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     AbsSqlStatement *getStmtFromHashTable(int stmtId);
  50     void removeFromHashTable(int stmtID);
  51     void addToHashTable(int stmtID, AbsSqlStatement* sHdl);
  52 #endif
  53     public:
  54     static List connList;
  55     static bool isInit;
  56 #if (defined MMDB && EMBED)
  57     static bool firstThread;
  58     static GlobalUniqueID UID;
  59     void *stmtBuckets;
  60 #endif
  61     void initialize();
  62     List cachedStmts;
  63     SqlConnection(){ innerConn = NULL; isConnOpen = false; }
  64     ~SqlConnection();
  65
  66     /** opens connection to the sql engine
  67     *   @param user username for authentication
  68     *   @param pass password for authentication
  69     *   @return DbRetVal
  70     */
  71     DbRetVal connect (char *user, char * pass);
  72
  73     /** closes connection to the database and releases all the resources
  74     *   @return DbRetVal
  75     */
  76     DbRetVal disconnect () {
  77         flushCacheStmt();
  78         DbRetVal ret = conn.close();
  79         if (ret == OK) isConnOpen = false;
  80 # if (defined MMDB && defined EMBED)
  81         if (Conf::config.useDurability() && connList.size()==1) UID.destroy();
  82 # endif
  83         connList.remove(this);
  84         return ret;
  85     }
  86
  87     /** Commits active transaction.
  88     *   It makes all the changes made in the current transaction permanent and <br/>
  89     *   it also releases the locks held by the current transaction.<br/>
  90     *   After a transaction commits, application is required to start another <br/>
  91     *   transaction for further database operations.
  92     *   @return DbRetVal
  93     */
  94     DbRetVal commit() { return conn.commit(); }
  95
  96     /** Aborts the active transaction.
  97     *   undo all the changes made in the current transaction and it also <br/>
  98     *   releases the locks held by the current transaction.<br/>
  99     *   After a transaction rollback, application is required to start another <br/>
 100     *   transaction for further database operations.
 101     *   @return DbRetVal
 102     */
 103     DbRetVal rollback() { return conn.rollback(); }
 104
 105     /** Starts a transaction.
 106     *   The previous transaction should be either committed or rollback <br/>
 107     *   before beginTrans is called. <br/>
 108     *   Applications are required to start transaction before they attempt any <br>
 109     *   database operation.
 110     *   @param isoLevel isolation level. Default is read committed.
 111     *   @return DbRetVal
 112     */
 113     DbRetVal beginTrans (IsolationLevel isoLevel = READ_COMMITTED,
 114                          TransSyncMode mode = OSYNC)
 115         { return conn.startTransaction(isoLevel); }
 116
 117     Connection& getConnObject(){  return conn; }
 118     bool isConnectionOpen() { if (isConnOpen) return true; return false; };
 119     DbRetVal getExclusiveLock(){ return conn.getExclusiveLock(); }
 120
 121     SqlStatement* findInCache(char *stmtStr);
 122     void flushCacheStmt();
 123     void addToCache(SqlStatement *stmt, char *stmtStr);
 124     void removeLeastUsed();
 125     void setStmtNotInUse(char *stmtStr);
 126     void displayStmtCache();
 127     void display() { displayStmtCache(); }
 128
 129
 130     friend class SqlFactory;
 131 };
 132
 133 #endif