repobrowse: use filename anchors for commit views

Having too many potential links is damaging to cacheability
and hurts performance.

diff --git a/lib/PublicInbox/RepobrowseGitCommit.pm b/lib/PublicInbox/RepobrowseGitCommit.pm
index b5ffb2bf3eff1ba981fa8398db48aefa45dcc673..e4e0f3c61de0866cf1167d7609e8a1ccec74c4f9 100644 (file)
--- a/lib/PublicInbox/RepobrowseGitCommit.pm
+++ b/lib/PublicInbox/RepobrowseGitCommit.pm
@@ -2,11 +2,20 @@
 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
 
 # shows the /commit/ endpoint for git repositories
+#
+# anchors used:
+#      D - diffstat
+#      P - parents
+#      ...and various filenames from to_attr
+# The 'D' and 'P' anchors may conflict with odd filenames, but we won't
+# punish the common case with extra bytes if somebody uses 'D' or 'P'
+# in filenames.
+
 package PublicInbox::RepobrowseGitCommit;
 use strict;
 use warnings;
 use base qw(PublicInbox::RepobrowseBase);
-use PublicInbox::Hval qw(utf8_html);
+use PublicInbox::Hval qw(utf8_html to_attr);
 use PublicInbox::RepobrowseGit qw(git_unquote git_commit_title);
 
 use constant GIT_FMT => '--pretty=format:'.join('%n',
@@ -73,15 +82,15 @@ sub git_commit_stream {
        local $/ = "\0";
        $l = <$log>;
        chomp $l;
-       $fh->write(utf8_html($l)."---\n");
-       git_show_diffstat($req, $h, $fh, $log);
+       $fh->write(utf8_html($l)."<a\nid=D>---</a>\n");
+       my $diff = { anchors => {}, h => $h, p => \@p, rel => $rel };
+       git_show_diffstat($diff, $req, $h, $fh, $log);
        my $help;
        $help = " This is a merge, showing combined diff:\n\n" if ($np > 1);
 
        # diff
        local $/ = "\n";
        my $cmt = '[a-f0-9]+';
-       my $diff = { h => $h, p => \@p, rel => $rel };
        my ($cc_ins, $cc_del);
        while (defined($l = <$log>)) {
                if ($help) {
@@ -117,6 +126,8 @@ sub git_commit_stream {
        if ($help) {
                $fh->write(" This is a merge, combined diff is empty.\n");
        }
+
+       show_unchanged($fh, $diff, $qs);
        $fh->write('</pre></body></html>');
 }
 
@@ -174,14 +185,13 @@ sub git_commit_404 {
 }
 
 sub git_show_diffstat {
-       my ($req, $h, $fh, $log) = @_;
+       my ($diff, $req, $h, $fh, $log) = @_;
        local $/ = "\0\0";
        my $l = <$log>;
        chomp $l;
        my @stat = split("\0", $l);
        my $nr = 0;
        my ($nadd, $ndel) = (0, 0);
-       my $rel = $req->{relcmd};
        while (defined($l = shift @stat)) {
                $l =~ s/\n?(\S+)\t+(\S+)\t+// or next;
                my ($add, $del) = ($1, $2);
@@ -193,15 +203,14 @@ sub git_show_diffstat {
                }
                my $num = sprintf('% 6s/%-6s', $del, $add);
                if (length $l) {
-                       $l = PublicInbox::Hval->utf8($l);
-                       my $lp = $l->as_path;
-                       my $lh = $l->as_html;
-                       $l = "<a\nhref=\"${rel}commit/$lp?id=$h\">$lh</a>";
-
+                       my $anchor = to_attr(git_unquote($l));
+                       $diff->{anchors}->{$anchor} = $l;
+                       $l = utf8_html($l);
+                       $l = qq(<a\nhref="#$anchor">$l</a>);
                } else {
                        my $from = shift @stat;
                        my $to = shift @stat;
-                       $l = git_diffstat_rename($rel, $h, $from, $to);
+                       $l = git_diffstat_rename($diff, $h, $from, $to);
                }
                ++$nr;
                $fh->write(' '.$num."\t".$l."\n");
@@ -233,6 +242,8 @@ sub git_diff_ab_hdr {
        $fb = git_unquote($fb);
        $fa =~ s!\Aa/!!;
        $fb =~ s!\Ab/!!;
+       my $anchor = to_attr($fb);
+       delete $diff->{anchors}->{$anchor};
        $fa = $diff->{fa} = PublicInbox::Hval->utf8($fa);
        $fb = $diff->{fb} = PublicInbox::Hval->utf8($fb);
        $diff->{path_a} = $fa->as_path;
@@ -240,7 +251,7 @@ sub git_diff_ab_hdr {
 
