//
// System.Collections.Specialized.HybridDictionary.cs
//
// Author:
// Lawrence Pit (loz@cable.a2000.nl)
// Raja R Harinath <rharinath@novell.com>
//
// Copyright (C) 2004, 2005 Novell (http://www.novell.com)
//
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
namespace System.Collections.Specialized{
[Serializable]
public class HybridDictionary : IDictionary, ICollection, IEnumerable {
private const int switchAfter = 10;
private IDictionary inner {
get { return list == null ? (IDictionary) hashtable : (IDictionary) list; }
}
private bool caseInsensitive;
private Hashtable hashtable;
private ListDictionary list;
// Constructors
public HybridDictionary() : this (0, false) { }
public HybridDictionary (bool caseInsensitive) : this (0, caseInsensitive) { }
public HybridDictionary (int initialSize) : this (initialSize, false) { }
public HybridDictionary (int initialSize, bool caseInsensitive)
{
this.caseInsensitive = caseInsensitive;
IComparer comparer = caseInsensitive ? CaseInsensitiveComparer.DefaultInvariant : null;
IHashCodeProvider hcp = caseInsensitive ? CaseInsensitiveHashCodeProvider.DefaultInvariant : null;
if (initialSize <= switchAfter)
list = new ListDictionary (comparer);
else
hashtable = new Hashtable (initialSize, hcp, comparer);
}
// Properties
public int Count {
get { return inner.Count; }
}
public bool IsFixedSize {
get { return false; }
}
public bool IsReadOnly {
get { return false; }
}
public bool IsSynchronized {
get { return false; }
}
public object this [object key] {
get { return inner [key]; }
set {
inner [key] = value;
if (list != null && Count > switchAfter)
Switch ();
}
}
public ICollection Keys {
get { return inner.Keys; }
}
public object SyncRoot {
get { return this; }
}
public ICollection Values {
get { return inner.Values; }
}
// Methods
public void Add (object key, object value)
{
inner.Add (key, value);
if (list != null && Count > switchAfter)
Switch ();
}
public void Clear ()
{
// According to MSDN, this doesn't switch a Hashtable back to a ListDictionary
inner.Clear ();
}
public bool Contains (object key)
{
#if NET_2_0
return inner.Contains (key);
#else
// if the dictionary is empty, 'Contains (null)' doesn't throw an ArgumentNullException
return Count != 0 && inner.Contains (key);
#endif
}
public void CopyTo (Array array, int index)
{
inner.CopyTo (array, index);
}
public IDictionaryEnumerator GetEnumerator ()
{
return inner.GetEnumerator ();
}
IEnumerator IEnumerable.GetEnumerator ()
{
return GetEnumerator ();
}
public void Remove (object key)
{
// According to MSDN, this does not switch a Hashtable back to a ListDictionary
// even if Count falls below switchAfter
inner.Remove (key);
}
private void Switch ()
{
IComparer comparer = caseInsensitive ? CaseInsensitiveComparer.DefaultInvariant : null;
IHashCodeProvider hcp = caseInsensitive ? CaseInsensitiveHashCodeProvider.DefaultInvariant : null;
hashtable = new Hashtable (list, hcp, comparer);
list.Clear ();
list = null;
}
}
}
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