Csaba Henk 9a4f91abc0 Indicate timezone offsets in timestamps ...

Logs and other output carrying timestamps
will have now timezone offsets indicated, eg.:

[2020-03-12 07:01:05.584482 +0000] I [MSGID: 106143] [glusterd-pmap.c:388:pmap_registry_remove] 0-pmap: removing brick (null) on port 49153

To this end,

- gf_time_fmt() now inserts timezone offset via %z strftime(3) template.
- A new utility function has been added, gf_time_fmt_tv(), that
  takes a struct timeval pointer (*tv) instead of a time_t value to
  specify the time. If tv->tv_usec is negative,

  gf_time_fmt_tv(... tv ...)

  is equivalent to

  gf_time_fmt(... tv->tv_sec ...)

  Otherwise it also inserts tv->tv_usec to the formatted string.
- Building timestamps of usec precision has been converted to
  gf_time_fmt_tv, which is necessary because the method of appending
  a period and the usec value to the end of the timestamp does not work
  if the timestamp has zone offset, but it's also beneficial in terms of
  eliminating repetition.
- The buffer passed to gf_time_fmt/gf_time_fmt_tv has been unified to
  be of GF_TIMESTR_SIZE size (256). We need slightly larger buffer space
  to accommodate the zone offset and it's preferable to use a buffer
  which is undisputedly large enough.

This change does *not* do the following:

- Retaining a method of timestamp creation without timezone offset.
  As to my understanding we don't need such backward compatibility
  as the code just emits timestamps to logs and other diagnostic
  texts, and doesn't do any later processing on them that would rely
  on their format. An exception to this, ie. a case where timestamp
  is built for internal use, is graph.c:fill_uuid(). As far as I can
  see, what matters in that case is the uniqueness of the produced
  string, not the format.
- Implementing a single-token (space free) timestamp format.
  While some timestamp formats used to be single-token, now all of
  them will include a space preceding the offset indicator. Again,
  I did not see a use case where this could be significant in terms
  of representation.
- Moving the codebase to a single unified timestamp format and
  dropping the fmt argument of gf_time_fmt/gf_time_fmt_tv.
  While the gf_timefmt_FT format is almost ubiquitous, there are
  a few cases where different formats are used. I'm not convinced
  there is any reason to not use gf_timefmt_FT in those cases too,
  but I did not want to make a decision in this regard.

Change-Id: I0af73ab5d490cca7ed8d07a2ce7ac22a6df2920a
Updates: #837
Signed-off-by: Csaba Henk <csaba@redhat.com>

2020-06-15 12:41:10 +00:00

..

bug-823081.t

Indicate timezone offsets in timestamps

2020-06-15 12:41:10 +00:00