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, 2005 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                 private StringCollection        events;
  46                 private IDatabase       db;
  47                 private int                     localId;
  48                 private int                     remoteId;
  49                 private bool            initialCounts;
  50                 private int[]           previousCounts;
  51                 private int[]           actualCounts;
  52
  53                 #endregion
  54
  55                 #region Properties
  56
  57                 public IDatabase Database
  58                 {
  59                         get { return this.db; }
  60                 }
  61
  62                 public int LocalId
  63                 {
  64                         get { return this.localId; }
  65                         set { this.localId = value; }
  66                 }
  67
  68                 public int RemoteId
  69                 {
  70                         get { return this.remoteId; }
  71                         set { this.remoteId = value; }
  72                 }
  73
  74                 public StringCollection Events
  75                 {
  76                         get
  77                         {
  78                                 if (this.events == null)
  79                                 {
  80                                         this.events = new StringCollection();
  81                                 }
  82
  83                                 return this.events;
  84                         }
  85                 }
  86
  87                 public bool HasChanges
  88                 {
  89                         get
  90                         {
  91                                 if (this.actualCounts == null && this.previousCounts == null)
  92                                 {
  93                                         return false;
  94                                 }
  95                                 else if (this.actualCounts != null && this.previousCounts == null)
  96                                 {
  97                                         return true;
  98                                 }
  99                                 else if (this.actualCounts.Length != this.previousCounts.Length)
 100                                 {
 101                                         return true;
 102                                 }
 103
 104                                 for (int i = 0; i < this.actualCounts.Length; i++)
 105                                 {
 106                                         if (this.actualCounts[i] != this.previousCounts[i])
 107                                         {
 108                                                 return true;
 109                                         }
 110                                 }
 111
 112                                 return false;
 113                         }
 114                 }
 115
 116                 public int[] PreviousCounts
 117                 {
 118                         get { return this.previousCounts; }
 119                 }
 120
 121                 public int[] ActualCounts
 122                 {
 123                         get { return this.actualCounts; }
 124                 }
 125
 126                 #endregion
 127
 128                 #region Constructors
 129
 130                 public RemoteEvent(IDatabase db) : this(db, 0, 0, null)
 131                 {
 132                 }
 133
 134                 public RemoteEvent(IDatabase db, int localId, int remoteId, StringCollection events)
 135                 {
 136                         this.db = db;
 137                         this.localId = localId;
 138                         this.remoteId = remoteId;
 139                         this.events = events;
 140                 }
 141
 142                 #endregion
 143
 144                 #region Methods
 145
 146                 public void QueueEvents()
 147                 {
 148                         lock (this.db)
 149                         {
 150                                 this.db.QueueEvents(this);
 151                         }
 152                 }
 153
 154                 public void CancelEvents()
 155                 {
 156                         lock (this.db)
 157                         {
 158                                 this.db.CancelEvents(this);
 159                                 this.ResetCounts();
 160                         }
 161                 }
 162
 163                 public void ResetCounts()
 164                 {
 165                         this.initialCounts      = false;
 166                         this.actualCounts       = null;
 167                         this.previousCounts = null;
 168                 }
 169
 170                 public void EventCounts(byte[] buffer)
 171                 {
 172                         int pos = 1;
 173                         Charset charset = this.db.Charset;
 174
 175                         if (buffer != null)
 176                         {
 177                                 if (this.initialCounts)
 178                                 {
 179                                         this.previousCounts = this.actualCounts;
 180                                 }
 181
 182                                 this.actualCounts = new int[this.events.Count];
 183
 184                                 while (pos < buffer.Length)
 185                                 {
 186                                         int length = buffer[pos++];
 187                                         string eventName = charset.GetString(buffer, pos, length);
 188
 189                                         pos += length;
 190
 191                                         int index = this.events.IndexOf(eventName);
 192                                         if (index != -1)
 193                                         {
 194                                                 this.actualCounts[index] = BitConverter.ToInt32(buffer, pos) - 1;
 195                                         }
 196
 197                                         pos += 4;
 198                                 }
 199
 200                                 if (!this.initialCounts)
 201                                 {
 202                                         this.QueueEvents();
 203                                         this.initialCounts = true;
 204                                 }
 205                                 else
 206                                 {
 207                                         if (this.EventCountsCallback != null)
 208                                         {
 209                                                 this.EventCountsCallback();
 210                                         }
 211                                 }
 212                         }
 213                 }
 214
 215                 public EventParameterBuffer ToEpb()
 216                 {
 217                         EventParameterBuffer epb = this.db.CreateEventParameterBuffer();
 218
 219                         epb.Append(IscCodes.EPB_version1);
 220
 221                         for (int i = 0; i < this.events.Count; i++)
 222                         {
 223                                 if (this.actualCounts != null)
 224                                 {
 225                                         epb.Append(this.events[i], this.actualCounts[i] + 1);
 226                                 }
 227                                 else
 228                                 {
 229                                         epb.Append(this.events[i], 0);
 230                                 }
 231                         }
 232
 233                         return epb;
 234                 }
 235
 236                 #endregion
 237         }
 238 }