From 721f7add0cf5ac6e6247483628e985742c09e45f Mon Sep 17 00:00:00 2001
From: Eric Wong <e@80x24.org>
Date: Fri, 27 Nov 2020 09:52:48 +0000
Subject: [PATCH] miscsearch: implement ->newsgroup_matches

This may be used to speed up newsgroup searches down-the-line,
but the grep perlop isn't too shabby, at the moment.
---
 lib/PublicInbox/MiscSearch.pm | 40 +++++++++++++++++++++++++++++++++++
 t/extsearch.t                 |  4 ++++
 2 files changed, 44 insertions(+)

diff --git a/lib/PublicInbox/MiscSearch.pm b/lib/PublicInbox/MiscSearch.pm
index 48ef6914..f2e31443 100644
--- a/lib/PublicInbox/MiscSearch.pm
+++ b/lib/PublicInbox/MiscSearch.pm
@@ -76,6 +76,46 @@ sub mset {
 	retry_reopen($self, \&misc_enquire_once, $qr, $opt);
 }
 
+sub ibx_matches_once { # retry_reopen callback
+	my ($self, $qr, $by_newsgroup) = @_;
+	# double in case no newsgroups are configured:
+	my $limit = scalar(keys %$by_newsgroup) * 2;
+	my $opt = { limit => $limit, offset => 0, relevance => -1 };
+	my $ret = {}; # newsgroup => $ibx of matches
+	while (1) {
+		my $mset = misc_enquire_once($self, $qr, $opt);
+		for my $mi ($mset->items) {
+			my $doc = $mi->get_document;
+			my $end = $doc->termlist_end;
+			my $cur = $doc->termlist_begin;
+			$cur->skip_to('Q');
+			if ($cur != $end) {
+				my $ng = $cur->get_termname; # eidx_key
+				$ng =~ s/\AQ// or warn "BUG: no `Q': $ng";
+				if (my $ibx = $by_newsgroup->{$ng}) {
+					$ret->{$ng} = $ibx;
+				}
+			} else {
+				warn <<EOF;
+W: docid=${\$mi->get_docid} has no `Q' (eidx_key) term
+EOF
+			}
+		}
+		my $nr = $mset->size;
+		return $ret if $nr < $limit;
+		$opt->{offset} += $nr;
+	}
+}
+
+# returns a newsgroup => PublicInbox::Inbox mapping
+sub newsgroup_matches {
+	my ($self, $qs, $pi_cfg) = @_;
+	my $qp = $self->{qp} //= mi_qp_new($self);
+	$qs .= ' type:inbox';
+	my $qr = $qp->parse_query($qs, $PublicInbox::Search::QP_FLAGS);
+	retry_reopen($self, \&ibx_matches_once, $qr, $pi_cfg->{-by_newsgroup});
+}
+
 sub ibx_data_once {
 	my ($self, $ibx) = @_;
 	my $xdb = $self->{xdb};
diff --git a/t/extsearch.t b/t/extsearch.t
index 0045294b..85cdf74a 100644
--- a/t/extsearch.t
+++ b/t/extsearch.t
@@ -79,5 +79,9 @@ my @it = $misc->mset('')->items;
 is(scalar(@it), 2, 'two inboxes');
 like($it[0]->get_document->get_data, qr/v2test/, 'docdata matched v2');
 like($it[1]->get_document->get_data, qr/v1test/, 'docdata matched v1');
+my $pi_cfg = PublicInbox::Config->new;
+$pi_cfg->fill_all;
+my $ret = $misc->newsgroup_matches('', $pi_cfg);
+is_deeply($pi_cfg->{-by_newsgroup}, $ret, '->newsgroup_matches');
 
 done_testing;
-- 
2.48.1