        # not wasting bandwidth on links here, yet
        # links in hunk headers are far more useful with line offsets
-       "diff --git $html_a <b>$html_b</b>";
+       qq(<a\nhref=#D\nid="$anchor">diff</a> --git $html_a <b>$html_b</b>);
 }
 
 # @@ -1,2 +3,4 @@ (regular diff)
@@ -272,9 +283,12 @@ sub git_diff_ab_hunk {
 sub git_diff_cc_hdr {
        my ($diff, $combined, $path) = @_;
        my $html_path = utf8_html($path);
-       my $cc = $diff->{cc} = PublicInbox::Hval->utf8(git_unquote($path));
+       $path = git_unquote($path);
+       my $anchor = to_attr($path);
+       delete $diff->{anchors}->{$anchor};
+       my $cc = $diff->{cc} = PublicInbox::Hval->utf8($path);
        $diff->{path_cc} = $cc->as_path;
-       "diff --$combined <b>$html_path</b>";
+       qq(<a\nhref=#D\nid="$anchor">diff</a> --$combined <b>$html_path</b>);
 }
 
 # index abcdef09,01234567..76543210
@@ -333,7 +347,9 @@ sub git_diff_cc_hunk {
 }
 
 sub git_diffstat_rename {
-       my ($rel, $h, $from, $to) = @_;
+       my ($diff, $h, $from, $to) = @_;
+       my $anchor = to_attr(git_unquote($to));
+       $diff->{anchors}->{$anchor} = $to;
        my @from = split('/', $from);
        my @to = split('/', $to);
        my $orig_to = $to;
@@ -348,7 +364,7 @@ sub git_diffstat_rename {
        $to = PublicInbox::Hval->utf8(join('/', @to), $orig_to);
        my $tp = $to->as_path;
        my $th = $to->as_html;
-       $to = "<a\nhref=\"${rel}/commit/$tp?id=$h\">$th</a>";
+       $to = qq(<a\nhref="#$anchor">$th</a>);
        @base ? "$base/{$from =&gt; $to}" : "$from =&gt; $to";
 }
 
@@ -383,7 +399,29 @@ sub git_parent_line {
        my $qs = $q->qs(id => $p);
        my $t = git_commit_title($git, $p);
        $t = defined $t ? utf8_html($t) : '';
-       $pfx . " <a\nhref=\"${rel}commit$path$qs\">$p</a> ". $t . "\n";
+       $pfx . qq( <a\nid=P\nhref="${rel}commit$path$qs">$p</a> $t\n);
+}
+
+# do not break anchor links if the combined diff doesn't show changes:
+sub show_unchanged {
+       my ($fh, $diff, $qs) = @_;
+
+       my @unchanged = sort keys %{$diff->{anchors}};
+       return unless @unchanged;
+       my $anchors = $diff->{anchors};
+       my $s = "\n There are uninteresting changes from this merge.\n" .
+               qq( See <a\nhref="#P">parents</a>, ) .
+               "or view final state(s) below:\n";
+       my $rel = $diff->{rel};
+       foreach my $anchor (@unchanged) {
+               my $fn = $anchors->{$anchor};
+               my $p = PublicInbox::Hval->utf8(git_unquote($fn));
+               $p = $p->as_path;
+               $fn = utf8_html($fn);
+               $s .= qq(\t<a\nid="$anchor"\nhref="${rel}tree/$p$qs">);
+               $s .= "$fn</a>\n";
+       }
+       $fh->write($s);
 }
 
 1;