TimeZone Updater Tool/Project, where would we put it?

[Andrew Leonard]

Thanks for all the input. So i'm going to set the "scene" on what we 
currently have and how it currently works, and a possible proposal:

Background:
Code is loosely based off of our bespoke IBM JDK 6/7/8 TimeZone Updater, 
but has been updated and extended to support OpenJDK8+ JDKs.

Current Architecture:
- The tool comes in two phases:
1) A Build by a Vendor|OpenJDK is done to produce a "jtzuYYYY[a-z].zip" 
that contains the latest IANA data built into a "rearguard" "tzdb.dat" 
along with the tzupdater client tool.
2) The "end user" who wants to patch their tzdb, simply downloads the 
"jtzuYYYY[a-z].zip" from the Vendor|OpenJDK unzips and runs the tool to 
patch their chosen JDKs...

Current features and limitations:
- Supports only "rearguard" format tzdb.dat, but this is then compatible 
with JDK8,11,13+
- tzupdater tool searchs for JDKs based on a "signature" recognition 
(layout of files...), but it only has to recognize "is it JDK8", "is it 
JDK11+" ?
- Various modes of operation to tzupdater client tool, for specifying 
specific JDK/JRE location(s), either via cmdline or using a GUI.

Possibilities:
For (1) maybe we could:
- Contribute all the tzupdater code to the JDK (jdk/jdk) project under the 
folder "src/tzupdater"
- Add configure option --build-latest-tzupdater
- When specified it:
    - upgrades the IANA files with the latest from IANA
    - once tzdb.dat has been built as part of gendata target, the 
src/tzupdater is built which produces 
"build/<platformdir>/images/tzupdater/jtzuYYYY[a-z].zip"
(2):
- Currently the built "jtzuYYYY[a-z]/zip" can be applied by the end user 
to any jdk8+ based on current features and "rearguard" compatibility.

Thoughts?
Thanks
Andrew

Andrew Leonard
Java Runtimes Development
IBM Hursley
IBM United Kingdom Ltd
internet email: andrew_m_leonard at uk.ibm.com 




From:   Stephen Colebourne <scolebourne at joda.org>
To:     jdk-dev <jdk-dev at openjdk.java.net>
Date:   26/11/2019 15:10
Subject:        [EXTERNAL] Re: TimeZone Updater Tool/Project, where would 
we put it?
Sent by:        "jdk-dev" <jdk-dev-bounces at openjdk.java.net>



To take the discussion in a different direction, the original
intention of JSR-310 was that time-zone updates should be delivered as
modular jar files. Developers would just use their favorite tooling
(maven/gradle etc) to add the new tzdb jar file to the module path,
and hey-presto the tzdb data would be updated.

Early versions of JSR-310 code had all of this working, although I'm
not certain whether it still does. (JSR-310 was introduced before the
module system, so there is likely to be some work needed). The
versioning system does still exist though. ie. the JDK can have
multiple versions of the tzdb loaded and pick the latest. See
ZoneRulesProvider and TzdbZoneRulesProvider for the code that may or
may not need tweaking (it uses ServiceLoader).

A tool that patches the JDK installation seems rather an old fashioned
approach compared to a modular jar one. That said, there are issues
around data other than the tzdb rules themselves, eg. the name of a
zone, that might trip up a modular jar file approach.

Does anyone else think a modular jar file approach is worth pursuing 
instead?

Stephen


On Mon, 25 Nov 2019 at 10:03, Andrew Leonard
<andrew_m_leonard at uk.ibm.com> wrote:
>
> Hi there,
> Not had a lot of interest in contributing this yet, so was going to ask
> the question a different way. If we were to contribute it where would we
> put it?
> - As part of the JDK project?
> - Create its own project? and associated mercurial repo?
> - Add to an existing other tooling project?
>
> Thanks
> Andrew
>
> Andrew Leonard
> Java Runtimes Development
> IBM Hursley
> IBM United Kingdom Ltd
> internet email: andrew_m_leonard at uk.ibm.com
>
> Unless stated otherwise above:
> IBM United Kingdom Limited - Registered in England and Wales with number
> 741598.
> Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 
3AU
>




Unless stated otherwise above:
IBM United Kingdom Limited - Registered in England and Wales with number 
741598. 
Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU