/// <summary>
/// Remove dead entries from the data for the given source. Returns true if
/// some entries were actually removed.
/// </summary>
protected override bool Purge(object source, object data, bool purgeAll)
{
bool foundDirt = false;
HybridDictionary dict = (HybridDictionary)data;
// copy the keys into a separate array, so that later on
// we can change the dictionary while iterating over the keys
ICollection ic = dict.Keys;
PropertyDescriptor[] keys = new PropertyDescriptor[ic.Count];
ic.CopyTo(keys, 0);
for (int i = keys.Length - 1; i >= 0; --i)
{
// for each key, remove dead entries in its list
bool removeList = purgeAll || source == null;
ValueChangedRecord record = (ValueChangedRecord)dict[keys[i]];
if (!removeList)
{
if (record.Purge())
{
foundDirt = true;
}
removeList = record.IsEmpty;
}
// if there are no more entries, remove the key
if (removeList)
{
record.StopListening();
if (!purgeAll)
{
dict.Remove(keys[i]);
}
}
}
// if there are no more listeners at all, remove the entry from
// the main table
if (dict.Count == 0)
{
foundDirt = true;
if (source != null) // source may have been GC'd
{
this.Remove(source);
}
}
return(foundDirt);
}
/// <summary>
/// Remove dead entries from the data for the given source. Returns true if
/// some entries were actually removed.
/// </summary>
protected override bool Purge(object source, object data, bool purgeAll)
{
bool foundDirt = false;
HybridDictionary dict = (HybridDictionary)data;
if (!MS.Internal.BaseAppContextSwitches.EnableWeakEventMemoryImprovements)
{
// copy the keys into a separate array, so that later on
// we can change the dictionary while iterating over the keys
ICollection ic = dict.Keys;
PropertyDescriptor[] keys = new PropertyDescriptor[ic.Count];
ic.CopyTo(keys, 0);
for (int i = keys.Length - 1; i >= 0; --i)
{
// for each key, remove dead entries in its list
bool removeList = purgeAll || source == null;
ValueChangedRecord record = (ValueChangedRecord)dict[keys[i]];
if (!removeList)
{
if (record.Purge())
{
foundDirt = true;
}
removeList = record.IsEmpty;
}
// if there are no more entries, remove the key
if (removeList)
{
record.StopListening();
if (!purgeAll)
{
dict.Remove(keys[i]);
}
}
}
#if WeakEventTelemetry
LogAllocation(ic.GetType(), 1, 12); // dict.Keys - Hashtable+KeyCollection
LogAllocation(typeof(String[]), 1, 12 + ic.Count * 4); // keys
#endif
}
else
{
Debug.Assert(_toRemove.Count == 0, "to-remove list should be empty");
// enumerate the dictionary using IDE explicitly rather than
// foreach, to avoid allocating temporary DictionaryEntry objects
IDictionaryEnumerator ide = dict.GetEnumerator() as IDictionaryEnumerator;
while (ide.MoveNext())
{
// for each key, remove dead entries in its list
bool removeList = purgeAll || source == null;
ValueChangedRecord record = (ValueChangedRecord)ide.Value;
if (!removeList)
{
if (record.Purge())
{
foundDirt = true;
}
removeList = record.IsEmpty;
}
// if there are no more entries, remove the key
if (removeList)
{
record.StopListening();
if (!purgeAll)
{
_toRemove.Add((PropertyDescriptor)ide.Key);
}
}
}
// do the actual removal (outside the dictionary iteration)
if (_toRemove.Count > 0)
{
foreach (PropertyDescriptor key in _toRemove)
{
dict.Remove(key);
}
_toRemove.Clear();
_toRemove.TrimExcess();
}
#if WeakEventTelemetry
Type enumeratorType = ide.GetType();
if (enumeratorType.Name.IndexOf("NodeEnumerator") >= 0)
{
LogAllocation(enumeratorType, 1, 24); // ListDictionary+NodeEnumerator
}
else
{
LogAllocation(enumeratorType, 1, 36); // Hashtable+HashtableEnumerator
}
#endif
}
// if there are no more listeners at all, remove the entry from
// the main table
if (dict.Count == 0)
{
foundDirt = true;
if (source != null) // source may have been GC'd
{
this.Remove(source);
}
}
return(foundDirt);
}