SingleInstanceTracker.java

//
// This file is part of the OpenNMS(R) Application.
//
// OpenNMS(R) is Copyright (C) 2005 The OpenNMS Group, Inc.  All rights reserved.
// OpenNMS(R) is a derivative work, containing both original code, included code and modified
// code that was published under the GNU General Public License. Copyrights for modified 
// and included code are below.
//
// OpenNMS(R) is a registered trademark of The OpenNMS Group, Inc.
//
// Original code base Copyright (C) 1999-2001 Oculan Corp.  All rights reserved.
//
// This program 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 2 of the License, or
// (at your option) any later version.
//
// This program 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 this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
//
// For more information contact:
// OpenNMS Licensing       <license@opennms.org>
//     http://www.opennms.org/
//     http://www.opennms.com/
//
package org.infosec.ismp.snmp;

import org.infosec.ismp.util.ThreadCategory;

public class SingleInstanceTracker extends CollectionTracker {

	private final SnmpObjId m_base;
	private final SnmpInstId m_inst;
	private final SnmpObjId m_oid;

	public SingleInstanceTracker(SnmpObjId base, SnmpInstId inst) {
		this(base, inst, null);
	}

	public SingleInstanceTracker(String baseOid, String instId) {
		
		this(SnmpObjId.get(baseOid), new SnmpInstId(instId));

	}

	public SingleInstanceTracker(SnmpObjId base, SnmpInstId inst,
			CollectionTracker parent) {
		super(parent);

		m_base = base;
		m_inst = inst;
		m_oid = SnmpObjId.get(m_base, m_inst);
	}

	@Override
	public void setMaxRepetitions(int maxRepititions) {
		// do nothing since we are not a repeater
	}

	@Override
	public ResponseProcessor buildNextPdu(PduBuilder pduBuilder) {
		if (pduBuilder.getMaxVarsPerPdu() < 1) {
			throw new IllegalArgumentException("maxVarsPerPdu < 1");
		}

		SnmpObjId requestOid = m_oid.decrement();

		log().debug("Requesting oid following: " + requestOid);
		pduBuilder.addOid(requestOid);
		pduBuilder.setNonRepeaters(1);
		pduBuilder.setMaxRepetitions(1);

		ResponseProcessor rp = new ResponseProcessor() {

			@Override
			public void processResponse(SnmpObjId responseObjId, SnmpValue val) {
				log().debug(
						"Processing varBind: " + responseObjId + " = " + val);

				if (val.isEndOfMib()) {
					receivedEndOfMib();
				}

				if (m_oid.equals(responseObjId)) {
					storeResult(new SnmpResult(m_base, m_inst, val));
				}

				setFinished(true);
			}

			@Override
			public boolean processErrors(int errorStatus, int errorIndex) {
				if (errorStatus == NO_ERR) {
					return false;
				} else if (errorStatus == TOO_BIG_ERR) {
					throw new IllegalArgumentException(
							"Unable to handle tooBigError for oid request "
									+ m_oid.decrement());
				} else if (errorStatus == GEN_ERR) {
					reportGenErr("Received genErr reqeusting oid "
							+ m_oid.decrement()
							+ ". Marking column is finished.");
					errorOccurred();
					return true;
				} else if (errorStatus == NO_SUCH_NAME_ERR) {
					reportNoSuchNameErr("Received noSuchName reqeusting oid "
							+ m_oid.decrement()
							+ ". Marking column is finished.");
					errorOccurred();
					return true;
				} else {
					throw new IllegalArgumentException(
							"Unexpected error processing oid "
									+ m_oid.decrement() + ". Aborting!");
				}
			}
		};

		return rp;

	}

	protected ThreadCategory log() {
		return ThreadCategory.getInstance(getClass());
	}

	protected void errorOccurred() {
		setFinished(true);
	}

	protected void receivedEndOfMib() {
		setFinished(true);
	}

}