/*
* This file is part of rasdaman community.
*
* Rasdaman community is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Rasdaman community is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with rasdaman community.  If not, see <http://www.gnu.org/licenses/>.
*
* Copyright 2003, 2004, 2005, 2006, 2007, 2008, 2009 Peter Baumann /
rasdaman GmbH.
*
* For more information please see <http://www.rasdaman.org>
* or contact Peter Baumann via <baumann@rasdaman.com>.
*/
/*************************************************************************
 *
 *
 * PURPOSE:
 *   Code with embedded SQL for relational DBMS
 *
 *
 * COMMENTS:
 * - reconsider this 604 ignorance!
 *
 ***********************************************************************/

static const char rcsid[] = "@(#)reladminif,TransactionIf: $Id: transactionif.ec,v 1.6 2003/12/27 23:11:43 rasdev Exp $";

#include "debug.hh"

// general embedded SQL related definitions
EXEC SQL include sqlglobals.h;

#include "transactionif.hh"
#include "raslib/rmdebug.hh"
#include "adminif.hh"
#include "oidif.hh"
#include "catalogmgr/typefactory.hh"
#include "sqlerror.hh"
#include "objectbroker.hh"
#include "databaseif.hh"

// PG stuff for libpg connection maintenance
#include "libpq-fe.h"
extern PGconn *pgConn;


void 
TransactionIf::begin( bool readOnly ) throw ( r_Error )
{
	RMDBGENTER(2, RMDebug::module_adminif, "TransactionIf", "begin(" << readOnly << ")");
	ENTER( "TransactionIf::begin, readOnly=" << readOnly );

	isReadOnly = readOnly;  
	AdminIf::setAborted(false);
	AdminIf::setReadOnlyTA(readOnly);

	TALK( "EXEC SQL BEGIN WORK" );
	EXEC SQL BEGIN WORK;
	if (sqlca.sqlwarn[2] == 'W')	// real error, not just a warning
	{
		SQLCODE = 0;		// FIXME: bad hack, as PG can't reset error state and SQLCODE is queried in many places -- PB 2005-jan-09
	}
	else
	{
		RMDBGMIDDLE(4, RMDebug::module_adminif, "TransactionIf", "error occured while issuing BEGIN");  
		LEAVE( "TransactionIf::begin(): error during BEGIN: " << SQLCODE );
		generateException();
	}
	
	if (readOnly)
	{
		TALK( "EXEC SQL SET TRANSACTION READ ONLY" );
		EXEC SQL SET TRANSACTION READ ONLY;
		// no error check, as this doesn't inhibit work
	}

	// prelim.:have additional libpq TA -- PB 2005-jan-09
	TALK( "PQexec( pgConn, BEGIN )" );
	PGresult *pgResult = PQexec( pgConn, "BEGIN" );
	if (PQresultStatus(pgResult) != PGRES_COMMAND_OK)
	{
		LEAVE( "TransactionIf::begin() Error: cannot open libpq TA: " << PQerrorMessage(pgConn) );
		generateException();
	}

#ifdef RMANBENCHMARK
	DBObject::readTimer.start();
	DBObject::readTimer.pause();
	
	DBObject::updateTimer.start();
	DBObject::updateTimer.pause();
	
	DBObject::deleteTimer.start();
	DBObject::deleteTimer.pause();
	
	DBObject::insertTimer.start();
	DBObject::insertTimer.pause();
  
        OId::oidAlloc.start();
        OId::oidAlloc.pause();

        OId::oidResolve.start();
        OId::oidResolve.pause();
#endif

	OId::initialize();
	TypeFactory::initialize();

	LEAVE( "TransactionIf::begin, SQLCODE=" << SQLCODE );
	RMDBGEXIT(2, RMDebug::module_adminif, "TransactionIf", "begin(" << readOnly << ") ");
}

void 
TransactionIf::commit() throw (  r_Error  )
{
	RMDBGENTER(2, RMDebug::module_adminif, "TransactionIf", "commit()");
	ENTER( "TransactionIf::commit" );

