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     bool inUse;
  33     CachedStmtNode() { sqlStmt = NULL; sqlString=NULL; stmtLength=0; hits=0; inUse=0;}
  34     void display() {
  35         printf(" SQL=%s hits=%d inuse=%d\n", sqlString, hits, inUse);
  36     }
  37
  38 };
  39 class SqlConnection : public AbsSqlConnection
  40 {
  41     Connection conn;
  42     bool isConnOpen;
  43 #if (defined MMDB && defined EMBED)
  44     DbRetVal recoverCsqlDB();
  45     DbRetVal recoverSystemAndUserDB();
  46     DbRetVal applySchemaFile(FILE *fp);
  47     char getQueryFromSchemaFile(FILE *fp, char *buf);
  48     int applyRedoLogs(char *redoFile);
  49 #endif
  50     public:
  51     static List connList;
  52     static bool isInit;
  53 #if (defined MMDB && EMBED)
  54     static bool firstThread;
  55     static GlobalUniqueID UID;
  56     void *stmtBuckets;
  57 #endif
  58     void initialize();
  59     List cachedStmts;
  60     SqlConnection(){ innerConn = NULL; isConnOpen = false; }
  61     ~SqlConnection();
  62
  63     /** opens connection to the sql engine
  64     *   @param user username for authentication
  65     *   @param pass password for authentication
  66     *   @return DbRetVal
  67     */
  68     DbRetVal connect (char *user, char * pass);
  69
  70     /** closes connection to the database and releases all the resources
  71     *   @return DbRetVal
  72     */
  73     DbRetVal disconnect () {
  74         flushCacheStmt();
  75         DbRetVal ret = conn.close();
  76         if (ret == OK) isConnOpen = false;
  77 # if (defined MMDB && defined EMBED)
  78         if (Conf::config.useDurability() && connList.size()==1) UID.destroy();
  79 # endif
  80         connList.remove(this);
  81         return ret;
  82     }
  83
  84     /** Commits active transaction.
  85     *   It makes all the changes made in the current transaction permanent and <br/>
  86     *   it also releases the locks held by the current transaction.<br/>
  87     *   After a transaction commits, application is required to start another <br/>
  88     *   transaction for further database operations.
  89     *   @return DbRetVal
  90     */
  91     DbRetVal commit() { return conn.commit(); }
  92
  93     /** Aborts the active transaction.
  94     *   undo all the changes made in the current transaction and it also <br/>
  95     *   releases the locks held by the current transaction.<br/>
  96     *   After a transaction rollback, application is required to start another <br/>
  97     *   transaction for further database operations.
  98     *   @return DbRetVal
  99     */
 100     DbRetVal rollback() { return conn.rollback(); }
 101
 102     /** Starts a transaction.
 103     *   The previous transaction should be either committed or rollback <br/>
 104     *   before beginTrans is called. <br/>
 105     *   Applications are required to start transaction before they attempt any <br>
 106     *   database operation.
 107     *   @param isoLevel isolation level. Default is read committed.
 108     *   @return DbRetVal
 109     */
 110     DbRetVal beginTrans (IsolationLevel isoLevel = READ_COMMITTED,
 111                          TransSyncMode mode = OSYNC)
 112         { return conn.startTransaction(isoLevel); }
 113
 114     Connection& getConnObject(){  return conn; }
 115     bool isConnectionOpen() { if (isConnOpen) return true; return false; };
 116     DbRetVal getExclusiveLock(){ return conn.getExclusiveLock(); }
 117
 118     SqlStatement* findInCache(char *stmtStr);
 119     void flushCacheStmt();
 120     void addToCache(SqlStatement *stmt, char *stmtStr);
 121     void removeLeastUsed();
 122     void setStmtNotInUse(char *stmtStr);
 123     void displayStmtCache();
 124     void display() { displayStmtCache(); }
 125
 126
 127     friend class SqlFactory;
 128 };
 129
 130 #endif