search: remove {mset} option for ->mset method

The ->mset method always returns a Xapian mset nowadays, so
naming a parameter {mset} is too confusing.  As it does with
MiscSearch, setting the {relevance} parameter to -1 now sorts by
ascending docid order.  -2 is now supported for descending
docid order, too, since it may be useful for lei users.

5 files changed, 17 insertions, 15 deletions

diff --git a/lib/PublicInbox/ExtMsg.pm b/lib/PublicInbox/ExtMsg.pm
index 6a173f67..4df885ab 100644
--- a/lib/PublicInbox/ExtMsg.pm
+++ b/lib/PublicInbox/ExtMsg.pm
@@ -33,7 +33,7 @@ sub search_partial ($$) {
         my ($ibx, $mid) = @_;
         return if length($mid) < $MIN_PARTIAL_LEN;
         my $srch = $ibx->search or return; # NOT ->isrch, we already try ->ALL
-        my $opt = { limit => PARTIAL_MAX, mset => 2 };
+        my $opt = { limit => PARTIAL_MAX, relevance => -1 };
         my @try = ("m:$mid*");
         my $chop = $mid;
         if ($chop =~ s/(\W+)(\w*)\z//) {
diff --git a/lib/PublicInbox/IMAP.pm b/lib/PublicInbox/IMAP.pm
index a3a10bde..2af5ab0c 100644
--- a/lib/PublicInbox/IMAP.pm
+++ b/lib/PublicInbox/IMAP.pm
@@ -1136,7 +1136,7 @@ sub search_common {
                 my $srch = $self->{ibx}->isrch or
                         return "$tag BAD search not available for mailbox\r\n";
                 my $opt = {
-                        mset => 2,
+                        relevance => -1,
                         limit => UID_SLICE,
                         uid_range => $range_info
                 };
diff --git a/lib/PublicInbox/Isearch.pm b/lib/PublicInbox/Isearch.pm
index e362c80a..7ca2f9e4 100644
--- a/lib/PublicInbox/Isearch.pm
+++ b/lib/PublicInbox/Isearch.pm
@@ -61,7 +61,7 @@ sub mset_to_artnums {
         my $docids = PublicInbox::Search::mset_to_artnums($self->{es}, $mset);
         my $ibx_id = $self->{-ibx_id} //= _ibx_id($self);
         my $qmarks = join(',', map { '?' } @$docids);
-        if ($opt && ($opt->{mset} // 0) == 2) { # opt->{mset} = 2 was used
+        if ($opt && ($opt->{relevance} // 0) == -1) { # -1 => ENQ_ASCENDING
                 my $range = '';
                 my @r;
                 if (my $r = $opt->{uid_range}) {
diff --git a/lib/PublicInbox/Mbox.pm b/lib/PublicInbox/Mbox.pm
index c8e4b406..83fa7d8a 100644
--- a/lib/PublicInbox/Mbox.pm
+++ b/lib/PublicInbox/Mbox.pm
@@ -235,7 +235,7 @@ sub mbox_all {
         my $over = $ctx->{ibx}->over or
                 return PublicInbox::WWW::need($ctx, 'Overview');
 
-        my $qopts = $ctx->{qopts} = { mset => 2 }; # order by docid
+        my $qopts = $ctx->{qopts} = { relevance => -1 }; # ORDER BY docid ASC
         $qopts->{thread} = 1 if $q->{t};
         my $mset = $srch->mset($q_string, $qopts);
         $qopts->{offset} = $mset->size or
diff --git a/lib/PublicInbox/Search.pm b/lib/PublicInbox/Search.pm
index ffd19a1f..fb3e9975 100644
--- a/lib/PublicInbox/Search.pm
+++ b/lib/PublicInbox/Search.pm
@@ -58,7 +58,11 @@ our $QP_FLAGS;
 our %X = map { $_ => 0 } qw(BoolWeight Database Enquire QueryParser Stem Query);
 our $Xap; # 'Search::Xapian' or 'Xapian'
 our $NVRP; # '$Xap::'.('NumberValueRangeProcessor' or 'NumberRangeProcessor')
-our $ENQ_ASCENDING;
+
+# ENQ_DESCENDING and ENQ_ASCENDING weren't in SWIG Xapian.pm prior to 1.4.16,
+# let's hope the ABI is stable
+our $ENQ_DESCENDING = 0;
+our $ENQ_ASCENDING = 1;
 
 sub load_xapian () {
         return 1 if defined $Xap;
@@ -84,12 +88,6 @@ sub load_xapian () {
                         'NumberRangeProcessor' : 'NumberValueRangeProcessor');
                 $X{$_} = $Xap.'::'.$_ for (keys %X);
 
-                # ENQ_ASCENDING doesn't seem exported by SWIG Xapian.pm,
-                # so lets hope this part of the ABI is stable because it's
-                # just an integer:
-                $ENQ_ASCENDING = $x eq 'Xapian' ?
-                                1 : Search::Xapian::ENQ_ASCENDING();
-
                 *sortable_serialise = $x.'::sortable_serialise';
                 *sortable_unserialise = $x.'::sortable_unserialise';
                 # n.b. FLAG_PURE_NOT is expensive not suitable for a public
@@ -344,13 +342,17 @@ sub _enquire_once { # retry_reopen callback
         $enquire->set_query($query);
         $opts ||= {};
         my $desc = !$opts->{asc};
-        if (($opts->{mset} || 0) == 2) { # mset == 2: ORDER BY docid/UID
+        my $rel = $opts->{relevance} // 0;
+        if ($rel == -1) { # ORDER BY docid/UID
+                $enquire->set_weighting_scheme($X{BoolWeight}->new);
                 $enquire->set_docid_order($ENQ_ASCENDING);
+        } elsif ($rel == 0) {
+                $enquire->set_sort_by_value_then_relevance(TS, $desc);
+        } elsif ($rel == -2) {
                 $enquire->set_weighting_scheme($X{BoolWeight}->new);
-        } elsif ($opts->{relevance}) {
+                $enquire->set_docid_order($ENQ_DESCENDING);
+        } else { # rel > 0
                 $enquire->set_sort_by_relevance_then_value(TS, $desc);
-        } else {
-                $enquire->set_sort_by_value_then_relevance(TS, $desc);
         }
 
         # `mairix -t / --threads' or JMAP collapseThreads