ActiveRecord/Castle.ActiveRecord/Framework/DictionaryAdapter.cs

   1 // Copyright 2004-2007 Castle Project - http://www.castleproject.org/
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License");
   4 // you may not use this file except in compliance with the License.
   5 // You may obtain a copy of the License at
   6 //
   7 //     http://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS,
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 // See the License for the specific language governing permissions and
  13 // limitations under the License.
  14
  15 namespace Castle.ActiveRecord.Framework
  16 {
  17         using System;
  18         using System.Collections;
  19
  20         /// <summary>
  21         /// Maps keys to position in the values array.
  22         /// Basically key -> index
  23         /// </summary>
  24         public class DictionaryAdapter : IDictionary
  25         {
  26                 private int _tablesize;
  27                 private Entry[] _table;
  28                 private object[] _values;
  29                 private string[] _keys;
  30
  31                 /// <summary>
  32                 /// Initializes a new instance of the <see cref="DictionaryAdapter"/> class.
  33                 /// </summary>
  34                 /// <param name="names">The names.</param>
  35                 /// <param name="values">The values.</param>
  36                 public DictionaryAdapter(String[] names, object[] values)
  37                 {
  38                         _tablesize = names.Length;
  39                         _table = new Entry[_tablesize];
  40                         _values = values;
  41                         _keys = names;
  42
  43                         for(int i=0; i<_tablesize; i++)
  44                         {
  45                                 InternalAdd(names[i], i);
  46                         }
  47                 }
  48
  49                 private void InternalAdd(String key, int index)
  50                 {
  51                         int position = CalculateHash(key);
  52                         System.Diagnostics.Debug.Assert(position >= 0);
  53
  54                         if (_table[position] == null)
  55                         {
  56                                 _table[position] = new Entry(key, index);
  57                         }
  58                         else
  59                         {
  60                                 _table[position].AddEntry(new Entry(key, index));
  61                         }
  62                 }
  63
  64                 private int CalculateHash(String key)
  65                 {
  66                         uint result = (uint)key.GetHashCode();
  67                         return (int) Math.Abs(result % _tablesize);
  68                 }
  69
  70                 /// <summary>
  71                 /// Simple link list entry
  72                 /// </summary>
  73                 public class Entry
  74                 {
  75                         int index;
  76                         String key;
  77                         Entry nextEntry;
  78
  79                         /// <summary>
  80                         /// Initializes a new instance of the <see cref="Entry"/> class.
  81                         /// </summary>
  82                         /// <param name="key">The key.</param>
  83                         /// <param name="index">The index.</param>
  84                         public Entry(String key, int index)
  85                         {
  86                                 this.key = key;
  87                                 this.index = index;
  88                         }
  89
  90                         internal void AddEntry(Entry entry)
  91                         {
  92                                 Entry walker = this;
  93
  94                                 while(walker.nextEntry != null)
  95                                 {
  96                                         walker = walker.nextEntry;
  97                                 }
  98
  99                                 walker.nextEntry = entry;
 100                         }
 101
 102                         /// <summary>
 103                         /// Finds the specified key.
 104                         /// </summary>
 105                         /// <param name="key">The key.</param>
 106                         /// <returns></returns>
 107                         public int Find(string key)
 108                         {
 109                                 Entry walker = this;
 110
 111                                 while(walker != null && !walker.key.Equals(key))
 112                                 {
 113                                         walker = walker.nextEntry;
 114                                 }
 115
 116                                 return walker != null ? walker.index : -1;
 117                         }
 118                 }
 119
 120                 /// <summary>
 121                 /// Determines whether the <see cref="T:System.Collections.IDictionary"></see> object contains an element with the specified key.
 122                 /// </summary>
 123                 /// <param name="key">The key to locate in the <see cref="T:System.Collections.IDictionary"></see> object.</param>
 124                 /// <returns>
 125                 /// true if the <see cref="T:System.Collections.IDictionary"></see> contains an element with the key; otherwise, false.
 126                 /// </returns>
 127                 /// <exception cref="T:System.ArgumentNullException">key is null. </exception>
 128                 public bool Contains(object key)
 129                 {
 130                         return GetValuesIndexByKey(key) != -1;
 131                 }
 132
 133                 /// <summary>
 134                 /// Adds an element with the provided key and value to the <see cref="T:System.Collections.IDictionary"></see> object.
