# [PATCH] send-email: more meaningful Message-ID 5 messages from 2016-04-05 to 2016-04-06. Participants: Eric Wong, Junio C Hamano, Johannes Schindelin. Thread: https://gitlist.dev/t/41935 ## Eric Wong, 2016-04-05 19:39 Subject: [PATCH] send-email: more meaningful Message-ID Message-ID: <20160405193952.5849-1-normalperson@yhbt.net> URL: https://gitlist.dev/e/20160405193952.5849-1-normalperson%40yhbt.net ``` Using a YYYYmmddHHMMSS date representation is more meaningful to humans, especially when used for lookups on NNTP servers or linking to archive sites via Message-ID (e.g. mid.gmane.org or mid.mail-archive.com). This timestamp format more easily gives a reader of the URL itself a rough date of a linked message compared to having them calculate the seconds since the Unix epoch. Furthermore, having the MUA name in the Message-ID seems to be a rare oddity I haven't noticed outside of git-send-email. We already have an optional X-Mailer header field to advertise for us, so extending the Message-ID by 15 characters can make for unpleasant Message-ID-based URLs to archive sites. Signed-off-by: Eric Wong --- git-send-email.perl | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/git-send-email.perl b/git-send-email.perl index d356901..23141e7 100755 --- a/git-send-email.perl +++ b/git-send-email.perl @@ -949,7 +949,8 @@ my ($message_id_stamp, $message_id_serial); sub make_message_id { my $uniq; if (!defined $message_id_stamp) { - $message_id_stamp = sprintf("%s-%s", time, $$); + use POSIX qw/strftime/; + $message_id_stamp = strftime("%Y%m%d%H%M%S.$$", gmtime(time)); $message_id_serial = 0; } $message_id_serial++; @@ -964,7 +965,7 @@ sub make_message_id { require Sys::Hostname; $du_part = 'user@' . Sys::Hostname::hostname(); } - my $message_id_template = "<%s-git-send-email-%s>"; + my $message_id_template = "<%s-%s>"; $message_id = sprintf($message_id_template, $uniq, $du_part); #print "new message id = $message_id\n"; # Was useful for debugging } -- EW ``` ## Junio C Hamano, 2016-04-05 21:10 Subject: Re: [PATCH] send-email: more meaningful Message-ID Message-ID: URL: https://gitlist.dev/e/xmqqinzv224x.fsf%40gitster.mtv.corp.google.com In-Reply-To: <20160405193952.5849-1-normalperson@yhbt.net> ``` Eric Wong writes: > Using a YYYYmmddHHMMSS date representation is more meaningful to > humans, especially when used for lookups on NNTP servers or linking > to archive sites via Message-ID (e.g. mid.gmane.org or > mid.mail-archive.com). This timestamp format more easily gives a > reader of the URL itself a rough date of a linked message compared > to having them calculate the seconds since the Unix epoch. > > Furthermore, having the MUA name in the Message-ID seems to be a > rare oddity I haven't noticed outside of git-send-email. We > already have an optional X-Mailer header field to advertise for > us, so extending the Message-ID by 15 characters can make for > unpleasant Message-ID-based URLs to archive sites. > > Signed-off-by: Eric Wong > --- Sounds like a sensible goal. Just a few comments. - Is it safe to assume that we always can use POSIX::strftime(), or do we need some fallback? I am guessing that this is safe, as POSIX has been part of the core modules for a long time, and the script does "use 5.008" upfront. - It is my understanding that, as "use" is a compilation-time thing, hiding it inside a block does not help reducing the start-up overhead (people can use "require" if they want to do a lazy loading and optionally a fallback). Is my Perl5 outdated? Otherwise, let's have it near the beginning of the script, close to where we use Term::ReadLine and others. Thanks. > git-send-email.perl | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/git-send-email.perl b/git-send-email.perl > index d356901..23141e7 100755 > --- a/git-send-email.perl > +++ b/git-send-email.perl > @@ -949,7 +949,8 @@ my ($message_id_stamp, $message_id_serial); > sub make_message_id { > my $uniq; > if (!defined $message_id_stamp) { > - $message_id_stamp = sprintf("%s-%s", time, $$); > + use POSIX qw/strftime/; > + $message_id_stamp = strftime("%Y%m%d%H%M%S.