/*_############################################################################
_##
_## SNMP4J-Agent - IndexGenerator.java
_##
_## Copyright (C) 2005-2009 Frank Fock (SNMP4J.org)
_##
_## Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
_##
_## Unless required by applicable law or agreed to in writing, software
_## distributed under the License is distributed on an "AS IS" BASIS,
_## WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
_## See the License for the specific language governing permissions and
_## limitations under the License.
_##
_##########################################################################*/
package org.snmp4j.agent.util;
import org.snmp4j.smi.Variable;
import org.snmp4j.smi.OID;
import org.snmp4j.smi.Integer32;
import org.snmp4j.smi.UnsignedInteger32;
import org.snmp4j.smi.Counter64;
/**
* The <code>IndexGenerator</code> class can be used to generate a sequence
* of unique index values.
*
* @author Frank Fock
* @version 1.0
*/
public class IndexGenerator {
private Variable seedSubIndex;
private boolean impliedLength;
/**
* Creates a sub-index sequence generator based on a seed value.
* @param seedSubIndex
* the seed value to start with (the seed itself will never be returned).
*/
public IndexGenerator(Variable seedSubIndex) {
if (!((seedSubIndex instanceof Integer32) ||
(seedSubIndex instanceof UnsignedInteger32) ||
(seedSubIndex instanceof Counter64))) {
throw new IllegalArgumentException("A seed subindex of type "+
seedSubIndex.getSyntaxString()+
"is not supported");
}
this.seedSubIndex = seedSubIndex;
}
/**
* Creates a sub-index sequence generator based on a seed value.
* @param seedSubIndex
* the seed value to start with (the seed itself will never be returned).
* @param impliedLength
* if <code>true</code> the length will not be included in the returned
* sub-index for variable-length types.
*/
public IndexGenerator(Variable seedSubIndex, boolean impliedLength) {
this(seedSubIndex);
this.impliedLength = impliedLength;
}
/**
* Creates the next sub-index OID value.
* @return
* a sub-index value corresponding to the seed sub-index type.
*/
public synchronized OID getNextSubIndex() {
if (seedSubIndex instanceof Integer32) {
Integer32 i = (Integer32)seedSubIndex;
i.setValue(i.getValue()+1);
}
else if (seedSubIndex instanceof UnsignedInteger32) {
UnsignedInteger32 ui = (UnsignedInteger32)seedSubIndex;
ui.setValue(ui.getValue()+1);
}
else if (seedSubIndex instanceof Counter64) {
Counter64 c = (Counter64)seedSubIndex;
c.setValue(c.getValue()+1);
}
return seedSubIndex.toSubIndex(impliedLength);
}
}