Diff -- /var/www/vhosts/3dshawn.com/site1/diff.cgi

O Operator
Diff

/var/www/vhosts/3dshawn.com/site1/diff.cgi

modified on local at 2026-07-10 22:25:08

Added
+6
lines
Removed
-0
lines
Context
188
unchanged
Blobs
from ba2f6f72e4fb
to d0239a381229
Restore this content →
Unified diff
Naive LCS-based line diff. Additions in emerald, deletions in rose. Both sides decompressed live from BLOB_STORE.
11#!/usr/bin/perl
22#======================================================================
33# DriftSense -- /diff.cgi
44#
55# Renders a two-pane diff for a single change captured in FILE_CHANGES
66# or SCHEMA_CHANGE. Pulls both blobs from BLOB_STORE, decompresses,
77# runs a naive LCS-style line diff, marks added / removed / context,
88# renders as syntax-highlight-ish HTML with monospace typography.
99#
1010# URL:
1111# /diff.cgi?kind=file&id=N -- FILE_CHANGES row
1212# /diff.cgi?kind=schema&id=N -- SCHEMA_CHANGE row
1313#======================================================================
1414use strict;
1515use warnings;
1616use CGI ();
1717use Compress::Zlib qw(uncompress);
1818use MODS::Config; use MODS::DBConnect; use MODS::Template; use MODS::PageWrapper;
1919
2020my $cgi = CGI->new;
2121my $db = MODS::DBConnect->new;
2222my $tpl = MODS::Template->new;
2323$|=1; print "Content-Type: text/html; charset=utf-8\nCache-Control: no-cache\n\n";
2424
2525my $kind = $cgi->param('kind') || '';
2626my $id = int($cgi->param('id') || 0);
2727
2828my $dbh = $db->db_connect or die "DB connect failed\n";
2929
3030my ($title, $subtitle, $blob_sha, $prev_sha, $meta) = ('', '', '', '', {});
3131
3232if ($kind eq 'file' && $id) {
3333 my $row = $db->db_readwrite($dbh, qq~
3434 SELECT fc.file_changes_id AS id, fc.file_name, fc.status, fc.blob_sha,
3535 fc.date_time, fc.uid, fc.gid, fc.permissions, fc.is_ts_only,
3636 fc.file_monitor_list_id, s.server_name
3737 FROM FILE_CHANGES fc LEFT JOIN SERVERS s ON s.server_id = fc.server_id
3838 WHERE fc.file_changes_id = $id LIMIT 1
3939 ~, __FILE__, __LINE__);
4040 if ($row && $row->{id}) {
4141 # Find the previous captured version of this file for the "before" pane.
4242 # Prefer same-monitor scope, but fall back to file-name-only for legacy
4343 # rows where file_monitor_list_id is NULL.
4444 my $q_fname = $dbh->quote($row->{file_name});
4545 my $scope = defined $row->{file_monitor_list_id}
4646 ? "file_monitor_list_id = $row->{file_monitor_list_id} AND "
4747 : '';
4848 my $prev = $db->db_readwrite($dbh, qq~
4949 SELECT blob_sha FROM FILE_CHANGES
5050 WHERE $scope
5151 file_name = $q_fname
5252 AND file_changes_id < $id
5353 AND blob_sha IS NOT NULL
5454 ORDER BY file_changes_id DESC LIMIT 1
5555 ~, __FILE__, __LINE__);
5656 $title = $row->{file_name};
5757 $subtitle = "$row->{status} on $row->{server_name} at $row->{date_time}";
5858 $blob_sha = $row->{blob_sha};
5959 $prev_sha = $prev && $prev->{blob_sha} ? $prev->{blob_sha} : '';
6060 $meta = { %$row };
6161 }
6262}
6363elsif ($kind eq 'schema' && $id) {
6464 my $row = $db->db_readwrite($dbh, qq~
6565 SELECT sc.schema_change_id AS id, sc.database_name, sc.table_name, sc.changes,
6666 sc.schema_blob_sha, sc.change_datetime, s.server_name, sc.server_id
6767 FROM SCHEMA_CHANGE sc LEFT JOIN SERVERS s ON s.server_id = sc.server_id
6868 WHERE sc.schema_change_id = $id LIMIT 1
6969 ~, __FILE__, __LINE__);
7070 if ($row && $row->{id}) {
7171 my $q_db = $dbh->quote($row->{database_name});
7272 my $q_t = $dbh->quote($row->{table_name});
7373 my $prev = $db->db_readwrite($dbh, qq~
7474 SELECT schema_blob_sha FROM SCHEMA_CHANGE
7575 WHERE server_id = $row->{server_id}
7676 AND database_name = $q_db AND table_name = $q_t
7777 AND schema_change_id < $id
7878 AND schema_blob_sha IS NOT NULL
7979 ORDER BY schema_change_id DESC LIMIT 1
8080 ~, __FILE__, __LINE__);
8181 $title = "$row->{database_name}.$row->{table_name}";
8282 $subtitle = "on $row->{server_name} at $row->{change_datetime}";
8383 $blob_sha = $row->{schema_blob_sha};
8484 $prev_sha = $prev && $prev->{schema_blob_sha} ? $prev->{schema_blob_sha} : '';
8585 $meta = { %$row };
8686 }
8787}
8888
8989# Fetch + decompress blobs
