[tz] zic option to generate smaller output files?
murch at fastmail.com
Wed Nov 22 21:41:56 UTC 2017
On 11/22/2017 01:49 PM, Paul Eggert wrote:
> On 11/22/2017 02:30 AM, Zefram wrote:
>> The binary tzfile usually provides a ruleset applicable to indefinitely
>> many years, in the form of a POSIX TZ string. But that's not the
>> rules, it's the rules to be applied when all of the file's explicit
>> transitions have run out.
> Changing the subject (and subject line)....
> Currently zic generates a bunch of explicit transitions at the end of
> the time transition table, even if these transitions merely repeat
> what a TZ string would generate. This is to support older clients that
> grok only version-1 tzfile format, and which don't know about the TZ
> string (which was introduced in version 2 tzfile format). Since
> version 2 format was introduced in release 2006b, I'm thinking now may
> be a good time to add an option to zic to suppress explicit
> transitions at the end of the table if these transitions agree with
> the TZ string. This will help uncover buggy client code that
> mishandles TZ string values and therefore mishandles future
> timestamps. By default this option will be off now (meaning no change
> to the default behavior), but we could turn it on later.
This option makes sense to me.
Would it also be possible to have this option (or a separate one) create
the first header and body (32-bit time values) with counts of zero? All
of the data that would appear in that body is duplicated in the second
Cyrus Development Team
FastMail Pty Ltd
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