class/IBM.Data.DB2/IBM.Data.DB2/DB2Transaction.cs

   1
   2 //
   3 // Permission is hereby granted, free of charge, to any person obtaining
   4 // a copy of this software and associated documentation files (the
   5 // "Software"), to deal in the Software without restriction, including
   6 // without limitation the rights to use, copy, modify, merge, publish,
   7 // distribute, sublicense, and/or sell copies of the Software, and to
   8 // permit persons to whom the Software is furnished to do so, subject to
   9 // the following conditions:
  10 //
  11 // The above copyright notice and this permission notice shall be
  12 // included in all copies or substantial portions of the Software.
  13 //
  14 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  15 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  16 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  17 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  18 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  19 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  20 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  21 //
  22 using System;
  23 using System.Data;
  24 using System.Runtime.InteropServices;
  25
  26 namespace IBM.Data.DB2
  27 {
  28         public sealed class DB2Transaction : MarshalByRefObject, IDbTransaction
  29         {
  30                 private enum TransactionState
  31                 {
  32                         Open,
  33                         Committed,
  34                         Rolledback,
  35                 }
  36                 IsolationLevel isolationLevel;
  37                 DB2Connection db2Conn;
  38                 TransactionState state;
  39
  40
  41
  42                 internal DB2Transaction(DB2Connection con, IsolationLevel isoL)
  43                 {
  44                         long db2IsoL;
  45                         db2Conn = con;
  46                         short sqlRet;
  47
  48                         isolationLevel = isoL;
  49
  50                         switch (isoL)
  51                         {
  52                                 default:
  53                                 case System.Data.IsolationLevel.Chaos:                          //No DB2equivalent, default to SQL_TXN_READ_COMMITTED
  54                                 case System.Data.IsolationLevel.ReadCommitted:          //SQL_TXN_READ_COMMITTED
  55                                         db2IsoL = DB2Constants.SQL_TXN_READ_COMMITTED;
  56                                         break;
  57                                 case System.Data.IsolationLevel.ReadUncommitted:        //SQL_TXN_READ_UNCOMMITTED
  58                                         db2IsoL = DB2Constants.SQL_TXN_READ_UNCOMMITTED;
  59                                         break;
  60                                 case System.Data.IsolationLevel.RepeatableRead:         //SQL_TXN_REPEATABLE_READ
  61                                         db2IsoL = DB2Constants.SQL_TXN_REPEATABLE_READ;
  62                                         break;
  63                                 case System.Data.IsolationLevel.Serializable:           //SQL_TXN_SERIALIZABLE_READ
  64                                         db2IsoL = DB2Constants.SQL_TXN_SERIALIZABLE_READ;
  65                                         break;
  66                         }
  67
  68                         if(db2Conn.openConnection.autoCommit)
  69                         {
  70                                 sqlRet = DB2CLIWrapper.SQLSetConnectAttr(db2Conn.DBHandle, DB2Constants.SQL_ATTR_AUTOCOMMIT, new IntPtr(DB2Constants.SQL_AUTOCOMMIT_OFF), 0);
  71                                 DB2ClientUtils.DB2CheckReturn(sqlRet, DB2Constants.SQL_HANDLE_DBC, db2Conn.DBHandle, "Error setting AUTOCOMMIT OFF in transaction CTOR.", db2Conn);
  72                                 db2Conn.openConnection.autoCommit = false;
  73                         }
  74                         sqlRet = DB2CLIWrapper.SQLSetConnectAttr(db2Conn.DBHandle, DB2Constants.SQL_ATTR_TXN_ISOLATION, new IntPtr(db2IsoL), 0);
  75                         DB2ClientUtils.DB2CheckReturn(sqlRet, DB2Constants.SQL_HANDLE_DBC, db2Conn.DBHandle, "Error setting isolation level.", db2Conn);
  76
  77                         state = TransactionState.Open;
  78                 }
  79
  80                 /// <summary>
  81                 /// DB2Connection associated with this transaction
  82                 /// </summary>
  83                 public IDbConnection Connection
  84                 {
  85                         get
  86                         {
  87                                 return db2Conn;
  88                         }
  89                 }
  90                 /// <summary>
  91                 /// IsolationLevel property
  92                 /// </summary>
  93                 ///
  94                 public IsolationLevel IsolationLevel
  95                 {
  96                         get
  97                         {
  98                                 CheckStateOpen();
  99                                 return isolationLevel;
 100                         }
 101                 }
 102
 103                 internal void CheckStateOpen()
 104                 {
 105                         if(state == TransactionState.Committed)
 106                                 throw new InvalidOperationException("Transaction was already committed. It is no longer usable.");
 107                         if(state == TransactionState.Rolledback)
 108                                 throw new InvalidOperationException("Transaction was already rolled back. It is no longer usable.");
 109                 }
 110
 111                 public void Commit()
 112                 {
 113                         CheckStateOpen();
 114                         DB2CLIWrapper.SQLEndTran(DB2Constants.SQL_HANDLE_DBC, db2Conn.DBHandle, DB2Constants.SQL_COMMIT);
 115                         this.state = TransactionState.Committed;
 116                         this.db2Conn.openConnection.transactionOpen = false;
 117                         this.db2Conn.WeakRefTransaction = null;
 118                         this.db2Conn = null;
 119                 }
 120
 121                 public void Rollback()
 122                 {
 123                         CheckStateOpen();
 124                         DB2CLIWrapper.SQLEndTran(DB2Constants.SQL_HANDLE_DBC, db2Conn.DBHandle, DB2Constants.SQL_ROLLBACK);
 125                         this.db2Conn.openConnection.transactionOpen = false;
 126                         this.state = TransactionState.Rolledback;
 127                         this.db2Conn.WeakRefTransaction = null;
 128                         this.db2Conn = null;
 129                 }
 130
 131                 /// <summary>
 132                 /// Dispose method.
 133                 /// </summary>
 134                 public void Dispose()
 135                 {
 136                         if (state != TransactionState.Open)
 137                                 return;
 138
 139                         Rollback();
 140                 }
 141         }
 142 }