MediaWiki REL1_34
migrateComments.php
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1<?php
25
26require_once __DIR__ . '/Maintenance.php';
27
35 public function __construct() {
36 parent::__construct();
37 $this->addDescription( 'Migrates comments from pre-1.30 columns to the \'comment\' table' );
38 $this->setBatchSize( 100 );
39 }
40
41 protected function getUpdateKey() {
42 return __CLASS__;
43 }
44
45 protected function updateSkippedMessage() {
46 return 'comments already migrated.';
47 }
48
49 protected function doDBUpdates() {
50 $this->migrateToTemp(
51 'revision', 'rev_id', 'rev_comment', 'revcomment_rev', 'revcomment_comment_id'
52 );
53 $this->migrate( 'archive', 'ar_id', 'ar_comment' );
54 $this->migrate( 'ipblocks', 'ipb_id', 'ipb_reason' );
55 $this->migrate( 'image', 'img_name', 'img_description' );
56 $this->migrate( 'oldimage', [ 'oi_name', 'oi_timestamp' ], 'oi_description' );
57 $this->migrate( 'filearchive', 'fa_id', 'fa_deleted_reason' );
58 $this->migrate( 'filearchive', 'fa_id', 'fa_description' );
59 $this->migrate( 'recentchanges', 'rc_id', 'rc_comment' );
60 $this->migrate( 'logging', 'log_id', 'log_comment' );
61 $this->migrate( 'protected_titles', [ 'pt_namespace', 'pt_title' ], 'pt_reason' );
62 return true;
63 }
64
71 private function loadCommentIDs( IDatabase $dbw, array &$comments ) {
72 $count = 0;
73 $needComments = $comments;
74
75 while ( true ) {
76 $where = [];
77 foreach ( $needComments as $need => $dummy ) {
78 $where[] = $dbw->makeList(
79 [
80 'comment_hash' => CommentStore::hash( $need, null ),
81 'comment_text' => $need,
82 ],
84 );
85 }
86
87 $res = $dbw->select(
88 'comment',
89 [ 'comment_id', 'comment_text' ],
90 [
91 $dbw->makeList( $where, LIST_OR ),
92 'comment_data' => null,
93 ],
94 __METHOD__
95 );
96 foreach ( $res as $row ) {
97 $comments[$row->comment_text] = $row->comment_id;
98 unset( $needComments[$row->comment_text] );
99 }
100
101 if ( !$needComments ) {
102 break;
103 }
104
105 $dbw->insert(
106 'comment',
107 array_map( function ( $v ) {
108 return [
109 'comment_hash' => CommentStore::hash( $v, null ),
110 'comment_text' => $v,
111 ];
112 }, array_keys( $needComments ) ),
113 __METHOD__
114 );
115 $count += $dbw->affectedRows();
116 }
117 return $count;
118 }
119
131 protected function migrate( $table, $primaryKey, $oldField ) {
132 $dbw = $this->getDB( DB_MASTER );
133 if ( !$dbw->fieldExists( $table, $oldField, __METHOD__ ) ) {
134 $this->output( "No need to migrate $table.$oldField, field does not exist\n" );
135 return;
136 }
137
138 $newField = $oldField . '_id';
139 $primaryKey = (array)$primaryKey;
140 $pkFilter = array_flip( $primaryKey );
141 $this->output( "Beginning migration of $table.$oldField to $table.$newField\n" );
143
144 $next = '1=1';
145 $countUpdated = 0;
146 $countComments = 0;
147 while ( true ) {
148 // Fetch the rows needing update
149 $res = $dbw->select(
150 $table,
151 array_merge( $primaryKey, [ $oldField ] ),
152 [
153 $newField => 0,
154 $next,
155 ],
156 __METHOD__,
157 [
158 'ORDER BY' => $primaryKey,
159 'LIMIT' => $this->getBatchSize(),
160 ]
161 );
162 if ( !$res->numRows() ) {
163 break;
164 }
165
166 // Collect the distinct comments from those rows
167 $comments = [];
168 foreach ( $res as $row ) {
169 $comments[$row->$oldField] = 0;
170 }
171 $countComments += $this->loadCommentIDs( $dbw, $comments );
172
173 // Update the existing rows
174 foreach ( $res as $row ) {
175 $dbw->update(
176 $table,
177 [
178 $newField => $comments[$row->$oldField],
179 $oldField => '',
180 ],
181 array_intersect_key( (array)$row, $pkFilter ) + [
182 $newField => 0
183 ],
184 __METHOD__
185 );
186 $countUpdated += $dbw->affectedRows();
187 }
188
189 // Calculate the "next" condition
190 $next = '';
191 $prompt = [];
192 for ( $i = count( $primaryKey ) - 1; $i >= 0; $i-- ) {
193 $field = $primaryKey[$i];
194 $prompt[] = $row->$field;
195 $value = $dbw->addQuotes( $row->$field );
196 if ( $next === '' ) {
197 $next = "$field > $value";
198 } else {
199 $next = "$field > $value OR $field = $value AND ($next)";
200 }
201 }
202 $prompt = implode( ' ', array_reverse( $prompt ) );
