private DictionaryTree <TKey, TValue> Underlay(DictionaryTree <TKey, TValue> overridingInstance)
{
lock (_syncRoot)
{
if (overridingInstance == null)
{
overridingInstance = new DictionaryTree <TKey, TValue>();
}
foreach (var pair in _localEntries)
{
if (!overridingInstance.LocalEntries.ContainsKey(pair.Key))
{
overridingInstance.LocalEntries.Add(pair.Key, pair.Value);
}
}
foreach (var pair in LocalDefaults)
{
if (!overridingInstance.LocalDefaults.ContainsKey(pair.Key))
{
overridingInstance.LocalDefaults.Add(pair.Key, pair.Value);
}
}
return(overridingInstance);
}
}
/// <summary>
/// This returns all entries found in Defaults, Parents, and the Primary dictionary.
/// Defaults are entered first, then each parent (from oldest to newest) adds or updates entries,
/// and finally the Primary entries are enumerated to update whatever already exists, adding
/// whatever has not yet been entered. This ensures that only the final values will appear for
/// each unique key.
/// </summary>
public DictionaryTree <TKey, TValue> Flatten(DictionaryTree <TKey, TValue> overridingInstance)
{
lock (_syncRoot)
{
if (overridingInstance == null)
{
overridingInstance = new DictionaryTree <TKey, TValue>();
}
overridingInstance = Underlay(overridingInstance);
// add missing entries from each of the parents, newest to oldest, flattening each in turn
for (var x = Parents.Count - 1; x >= 0; x--)
{
// parents are only adding entries for keys that don't yet exist
overridingInstance = Parents[x].Flatten(overridingInstance);
}
return(overridingInstance);
}
}
