extmsg: use Xapian only for partial matches

[public-inbox.git] / lib / PublicInbox / ExtMsg.pm

diff --git a/lib/PublicInbox/ExtMsg.pm b/lib/PublicInbox/ExtMsg.pm
index 04cb40623de30f8105e5af1cb8c6254f2128607c..51e7799de8640929be9538713d3f2ee7e1b1081d 100644 (file)
--- a/lib/PublicInbox/ExtMsg.pm
+++ b/lib/PublicInbox/ExtMsg.pm
@@ -26,6 +26,52 @@ our @EXT_URL = (
                'doc-url=/lurker&format=en.html&query=id:%s'
 );
 
+sub PARTIAL_MAX () { 100 }
+
+sub search_partial ($$) {
+       my ($srch, $mid) = @_;
+       my $opt = { limit => PARTIAL_MAX, mset => 2 };
+       my @try = ("m:$mid*");
+       my $chop = $mid;
+       if ($chop =~ s/(\W+)(\w*)\z//) {
+               my ($delim, $word) = ($1, $2);
+               if (length($word)) {
+                       push @try, "m:$chop$delim";
+                       push @try, "m:$chop$delim*";
+               }
+               push @try, "m:$chop";
+               push @try, "m:$chop*";
+       }
+
+       # break out long words individually to search for, because
+       # too many messages begin with "Pine.LNX." (or "alpine" or "nycvar")
+       if ($mid =~ /\w{9,}/) {
+               my @long = ($mid =~ m!(\w{3,})!g);
+               push(@try, join(' ', map { "m:$_" } @long));
+
+               # is the last element long enough to not trigger excessive
+               # wildcard matches?
+               if (length($long[-1]) > 8) {
+                       $long[-1] .= '*';
+                       push(@try, join(' ', map { "m:$_" } @long));
+               }
+       }
+
+       foreach my $m (@try) {
+               my $mset = eval { $srch->query($m, $opt) };
+               if (ref($@) eq 'Search::Xapian::QueryParserError') {
+                       # If Xapian can't handle the wildcard since it
+                       # has too many results.
+                       next;
+               }
+               my @mids = map {
+                       my $doc = $_->get_document;
+                       PublicInbox::SearchMsg->load_doc($doc)->mid;
+               } $mset->items;
+               return \@mids if scalar(@mids);
+       }
+}
+
 sub ext_msg {
        my ($ctx) = @_;
        my $cur = $ctx->{-inbox};
@@ -56,41 +102,23 @@ sub ext_msg {
        return exact($ctx, \@found, $mid) if @found;
 
        # fall back to partial MID matching
-       my $n_partial = 0;
        my @partial;
-
-       if (my $mm = $cur->mm) {
-               my $tmp_mid = $mid;
-               my $res = $mm->mid_prefixes($tmp_mid, 100);
-               if ($res && scalar(@$res)) {
-                       $n_partial += scalar(@$res);
-                       push @partial, [ $cur, $res ];
-               # fixup common errors:
-               } elsif ($tmp_mid =~ s,/[tTf],,) {
-                       $res = $mm->mid_prefixes($tmp_mid, 100);
-                       if ($res && scalar(@$res)) {
-                               $n_partial += scalar(@$res);
-                               push @partial, [ $cur, $res ];
-                       }
-               }
+       my $n_partial = 0;
+       my $srch = $cur->search;
+       my $mids = search_partial($srch, $mid) if $srch;
+       if ($mids) {
+               $n_partial = scalar(@$mids);
+               push @partial, [ $cur, $mids ];
        }
 
        # can't find a partial match in current inbox, try the others:
        if (!$n_partial && length($mid) >= 16) {
-               my $tmp_mid = $mid;
-again:
                foreach my $ibx (@ibx) {
-                       my $mm = $ibx->mm or next;
-                       my $res = $mm->mid_prefixes($tmp_mid, 100);
-                       if ($res && scalar(@$res)) {
-                               $n_partial += scalar(@$res);
-                               push @partial, [ $ibx, $res ];
-                               last if $n_partial >= 100;
-                       }
-               }
-               # fixup common errors:
-               if (!$n_partial && $tmp_mid =~ s,/[tTf],,) {
-                       goto again;
+                       $srch = $ibx->search or next;
+                       $mids = search_partial($srch, $mid) or next;
+                       $n_partial += scalar(@$mids);
+                       push @partial, [ $ibx, $mids];
+                       last if $n_partial >= PARTIAL_MAX;
                }
        }
 
@@ -103,6 +131,7 @@ again:
        if ($n_partial) {
                $code = 300;
                my $es = $n_partial == 1 ? '' : 'es';
+               $n_partial .= '+' if ($n_partial == PARTIAL_MAX);
                $s .= "\n$n_partial partial match$es found:\n\n";
                my $cur_name = $cur->{name};
                foreach my $pair (@partial) {