 135                 /// </summary>
 136                 /// <param name="key">The <see cref="T:System.Object"></see> to use as the key of the element to add.</param>
 137                 /// <param name="value">The <see cref="T:System.Object"></see> to use as the value of the element to add.</param>
 138                 /// <exception cref="T:System.ArgumentException">An element with the same key already exists in the <see cref="T:System.Collections.IDictionary"></see> object. </exception>
 139                 /// <exception cref="T:System.ArgumentNullException">key is null. </exception>
 140                 /// <exception cref="T:System.NotSupportedException">The <see cref="T:System.Collections.IDictionary"></see> is read-only.-or- The <see cref="T:System.Collections.IDictionary"></see> has a fixed size. </exception>
 141                 public void Add(object key, object value)
 142                 {
 143                         throw new NotSupportedException();
 144                 }
 145
 146                 /// <summary>
 147                 /// Removes all elements from the <see cref="T:System.Collections.IDictionary"></see> object.
 148                 /// </summary>
 149                 /// <exception cref="T:System.NotSupportedException">The <see cref="T:System.Collections.IDictionary"></see> object is read-only. </exception>
 150                 public void Clear()
 151                 {
 152                         throw new NotSupportedException();
 153                 }
 154
 155                 /// <summary>
 156                 /// Returns an <see cref="T:System.Collections.IDictionaryEnumerator"></see> object for the <see cref="T:System.Collections.IDictionary"></see> object.
 157                 /// </summary>
 158                 /// <returns>
 159                 /// An <see cref="T:System.Collections.IDictionaryEnumerator"></see> object for the <see cref="T:System.Collections.IDictionary"></see> object.
 160                 /// </returns>
 161                 IDictionaryEnumerator IDictionary.GetEnumerator()
 162                 {
 163                         throw new NotSupportedException();
 164                 }
 165
 166                 /// <summary>
 167                 /// Removes the element with the specified key from the <see cref="T:System.Collections.IDictionary"></see> object.
 168                 /// </summary>
 169                 /// <param name="key">The key of the element to remove.</param>
 170                 /// <exception cref="T:System.NotSupportedException">The <see cref="T:System.Collections.IDictionary"></see> object is read-only.-or- The <see cref="T:System.Collections.IDictionary"></see> has a fixed size. </exception>
 171                 /// <exception cref="T:System.ArgumentNullException">key is null. </exception>
 172                 public void Remove(object key)
 173                 {
 174                         throw new NotSupportedException();
 175                 }
 176
 177                 /// <summary>
 178                 /// Gets an <see cref="T:System.Collections.ICollection"></see> object containing the keys of the <see cref="T:System.Collections.IDictionary"></see> object.
 179                 /// </summary>
 180                 /// <value></value>
 181                 /// <returns>An <see cref="T:System.Collections.ICollection"></see> object containing the keys of the <see cref="T:System.Collections.IDictionary"></see> object.</returns>
 182                 public ICollection Keys
 183                 {
 184                         get
 185                         {
 186                                 return _keys;
 187                         }
 188                 }
 189
 190                 /// <summary>
 191                 /// Gets an <see cref="T:System.Collections.ICollection"></see> object containing the values in the <see cref="T:System.Collections.IDictionary"></see> object.
 192                 /// </summary>
 193                 /// <value></value>
 194                 /// <returns>An <see cref="T:System.Collections.ICollection"></see> object containing the values in the <see cref="T:System.Collections.IDictionary"></see> object.</returns>
 195                 public ICollection Values
 196                 {
 197                         get { throw new NotSupportedException(); }
 198                 }
 199
 200                 /// <summary>
 201                 /// Gets a value indicating whether the <see cref="T:System.Collections.IDictionary"></see> object is read-only.
 202                 /// </summary>
 203                 /// <value></value>
 204                 /// <returns>true if the <see cref="T:System.Collections.IDictionary"></see> object is read-only; otherwise, false.</returns>
 205                 public bool IsReadOnly
 206                 {
 207                         get { return true; }
 208                 }
 209
 210                 /// <summary>
 211                 /// Gets a value indicating whether the <see cref="T:System.Collections.IDictionary"></see> object has a fixed size.
 212                 /// </summary>
 213                 /// <value></value>
 214                 /// <returns>true if the <see cref="T:System.Collections.IDictionary"></see> object has a fixed size; otherwise, false.</returns>
 215                 public bool IsFixedSize
 216                 {
 217                         get { return true; }
 218                 }
 219
 220                 /// <summary>
 221                 /// Gets or sets the <see cref="System.Object"/> with the specified key.
