private LinkedListNode <OrderBook> PrepareNextNode()
{
LinkedListNode <OrderBook> nextNode;
int?periodSynchronizationToken;
lock (_locker)
{
nextNode = _currentNode != null ? _currentNode.Next : _history.First;
periodSynchronizationToken = _lastPeriodSynchronizationToken;
}
if (nextNode == null)
{
if (!_loader.LoadData(periodSynchronizationToken))
{
_hasNoMoreData = true;
return(null);
}
}
lock (_locker)
{
return(_currentNode != null ? _currentNode.Next : _history.First);
}
}
/// <summary>
/// Removes next order book entry from history and returns it.
/// </summary>
/// <returns>Next order book entry from history.</returns>
public OrderBook GetNext()
{
int historyCount;
int?periodSynchronizationToken;
lock (_locker)
{
historyCount = _history.Count;
periodSynchronizationToken = _lastPeriodSynchronizationToken;
}
if (historyCount == 0)
{
if (!_loader.LoadData(periodSynchronizationToken))
{
return(null);
}
}
lock (_locker)
{
var next = _history.First;
_history.RemoveFirst();
return(next.Value);
}
}
