(feat): Add a minimum polling interval for CHANGE_ON_EVENT subscription type

[kostinkirill]

Improvement for #2335

Added minimum polling interval for CHANGE_ON_EVENT subscription type

[chrisdutz]

Generally ok ... but in this case I guess we would need matching Duration-counterparts for:

• addChangeOfStateTagAddress (Without consumer)
• addChangeOfStateTag (Without consumer)
• addChangeOfStateTag (With consumer)

[kostinkirill]

@chrisdutz added methods with dueration:

• addChangeOfStateTagAddress (Without consumer)
• addChangeOfStateTagAddress (With consumer)
• addChangeOfStateTag (Without consumer)

[chrisdutz]

I assume the next step would be to extend the ADS and possibly the OPC-UA driver to support this, right? Are you planning on continuing to work on this? I's prefer to mentor you through this as it's a bit like the "give a man a fish and he's fed for a day, teach him to fish and he's fed for life" sort of thing ;-)

[chrisdutz]

The question now is: If a driver doesn't implement this Duration-based limiting ... should we throw an "unsupported" error, or should we silently forward it to the duration-less version and log a message?

[kostinkirill]

I assume the next step would be to extend the ADS and possibly the OPC-UA driver to support this, right? Are you planning on continuing to work on this? I's prefer to mentor you through this as it's a bit like the "give a man a fish and he's fed for a day, teach him to fish and he's fed for life" sort of thing ;-)

I believe ADS drive already supports it, I've already checked the behavior and minInterval is applied for CHANGE_ON_EVENT subscriptions and works as epxected.
This the code where the minInterval is set up as cycleTimeInMs in AdsAddDeviceNotificationRequest
`AdsProtocolLogic#executeSubscribe:

return new AmsTCPPacket(new AdsAddDeviceNotificationRequest(configuration.getTargetAmsNetId(), configuration.getTargetAmsPort(),
                    configuration.getSourceAmsNetId(), configuration.getSourceAmsPort(),
                    0, getInvokeId(),
                    directAdsTag.getIndexGroup(),
                    directAdsTag.getIndexOffset(),
                    adsDataTypeTableEntry.getSize() * numberOfElements,
                    tag.getPlcSubscriptionType() == PlcSubscriptionType.CYCLIC ? AdsTransMode.CYCLIC : AdsTransMode.ON_CHANGE, // if it's not cyclic, it's on change or event
                    0, // there is no api for that yet
                    tag.getDuration().orElse(Duration.ZERO).toMillis()));

(the last argument)

As for OPCUA, I haven't checked it, but based on the code it should work as well

[kostinkirill]

The question now is: If a driver doesn't implement this Duration-based limiting ... should we throw an "unsupported" error, or should we silently forward it to the duration-less version and log a message?

I'd say drive implements it

[chrisdutz]

Interesting ... wasn't expecting that to work ;-)

But yeah ... having a look at the code, it actually makes sense. Cool ... so I guess this is ready to being merged ;-)

Thanks :-)