mcs/class/FirebirdSql.Data.Firebird/FirebirdSql.Data.Common/RemoteEvent.cs

   1 /*
   2  *      Firebird ADO.NET Data provider for .NET and     Mono
   3  *
   4  *         The contents of this file are subject to     the     Initial
   5  *         Developer's Public License Version 1.0 (the "License");
   6  *         you may not use this file except     in compliance with the
   7  *         License.     You     may     obtain a copy of the License at
   8  *         http://www.firebirdsql.org/index.php?op=doc&id=idpl
   9  *
  10  *         Software     distributed     under the License is distributed on
  11  *         an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either
  12  *         express or implied.  See     the     License for     the     specific
  13  *         language     governing rights and limitations under the License.
  14  *
  15  *      Copyright (c) 2002,     2004 Carlos     Guzman Alvarez
  16  *      All     Rights Reserved.
  17  */
  18
  19 using System;
  20 using System.Collections.Specialized;
  21
  22 namespace FirebirdSql.Data.Common
  23 {
  24         #region Delegates
  25
  26         internal delegate void EventCountsCallback();
  27
  28         #endregion
  29
  30         internal class RemoteEvent
  31         {
  32                 #region Callbacks
  33
  34                 public EventCountsCallback EventCountsCallback
  35                 {
  36                         get     { return this.eventCountsCallback; }
  37                         set     { this.eventCountsCallback = value;     }
  38                 }
  39
  40                 #endregion
  41
  42                 #region Fields
  43
  44                 private EventCountsCallback     eventCountsCallback;
  45
  46                 private IDatabase                       db;
  47                 private int                                     localId;
  48                 private int                                     remoteId;
  49                 private StringCollection        events;
  50                 private bool                            initialCounts;
  51                 private int[]                           previousCounts;
  52                 private int[]                           actualCounts;
  53
  54                 #endregion
  55
  56                 #region Properties
  57
  58                 public IDatabase Database
  59                 {
  60                         get     { return this.db; }
  61                 }
  62
  63                 public int LocalId
  64                 {
  65                         get     { return this.localId; }
  66                         set     { this.localId = value; }
  67                 }
  68
  69                 public int RemoteId
  70                 {
  71                         get     { return this.remoteId; }
  72                         set     { this.remoteId = value; }
  73                 }
  74
  75                 public StringCollection Events
  76                 {
  77                         get
  78                         {
  79                                 if (this.events == null)
  80                                 {
  81                                         this.events     = new StringCollection();
  82                                 }
  83
  84                                 return this.events;
  85                         }
  86                 }
  87
  88                 public bool     HasChanges
  89                 {
  90                         get
  91                         {
  92                                 if (this.actualCounts == null && this.previousCounts == null)
  93                                 {
  94                                         return false;
  95                                 }
  96                                 else if (this.actualCounts != null && this.previousCounts == null)
  97                                 {
  98                                         return true;
  99                                 }
 100                                 else if (this.actualCounts.Length != this.previousCounts.Length)
 101                                 {
 102                                         return true;
 103                                 }
 104
 105                                 for     (int i = 0;     i <     this.actualCounts.Length; i++)
 106                                 {
 107                                         if (this.actualCounts[i] !=     this.previousCounts[i])
 108                                         {
 109                                                 return true;
 110                                         }
 111                                 }
 112
 113                                 return false;
 114                         }
 115                 }
 116
 117                 public int[] PreviousCounts
 118                 {
 119                         get     { return this.previousCounts; }
 120                 }
 121
 122                 public int[] ActualCounts
 123                 {
 124                         get     { return this.actualCounts;     }
 125                 }
 126
 127                 #endregion
 128
 129                 #region Constructors
 130
 131                 public RemoteEvent(IDatabase db) : this(db,     0, 0, null)
 132                 {
 133                 }
 134
 135                 public RemoteEvent(IDatabase db, int localId, int remoteId,     StringCollection events)
 136                 {
 137                         this.db                 = db;
 138                         this.localId    = localId;
 139                         this.remoteId   = remoteId;
 140                         this.events             = events;
 141                 }
 142
 143                 #endregion
 144
 145                 #region Methods
 146
 147                 public void     QueueEvents()
 148                 {
 149                         lock (this.db)
 150                         {
 151                                 this.db.QueueEvents(this);
 152                         }
 153                 }
 154
 155                 public void     CancelEvents()
 156                 {
 157                         lock (this.db)
 158                         {
 159                                 this.db.CancelEvents(this);
 160                                 this.ResetCounts();
 161                         }
 162                 }
 163
 164                 public void     ResetCounts()
 165                 {
 166                         this.initialCounts      = false;
 167                         this.actualCounts       = null;
 168                         this.previousCounts     = null;
 169                 }
 170
 171                 public void     EventCounts(byte[] buffer)
 172                 {
 173                         int             pos                             = 1;
 174                         Charset charset                 = this.db.Charset;
 175
 176                         if (buffer != null)
 177                         {
 178                                 if (this.initialCounts)
 179                                 {
 180                                         this.previousCounts     = this.actualCounts;
 181                                 }
 182
 183                                 this.actualCounts =     new     int[this.events.Count];
 184
 185                                 while (pos < buffer.Length)
 186                                 {
 187                                         int     length = buffer[pos++];
 188                                         string eventName = charset.GetString(buffer, pos, length);
 189
 190                                         pos     += length;
 191
 192                                         int     index = this.events.IndexOf(eventName);
 193                                         if (index != -1)
 194                                         {
 195                                                 this.actualCounts[index] = BitConverter.ToInt32(buffer, pos) - 1;
 196                                         }
 197
 198                                         pos     += 4;
 199                                 }
 200
 201                                 if (!this.initialCounts)
 202                                 {
 203                                         this.QueueEvents();
 204                                         this.initialCounts = true;
 205                                 }
 206                                 else
 207                                 {
 208                                         if (this.EventCountsCallback != null)
 209                                         {
 210                                                 this.EventCountsCallback();
 211                                         }
 212                                 }
 213                         }
 214                 }
 215
 216                 public EventParameterBuffer     ToEpb()
 217                 {
 218                         EventParameterBuffer epb = this.db.CreateEventParameterBuffer();
 219
 220                         epb.Append(IscCodes.EPB_version1);
 221
 222                         for     (int i = 0;     i <     this.events.Count; i++)
 223                         {
 224                                 if (this.actualCounts != null)
 225                                 {
 226                                         epb.Append(this.events[i], this.actualCounts[i] + 1);
 227                                 }
 228                                 else
 229                                 {
 230                                         epb.Append(this.events[i], 0);
 231                                 }
 232                         }
 233
 234                         return epb;
 235                 }
 236
 237                 #endregion
 238         }
 239 }