lei: propagate keyword changes from lei/store

This works with existing inotify/EVFILT_VNODE functionality to
propagate changes made from one Maildir to another Maildir.

I chose the lei/store worker process to handle this since
propagating changes back into lei-daemon on a massive scale
could lead to dead-locking while both processes are attempting
to write to each other.  Eliminating IPC overhead is a nice
side effect, but could hurt performance if Maildirs are slow.

The code for "lei export-kw" is significantly revamped to match
the new code used in the "lei/store" daemon.  It should be more
correct w.r.t. corner-cases and stale entries, but perhaps
better tests need to be written.

squashed:
  t/lei-auto-watch: increase delay for FreeBSD kevent

  My FreeBSD VM seems to need longer for this test than inotify
  under Linux, likely because the kevent support code needs to be
  more complicated.

1 files changed, 45 insertions, 0 deletions

diff --git a/t/lei-auto-watch.t b/t/lei-auto-watch.t
new file mode 100644
index 00000000..146402a6
--- /dev/null
+++ b/t/lei-auto-watch.t
@@ -0,0 +1,45 @@
+#!perl -w
+# Copyright all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+use strict; use v5.10.1; use PublicInbox::TestCommon;
+use File::Basename qw(basename);
+my ($ro_home, $cfg_path) = setup_public_inboxes;
+my $tick = 2.1;
+my $have_fast_inotify = eval { require Linux::Inotify2; $tick = 0.1 } ||
+        eval { require IO::KQueue; $tick = 0.5 };
+
+$have_fast_inotify or
+        diag("$0 IO::KQueue or Linux::Inotify2 missing, test will be slow");
+
+test_lei(sub {
+        my $x = "$ENV{HOME}/x";
+        my $y = "$ENV{HOME}/y";
+        lei_ok qw(add-external), "$ro_home/t1";
+        lei_ok qw(q mid:testmessage@example.com -o), $x;
+        lei_ok qw(q mid:testmessage@example.com -o), $y;
+        my @x = glob("$x/cur/*");
+        my @y = glob("$y/cur/*");
+        scalar(@x) == 1 or xbail 'expected 1 file', \@x;
+        scalar(@y) == 1 or xbail 'expected 1 file', \@y;
+
+        my $oid = '9bf1002c49eb075df47247b74d69bcd555e23422';
+        lei_ok qw(inspect), "blob:$oid";
+        my $ins = json_utf8->decode($lei_out);
+        my $exp = { "maildir:$x" => [ map { basename($_) } @x ],
+                "maildir:$y" => [ map { basename($_) } @y ] };
+        is_deeply($ins->{'mail-sync'}, $exp, 'inspect as expected');
+        lei_ok qw(add-watch), $x;
+        my $dst = $x[0] . 'S';
+        rename($x[0], $dst) or xbail "rename($x[0], $dst): $!";
+        tick($tick); # wait for inotify or kevent
+        my @y2 = glob("$y/*/*");
+        is_deeply(\@y2, [ "$y[0]S" ], "`seen' kw propagated to `y' dir");
+        lei_ok qw(note-event done);
+        lei_ok qw(inspect), "blob:$oid";
+        $ins = json_utf8->decode($lei_out);
+        $exp = { "maildir:$x" => [ map { basename($_) } glob("$x/*/*") ],
+                "maildir:$y" => [ map { basename($_) } glob("$y/*/*") ] };
+        is_deeply($ins->{'mail-sync'}, $exp, 'mail_sync matches FS');
+});
+
+done_testing;