internal Enumerator(LinkedQueue <T> q)
{
this._q = q;
this._version = q._version;
this._status = 0;
this._currentElement = null;
}
/// <summary>Determines whether an element is in the <see cref="T:Common.Collections.Generic.LinkedQueue`1" />.</summary>
/// <returns>true if <paramref name="item" /> is found in the <see cref="T:Common.Collections.Generic.LinkedQueue`1" />; otherwise, false.</returns>
/// <param name="item">The object to locate in the <see cref="T:Common.Collections.Generic.LinkedQueue`1" />. The value can be null for reference types.</param>
public bool Contains(T item)
{
bool find = false;
LinkedQueueNode <T> temp = _head;
while (temp != null && !find)
{
find = temp.Value.Equals(item);
temp = temp._next;
}
return(find);
}
/// <summary>Copies the <see cref="T:Common.Collections.Generic.LinkedQueue`1" /> elements to a new array.</summary>
/// <returns>A new array containing elements copied from the <see cref="T:Common.Collections.Generic.LinkedQueue`1" />.</returns>
public T[] ToArray()
{
T[] array = new T[_size];
LinkedQueueNode <T> temp = _head;
int i = 0;
while (temp != null)
{
array[i++] = temp.Value;
temp = temp._next;
}
return(array);
}
/// <summary>Sets the enumerator to its initial position, which is before the first element in the collection.</summary>
/// <exception cref="T:System.InvalidOperationException">The collection was modified or disposed after the enumerator was created. </exception>
void IEnumerator.Reset()
{
if (this._status == 3)
{
throw new InvalidOperationException("It has been disposed");
}
if (this._version != this._q._version)
{
throw new InvalidOperationException("The queue has been changed");
}
this._status = 0;
this._currentElement = null;
}
/// <summary>
/// Removes all objects from the <see cref="T:Common.Collections.Generic.LinkedQueue`1" />.
/// </summary>
public void Clear()
{
if (_head == null)
{
return;
}
LinkedQueueNode <T> temp = _head;
do
{
temp.Invalid();
temp = temp._next;
}while (temp != null);
_size = 0;
_version++;
}
/// <summary>Adds an object to the end of the <see cref="T:Common.Collections.Generic.LinkedQueue`1" />.</summary>
/// <param name="item">The object to add to the <see cref="T:Common.Collections.Generic.LinkedQueue`1" />. The value can be null for reference types.</param>
public void Enqueue(T item)
{
LinkedQueueNode <T> newNode = new LinkedQueueNode <T>(item);
if (_tail == null)
{
_head = newNode;
_tail = newNode;
}
else
{
_tail._next = newNode;
_tail = newNode;
}
_size++;
_version++;
}
/// <summary>Advances the enumerator to the next element of the <see cref="T:Common.Collections.Generic.LinkedQueue`1" />.</summary>
/// <returns>true if the enumerator was successfully advanced to the next element; false if the enumerator has passed the end of the collection.</returns>
/// <exception cref="T:System.InvalidOperationException">The collection was modified or disposed after the enumerator was created. </exception>
public bool MoveNext()
{
if (this._status == 3)
{
throw new InvalidOperationException("It has been disposed");
}
if (this._version != this._q._version)
{
throw new InvalidOperationException("The queue has been changed");
}
if (this._status == 2)
{
return(false);
}
if (this._q.Count == 0)
{
this._status = 2;
return(false);
}
if (this._status == 0)
{
this._currentElement = _q._head;
this._status = 1;
return(true);
}
if (this._currentElement._next == null)
{
this._status = 2;
this._currentElement = null;
return(false);
}
this._currentElement = _currentElement._next;
return(true);
}
/// <summary>Removes and returns the object at the beginning of the <see cref="T:Common.Collections.Generic.LinkedQueue`1" />.</summary>
/// <returns>The object that is removed from the beginning of the <see cref="T:Common.Collections.Generic.LinkedQueue`1" />.</returns>
/// <exception cref="T:System.InvalidOperationException">The <see cref="T:Common.Collections.Generic.LinkedQueue`1" /> is empty.</exception>
public LinkedQueueNode <T> Dequeue()
{
if (_head == null)
{
throw new InvalidOperationException("The queue is empty.");
}
LinkedQueueNode <T> node = _head;
_head = _head._next;
if (_head == null)
{
_tail = null;
}
_size--;
_version++;
return(node);
}
internal void Invalid()
{
_item = default(T);
_next = null;
}
/// <summary>Releases all resources used by the <see cref="T:Common.Collections.Generic.LinkedQueue`1.Enumerator" />.</summary>
public void Dispose()
{
this._status = 3;
this._q = null;
this._currentElement = null;
}
/// <summary>
/// Initializes a new instance of the <see cref="T:Common.Collections.Generic.LinkedQueue`1" /> class that is empty.
/// </summary>
public LinkedQueue()
{
_head = null;
_tail = null;
}