include/SqlConnection.h

   1 /***************************************************************************
   2  *   Copyright (C) 2007 by Prabakaran Thirumalai   *
   3  *   praba_tuty@yahoo.com   *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with this program; if not, write to the                         *
  17  *   Free Software Foundation, Inc.,                                       *
  18  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  19  ***************************************************************************/
  20 #ifndef SQLCONNECTION_H
  21 #define SQLCONNECTION_H
  22 #include<CSql.h>
  23 #include<AbsSqlConnection.h>
  24 #include<SqlFactory.h>
  25 class SqlStatement;
  26
  27 struct CachedStmtNode{
  28     SqlStatement *sqlStmt;
  29     int stmtLength;
  30     char *sqlString;
  31     int hits;
  32     CachedStmtNode() { sqlStmt = NULL; sqlString=NULL; stmtLength=0; hits=0;}
  33
  34 };
  35 class SqlConnection : public AbsSqlConnection
  36 {
  37     Connection conn;
  38     bool isConnOpen;
  39     public:
  40     List cachedStmts;
  41     SqlConnection(){ innerConn = NULL; isConnOpen = false; }
  42     ~SqlConnection();
  43
  44     /** opens connection to the sql engine
  45     *   @param user username for authentication
  46     *   @param pass password for authentication
  47     *   @return DbRetVal
  48     */
  49     DbRetVal connect (char *user, char * pass) {
  50         DbRetVal ret = conn.open(user, pass);
  51         if (ret == OK) isConnOpen = true;
  52         return ret;
  53     }
  54
  55     /** closes connection to the database and releases all the resources
  56     *   @return DbRetVal
  57     */
  58     DbRetVal disconnect () {
  59         DbRetVal ret = conn.close();
  60         if (ret == OK) isConnOpen = false;
  61         return ret;
  62     }
  63
  64     /** Commits active transaction.
  65     *   It makes all the changes made in the current transaction permanent and <br/>
  66     *   it also releases the locks held by the current transaction.<br/>
  67     *   After a transaction commits, application is required to start another <br/>
  68     *   transaction for further database operations.
  69     *   @return DbRetVal
  70     */
  71     DbRetVal commit() { return conn.commit(); }
  72
  73     /** Aborts the active transaction.
  74     *   undo all the changes made in the current transaction and it also <br/>
  75     *   releases the locks held by the current transaction.<br/>
  76     *   After a transaction rollback, application is required to start another <br/>
  77     *   transaction for further database operations.
  78     *   @return DbRetVal
  79     */
  80     DbRetVal rollback() { return conn.rollback(); }
  81
  82     /** Starts a transaction.
  83     *   The previous transaction should be either committed or rollback <br/>
  84     *   before beginTrans is called. <br/>
  85     *   Applications are required to start transaction before they attempt any <br>
  86     *   database operation.
  87     *   @param isoLevel isolation level. Default is read committed.
  88     *   @return DbRetVal
  89     */
  90     DbRetVal beginTrans (IsolationLevel isoLevel = READ_COMMITTED,
  91                          TransSyncMode mode = OSYNC)
  92         { return conn.startTransaction(isoLevel); }
  93
  94     Connection& getConnObject(){  return conn; }
  95     bool isConnectionOpen() { if (isConnOpen) return true; return false; };
  96     DbRetVal getExclusiveLock(){ return conn.getExclusiveLock(); }
  97
  98     SqlStatement* findInCache(char *stmtStr);
  99     void flushCacheStmt();
 100     void addToCache(SqlStatement *stmt, char *stmtStr);
 101     void removeLeastUsed();
 102
 103     friend class SqlFactory;
 104 };
 105
 106 #endif