view: avoid offset during pagination

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

diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index cad90a7934e1632c2a5a42b95b22c9698831b024..cbed91639c08458987da1c3ee7bcaebcf4b8847c 100644 (file)
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -15,6 +15,7 @@ use PublicInbox::Address;
 use PublicInbox::WwwStream;
 use PublicInbox::Reply;
 require POSIX;
+use Time::Local qw(timegm);
 
 use constant INDENT => '  ';
 use constant TCHILD => '` ';
@@ -1032,43 +1033,82 @@ sub dump_topics {
        200;
 }
 
+sub ts2str ($) {
+       my ($ts) = @_;
+       POSIX::strftime('%Y%m%d%H%M%S', gmtime($ts));
+}
+
+sub str2ts ($) {
+       my ($yyyy, $mon, $dd, $hh, $mm, $ss) = unpack('A4A2A2A2A2A2', $_[0]);
+       timegm($ss, $mm, $hh, $dd, $mon - 1, $yyyy);
+}
+
+sub pagination_footer ($$) {
+       my ($ctx, $latest) = @_;
+       delete $ctx->{qp} or return;
+       my $next = $ctx->{next_page} || '';
+       my $prev = $ctx->{prev_page} || '';
+       if ($prev) {
+               $next = $next ? "$next " : '     ';
+               $prev .= qq! <a\nhref='$latest'>latest</a>!;
+       }
+       "<hr><pre>page: $next$prev</pre>";
+}
+
 sub index_nav { # callback for WwwStream
        my (undef, $ctx) = @_;
-       delete $ctx->{qp} or return;
-       my ($next, $prev);
-       $next = $prev = '    ';
-       my $latest = '';
+       pagination_footer($ctx, '.')
+}
+
+sub paginate_recent ($) {
+       my ($ctx) = @_;
+       my $t = $ctx->{qp}->{t} || '';
+       my $lim = 200; # this is our window
+       my $opts = { limit => $lim };
+       my ($after, $before);
+
+       # Xapian uses '..' but '-' is perhaps friendier to URL linkifiers
+       # if only $after exists "YYYYMMDD.." because "." could be skipped
+       # if interpreted as an end-of-sentence
+       $t =~ s/\A(\d{8,14})-// and $after = str2ts($1);
+       $t =~ /\A(\d{8,14})\z/ and $before = str2ts($1);
 
-       my $next_o = $ctx->{-next_o};
-       if ($next_o) {
-               $next = qq!<a\nhref="?o=$next_o"\nrel=next>next</a>!;
+       my $ibx = $ctx->{-inbox};
+       my $msgs = $ibx->recent($opts, $after, $before);
+       my $nr = scalar @$msgs;
+       if ($nr < $lim && defined($after)) {
+               $after = $before = undef;
+               $msgs = $ibx->recent($opts);
+               $nr = scalar @$msgs;
        }
-       if (my $cur_o = $ctx->{-cur_o}) {
-               $latest = qq! <a\nhref=.>latest</a>!;
-
-               my $o = $cur_o - ($next_o - $cur_o);
-               if ($o > 0) {
-                       $prev = qq!<a\nhref="?o=$o"\nrel=prev>prev</a>!;
-               } elsif ($o == 0) {
-                       $prev = qq!<a\nhref=.\nrel=prev>prev</a>!;
+       my $more = $nr == $lim;
+       my ($newest, $oldest);
+       if ($nr) {
+               $newest = $msgs->[0]->{ts};
+               $oldest = $msgs->[-1]->{ts};
+               # if we only had $after, our SQL query in ->recent ordered
+               if ($newest < $oldest) {
+                       ($oldest, $newest) = ($newest, $oldest);
+                       $more = 0 if defined($after) && $after < $oldest;
                }
        }
-       "<hr><pre>page: $next $prev$latest</pre>";
+       if (defined($oldest) && $more) {
+               my $s = ts2str($oldest);
+               $ctx->{next_page} = qq!<a\nhref="?t=$s"\nrel=next>next</a>!;
+       }
+       if (defined($newest) && (defined($before) || defined($after))) {
+               my $s = ts2str($newest);
+               $ctx->{prev_page} = qq!<a\nhref="?t=$s-"\nrel=prev>prev</a>!;
+       }
+       $msgs;
 }
 
 sub index_topics {
        my ($ctx) = @_;
-       my ($off) = (($ctx->{qp}->{o} || '0') =~ /(\d+)/);
-
-       $ctx->{order} = [];
-       my $srch = $ctx->{srch};
-       my $msgs = $ctx->{-inbox}->recent({offset => $off, limit => 200 });
-       my $nr = scalar @$msgs;
-       if ($nr) {
+       my $msgs = paginate_recent($ctx);
+       if (@$msgs) {
                walk_thread(thread_results($ctx, $msgs), $ctx, *acc_topic);
        }
-       $ctx->{-next_o} = $off + $nr;
-       $ctx->{-cur_o} = $off;
        PublicInbox::WwwStream->response($ctx, dump_topics($ctx), *index_nav);
 }