/// <summary>Adds the given element to this lookup.</summary>
public void Add(string key, Element ele)
{
// Create link:
AttributeLookupLink link = new AttributeLookupLink(ele);
// Already got a link?
AttributeLookupLink chain;
if (!Lookup.TryGetValue(key, out chain))
{
// Add it now:
Lookup.Add(key, link);
return;
}
// Follow the chain to the end and add it there:
// We do this because it's rare in comparison to finding the "first" one which is always at the front.
while (chain.Next != null)
{
chain = chain.Next;
}
// Add to the end:
chain.Next = link;
}
/// <summary>Removes the given element value from this lookup.</summary>
/// <returns>True if the cache should also be removed.</returns>
public bool Remove(string key, Element ele)
{
AttributeLookupLink chain;
if (!Lookup.TryGetValue(key, out chain))
{
return(false);
}
AttributeLookupLink previous = null;
// Scan the chain looking for ele:
while (chain != null)
{
if (chain.Element == ele)
{
// Chop it out.
if (previous == null)
{
// Removing the first one.
if (chain.Next == null)
{
// Obliterate it!
Lookup.Remove(key);
if (Lookup.Count == 0)
{
// Remove this cache.
return(true);
}
return(false);
}
else
{
// We're going to keep this link in the lookup,
// rather than removing it and putting the next one in instead.
chain.Element = chain.Next.Element;
chain.Next = chain.Next.Next;
}
}
else
{
previous.Next = chain.Next;
}
}
previous = chain;
chain = chain.Next;
}
return(false);
}