[JSR310 M7 Review request] 8007572: Replace existing jdk timezone data at <java.home>/lib/zi with JSR310's tzdb.

[Andrew Hughes]

----- Original Message -----
> On 14/03/2013 12:51 PM, Xueming Shen wrote:
> > This should have been addessed via
> >
> > JDK-8008348 *The leftover jdk/make/tools/javazic causes build
> > problems
> > with hs25-b19 control job*
> > <https://jbs.oracle.com/bugs/browse/JDK-8008348>
> 
> Which is still in the tl repo and unlikely to reach jdk8/jdk8 till
> b82
> promotion next week.
> 

Yep, that's exactly why I'm seeing it.  This is in an IcedTea build
using the latest build drop, b80.

Glad it's been caught and dealt with :)

> David
> 
> > -Sherman
> >
> > On 3/13/13 7:19 PM, Andrew Hughes wrote:
> >> ----- Original Message -----
> >>> The build part of this review looks good to me.
> >>>
> >> Judging by this changeset, I gather javazic is no longer being
> >> run.
> >> If so, why is the source code being retained in the tree?  It
> >> means
> >> that a build of OpenJDK against itself now fails.  The new
> >> build system currently finds the javazic source code and tries to
> >> compile it,
> >> but fails because ZoneInfoFile.java has changed and Gen.java can
> >> no
> >> longer
> >> compile against it.  Deleting the javazic source code fixes the
> >> build.
> >>
> >> Any reason not to commit this?
> >>
> >> http://cr.openjdk.java.net/~andrew/build/javazic/webrev.01/
> >>
> >>> /Erik
> >>>
> >>> On 2013-02-07 19:31, Xueming Shen wrote:
> >>>> Hi,
> >>>>
> >>>> 8007572: Replace existing jdk timezone data at
> >>>> <java.home>/lib/zi
> >>>> with
> >>>> JSR310's tzdb.
> >>>>
> >>>> Webrev:
> >>>> http://cr.openjdk.java.net/~sherman/8007572/
> >>>>
> >>>> Note:
> >>>> JDK/JRE has been using the time zone data at <java.home>/lib/zi
> >>>> for
> >>>> j.u.TimeZone since JDK 1.4.0 [1]. JSR310 has introduced in its
> >>>> own
> >>>> time zone data file/format <java.home>lib/tzdb.jar to provide
> >>>> the
> >>>> time
> >>>> zone data support for its new java.time date-time classes.
> >>>>
> >>>> So we now have two different time zone data files in different
> >>>> formats
> >>>> (though from the same time zone data source, Olson tz data, now
> >>>> the
> >>>> IANA
> >>>> Time Zone Datebase) to support two sets of date-time APIs
> >>>> (java.util
> >>>> date-time classes and java.time date-time classes) in one
> >>>> JDK/JRE,
> >>>> which
> >>>> definitely will add the maintenance burden going forward, given
> >>>> the
> >>>> fact
> >>>> that we will have to update/distribute the latest tzdb data in
> >>>> JDK/JRE
> >>>> periodically [2].
> >>>>
> >>>> Also the current way the time-zone data is being
> >>>> distributed/installed
> >>>> (at <java.home>/lib.zi, as individual file for each time zone)
> >>>> has
> >>>> been
> >>>> a footprint concern for some configurations, especially the
> >>>> small
> >>>> embedded
> >>>> environment. The JEP151 [3] was originally submitted to propose
> >>>> to
> >>>> store
> >>>> the time-zone data more efficiently into a single compressed
> >>>> file.
> >>>> The
> >>>> JEP 151 has been withdrawn since, with the assumption that JDK 8
> >>>> may
> >>>> replace the "zi" data with the much smaller JSR310 tzdb data
> >>>> file.
> >>>>
> >>>> As indicated in JEP151, current installed "zi" directory
> >>>> probably
> >>>> takes
> >>>> up 1M of disk-space with the 0.5k default
> >>>> file-system-block-size.
> >>>> Even
> >>>> with the proposed "store in one single compressed file"
> >>>> approach,
> >>>> it will
> >>>> still take about 250K space for all tzdb data in "zi" directory.
> >>>> JSR310
> >>>> tzdb data file however is much smaller. It is around 40K for
> >>>> compressed
> >>>> and 100k uncompressed, for the same tz data.
> >>>>
> >>>> The proposed change is to share the JSR310 time zone data
> >>>> tzdb.jar
> >>>> with j.u.TimeZone by converting the JSR310 tzdb data completely
> >>>> (bits
> >>>> to bits compatible) at runtime into the internal data structure
> >>>> that
> >>>> j.u.TimeZone needs for its time zone data functionality/needs.
> >>>>
> >>>> Thanks!
> >>>> -Sherman
> >>>>
> >>>> [1] https://jbs.oracle.com/bugs/browse/JDK-4230123
> >>>> [2]
> >>>> http://www.oracle.com/technetwork/java/javase/tzupdater-readme-136440.html
> >>>>
> >>>> [3] http://openjdk.java.net/jeps/151
> >
> 

-- 
Andrew :)

Free Java Software Engineer
Red Hat, Inc. (http://www.redhat.com)

PGP Key: 248BDC07 (https://keys.indymedia.org/)
Fingerprint = EC5A 1F5E C0AD 1D15 8F1F  8F91 3B96 A578 248B DC07