firebird-mirror/src/jrd/recsrc/VirtualTableScan.cpp

/*
 *  The contents of this file are subject to the Initial
 *  Developer's Public License Version 1.0 (the "License");
 *  you may not use this file except in compliance with the
 *  License. You may obtain a copy of the License at
 *  http://www.ibphoenix.com/main.nfs?a=ibphoenix&page=ibp_idpl.
 *
 *  Software distributed under the License is distributed AS IS,
 *  WITHOUT WARRANTY OF ANY KIND, either express or implied.
 *  See the License for the specific language governing rights
 *  and limitations under the License.
 *
 *  The Original Code was created by Dmitry Yemanov
 *  for the Firebird Open Source RDBMS project.
 *
 *  Copyright (c) 2009 Dmitry Yemanov <dimitr@firebirdsql.org>
 *  and all contributors signed below.
 *
 *  All Rights Reserved.
 *  Contributor(s): ______________________________________.
 */

#include "firebird.h"
#include "../jrd/jrd.h"
#include "../jrd/req.h"
#include "../jrd/rse.h"
#include "../jrd/cmp_proto.h"
#include "../jrd/met_proto.h"
#include "../jrd/vio_proto.h"

#include "RecordSource.h"

using namespace Firebird;
using namespace Jrd;

// -------------------------------
// Data access: virtual table scan
// -------------------------------

VirtualTableScan::VirtualTableScan(CompilerScratch* csb, const string& name, UCHAR stream)
	: RecordStream(csb, stream), m_name(csb->csb_pool, name)
{
	m_impure = CMP_impure(csb, sizeof(Impure));
}

void VirtualTableScan::open(thread_db* tdbb) const
{
	jrd_req* const request = tdbb->getRequest();
	Impure* const impure = request->getImpure<Impure>(m_impure);

	impure->irsb_flags = irsb_open;

	record_param* const rpb = &request->req_rpb[m_stream];
	rpb->getWindow(tdbb).win_flags = 0;

	jrd_rel* const relation = rpb->rpb_relation;

	const Record* const record = rpb->rpb_record;
	const Format* format = NULL;
	if (!record || !record->rec_format)
	{
		format = MET_current(tdbb, relation);
		VIO_record(tdbb, rpb, format, request->req_pool);
	}
	else
	{
		format = record->rec_format;
	}

	rpb->rpb_number.setValue(BOF_NUMBER);

	DatabaseSnapshot* const snapshot = DatabaseSnapshot::create(tdbb);
	impure->irsb_record_buffer = snapshot->getData(relation);
}

void VirtualTableScan::close(thread_db* tdbb) const
{
	jrd_req* const request = tdbb->getRequest();

	invalidateRecords(request);

	Impure* const impure = request->getImpure<Impure>(m_impure);

	if (impure->irsb_flags & irsb_open)
	{
		impure->irsb_flags &= ~irsb_open;
		impure->irsb_record_buffer = NULL;
	}
}

bool VirtualTableScan::getRecord(thread_db* tdbb) const
{
	jrd_req* const request = tdbb->getRequest();
	record_param* const rpb = &request->req_rpb[m_stream];
	Impure* const impure = request->getImpure<Impure>(m_impure);

	if (!(impure->irsb_flags & irsb_open))
	{
		rpb->rpb_number.setValid(false);
		return false;
	}

	rpb->rpb_number.increment();

	fb_assert(impure->irsb_record_buffer);

	if (impure->irsb_record_buffer->fetch(rpb->rpb_number.getValue(), rpb->rpb_record))
	{
		rpb->rpb_number.setValid(true);
		return true;
	}

	rpb->rpb_number.setValid(false);
	return false;
}

bool VirtualTableScan::refetchRecord(thread_db* tdbb) const
{
	return true;
}

bool VirtualTableScan::lockRecord(thread_db* tdbb) const
{
	status_exception::raise(Arg::Gds(isc_record_lock_not_supp));
	return false; // compiler silencer
}

void VirtualTableScan::dump(thread_db* tdbb, UCharBuffer& buffer) const
{
	buffer.add(isc_info_rsb_begin);

	buffer.add(isc_info_rsb_relation);
	dumpName(tdbb, m_name, buffer);

	buffer.add(isc_info_rsb_type);
	buffer.add(isc_info_rsb_virt_sequential);

	buffer.add(isc_info_rsb_end);
}