 222                 /// </summary>
 223                 /// <value></value>
 224                 public object this[object key]
 225                 {
 226                         get
 227                         {
 228                                 if (_values == null || _values.Length.Equals(0))
 229                                         return null;
 230
 231                                 int index = GetValuesIndexByKey(key);
 232
 233                                 if (index >= 0)
 234                                 {
 235                                         return _values[index];
 236                                 }
 237
 238                                 return null;
 239                         }
 240                         set
 241                         {
 242                                 int index = GetValuesIndexByKey(key);
 243
 244                                 if (index >= 0)
 245                                 {
 246                                         _values[index] = value;
 247                                 }
 248                                 else
 249                                 {
 250                                         throw new ArgumentException(
 251                                                 "DictionaryAdapter: Could not find value related to key {" + key + "}. " +
 252                                                 "This column is probably not mapped on ActiveRecord");
 253                                 }
 254                         }
 255                 }
 256
 257                 private int GetValuesIndexByKey(object key)
 258                 {
 259                         int pos = CalculateHash(key.ToString());
 260
 261                         if (_table[pos] == null) return -1;
 262
 263                         return _table[pos].Find(key.ToString());
 264                 }
 265
 266                 /// <summary>
 267                 /// Copies the elements of the <see cref="T:System.Collections.ICollection"></see> to an <see cref="T:System.Array"></see>, starting at a particular <see cref="T:System.Array"></see> index.
 268                 /// </summary>
 269                 /// <param name="array">The one-dimensional <see cref="T:System.Array"></see> that is the destination of the elements copied from <see cref="T:System.Collections.ICollection"></see>. The <see cref="T:System.Array"></see> must have zero-based indexing.</param>
 270                 /// <param name="index">The zero-based index in array at which copying begins.</param>
 271                 /// <exception cref="T:System.ArgumentNullException">array is null. </exception>
 272                 /// <exception cref="T:System.ArgumentOutOfRangeException">index is less than zero. </exception>
 273                 /// <exception cref="T:System.ArgumentException">array is multidimensional.-or- index is equal to or greater than the length of array.-or- The number of elements in the source <see cref="T:System.Collections.ICollection"></see> is greater than the available space from index to the end of the destination array. </exception>
 274                 /// <exception cref="T:System.InvalidCastException">The type of the source <see cref="T:System.Collections.ICollection"></see> cannot be cast automatically to the type of the destination array. </exception>
 275                 public void CopyTo(Array array, int index)
 276                 {
 277                         throw new NotSupportedException();
 278                 }
 279
 280                 /// <summary>
 281                 /// Gets the number of elements contained in the <see cref="T:System.Collections.ICollection"></see>.
 282                 /// </summary>
 283                 /// <value></value>
 284                 /// <returns>The number of elements contained in the <see cref="T:System.Collections.ICollection"></see>.</returns>
 285                 public int Count
 286                 {
 287                         get { return _tablesize; }
 288                 }
 289
 290                 /// <summary>
 291                 /// Gets an object that can be used to synchronize access to the <see cref="T:System.Collections.ICollection"></see>.
 292                 /// </summary>
 293                 /// <value></value>
 294                 /// <returns>An object that can be used to synchronize access to the <see cref="T:System.Collections.ICollection"></see>.</returns>
 295                 public object SyncRoot
 296                 {
 297                         get { return this; }
 298                 }
 299
 300                 /// <summary>
 301                 /// Gets a value indicating whether access to the <see cref="T:System.Collections.ICollection"></see> is synchronized (thread safe).
 302                 /// </summary>
 303                 /// <value></value>
 304                 /// <returns>true if access to the <see cref="T:System.Collections.ICollection"></see> is synchronized (thread safe); otherwise, false.</returns>
 305                 public bool IsSynchronized
 306                 {
 307                         get { return false; }
 308                 }
 309
 310                 /// <summary>
 311                 /// Returns an enumerator that iterates through a collection.
 312                 /// </summary>
 313                 /// <returns>
 314                 /// An <see cref="T:System.Collections.IEnumerator"></see> object that can be used to iterate through the collection.
 315                 /// </returns>
 316                 public IEnumerator GetEnumerator()
 317                 {
 318                         throw new NotSupportedException();
 319                 }
 320         }
 321 }