1 # Copyright (C) 2019-2020 all contributors <meta@public-inbox.org>
2 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
4 # used by PublicInbox::View
5 # This adds CSS spans for diff highlighting.
6 # It also generates links for ViewVCS + SolverGit to show
7 # (or reconstruct) blobs.
9 package PublicInbox::ViewDiff;
13 use base qw(Exporter);
14 our @EXPORT_OK = qw(flush_diff);
15 use URI::Escape qw(uri_escape_utf8);
16 use PublicInbox::Hval qw(ascii_html to_attr);
17 use PublicInbox::Git qw(git_unquote);
19 sub UNSAFE () { "^A-Za-z0-9\-\._~/" }
21 my $OID_NULL = '0{7,40}';
22 my $OID_BLOB = '[a-f0-9]{7,40}';
25 my $FN = qr!(?:"?[^/\n]+/[^\n]+|/dev/null)!;
27 # cf. git diff.c :: get_compact_summary
28 my $DIFFSTAT_COMMENT = qr/\((?:new|gone|(?:(?:new|mode) [\+\-][lx]))\)/;
30 # link to line numbers in blobs
31 sub diff_hunk ($$$$) {
32 my ($dst, $dctx, $ca, $cb) = @_;
33 my ($oid_a, $oid_b, $spfx) = @$dctx{qw(oid_a oid_b spfx)};
35 if (defined($spfx) && defined($oid_a) && defined($oid_b)) {
36 my ($n) = ($ca =~ /^-([0-9]+)/);
37 $n = defined($n) ? do { ++$n; "#n$n" } : '';
39 $$dst .= qq(@@ <a\nhref="$spfx$oid_a/s/$dctx->{Q}$n">$ca</a>);
41 ($n) = ($cb =~ /^\+([0-9]+)/);
42 $n = defined($n) ? do { ++$n; "#n$n" } : '';
43 $$dst .= qq( <a\nhref="$spfx$oid_b/s/$dctx->{Q}$n">$cb</a> @@);
45 $$dst .= "@@ $ca $cb @@";
50 my ($dctx, $spfx, $oid) = @_;
51 defined($spfx) ? qq(<a\nhref="$spfx$oid/s/$dctx->{Q}">$oid</a>) : $oid;
54 # returns true if diffstat anchor written, false otherwise
56 my ($dst, $ctx, $fn, $rest) = @_;
60 # normal git diffstat output is impossible to parse reliably
61 # without --numstat, and that isn't the default for format-patch.
62 # So only do best-effort handling of renames for common cases;
63 # which works well in practice. If projects put "=>", or trailing
64 # spaces in filenames, oh well :P
65 $fn =~ s/(?: *$DIFFSTAT_COMMENT)? *\z//so;
66 $fn =~ s/{(?:.+) => (.+)}/$1/ or $fn =~ s/.* => (.+)/$1/;
67 $fn = git_unquote($fn);
69 # long filenames will require us to walk backwards in anchor1
70 if ($fn =~ s!\A\.\.\./?!!) {
71 $ctx->{-long_path}->{$fn} = qr/\Q$fn\E\z/s;
74 if (my $attr = to_attr($ctx->{-apfx}.$fn)) {
75 $ctx->{-anchors}->{$attr} = 1;
76 my $spaces = ($orig =~ s/( +)\z//) ? $1 : '';
77 $$dst .= " <a\nid=i$attr\nhref=#$attr>" .
78 ascii_html($orig) . '</a>' . $spaces .
