MediaWiki REL1_30
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() {
51
53 $this->output(
54 "...cannot update while \$wgCommentTableSchemaMigrationStage < MIGRATION_WRITE_NEW\n"
55 );
56 return false;
57 }
58
59 $this->migrateToTemp(
60 'revision', 'rev_id', 'rev_comment', 'revcomment_rev', 'revcomment_comment_id'
61 );
62 $this->migrate( 'archive', 'ar_id', 'ar_comment' );
63 $this->migrate( 'ipblocks', 'ipb_id', 'ipb_reason' );
64 $this->migrateToTemp(
65 'image', 'img_name', 'img_description', 'imgcomment_name', 'imgcomment_description_id'
66 );
67 $this->migrate( 'oldimage', [ 'oi_name', 'oi_timestamp' ], 'oi_description' );
68 $this->migrate( 'filearchive', 'fa_id', 'fa_deleted_reason' );
69 $this->migrate( 'filearchive', 'fa_id', 'fa_description' );
70 $this->migrate( 'recentchanges', 'rc_id', 'rc_comment' );
71 $this->migrate( 'logging', 'log_id', 'log_comment' );
72 $this->migrate( 'protected_titles', [ 'pt_namespace', 'pt_title' ], 'pt_reason' );
73 return true;
74 }
75
82 private function loadCommentIDs( IDatabase $dbw, array &$comments ) {
83 $count = 0;
84 $needComments = $comments;
85
86 while ( true ) {
87 $where = [];
88 foreach ( $needComments as $need => $dummy ) {
89 $where[] = $dbw->makeList(
90 [
91 'comment_hash' => CommentStore::hash( $need, null ),
92 'comment_text' => $need,
93 ],
95 );
96 }
97
98 $res = $dbw->select(
99 'comment',
100 [ 'comment_id', 'comment_text' ],
101 [
102 $dbw->makeList( $where, LIST_OR ),
103 'comment_data' => null,
104 ],
105 __METHOD__
106 );
107 foreach ( $res as $row ) {
108 $comments[$row->comment_text] = $row->comment_id;
109 unset( $needComments[$row->comment_text] );
110 }
111
112 if ( !$needComments ) {
113 break;
114 }
115
116 $dbw->insert(
117 'comment',
118 array_map( function ( $v ) {
119 return [
120 'comment_hash' => CommentStore::hash( $v, null ),
121 'comment_text' => $v,
122 ];
123 }, array_keys( $needComments ) ),
124 __METHOD__
125 );
126 $count += $dbw->affectedRows();
127 }
128 return $count;
129 }
130
142 protected function migrate( $table, $primaryKey, $oldField ) {
143 $newField = $oldField . '_id';
144 $primaryKey = (array)$primaryKey;
145 $pkFilter = array_flip( $primaryKey );
146 $this->output( "Beginning migration of $table.$oldField to $table.$newField\n" );
148
149 $dbw = $this->getDB( DB_MASTER );
150 $next = '1=1';
151 $countUpdated = 0;
152 $countComments = 0;
153 while ( true ) {
154 // Fetch the rows needing update
155 $res = $dbw->select(
156 $table,
157 array_merge( $primaryKey, [ $oldField ] ),
158 [
159 $newField => 0,
160 $next,
161 ],
162 __METHOD__,
163 [
164 'ORDER BY' => $primaryKey,
165 'LIMIT' => $this->mBatchSize,
166 ]
167 );
168 if ( !$res->numRows() ) {
169 break;
170 }
171
172 // Collect the distinct comments from those rows
173 $comments = [];
174 foreach ( $res as $row ) {
175 $comments[$row->$oldField] = 0;
176 }
177 $countComments += $this->loadCommentIDs( $dbw, $comments );
178
179 // Update the existing rows
180 foreach ( $res as $row ) {
181 $dbw->update(
182 $table,
183 [
184 $newField => $comments[$row->$oldField],
185 $oldField => '',
186 ],
187 array_intersect_key( (array)$row, $pkFilter ) + [
188 $newField => 0
189 ],
190 __METHOD__
191 );
192 $countUpdated += $dbw->affectedRows();
193 }
194
195 // Calculate the "next" condition
196 $next = '';
197 $prompt = [];
198 for ( $i = count( $primaryKey ) - 1; $i >= 0; $i-- ) {
199 $field = $primaryKey[$i];
200 $prompt[] = $row->$field;
201 $value = $dbw->addQuotes( $row->$field );
202 if ( $next === '' ) {
203 $next = "$field > $value";
204 } else {
205 $next = "$field > $value OR $field = $value AND ($next)";
206 }
207 }
208 $prompt = join( ' ', array_reverse( $prompt ) );
209 $this->output( "... $prompt\n" );
211 }
212
213 $this->output(
214 "Completed migration, updated $countUpdated row(s) with $countComments new comment(s)\n"
215 );
216 }
217
233 protected function migrateToTemp( $table, $primaryKey, $oldField, $newPrimaryKey, $newField ) {
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->mBatchSize,
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" );
286 }
287
288 $this->output(
289 "Completed migration, updated $countUpdated row(s) with $countComments new comment(s)\n"
290 );
291 }
292}
293
294$maintClass = "MigrateComments";
295require_once RUN_MAINTENANCE_IF_MAIN;
int $wgCommentTableSchemaMigrationStage
Comment table schema migration stage.
wfWaitForSlaves( $ifWritesSince=null, $wiki=false, $cluster=false, $timeout=null)
Waits for the replica DBs to catch up to the master position.
static hash( $text, $data)
Hashing function for comment storage.
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.
getDB( $db, $groups=[], $wiki=false)
Returns a database to be used by current maintenance script.
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.
$res
Definition database.txt:21
design txt This is a brief overview of the new design More thorough and up to date information is available on the documentation wiki at etc Handles the details of getting and saving to the user table of the and dealing with sessions and cookies OutputPage Encapsulates the entire HTML page that will be sent in response to any server request It is used by calling its functions to add in any and then calling output() to send it all. It could be easily changed to send incrementally if that becomes useful
the array() calling protocol came about after MediaWiki 1.4rc1.
const MIGRATION_WRITE_NEW
Definition Defines.php:295
const LIST_OR
Definition Defines.php:47
const LIST_AND
Definition Defines.php:44
Basic database interface for live and lazy-loaded relation database handles.
Definition IDatabase.php:40
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.
require_once RUN_MAINTENANCE_IF_MAIN
const DB_MASTER
Definition defines.php:26