203 $this->output( "... $prompt\n" );
205 }
206
207 $this->output(
208 "Completed migration, updated $countUpdated row(s) with $countComments new comment(s)\n"
209 );
210 }
211
227 protected function migrateToTemp( $table, $primaryKey, $oldField, $newPrimaryKey, $newField ) {
228 $dbw = $this->getDB( DB_MASTER );
229 if ( !$dbw->fieldExists( $table, $oldField, __METHOD__ ) ) {
230 $this->output( "No need to migrate $table.$oldField, field does not exist\n" );
231 return;
232 }
233
234 $newTable = $table . '_comment_temp';
235 $this->output( "Beginning migration of $table.$oldField to $newTable.$newField\n" );
237
238 $dbw = $this->getDB( DB_MASTER );
239 $next = [];
240 $countUpdated = 0;
241 $countComments = 0;
242 while ( true ) {
243 // Fetch the rows needing update
244 $res = $dbw->select(
245 [ $table, $newTable ],
246 [ $primaryKey, $oldField ],
247 [ $newPrimaryKey => null ] + $next,
248 __METHOD__,
249 [
250 'ORDER BY' => $primaryKey,
251 'LIMIT' => $this->getBatchSize(),
252 ],
253 [ $newTable => [ 'LEFT JOIN', "{$primaryKey}={$newPrimaryKey}" ] ]
254 );
255 if ( !$res->numRows() ) {
256 break;
257 }
258
259 // Collect the distinct comments from those rows
260 $comments = [];
261 foreach ( $res as $row ) {
262 $comments[$row->$oldField] = 0;
263 }
264 $countComments += $this->loadCommentIDs( $dbw, $comments );
265
266 // Update rows
267 $inserts = [];
268 $updates = [];
269 foreach ( $res as $row ) {
270 $inserts[] = [
271 $newPrimaryKey => $row->$primaryKey,
272 $newField => $comments[$row->$oldField]
273 ];
274 $updates[] = $row->$primaryKey;
275 }
276 $this->beginTransaction( $dbw, __METHOD__ );
277 $dbw->insert( $newTable, $inserts, __METHOD__ );
278 $dbw->update( $table, [ $oldField => '' ], [ $primaryKey => $updates ], __METHOD__ );
279 $countUpdated += $dbw->affectedRows();
280 $this->commitTransaction( $dbw, __METHOD__ );
281
282 // Calculate the "next" condition
283 $next = [ $primaryKey . ' > ' . $dbw->addQuotes( $row->$primaryKey ) ];
284 $this->output( "... {$row->$primaryKey}\n" );
285 }
286
287 $this->output(
288 "Completed migration, updated $countUpdated row(s) with $countComments new comment(s)\n"
289 );
290 }
291}
292
293$maintClass = MigrateComments::class;
294require_once RUN_MAINTENANCE_IF_MAIN;
getDB()
wfWaitForSlaves( $ifWritesSince=null, $wiki=false, $cluster=false, $timeout=null)
Waits for the replica DBs to catch up to the master position.
const RUN_MAINTENANCE_IF_MAIN
Class for scripts that perform database maintenance and want to log the update in updatelog so we can...
beginTransaction(IDatabase $dbw, $fname)
Begin a transcation on a DB.
commitTransaction(IDatabase $dbw, $fname)
Commit the transcation on a DB handle and wait for replica DBs to catch up.
output( $out, $channel=null)
Throw some output to the user.
getBatchSize()
Returns batch size.
addDescription( $text)
Set the description text.
setBatchSize( $s=0)
Set the batch size.
Maintenance script that migrates comments from pre-1.30 columns to the 'comment' table.
__construct()
Default constructor.
updateSkippedMessage()
Message to show that the update was done already and was just skipped.
migrateToTemp( $table, $primaryKey, $oldField, $newPrimaryKey, $newField)
Migrate comments in a table to a temporary table.
doDBUpdates()
Do the actual work.
migrate( $table, $primaryKey, $oldField)
Migrate comments in a table.
getUpdateKey()
Get the update key name to go in the update log table.
loadCommentIDs(IDatabase $dbw, array &$comments)
Fetch comment IDs for a set of comments.
const LIST_OR
Definition Defines.php:51
const LIST_AND
Definition Defines.php:48
Basic database interface for live and lazy-loaded relation database handles.
Definition IDatabase.php:38
select( $table, $vars, $conds='', $fname=__METHOD__, $options=[], $join_conds=[])
Execute a SELECT query constructed using the various parameters provided.
affectedRows()
Get the number of rows affected by the last write query.
makeList( $a, $mode=self::LIST_COMMA)
Makes an encoded list of strings from an array.
insert( $table, $a, $fname=__METHOD__, $options=[])
INSERT wrapper, inserts an array into a table.
const DB_MASTER
Definition defines.php:26