// Removes the left-over weak references for entries in the dictionary
// whose key has already been reclaimed by the garbage
// collector. This will reduce the dictionary's Count by the number
// of dead key-value pairs that were eliminated.
public void RemoveCollectedEntries()
{
List <object> toRemove = null;
foreach (KeyValuePair <object, TValue> pair in this.dictionary)
{
WeakKeyReference <TKey> weakKey = (WeakKeyReference <TKey>)(pair.Key);
if (!weakKey.IsAlive)
{
if (toRemove == null)
{
toRemove = new List <object>();
}
toRemove.Add(weakKey);
}
}
if (toRemove != null)
{
foreach (object key in toRemove)
{
this.dictionary.Remove(key);
}
}
}
public override void Add(TKey key, TValue value)
{
if (key == null)
{
throw new ArgumentNullException("key");
}
WeakKeyReference <TKey> weakKey = new WeakKeyReference <TKey>(key, this.comparer);
this.dictionary.Add(weakKey, value);
}
public int GetHashCode(object obj)
{
WeakKeyReference <T> weakKey = obj as WeakKeyReference <T>;
if (weakKey != null)
{
return(weakKey.HashCode);
}
return(this.comparer.GetHashCode((T)obj));
}
public override IEnumerator <KeyValuePair <TKey, TValue> > GetEnumerator()
{
foreach (KeyValuePair <object, TValue> kvp in this.dictionary)
{
WeakKeyReference <TKey> weakKey = (WeakKeyReference <TKey>)(kvp.Key);
TKey key = weakKey.Target;
TValue value = kvp.Value;
if (weakKey.IsAlive)
{
yield return(new KeyValuePair <TKey, TValue>(key, value));
}
}
}
private static T GetTarget(object obj, out bool isDead)
{
WeakKeyReference <T> wref = obj as WeakKeyReference <T>;
T target;
if (wref != null)
{
target = wref.Target;
isDead = !wref.IsAlive;
}
else
{
target = (T)obj;
isDead = false;
}
return(target);
}
protected override void SetValue(TKey key, TValue value)
{
WeakKeyReference <TKey> weakKey = new WeakKeyReference <TKey>(key, this.comparer);
this.dictionary[weakKey] = value;
}
