public bool HasAttribute <T>(AttributeKey <T> key)
where T : class
{
Contract.Requires(key != null);
DefaultAttribute[] attrs = this.attributes;
if (attrs == null)
{
// no attribute exists
return(false);
}
int i = Index(key);
DefaultAttribute head = Volatile.Read(ref attrs[i]);
if (head == null)
{
// No attribute exists which point to the bucket in which the head should be located
return(false);
}
// check on the head can be done without synchronization
if (head.GetKey() == key && !head.Removed)
{
return(true);
}
lock (head)
{
// we need to synchronize on the head
DefaultAttribute curr = head.Next;
while (curr != null)
{
if (!curr.Removed && curr.GetKey() == key)
{
return(true);
}
curr = curr.Next;
}
return(false);
}
}
static int Index <T>(AttributeKey <T> key) => key.Id & Mask;