79 $ctx->{-linkify}->to_html($rest);
85 # returns "diff --git" anchor destination, undef otherwise
88 my $attr = to_attr($ctx->{-apfx}.$pb) or return;
90 my $ok = delete $ctx->{-anchors}->{$attr};
92 # unlikely, check the end of all long path names we captured:
94 my $lp = $ctx->{-long_path} or return;
95 foreach my $fn (keys %$lp) {
96 $pb =~ $lp->{$fn} or next;
99 $attr = to_attr($ctx->{-apfx}.$fn) or return;
100 $ok = delete $ctx->{-anchors}->{$attr} or return;
104 $ok ? "<a\nhref=#i$attr\nid=$attr>diff</a> --git" : undef
107 sub diff_header ($$$$) {
108 my ($dst, $x, $ctx, $top) = @_;
109 my (undef, undef, $pa, $pb) = splice(@$top, 0, 4); # ignore oid_{a,b}
110 my $spfx = $ctx->{-spfx};
111 my $dctx = { spfx => $spfx };
113 # get rid of leading "a/" or "b/" (or whatever --{src,dst}-prefix are)
114 $pa = (split('/', git_unquote($pa), 2))[1] if $pa ne '/dev/null';
115 $pb = (split('/', git_unquote($pb), 2))[1] if $pb ne '/dev/null';
116 if ($pa eq $pb && $pb ne '/dev/null') {
117 $dctx->{Q} = "?b=".uri_escape_utf8($pb, UNSAFE);
120 if ($pb ne '/dev/null') {
121 push @q, 'b='.uri_escape_utf8($pb, UNSAFE);
123 if ($pa ne '/dev/null') {
124 push @q, 'a='.uri_escape_utf8($pa, UNSAFE);
126 $dctx->{Q} = '?'.join('&', @q);
129 # linkify early and all at once, since we know the following
130 # subst ops on $$x won't need further escaping:
131 $$x = $ctx->{-linkify}->to_html($$x);
133 # no need to capture oid_a and oid_b on add/delete,
134 # we just linkify OIDs directly via s///e in conditional
135 if (($$x =~ s/^(index $OID_NULL\.\.)($OID_BLOB)\b/
136 $1 . oid($dctx, $spfx, $2)/emos) ||
137 ($$x =~ s/^index ($OID_BLOB)(\.\.$OID_NULL)\b/
138 'index ' . oid($dctx, $spfx, $1) . $2/emos)) {
139 } elsif ($$x =~ /^index ($OID_BLOB)\.\.($OID_BLOB)/mos) {
140 # modification-only, not add/delete:
141 # linkify hunk headers later using oid_a and oid_b
142 @$dctx{qw(oid_a oid_b)} = ($1, $2);
144 warn "BUG? <$$x> had no ^index line";
146 $$x =~ s!^diff --git!anchor1($ctx, $pb) // 'diff --git'!emos;
147 $$dst .= qq(<span\nclass="head">);
153 sub diff_before_or_after ($$$) {
154 my ($dst, $ctx, $x) = @_;
155 my $linkify = $ctx->{-linkify};
156 for my $y (split(/(^---\n)/sm, $$x)) {
157 if ($y =~ /\A---\n\z/s) {
158 $$dst .= "---\n"; # all HTML is "\r\n" => "\n"
159 } elsif ($y =~ /^ [0-9]+ files? changed, /sm) {
160 # ok, looks like a diffstat, go line-by-line:
161 for my $l (split(/^/m, $y)) {
162 if ($l =~ /^ (.+)( +\| .*\z)/s) {
163 anchor0($dst, $ctx, $1, $2) and next;
165 $$dst .= $linkify->to_html($l);
167 } else { # commit message, notes, etc
168 $$dst .= $linkify->to_html($y);
173 # callers must do CRLF => LF conversion before calling this
174 sub flush_diff ($$$) {
175 my ($dst, $ctx, $cur) = @_;
178 (?: # begin header stuff, don't capture filenames, here,
179 # but instead wait for the --- and +++ lines.
180 (?:^diff\x20--git\x20$FN\x20$FN$LF)
182 # old mode || new mode || copy|rename|deleted|...
184 )? # end of optional stuff, everything below is required
185 ^index\x20($OID_BLOB)\.\.($OID_BLOB)$ANY*$LF
187 ^\+{3}\x20($FN)$LF)/smxo, $$cur);
190 my $linkify = $ctx->{-linkify};
191 my $dctx; # {}, keys: Q, oid_a, oid_b
193 while (defined(my $x = shift @top)) {
194 if (scalar(@top) >= 4 &&
195 $top[1] =~ /\A$OID_BLOB\z/os &&
196 $top[0] =~ /\A$OID_BLOB\z/os) {
197 $dctx = diff_header($dst, \$x, $ctx, \@top);
200 for my $s (split(/((?:(?:^\+[^\n]*\n)+)|
202 (?:^@@ [^\n]+\n))/xsm, $x)) {
203 if (!defined($dctx)) {
205 } elsif ($s =~ s/\A@@ (\S+) (\S+) @@//) {
206 $$dst .= qq(<span\nclass="hunk">);
207 diff_hunk($dst, $dctx, $1, $2);
208 $$dst .= $linkify->to_html($s);
210 } elsif ($s =~ /\A\+/) {
211 $$dst .= qq(<span\nclass="add">);
212 $$dst .= $linkify->to_html($s);
214 } elsif ($s =~ /\A-- $/sm) { # email sig starts
217 } elsif ($s =~ /\A-/) {
218 $$dst .= qq(<span\nclass="del">);
219 $$dst .= $linkify->to_html($s);
222 $$dst .= $linkify->to_html($s);
225 diff_before_or_after($dst, $ctx, \$after) unless $dctx;
227 diff_before_or_after($dst, $ctx, \$x);