/// <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 && _bucket.TryGet(index, out item))
{
return(item);
}
else
{
throw new System.InvalidOperationException("Empty");
}
}
/// <summary>
/// Determines whether the specified item is contained.
/// </summary>
/// <param name="item">The item.</param>
/// <param name="offset">The offset from the default index.</param>
/// <returns>The index where the item is set; -1 otherwise.</returns>
public int Contains(T item, int offset)
{
int index = Index(item, offset);
T entry;
if (_entries.TryGet(index, out entry))
{
if (_comparer.Equals(entry, item))
{
return(index);
}
else
{
return(-1);
}
}
else
{
return(-1);
}
}
/// <summary>
/// Determines whether the specified key is contained.
/// </summary>
/// <param name="key">The key.</param>
/// <param name="offset">The offset from the default index.</param>
/// <returns>The index where the key is set; -1 otherwise.</returns>
public int ContainsKey(TKey key, int offset)
{
int index = Index(key, offset);
KeyValuePair <TKey, TValue> entry;
if (_entries.TryGet(index, out entry))
{
if (_keyComparer.Equals(entry.Key, key))
{
return(index);
}
else
{
return(-1);
}
}
else
{
return(-1);
}
}
/// <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(_bucket.TryGet(index, out value));
}