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 #if (defined MMDB && defined EMBED)
  40     DbRetVal recoverCsqlDB();
  41     DbRetVal recoverSystemAndUserDB();
  42     DbRetVal applySchemaFile(FILE *fp);
  43     char getQueryFromSchemaFile(FILE *fp, char *buf);
  44     int applyRedoLogs(char *redoFile);
  45     AbsSqlStatement *getStmtFromHashTable(int stmtId);
  46     void removeFromHashTable(int stmtID);
  47     void addToHashTable(int stmtID, AbsSqlStatement* sHdl);
  48 #endif
  49     public:
  50     static List connList;
  51     static bool isInit;
  52 #if (defined MMDB && EMBED)
  53     static bool firstThread;
  54     static GlobalUniqueID UID;
  55     void *stmtBuckets;
  56 #endif
  57     void initialize();
  58     List cachedStmts;
  59     SqlConnection(){ innerConn = NULL; isConnOpen = false; }
  60     ~SqlConnection();
  61
  62     /** opens connection to the sql engine
  63     *   @param user username for authentication
  64     *   @param pass password for authentication
  65     *   @return DbRetVal
  66     */
  67     DbRetVal connect (char *user, char * pass);
  68
  69     /** closes connection to the database and releases all the resources
  70     *   @return DbRetVal
  71     */
  72     DbRetVal disconnect () {
  73         DbRetVal ret = conn.close();
  74         if (ret == OK) isConnOpen = false;
  75 # if (defined MMDB && defined EMBED)
  76         if (Conf::config.useDurability() && connList.size()==1) UID.destroy();
  77 # endif
  78         connList.remove(this);
  79         return ret;
  80     }
  81
  82     /** Commits active transaction.
  83     *   It makes all the changes made in the current transaction permanent and <br/>
  84     *   it also releases the locks held by the current transaction.<br/>
  85     *   After a transaction commits, application is required to start another <br/>
  86     *   transaction for further database operations.
  87     *   @return DbRetVal
  88     */
  89     DbRetVal commit() { return conn.commit(); }
  90
  91     /** Aborts the active transaction.
  92     *   undo all the changes made in the current transaction and it also <br/>
  93     *   releases the locks held by the current transaction.<br/>
  94     *   After a transaction rollback, application is required to start another <br/>
  95     *   transaction for further database operations.
  96     *   @return DbRetVal
  97     */
  98     DbRetVal rollback() { return conn.rollback(); }
  99
 100     /** Starts a transaction.
 101     *   The previous transaction should be either committed or rollback <br/>
 102     *   before beginTrans is called. <br/>
 103     *   Applications are required to start transaction before they attempt any <br>
 104     *   database operation.
 105     *   @param isoLevel isolation level. Default is read committed.
 106     *   @return DbRetVal
 107     */
 108     DbRetVal beginTrans (IsolationLevel isoLevel = READ_COMMITTED,
 109                          TransSyncMode mode = OSYNC)
 110         { return conn.startTransaction(isoLevel); }
 111
 112     Connection& getConnObject(){  return conn; }
 113     bool isConnectionOpen() { if (isConnOpen) return true; return false; };
 114     DbRetVal getExclusiveLock(){ return conn.getExclusiveLock(); }
 115
 116     SqlStatement* findInCache(char *stmtStr);
 117     void flushCacheStmt();
 118     void addToCache(SqlStatement *stmt, char *stmtStr);
 119     void removeLeastUsed();
 120
 121     friend class SqlFactory;
 122 };
 123
 124 #endif