Re: EPICS 7 PVA for Java

[Marty Kraimer via Core-talk <core-talk@aps.anl.gov>]

On 6/13/19 8:46 AM, Kasemir, Kay via Core-talk wrote:

Hi:

> By the way, are the following modules still relevant for EPICS 7 Java?

> (1) pvaClientJava

> (2) pvDatabaseJava

Not sure what type of answer you expect. A relevance rating from 0 to 50?

Java as in Oracle or the OpenJDK community probably couldn't care less about those two packages.

And how do you define EPICS 7? I would mostly look at the people who work on it.

If you like to use pvaClientJava and/or pvDatabaseJava, by all means use it and take on its maintenance.

At this time, we have pvData[Java,CPP], pvAccess[Java,CPP], pvDatabase[Java,CPP].

Michael Davidsaver is currently a key developer on the CPP side.

When implementing QSRV and the gateway, I think he decided that pvDatabaseCPP isn't adding value.

I've implemented PV support for CS-Studio (Eclipse-based and now Phoebus), but that's a client, so not using pvDatabaseJava.

I know several people who looked at the current XXX[Java,CPP] code and found that it's overly complicated because it's trying to be the same for the two languages, i.e. not taking advantage of each language, in fact quite the opposite.

For the CS-Studio/Phoebus development, I'm looking into a new Java PVAccess client & server development that focuses on the needs of CS-Studio/Phoebus and takes full advantage of Java. For example, using

  Future<Data> read()

instead of a 'GetRequestor'. It's in the early stages, a first update could be expected at the BNL EPICS meeting.

If that works out, my relevance rating for pvaClientJava and pvDatabaseJava in their current form would be very low.

-Kay

I am still actively developing pvDatabaseCPP and pvaClientCPP.

I believe that they are actively used at at least a few sites.

pvDatabaseCPP is used by areaDetector to provide image data.

Comments from sites that use either would be useful.

pvDatabaseCPP has plugin support.See

https://mrkraimer.github.io/website/developerGuide/pluginSupport/pluginSupport.html

As far as I know the pvDatabaseJava and pvaClientJava have not been updated for some time.

I have no plans to work on either.

I believe that the main use for pvDatabaseCPP is for use as part of an IOC.

Both pvaClientCPP and pvaClientJava should be able to use the new features of pvDatabaseCPP.

I do have one comment about

For the CS-Studio/Phoebus development, I'm looking into a new Java PVAccess client & server development that focuses on the needs of CS-Studio/Phoebus and takes full advantage of Java.

In order to be able to access current and new features of pvDatabaseCPP it is important to still have the pvRequest arguments

work like they do in pvaClientJava.

Marty