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

O Operator
Diff

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

modified on local at 2026-07-12 00:02:03

Added
+2
lines
Removed
-1
lines
Context
199
unchanged
Blobs
from 4de410454737
to 7d22f9eb85f4
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;
19use MODS::Diff;
1920
2021my $cgi = CGI->new;
2122my $db = MODS::DBConnect->new;
2223my $tpl = MODS::Template->new;
2324$|=1; print "Content-Type: text/html; charset=utf-8\nCache-Control: no-cache\n\n";
2425
2526my $kind = $cgi->param('kind') || '';
2627my $id = int($cgi->param('id') || 0);
2728
2829my $dbh = $db->db_connect or die "DB connect failed\n";
2930
3031my ($title, $subtitle, $blob_sha, $prev_sha, $meta) = ('', '', '', '', {});
3132
3233if ($kind eq 'file' && $id) {
3334 my $row = $db->db_readwrite($dbh, qq~
3435 SELECT fc.file_changes_id AS id, fc.file_name, fc.status, fc.blob_sha,
3536 fc.date_time, UNIX_TIMESTAMP(fc.date_time) AS ts_epoch,
3637 fc.uid, fc.gid, fc.permissions, fc.is_ts_only,
3738 fc.file_monitor_list_id, s.server_name
3839 FROM FILE_CHANGES fc LEFT JOIN SERVERS s ON s.server_id = fc.server_id
3940 WHERE fc.file_changes_id = $id LIMIT 1
4041 ~, __FILE__, __LINE__);
4142 if ($row && $row->{id}) {
4243 # Find the previous captured version of this file for the "before" pane.
4344 # Prefer same-monitor scope, but fall back to file-name-only for legacy
4445 # rows where file_monitor_list_id is NULL.
4546 my $q_fname = $dbh->quote($row->{file_name});
4647 my $scope = defined $row->{file_monitor_list_id}
4748 ? "file_monitor_list_id = $row->{file_monitor_list_id} AND "
4849 : '';
4950 my $prev = $db->db_readwrite($dbh, qq~
5051 SELECT blob_sha FROM FILE_CHANGES
5152 WHERE $scope
5253 file_name = $q_fname
5354 AND file_changes_id < $id
5455 AND blob_sha IS NOT NULL
5556 ORDER BY file_changes_id DESC LIMIT 1
5657 ~, __FILE__, __LINE__);
5758 $title = $row->{file_name};
5859 my $ep = int($row->{ts_epoch} || 0);
5960 $subtitle = qq~$row->{status} on $row->{server_name} at <span class="ts" data-ts="$ep" data-fmt="datetime">$row->{date_time}</span>~;
6061 $blob_sha = $row->{blob_sha};
6162 $prev_sha = $prev && $prev->{blob_sha} ? $prev->{blob_sha} : '';
6263 $meta = { %$row };
6364 }
6465}
6566elsif ($kind eq 'schema' && $id) {
6667 my $row = $db->db_readwrite($dbh, qq~
6768 SELECT sc.schema_change_id AS id, sc.database_name, sc.table_name, sc.changes,
6869 sc.schema_blob_sha, sc.change_datetime,
6970 UNIX_TIMESTAMP(sc.change_datetime) AS ts_epoch,
7071 s.server_name, sc.server_id
7172 FROM SCHEMA_CHANGE sc LEFT JOIN SERVERS s ON s.server_id = sc.server_id
7273 WHERE sc.schema_change_id = $id LIMIT 1
7374 ~, __FILE__, __LINE__);
7475 if ($row && $row->{id}) {
7576 my $q_db = $dbh->quote($row->{database_name});
7677 my $q_t = $dbh->quote($row->{table_name});
7778 my $prev = $db->db_readwrite($dbh, qq~
7879 SELECT schema_blob_sha FROM SCHEMA_CHANGE
7980 WHERE server_id = $row->{server_id}
8081 AND database_name = $q_db AND table_name = $q_t
8182 AND schema_change_id < $id
8283 AND schema_blob_sha IS NOT NULL
8384 ORDER BY schema_change_id DESC LIMIT 1
8485 ~, __FILE__, __LINE__);
8586 $title = "$row->{database_name}.$row->{table_name}";
8687 my $ep = int($row->{ts_epoch} || 0);
8788 $subtitle = qq~on $row->{server_name} at <span class="ts" data-ts="$ep" data-fmt="datetime">$row->{change_datetime}</span>~;
8889 $blob_sha = $row->{schema_blob_sha};
8990 $prev_sha = $prev && $prev->{schema_blob_sha} ? $prev->{schema_blob_sha} : '';
9091 $meta = { %$row };
9192 }
9293}
9394
9495# Fetch + decompress blobs
9596my $curr = $blob_sha ? _fetch_blob($db, $dbh, $blob_sha) : '';
9697my $prev = $prev_sha ? _fetch_blob($db, $dbh, $prev_sha) : '';
9798
9899$db->db_disconnect($dbh);
99100
100101# Compute a naive line-level diff
101my @lines = _line_diff($prev // '', $curr // '');
102my @lines = MODS::Diff::lines($prev // '', $curr // '');
102103my ($ct_add, $ct_del) = (0, 0);
