditionConcurrentQueue<Post> Posts { get; set; }
}
class Post
{
public DateTime Time { get; set; }
public string Text { get; set; }
}
class Program
{
static void Main(string[] args)
{
Blog blog = new Blog
{
Posts = new ConditionConcurrentQueue<Post>(
new Post[] {
new Post { Time = DateTime.Now - TimeSpan.FromMinutes(80), Text = "Title 1" },
new Post { Time = DateTime.Now - TimeSpan.FromMinutes(60), Text = "Title 2" },
new Post { Time = DateTime.Now - TimeSpan.FromMinutes(40), Text = "Title 3" },
},
p => p.Time > DateTime.Now - TimeSpan.FromHours(1))
};
blog.Posts.Enqueue(new Post { Time = DateTime.Now - TimeSpan.FromMinutes(20), Text = "Title 4" });
foreach (Post post in blog.Posts.ToList())
Console.WriteLine(post.Text);
}
}
maybe it is too primitive solution.
I would appreciate any improvements. Thanks.

Answer 1

also, you can try through the extension method:
public static ICollection<T> Enqueue<T>(this ConcurrentQueue<T> field, T item, Func<T, bool> predicate)
{
ICollection<T> removed = field.TryDequeue<T>(predicate);
field.Enqueue(item);
return removed;
}
public static ICollection<T> TryDequeue<T>(this ConcurrentQueue<T> field, Func<T, bool> predicate)
{
T comparedItem;
var removedList = new List<T>();
while (field.TryPeek(out comparedItem))
{
if (!predicate.Invoke(comparedItem))
{
if (field.TryDequeue(out comparedItem))
removedList.Add(comparedItem);
else
break;
}
else
break;
}
return removedList;
}

Answer 2

As of .NET Core 2.0 / .NET Standard 2.1 / .NET Framework 5.0, there is a Clear() method on ConcurrentQueue<T>. See: ConcurrentQueue.Clear.