9090my $curr = $blob_sha ? _fetch_blob($db, $dbh, $blob_sha) : '';
9191my $prev = $prev_sha ? _fetch_blob($db, $dbh, $prev_sha) : '';
9292
9393$db->db_disconnect($dbh);
9494
9595# Compute a naive line-level diff
9696my @lines = _line_diff($prev // '', $curr // '');
9797my ($ct_add, $ct_del) = (0, 0);
9898foreach my $L (@lines) {
9999 $ct_add++ if $L->{op} eq 'add';
100100 $ct_del++ if $L->{op} eq 'del';
101 # HTML-escape diff'd content -- files under monitor may themselves be
102 # HTML/JS/CSS, and dumping raw content into an on-screen table renders
103 # the tags live. Escape it so it displays as source.
104 my $t = $L->{text}; $t = '' unless defined $t;
105 $t =~ s/&/&amp;/g; $t =~ s/</&lt;/g; $t =~ s/>/&gt;/g;
106 $L->{text} = $t;
101107}
102108
103109my $tvars = {
104110 title => $title || '(unknown)',
105111 subtitle => $subtitle,
106112 kind => $kind,
107113 id => $id,
108114 has_diff => scalar(@lines) ? 1 : 0,
109115 lines => \@lines,
110116 ct_add => $ct_add,
111117 ct_del => $ct_del,
112118 ct_context => scalar(@lines) - $ct_add - $ct_del,
113119 has_prev => $prev_sha ? 1 : 0,
114120 curr_sha => substr($blob_sha || '', 0, 12),
115121 prev_sha => substr($prev_sha || '', 0, 12),
116122};
117123
118124my @body = $tpl->template('diff.html', $tvars);
119125MODS::PageWrapper->new->wrapper(
120126 page_title => "Diff -- $title",
121127 page_key => ($kind eq 'schema' ? 'schema_changes' : 'file_changes'),
122128 body_html => join('', @body),
123129 userinfo => { display_name => 'Operator' },
124130);
125131
126132#---------------------------------------------------------------------
127133sub _fetch_blob {
128134 my ($db, $dbh, $sha) = @_;
129135 my $sth = $dbh->prepare("SELECT content_gz FROM BLOB_STORE WHERE blob_sha = ?");
130136 return '' unless $sth && $sth->execute($sha);
131137 my $row = $sth->fetchrow_arrayref;
132138 $sth->finish;
133139 return '' unless $row && $row->[0];
134140 my $decompressed = eval { uncompress($row->[0]) };
135141 return $decompressed // '';
136142}
137143
138144#---------------------------------------------------------------------
139145# _line_diff -- naive line-level diff. Returns an array of hashrefs:
140146# { op => 'add' | 'del' | 'ctx', text => $line, old_n, new_n }
141147# Uses a simple LCS-based approach; adequate for small-to-medium files.
142148# For huge diffs shell out to /usr/bin/diff (future optimization).
143149#---------------------------------------------------------------------
144150sub _line_diff {
145151 my ($old, $new) = @_;
146152 my @old_lines = split /\r?\n/, ($old // '');
147153 my @new_lines = split /\r?\n/, ($new // '');
148154
149155 # LCS length table (dynamic programming) -- capped to prevent
150156 # runaway memory on huge inputs.
151157 my $O = scalar @old_lines;
152158 my $N = scalar @new_lines;
153159 if ($O > 5000 || $N > 5000) {
154160 # Fall back: just dump both sides linearly, marked as del/add.
155161 my @out;
156162 my $i = 0;
157163 push @out, { op => 'del', text => $_, old_n => ++$i, new_n => '' } for @old_lines;
158164 my $j = 0;
159165 push @out, { op => 'add', text => $_, old_n => '', new_n => ++$j } for @new_lines;
160166 return @out;
161167 }
162168
163169 my @lcs; for my $i (0..$O) { $lcs[$i][0] = 0; }
164170 for my $j (0..$N) { $lcs[0][$j] = 0; }
165171 for my $i (1..$O) {
166172 for my $j (1..$N) {
167173 $lcs[$i][$j] = $old_lines[$i-1] eq $new_lines[$j-1]
168174 ? $lcs[$i-1][$j-1] + 1
169175 : ($lcs[$i-1][$j] >= $lcs[$i][$j-1] ? $lcs[$i-1][$j] : $lcs[$i][$j-1]);
170176 }
171177 }
172178
173179 my @out;
174180 my ($i, $j) = ($O, $N);
175181 while ($i > 0 || $j > 0) {
176182 if ($i > 0 && $j > 0 && $old_lines[$i-1] eq $new_lines[$j-1]) {
177183 unshift @out, { op => 'ctx', text => $old_lines[$i-1], old_n => $i, new_n => $j };
178184 $i--; $j--;
179185 } elsif ($j > 0 && ($i == 0 || $lcs[$i][$j-1] >= $lcs[$i-1][$j])) {
180186 unshift @out, { op => 'add', text => $new_lines[$j-1], old_n => '', new_n => $j };
181187 $j--;
182188 } else {
183189 unshift @out, { op => 'del', text => $old_lines[$i-1], old_n => $i, new_n => '' };
184190 $i--;
185191 }
186192 }
187193 return @out;
188194}