searchidx: fix incremental index with indexlevel=basic on v1

We were reindexing the full history every invocation of -index
when Xapian was not used because we were incorrectly relying on
'last_commit' metadata stored in Xapian.

Rewrite the indexing logic to be less confusing while we're
at it, since we rely on `git merge-base --is-ancestor' nowadays.

Furthermore, we need to handle message removals from the
overview index correctly when Xapian is not in use.

Co-authored-by: Eric W. Biederman <ebiederm@xmission.com>

1 files changed, 125 insertions, 0 deletions

diff --git a/t/indexlevels-mirror.t b/t/indexlevels-mirror.t
new file mode 100644
index 00000000..e25b827f
--- /dev/null
+++ b/t/indexlevels-mirror.t
@@ -0,0 +1,125 @@
+# Copyright (C) 2019 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+use strict;
+use warnings;
+use Test::More;
+use PublicInbox::MIME;
+use PublicInbox::Inbox;
+use File::Temp qw/tempdir/;
+require './t/common.perl';
+require_git(2.6);
+my $this = (split('/', __FILE__))[-1];
+
+# TODO: remove Search::Xapian as a requirement for basic
+foreach my $mod (qw(DBD::SQLite Search::Xapian)) {
+        eval "require $mod";
+        plan skip_all => "$mod missing for $this" if $@;
+}
+
+my $path = 'blib/script';
+my $index = "$path/public-inbox-index";
+
+my $mime = PublicInbox::MIME->create(
+        header => [
+                From => 'a@example.com',
+                To => 'test@example.com',
+                Subject => 'this is a subject',
+                Date => 'Fri, 02 Oct 1993 00:00:00 +0000',
+        ],
+        body => "hello world\n",
+);
+
+sub import_index_incremental {
+        my ($v, $level) = @_;
+        my $tmpdir = tempdir("pi-$this-tmp-XXXXXX", TMPDIR => 1, CLEANUP => 1);
+        my $ibx = PublicInbox::Inbox->new({
+                mainrepo => "$tmpdir/testbox",
+                name => "$this-$v",
+                version => $v,
+                -primary_address => 'test@example.com',
+                indexlevel => $level,
+        });
+        my $cls = "PublicInbox::V${v}Writable";
+        use_ok $cls;
+        my $im = $cls->new($ibx, {nproc=>1});
+        $mime->header_set('Message-ID', '<m@1>');
+        ok($im->add($mime), 'first message added');
+        $im->done;
+
+        # index master (required for v1)
+        is(system($index, $ibx->{mainrepo}), 0, 'index master OK');
+        my $ro_master = PublicInbox::Inbox->new({mainrepo => $ibx->{mainrepo}});
+        my ($nr, $msgs) = $ro_master->recent;
+        is($nr, 1, 'only one message in master, so far');
+        is($msgs->[0]->{mid}, 'm@1', 'first message in master indexed');
+
+        # clone
+        my @cmd = (qw(git clone --mirror -q));
+        my $mirror = "$tmpdir/mirror-$v";
+        if ($v == 1) {
+                push @cmd, $ibx->{mainrepo}, $mirror;
+        } else {
+                push @cmd, "$ibx->{mainrepo}/git/0.git", "$mirror/git/0.git";
+        }
+        my $fetch_dir = $cmd[-1];
+        is(system(@cmd), 0, "v$v clone OK");
+
+        # inbox init
+        local $ENV{PI_CONFIG} = "$tmpdir/.picfg";
+        @cmd = ("$path/public-inbox-init", '-L', $level,
+                'mirror', $mirror, '//example.com/test', 'test@example.com');
+        push @cmd, '-V2' if $v == 2;
+        is(system(@cmd), 0, "v$v init OK");
+
+        # index mirror
+        is(system($index, $mirror), 0, "v$v index mirror OK");
+
+        # read-only access
+        my $ro_mirror = PublicInbox::Inbox->new({mainrepo => $mirror});
+        ($nr, $msgs) = $ro_mirror->recent;
+        is($nr, 1, 'only one message, so far');
+        is($msgs->[0]->{mid}, 'm@1', 'read first message');
+
+        # update master
+        $mime->header_set('Message-ID', '<m@2>');
+        ok($im->add($mime), '2nd message added');
+        $im->done;
+
+        # mirror updates
+        is(system('git', "--git-dir=$fetch_dir", qw(fetch -q)), 0, 'fetch OK');
+        is(system($index, $mirror), 0, "v$v index mirror again OK");
+        ($nr, $msgs) = $ro_mirror->recent;
+        is($nr, 2, '2nd message seen in mirror');
+        is_deeply([sort { $a cmp $b } map { $_->{mid} } @$msgs],
+                ['m@1','m@2'], 'got both messages in mirror');
+
+        # incremental index master (required for v1)
+        is(system($index, $ibx->{mainrepo}), 0, 'index master OK');
+        ($nr, $msgs) = $ro_master->recent;
+        is($nr, 2, '2nd message seen in master');
+        is_deeply([sort { $a cmp $b } map { $_->{mid} } @$msgs],
+                ['m@1','m@2'], 'got both messages in master');
+
+        # remove message from master
+        ok($im->remove($mime), '2nd message removed');
+        $im->done;
+
+        # sync the mirror
+        is(system('git', "--git-dir=$fetch_dir", qw(fetch -q)), 0, 'fetch OK');
+        is(system($index, $mirror), 0, "v$v index mirror again OK");
+        ($nr, $msgs) = $ro_mirror->recent;
+        is($nr, 1, '2nd message gone from mirror');
+        is_deeply([map { $_->{mid} } @$msgs], ['m@1'],
+                'message unavailable in mirror');
+}
+
+# we can probably cull some other tests and put full/medium tests, here
+for my $level (qw(basic)) {
+        for my $v (1..2) {
+                subtest("v$v indexlevel=$level" => sub {
+                        import_index_incremental($v, $level);
+                })
+        }
+}
+
+done_testing();