$$", gmtime(time)); > $message_id_serial = 0; > } > $message_id_serial++; > @@ -964,7 +965,7 @@ sub make_message_id { > require Sys::Hostname; > $du_part = 'user@' . Sys::Hostname::hostname(); > } > - my $message_id_template = "<%s-git-send-email-%s>"; > + my $message_id_template = "<%s-%s>"; > $message_id = sprintf($message_id_template, $uniq, $du_part); > #print "new message id = $message_id\n"; # Was useful for debugging > } ``` ## Eric Wong, 2016-04-05 21:36 Subject: Re: [PATCH] send-email: more meaningful Message-ID Message-ID: <20160405213607.GA15023@dcvr.yhbt.net> URL: https://gitlist.dev/e/20160405213607.GA15023%40dcvr.yhbt.net In-Reply-To: ``` Junio C Hamano wrote: > Eric Wong writes: > > > Using a YYYYmmddHHMMSS date representation is more meaningful to > > humans, especially when used for lookups on NNTP servers or linking > > to archive sites via Message-ID (e.g. mid.gmane.org or > > mid.mail-archive.com). This timestamp format more easily gives a > > reader of the URL itself a rough date of a linked message compared > > to having them calculate the seconds since the Unix epoch. > > > > Furthermore, having the MUA name in the Message-ID seems to be a > > rare oddity I haven't noticed outside of git-send-email. We > > already have an optional X-Mailer header field to advertise for > > us, so extending the Message-ID by 15 characters can make for > > unpleasant Message-ID-based URLs to archive sites. > > > > Signed-off-by: Eric Wong > > --- > > Sounds like a sensible goal. Just a few comments. > > - Is it safe to assume that we always can use POSIX::strftime(), or > do we need some fallback? I am guessing that this is safe, as > POSIX has been part of the core modules for a long time, and the > script does "use 5.008" upfront. I'm hoping so :) And none of the format specifiers used here should be subject to locale-dependent weirdness, at least. +Cc both Johannes for Windows knowledge. > - It is my understanding that, as "use" is a compilation-time > thing, hiding it inside a block does not help reducing the > start-up overhead (people can use "require" if they want to do a > lazy loading and optionally a fallback). Is my Perl5 outdated? > Otherwise, let's have it near the beginning of the script, close > to where we use Term::ReadLine and others. You're correct, I'll move the "use" to the top in v2. I could call "require" and call the sub as "POSIX::strftime", but this code path is likely enough that any startup time improvement for uncommon cases wouldn't be worth it. Will wait a bit for strftime portability comments before v2. > > --- a/git-send-email.perl > > +++ b/git-send-email.perl > > @@ -949,7 +949,8 @@ my ($message_id_stamp, $message_id_serial); > > sub make_message_id { > > my $uniq; > > if (!defined $message_id_stamp) { > > - $message_id_stamp = sprintf("%s-%s", time, $$); > > + use POSIX qw/strftime/; > > + $message_id_stamp = strftime("%Y%m%d%H%M%S.