You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
Zero/ZeroLevel/Services/Collections/FixSizeQueue.cs

140 lines
3.8 KiB

using System;
using System.Collections.Generic;
namespace ZeroLevel.Services.Collections
{
public sealed class FixSizeQueue<T> :
IFixSizeQueue<T>
{
private readonly T[] _array;
private long _nextIndex;
private long _startIndex;
private long _count;
private readonly object _accessLocker = new object();
public FixSizeQueue(long capacity)
{
if (capacity <= 0)
{
capacity = 1024;
}
_array = new T[capacity];
_nextIndex = 0;
_count = 0;
}
/// <summary>
/// If count is limited when intem adding, oldest item replace with new item
/// </summary>
public void Push(T item)
{
lock (_accessLocker)
{
_array[_nextIndex] = item;
_nextIndex = (_nextIndex + 1) % _array.Length;
if (_count < _array.Length)
{
_count++;
}
else
{
_startIndex = (_startIndex + 1) % _array.Length;
}
}
}
public bool Equals(T x, T y)
{
if (x == null && y == null!) return true;
if (x == null || y == null!) return false;
if ((object)x == (object)y) return true;
if (ReferenceEquals(x, y)) return true;
return x.Equals(y);
}
public bool Contains(T item, IComparer<T> comparer = null!)
{
lock (_accessLocker)
{
Func<T, T, bool> eq_func;
if (comparer == null!)
{
eq_func = Equals;
}
else
{
eq_func = (x, y) => comparer.Compare(x, y) == 0;
}
var cursor = _startIndex;
if (_count > 0)
{
do
{
if (eq_func(_array[cursor], item))
return true;
cursor = (cursor + 1) % _array.Length;
} while (cursor != _nextIndex);
}
}
return false;
}
public long Count
{
get
{
return _count;
}
}
public bool TryTake(out T t)
{
lock (_accessLocker)
{
if (_count > 0)
{
t = _array[_startIndex];
_array[_startIndex] = default(T)!;
_startIndex = (_startIndex + 1) % _array.Length;
_count--;
return true;
}
}
t = default(T)!;
return false;
}
public T Take()
{
T ret;
lock (_accessLocker)
{
if (_count > 0)
{
ret = _array[_startIndex];
_array[_startIndex] = default(T)!;
_startIndex = (_startIndex + 1) % _array.Length;
_count--;
return ret;
}
}
throw new System.Exception("Collection is empty");
}
public IEnumerable<T> Dump()
{
lock (_accessLocker)
{
var cursor = _startIndex;
if (_count > 0)
{
do
{
yield return _array[cursor];
cursor = (cursor + 1) % _array.Length;
} while (cursor != _nextIndex);
}
}
}
}
}

Powered by TurnKey Linux.