Pete Harlan <pgit@xxxxxxxxxxxx> wrote:
> By default git svn stores timestamps of fetched commits in
> Subversion's UTC format, to facilitate interoperating with a
> Subversion repository.
>
> If you're using git svn to convert a repository to Git and aren't
> interested in pushing Git commits back to Subversion, you can use this
> option to store timestamps of fetched commits as though they were made
> in the local timezone of the host on which git svn is run. This makes
> the times and timezones of a resulting "git log" agree with what "svn
> log" shows for the same repository.
>
> Signed-off-by: Pete Harlan <pgit@xxxxxxxxxxxx>
> ---
>
> This is a patch I've had floating around for a while. I haven't
> submitted it before because I find the solution ungainly. There has
> to be a better way to convert from one timezone to the other, but I
> didn't run across it and now that I've converted away from Subversion
> I'm sort of done thinking about it. I'm submitting it now because
> even in its current state it would have saved me some headache.
>
> Also, I'm not sure I'm correct when asserting that converting
> timezones like this will break Subversion interoperability. Eric, if
> that isn't true then I can remove that claim and resubmit. If
> converting timezones breaks nothing, then maybe it could even be the
> default.
Hi,
It'll break interoperability between multiple users of git-svn
tracking the same repo. But several options already allow for
this (authors file, noMetdata, ...), so I'm fine with it as long
as it's optional.
> One improvement that I didn't bother to make would be to convert to
> different local timezones based on author. This change uses the
> timezone of the machine running git-svn, which in my case was fine.
> Using per-author timezones would be nice, but since parse_svn_date()
> doesn't already know which author the date is associated with it would
> be a more intrusive change.
Could be an interesting idea, but on the other hand I doubt many people
would bother configuring the authors-file for it.
On a side note, for the total conversions I've done, I've found it
easier/faster/more bandwidth efficient to just forgo authors-file
entirely and use git-filter-branch after-the-fact.
> My primary motivation in this was to reduce transition shock among our
> development team. The fewer ways "git log" looks unhelpfully
> different than the old "svn log" the better; converting all commit
> times into GMT wasn't going to look friendly.
>
> Comments welcome.
My usual coding style nits apply (pretty much git (and Linux kernel)
standard coding style things, too).
No space between "function(arguments)".
lower_snake_case, especially for local variables. mixedCase requires
more effort to read IMO.
More comments inline...
> --Pete
>
> Documentation/git-svn.txt | 8 ++++
> contrib/completion/git-completion.bash | 2 +-
> git-svn.perl | 56 ++++++++++++++++++++++++++++++-
> 3 files changed, 63 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/git-svn.txt b/Documentation/git-svn.txt
> index 8d0c421..8811bf0 100644
> --- a/Documentation/git-svn.txt
> +++ b/Documentation/git-svn.txt
> @@ -92,6 +92,14 @@ COMMANDS
> .git/config file may be specified as an optional command-line
> argument.
>
> +--convert-timezones;;
Is it "timezone" or "timezones" here? I think "convert-timezone" is
more correct since we only use the local timezone, not different
ones for each author. On the other hand, maybe "--localtime" is
an even better name for this option...
Any other opinions out there?
> + Store Git commit times in the local timezone instead of UTC. This
> + makes 'git-log' (even without --date=local) show the same times
> + that `svn log` would in the local timezone.
> +
> +This breaks interoperability with SVN, but may be cosmetically
> +desirable when converting a repository from SVN to Git.
Again, this only breaks interoperability with other users of git-svn
using the default configuration on the same repo.
> 'clone'::
> Runs 'init' and 'fetch'. It will automatically create a
> directory based on the basename of the URL passed to it;
> diff --git a/git-svn.perl b/git-svn.perl
> index ad01e18..c2f600d 100755
> --- a/git-svn.perl
> +++ b/git-svn.perl
> @@ -66,7 +66,7 @@ my ($_stdin, $_help, $_edit,
> $_version, $_fetch_all, $_no_rebase,
> $_merge, $_strategy, $_dry_run, $_local,
> $_prefix, $_no_checkout, $_url, $_verbose,
> - $_git_format, $_commit_url, $_tag);
> + $_git_format, $_commit_url, $_tag, $_convert_timezones);
Not easy to tell (and apologies for that) but this new variable probably
belongs in the Git::SVN namespace. I really need to find some time to
reorganize and split out the source to git-svn.
> $Git::SVN::_follow_parent = 1;
> my %remote_opts = ( 'username=s' => \$Git::SVN::Prompt::_username,
> 'config-dir=s' => \$Git::SVN::Ra::config_dir,
> @@ -84,6 +84,7 @@ my %fc_opts = ( 'follow-parent|follow!' => \$Git::SVN::_follow_parent,
> \$Git::SVN::_repack_flags,
> 'use-log-author' => \$Git::SVN::_use_log_author,
> 'add-author-from' => \$Git::SVN::_add_author_from,
> + 'convert-timezones' => \$_convert_timezones,
> %remote_opts );
>
> my ($_trunk, $_tags, $_branches, $_stdlayout);
> @@ -2526,12 +2527,63 @@ sub get_untracked {
> \@out;
> }
>
> +# parse_svn_date(DATE)
> +# --------------------
> +# Given a date (in UTC) from Subversion, return a string in the format
> +# "<TZ Offset> <local date/time>" that Git will use.
> +#
> +# By default the parsed date will be in UTC for interoperating with
> +# Subversion, but if $_convert_timezones is true we'll convert it to
> +# the local timezone instead.
> sub parse_svn_date {
> my $date = shift || return '+0000 1970-01-01 00:00:00';
> my ($Y,$m,$d,$H,$M,$S) = ($date =~ /^(\d{4})\-(\d\d)\-(\d\d)T
> (\d\d)\:(\d\d)\:(\d\d).\d+Z$/x) or
> croak "Unable to parse date: $date\n";
> - "+0000 $Y-$m-$d $H:$M:$S";
> + my $parsed_date; # Set next.
> +
> + if ($_convert_timezones) {
> + # Translate the Subversion datetime to an epoch time.
> + # We need to switch ourselves to $date's timezone,
> + # UTC, for this.
> + my $oldEnvTZ = $ENV{TZ};
> + $ENV{TZ} = 'UTC';
> +
> + my $epochUTC =
> + POSIX::strftime ('%s', $S, $M, $H, $d, $m - 1, $Y - 1900);
> +
> + # Determine our local timezone (including DST) at the
> + # time of $epochUTC. $Git::SVN::Log::TZ stored the
> + # value of TZ, if any, at the time we were run.
> + if (defined $Git::SVN::Log::TZ) {
> + $ENV{TZ} = $Git::SVN::Log::TZ;
> + } else {
> + delete $ENV{TZ};
> + }
> +
> + my $ourTZ =
> + POSIX::strftime ('%Z', $S, $M, $H, $d, $m - 1, $Y - 1900);
> +
> + # This converts $epochUTC into our local timezone.
> + my ($sec, $min, $hour, $mday, $mon, $year,
> + $wday, $yday, $isdst) = localtime ($epochUTC);
> +
> + $parsed_date = sprintf ('%s %04d-%02d-%02d %02d:%02d:%02d',
> + $ourTZ, $year + 1900, $mon + 1,
> + $mday, $hour, $min, $sec);
There's probably a reason you didn't use strftime here, or is there?
The stock Perl time/date handling functions have always frightened me,
so I'll just trust the (+|-) (1|1900) things are correct :)
--
Eric Wong
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