	if (isReadOnly)
	{
		RMDBGMIDDLE(9, RMDebug::module_adminif, "TransactionIf", "read only: aborting");
		TALK( "TA is readonly: aborting" );
		abort();
	}
	else
	{
		AdminIf::setAborted(false);
		RMDBGMIDDLE(9, RMDebug::module_adminif, "TransactionIf", "set aborted false");
		TypeFactory::freeTempTypes();
		RMDBGMIDDLE(9, RMDebug::module_adminif, "TransactionIf", "freed temp types");
		ObjectBroker::clearBroker();
		RMDBGMIDDLE(9, RMDebug::module_adminif, "TransactionIf", "cleared broker");
		OId::deinitialize();
		RMDBGMIDDLE(9, RMDebug::module_adminif, "TransactionIf", "wrote oid counters");
		AdminIf::setReadOnlyTA(false);
		RMDBGMIDDLE(9, RMDebug::module_adminif, "TransactionIf", "committing");

		// prelim.:have additional libpq TA -- PB 2005-jan-09
		TALK( "PQexec( pgConn, END )" );
		PGresult *pgResult = PQexec( pgConn, "END" );
		if (PQresultStatus(pgResult) != PGRES_COMMAND_OK)
		{
			LEAVE( "TransactionIf::commit() Error: cannot commit libpq TA: " << PQerrorMessage(pgConn) );
			generateException();
		}

		TALK( "EXEC SQL COMMIT WORK" );
		EXEC SQL COMMIT WORK;
		if (SQLCODE == -604)	// = "no TA open" - seems to be a hickup from our double transaction
					// so we ignore it; FIXME: reinvestigate! -- PB 25-aug-2005
		{
			TALK( "TransactionIf::commit(): ignoring 'no TA open' error (SQLCODE -604) during COMMIT." );
		}
		else if (check("TransactionIf::begin() COMMIT\0"))
		{
			RMDBGMIDDLE(4, RMDebug::module_adminif, "TransactionIf", "error occured while issuing COMMIT");  
			LEAVE( "TransactionIf::commit(): error during COMMIT:" << SQLCODE );
			generateException();
		}
		if (lastBase) 
		{
			RMDBGMIDDLE(9, RMDebug::module_adminif, "TransactionIf", "closing dbms");
			lastBase->baseDBMSClose();
		}
	}

#ifdef RMANBENCHMARK
	DBObject::readTimer.stop();
	
	DBObject::updateTimer.stop();
	
	DBObject::deleteTimer.stop();
	
	DBObject::insertTimer.stop();

	OId::oidAlloc.stop();

        OId::oidResolve.stop();
#endif

	LEAVE( "TransactionIf::commit" );
	RMDBGEXIT(2, RMDebug::module_adminif, "TransactionIf", "commit() " << endl << endl);
}

void 
TransactionIf::abort()
{
	RMDBGENTER(2, RMDebug::module_adminif, "TransactionIf", "abort()");
	ENTER( "TransactionIf::abort" );
  
	// prelim.:have additional libpq TA -- PB 2005-jan-09
	TALK( "PQexec( pgConn, ABORT )" );
	PGresult *pgResult = PQexec( pgConn, "ABORT" );
	if (PQresultStatus(pgResult) != PGRES_COMMAND_OK)
	{
		LEAVE( "TransactionIf::abort() Error: cannot abort libpq TA: " << PQerrorMessage(pgConn) );
		generateException();
	}

	AdminIf::setAborted(true);
	TypeFactory::freeTempTypes();
	ObjectBroker::clearBroker();
	OId::deinitialize();
	AdminIf::setReadOnlyTA(false);

	TALK( "EXEC SQL ROLLBACK WORK" );
	EXEC SQL ROLLBACK WORK;
	if (check("TransactionIf::abort() ROLLBACK\0"))
	{
		RMDBGMIDDLE(4, RMDebug::module_adminif, "TransactionIf", "error occured while issuing ROLLBACK");  
		TALK( "TransactionIf::abort(): error during ROLLBACK, still continuing: " << SQLCODE );
	}
	if(lastBase)
		lastBase->baseDBMSClose();

#ifdef RMANBENCHMARK
	DBObject::readTimer.stop();
	
	DBObject::updateTimer.stop();
	
	DBObject::deleteTimer.stop();
	
	DBObject::insertTimer.stop();

	OId::oidAlloc.stop();

        OId::oidResolve.stop();
#endif

	LEAVE( "TransactionIf::abort, SQLCODE=" << SQLCODE );
	RMDBGEXIT(2, RMDebug::module_adminif, "TransactionIf", "abort() " << endl << endl);
}