/// <summary>
/// Returns the next item to be taken from the back without removing it.
/// </summary>
/// <exception cref="System.InvalidOperationException">No more items to be taken.</exception>
public T Peek()
{
T item;
int index = Interlocked.Add(ref _indexEnqueue, 0);
if (index < _capacity && index > 0 && _entries.TryGet(index, out item))
{
return(item);
}
throw new InvalidOperationException("Empty");
}
/// <inheritdoc />
/// <summary>
/// Determines whether the specified value is contained.
/// </summary>
/// <param name="value">The value.</param>
/// <returns>
/// <c>true</c> if the specified value is contained; otherwise, <c>false</c>.
/// </returns>
public bool Contains(T value)
{
// ReSharper disable once AssignNullToNotNullAttribute
var hashCode = Comparer.GetHashCode(value);
for (var attempts = 0; attempts < _probing; attempts++)
{
if (_bucket.TryGet(hashCode + attempts, out var found) && Comparer.Equals(found, value))
{
return(true);
}
}
return(false);
}
/// <summary>
/// Determines whether the specified value is contained.
/// </summary>
/// <param name="value">The value.</param>
/// <returns>
/// <c>true</c> if the specified value is contained; otherwise, <c>false</c>.
/// </returns>
public bool Contains(T value)
{
var hashCode = _comparer.GetHashCode(value);
for (var attempts = 0; attempts < _probing; attempts++)
{
T found;
if (_bucket.TryGet(hashCode + attempts, out found))
{
if (_comparer.Equals(found, value))
{
return(true);
}
}
}
return(false);
}
/// <summary>
/// Determines whether the specified value is contained.
/// </summary>
/// <param name="hashCode">The hash code to look for.</param>
/// <param name="check">The value predicate.</param>
/// <returns>
/// <c>true</c> if the specified value is contained; otherwise, <c>false</c>.
/// </returns>
public bool Contains(int hashCode, Predicate <T> check)
{
if (check == null)
{
throw new ArgumentNullException(nameof(check));
}
for (var attempts = 0; attempts < _probing; attempts++)
{
if (_bucket.TryGet(hashCode + attempts, out var found) && GetHashCode(found) == hashCode && check(found))
{
return(true);
}
}
return(false);
}
/// <summary>
/// Tries to retrieve the item at the specified index.
/// </summary>
/// <param name="index">The index.</param>
/// <param name="value">The value.</param>
/// <returns>
/// <c>true</c> if the item was retrieved; otherwise, <c>false</c>.
/// </returns>
/// <exception cref="System.ArgumentOutOfRangeException">index;index must be greater or equal to 0 and less than capacity</exception>
public bool TryGet(int index, out T value)
{
return(_entries.TryGet(index, out value));
}