replace Xapian skeleton with SQLite overview DB

This ought to provide better performance and scalability
which is less dependent on inbox size.  Xapian does not
seem optimized for some queries used by the WWW homepage,
Atom feeds, XOVER and NEWNEWS NNTP commands.

This can actually make Xapian optional for NNTP usage,
and allow more functionality to work without Xapian
installed.

Indexing performance was extremely bad at first, but
DBI::Profile helped me optimize away problematic queries.

1 files changed, 38 insertions, 0 deletions

diff --git a/t/over.t b/t/over.t
new file mode 100644
index 00000000..1d3f9b37
--- /dev/null
+++ b/t/over.t
@@ -0,0 +1,38 @@
+# Copyright (C) 2018 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 File::Temp qw/tempdir/;
+foreach my $mod (qw(DBD::SQLite)) {
+        eval "require $mod";
+        plan skip_all => "$mod missing for over.t" if $@;
+}
+
+use_ok 'PublicInbox::OverIdx';
+my $tmpdir = tempdir('pi-over-XXXXXX', TMPDIR => 1, CLEANUP => 1);
+my $over = PublicInbox::OverIdx->new("$tmpdir/over.sqlite3");
+$over->connect;
+my $x = $over->next_tid;
+is(int($x), $x, 'integer tid');
+my $y = $over->next_tid;
+is($y, $x+1, 'tid increases');
+
+$x = $over->sid('hello-world');
+is(int($x), $x, 'integer sid');
+$y = $over->sid('hello-WORLD');
+is($y, $x+1, 'sid ncreases');
+is($over->sid('hello-world'), $x, 'idempotent');
+$over->disconnect;
+
+$over = PublicInbox::OverIdx->new("$tmpdir/over.sqlite3");
+$over->connect;
+is($over->sid('hello-world'), $x, 'idempotent across reopen');
+$over->each_by_mid('never', sub { fail('should not be called') });
+
+$x = $over->create_ghost('never');
+is(int($x), $x, 'integer tid for ghost');
+$y = $over->create_ghost('NEVAR');
+is($y, $x + 1, 'integer tid for ghost increases');
+
+done_testing();