mcs/class/System/System.Collections.Specialized/HybridDictionary.cs

   1 //
   2 // System.Collections.Specialized.HybridDictionary.cs
   3 //
   4 // Author:
   5 //   Lawrence Pit (loz@cable.a2000.nl)
   6 //
   7 // Copyright (C) 2004 Novell (http://www.novell.com)
   8 //
   9
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 using System;
  32 using System.Collections;
  33
  34 namespace System.Collections.Specialized {
  35
  36         [Serializable]
  37         public class HybridDictionary : IDictionary, ICollection, IEnumerable {
  38
  39                 private const int switchAfter = 10;
  40
  41                 private ListDictionary list;
  42                 private Hashtable hashtable;
  43                 private bool caseInsensitive = false;
  44
  45                 // Constructors
  46
  47                 public HybridDictionary() : this (0, false) { }
  48
  49                 public HybridDictionary (bool caseInsensitive) : this (0, caseInsensitive) { }
  50
  51                 public HybridDictionary (int initialSize) : this (initialSize, false) { }
  52
  53                 public HybridDictionary(int initialSize, bool caseInsensitive)
  54                 {
  55                         this.caseInsensitive = caseInsensitive;
  56
  57                         if (initialSize <= switchAfter)
  58                                 if (caseInsensitive)
  59                                         list = new ListDictionary (CaseInsensitiveComparer.Default);
  60                                 else
  61                                         list = new ListDictionary ();
  62                         else
  63                                 if (caseInsensitive)
  64                                         hashtable = new Hashtable (initialSize,
  65                                                         CaseInsensitiveHashCodeProvider.Default,
  66                                                         CaseInsensitiveComparer.Default);
  67                                 else
  68                                         hashtable = new Hashtable (initialSize);
  69                 }
  70
  71
  72                 // Properties
  73
  74                 public int Count {
  75                         get {
  76                                 if (list != null)
  77                                         return list.Count;
  78                                 return hashtable.Count;
  79                         }
  80                 }
  81
  82                 public bool IsFixedSize {
  83                         get { return false; }
  84                 }
  85
  86                 public bool IsReadOnly {
  87                         get { return false; }
  88                 }
  89
  90                 public bool IsSynchronized {
  91                         get { return false; }
  92                 }
  93
  94                 public object this [object key] {
  95                         get {
  96                                 if (key == null)
  97                                         throw new ArgumentNullException("key");
  98                                 if (list != null)
  99                                         return list [key];
 100                                 return hashtable [key];
 101                         }
 102                         set {
 103                                 if (list != null)
 104                                         if (list.Count >= switchAfter)
 105                                                 Switch ();
 106                                         else {
 107                                                 list [key] = value;
 108                                                 return;
 109                                         }
 110                                 hashtable [key] = value;
 111                         }
 112                 }
 113
 114                 public ICollection Keys {
 115                         get {
 116                                 if (list != null)
 117                                         return list.Keys;
 118                                 return hashtable.Keys;
 119                         }
 120                 }
 121
 122                 public object SyncRoot {
 123                         get { return this; }
 124                 }
 125
 126                 public ICollection Values {
 127                         get {
 128                                 if (list != null)
 129                                         return list.Values;
 130                                 return hashtable.Values;
 131                         }
 132                 }
 133
 134
 135                 // Methods
 136
 137                 public void Add (object key, object value)
 138                 {
 139                         if (list != null)
 140                                 if (list.Count >= switchAfter)
 141                                         Switch ();
 142                                 else {
 143                                         list.Add (key, value);
 144                                         return;
 145                                 }
 146                         hashtable.Add (key, value);
 147                 }
 148
 149                 public void Clear ()
 150                 {
 151                         if (caseInsensitive)
 152                                 list = new ListDictionary (CaseInsensitiveComparer.Default);
 153                         else
 154                                 list = new ListDictionary ();
 155                         hashtable = null;
 156                 }
 157
 158                 public bool Contains (object key)
 159                 {
 160                         if (key == null) {
 161                                 if (this.Count == 0)
 162                                         return false;
 163                                 else
 164                                         throw new ArgumentNullException ("key");
 165                         }
 166                         if (list != null)
 167                                 return list.Contains (key);
 168                         return hashtable.Contains (key);
 169                 }
 170
 171                 public void CopyTo (Array array, int index)
 172                 {
 173                         if (list != null)
 174                                 list.CopyTo (array, index);
 175                         else
 176                                 hashtable.CopyTo (array, index);
 177                 }
 178
 179                 public IDictionaryEnumerator GetEnumerator ()
 180                 {
 181                         if (list != null)
 182                                 return list.GetEnumerator ();
 183                         return hashtable.GetEnumerator ();
 184                 }
 185
 186                 IEnumerator IEnumerable.GetEnumerator ()
 187                 {
 188                         return GetEnumerator ();
 189                 }
 190
 191                 public void Remove (object key)
 192                 {
 193                         if (list != null)
 194                                 list.Remove (key);
 195                         else
 196                                 hashtable.Remove (key);
 197                 }
 198
 199                 private void Switch ()
 200                 {
 201                         if (caseInsensitive)
 202                                 hashtable = new Hashtable (switchAfter + 1,
 203                                                         CaseInsensitiveHashCodeProvider.Default,
 204                                                         CaseInsensitiveComparer.Default);
 205                         else
 206                                 hashtable = new Hashtable (switchAfter + 1);
 207                         IDictionaryEnumerator e = list.GetEnumerator ();
 208                         while (e.MoveNext ())
 209                                 hashtable.Add (e.Key, e.Value);
 210                         list = null;
 211                 }
 212         }
 213 }