$$", gmtime(time)); > > $message_id_serial = 0; > > } > > $message_id_serial++; ``` ## Johannes Schindelin, 2016-04-06 13:08 Subject: Re: [PATCH] send-email: more meaningful Message-ID Message-ID: URL: https://gitlist.dev/e/alpine.DEB.2.20.1604061505010.3371%40virtualbox In-Reply-To: <20160405213607.GA15023@dcvr.yhbt.net> ``` Hi, On Tue, 5 Apr 2016, Eric Wong wrote: > Junio C Hamano wrote: > > Eric Wong writes: > > > > > Using a YYYYmmddHHMMSS date representation is more meaningful to > > > humans, especially when used for lookups on NNTP servers or linking > > > to archive sites via Message-ID (e.g. mid.gmane.org or > > > mid.mail-archive.com). This timestamp format more easily gives a > > > reader of the URL itself a rough date of a linked message compared > > > to having them calculate the seconds since the Unix epoch. > > > > > > Furthermore, having the MUA name in the Message-ID seems to be a > > > rare oddity I haven't noticed outside of git-send-email. We > > > already have an optional X-Mailer header field to advertise for > > > us, so extending the Message-ID by 15 characters can make for > > > unpleasant Message-ID-based URLs to archive sites. > > > > > > Signed-off-by: Eric Wong > > > --- > > > > Sounds like a sensible goal. Just a few comments. > > > > - Is it safe to assume that we always can use POSIX::strftime(), or > > do we need some fallback? I am guessing that this is safe, as > > POSIX has been part of the core modules for a long time, and the > > script does "use 5.008" upfront. > > I'm hoping so :) And none of the format specifiers used here > should be subject to locale-dependent weirdness, at least. > > +Cc both Johannes for Windows knowledge. Thanks. send-email is implemented as a Perl script, and Git for Windows uses a Perl interpreter for such scripts which uses MSYS2's POSIX emulation layer, i.e. POSIX calls are fine. Short answer: no problem there, not even on Windows. Of course, Git for Windows users are much more likely to use a Pull Request based workflow than a mail-based one, so it is even less of a problem for us. Ciao, Dscho ``` ## Eric Wong, 2016-04-06 20:07 Subject: [PATCH v2] send-email: more meaningful Message-ID Message-ID: <20160406200714.GA19315@dcvr.yhbt.net> URL: https://gitlist.dev/e/20160406200714.GA19315%40dcvr.yhbt.net In-Reply-To: <20160405213607.GA15023@dcvr.yhbt.net> ``` Using a YYYYmmddHHMMSS date representation is more meaningful to humans, especially when used for lookups on NNTP servers or linking to archive sites via Message-ID (e.g. mid.gmane.org or mid.mail-archive.com). This timestamp format more easily gives a reader of the URL itself a rough date of a linked message compared to having them calculate the seconds since the Unix epoch. Furthermore, having the MUA name in the Message-ID seems to be a rare oddity I haven't noticed outside of git-send-email. We already have an optional X-Mailer header field to advertise for us, so extending the Message-ID by 15 characters can make for unpleasant Message-ID-based URLs to archive sites. Signed-off-by: Eric Wong --- v2 - moved "use" to the top Thanks to Dscho for addressing Windows comments: http://mid.gmane.org/alpine.DEB.2.20.1604061505010.3371@virtualbox git-send-email.perl | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/git-send-email.perl b/git-send-email.perl index d356901..52cf828 100755 --- a/git-send-email.perl +++ b/git-send-email.perl @@ -19,6 +19,7 @@ use 5.008; use strict; use warnings; +use POSIX qw/strftime/; use Term::ReadLine; use Getopt::Long; use Text::ParseWords; @@ -949,7 +950,7 @@ my ($message_id_stamp, $message_id_serial); sub make_message_id { my $uniq; if (!defined $message_id_stamp) { - $message_id_stamp = sprintf("%s-%s", time, $$); + $message_id_stamp = strftime("%Y%m%d%H%M%S.$$", gmtime(time)); $message_id_serial = 0; } $message_id_serial++; @@ -964,7 +965,7 @@ sub make_message_id { require Sys::Hostname; $du_part = 'user@' . Sys::Hostname::hostname(); } - my $message_id_template = "<%s-git-send-email-%s>"; + my $message_id_template = "<%s-%s>"; $message_id = sprintf($message_id_template, $uniq, $du_part); #print "new message id = $message_id\n"; # Was useful for debugging } -- EW ```