103104foreach my $L (@lines) {
104105 $ct_add++ if $L->{op} eq 'add';
105106 $ct_del++ if $L->{op} eq 'del';
106107 # HTML-escape diff'd content -- files under monitor may themselves be
107108 # HTML/JS/CSS, and dumping raw content into an on-screen table renders
108109 # the tags live. Escape it so it displays as source.
109110 my $t = $L->{text}; $t = '' unless defined $t;
110111 $t =~ s/&/&amp;/g; $t =~ s/</&lt;/g; $t =~ s/>/&gt;/g;
111112 $L->{text} = $t;
112113}
113114
114115my $tvars = {
115116 title => $title || '(unknown)',
116117 subtitle => $subtitle,
117118 kind => $kind,
118119 id => $id,
119120 has_diff => scalar(@lines) ? 1 : 0,
120121 lines => \@lines,
121122 ct_add => $ct_add,
122123 ct_del => $ct_del,
123124 ct_context => scalar(@lines) - $ct_add - $ct_del,
124125 has_prev => $prev_sha ? 1 : 0,
125126 curr_sha => substr($blob_sha || '', 0, 12),
126127 prev_sha => substr($prev_sha || '', 0, 12),
127128 restore_url => ($kind eq 'file' && $blob_sha) ? "/restore.cgi?id=$id" : '',
128129};
129130
130131my @body = $tpl->template('diff.html', $tvars);
131132MODS::PageWrapper->new->wrapper(
132133 page_title => "Diff -- $title",
133134 page_key => ($kind eq 'schema' ? 'schema_changes' : 'file_changes'),
134135 body_html => join('', @body),
135136 userinfo => { display_name => 'Operator' },
136137);
137138
138139#---------------------------------------------------------------------
139140sub _fetch_blob {
140141 my ($db, $dbh, $sha) = @_;
141142 my $sth = $dbh->prepare("SELECT content_gz FROM BLOB_STORE WHERE blob_sha = ?");
142143 return '' unless $sth && $sth->execute($sha);
143144 my $row = $sth->fetchrow_arrayref;
144145 $sth->finish;
145146 return '' unless $row && $row->[0];
146147 my $decompressed = eval { uncompress($row->[0]) };
147148 return $decompressed // '';
148149}
149150
150151#---------------------------------------------------------------------
151152# _line_diff -- naive line-level diff. Returns an array of hashrefs:
152153# { op => 'add' | 'del' | 'ctx', text => $line, old_n, new_n }
153154# Uses a simple LCS-based approach; adequate for small-to-medium files.
154155# For huge diffs shell out to /usr/bin/diff (future optimization).
155156#---------------------------------------------------------------------
156157sub _line_diff {
157158 my ($old, $new) = @_;
158159 my @old_lines = split /\r?\n/, ($old // '');
159160 my @new_lines = split /\r?\n/, ($new // '');
160161
161162 # LCS length table (dynamic programming) -- capped to prevent
162163 # runaway memory on huge inputs.
163164 my $O = scalar @old_lines;
164165 my $N = scalar @new_lines;
165166 if ($O > 5000 || $N > 5000) {
166167 # Fall back: just dump both sides linearly, marked as del/add.
167168 my @out;
168169 my $i = 0;
169170 push @out, { op => 'del', text => $_, old_n => ++$i, new_n => '' } for @old_lines;
170171 my $j = 0;
171172 push @out, { op => 'add', text => $_, old_n => '', new_n => ++$j } for @new_lines;
172173 return @out;
173174 }
174175
175176 my @lcs; for my $i (0..$O) { $lcs[$i][0] = 0; }
176177 for my $j (0..$N) { $lcs[0][$j] = 0; }
177178 for my $i (1..$O) {
178179 for my $j (1..$N) {
179180 $lcs[$i][$j] = $old_lines[$i-1] eq $new_lines[$j-1]
180181 ? $lcs[$i-1][$j-1] + 1
181182 : ($lcs[$i-1][$j] >= $lcs[$i][$j-1] ? $lcs[$i-1][$j] : $lcs[$i][$j-1]);
182183 }
183184 }
184185
185186 my @out;
186187 my ($i, $j) = ($O, $N);
187188 while ($i > 0 || $j > 0) {
188189 if ($i > 0 && $j > 0 && $old_lines[$i-1] eq $new_lines[$j-1]) {
189190 unshift @out, { op => 'ctx', text => $old_lines[$i-1], old_n => $i, new_n => $j };
190191 $i--; $j--;
191192 } elsif ($j > 0 && ($i == 0 || $lcs[$i][$j-1] >= $lcs[$i-1][$j])) {
192193 unshift @out, { op => 'add', text => $new_lines[$j-1], old_n => '', new_n => $j };
193194 $j--;
194195 } else {
195196 unshift @out, { op => 'del', text => $old_lines[$i-1], old_n => $i, new_n => '' };
196197 $i--;
197198 }
198199 }
199200 return @out;
200201}