[SNMP4J] SnmpEngineListener fired multiple time for same address

[Christy Jones (christyj)]

Thanks Frank,

I also think splitting the conditions would help so that for a change in
engineID the code can fire a remove event followed by add event.

public boolean addEngineID(Address address, OctetString engineID) {
if (!Arrays.equals(this.localEngineID, engineID.getValue()))

    {
        OctetString previousEngineID = engineIDs.put(address, engineID);
        if ((snmpEngineListeners != null))
        {
            if ((previousEngineID == null))
            {
                fireEngineChanged(new SnmpEngineEvent(this,
                    SnmpEngineEvent.ADDED_ENGINE_ID,engineID, address));
            }
            else if (!previousEngineID.equals(engineID))
            {
                fireEngineChanged(new SnmpEngineEvent(this,
                    SnmpEngineEvent.REMOVED_ENGINE_ID,previousEngineID,
address));
            
                fireEngineChanged(new SnmpEngineEvent(this,
                    SnmpEngineEvent.ADDED_ENGINE_ID,engineID, address));
            }
        }
        return true;
      }
      return false;
}


Regards
Christy


On 9/25/13 1:55 PM, "Frank Fock" <fock at agentpp.com> wrote:

>Hi Christy,
>
>This is indeed not optimal to fire the event, even if the engine ID did
>not change
>for an address. By replacing the method addEngineID in MPv3.java as
>follows you
>can improve the behavior:
>
>   public boolean addEngineID(Address address, OctetString engineID) {
>     if (!Arrays.equals(this.localEngineID, engineID.getValue())) {
>       OctetString previousEngineID = engineIDs.put(address, engineID);
>       if ((snmpEngineListeners != null) && ((previousEngineID == null)
>|| (!previousEngineID.equals(engineID)))) {
>         fireEngineChanged(new SnmpEngineEvent(this,
>SnmpEngineEvent.ADDED_ENGINE_ID,
>                                               engineID, address));
>       }
>       return true;
>     }
>     return false;
>   }
>
>The next version of SNMP4J will include this patch.
>
>Best regards,
>Frank
>
>Am 25.09.2013 17:38, schrieb Christy Jones (christyj):
>> Hi,
>>
>> I'm using version 2.0.2 and in the process of implementing a
>> SnmpEngineListener.
>>
>>  From what I observe the even when I'm polling for the same Address the
>> MPv3.addEngineID fires the listeners for every message sent.
>>
>> The if condition in MPv3.addEngineID to check with localEngineID does
>>not
>> appear to work well. The Address is available in the engineIDs map but
>>the
>> localEngineID does not match with the input engineID. The localengineID
>> appears to default one.
>>   
>> Is there a specific reason to check against the localEngineID before
>> adding to the engineIDs map ? Could we not check if the Address is there
>> in endingIDs map directly?
>>
>>      (!Arrays.equals(this.localEngineID, engineID.getValue()))
>>
>> Christy
>>
>>
>>
>>
>
>-- 
>---
>AGENT++
>Maximilian-Kolbe-Str. 10
>73257 Koengen, Germany
>https://agentpp.com
>Phone: +49 7024 8688230
>Fax:   +49 7024 8688231
>