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deduplicateArchiveRevId.php
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1 <?php
2 
4 
5 require_once __DIR__ . '/Maintenance.php';
6 
15 
17  private $arActorQuery = null;
18 
19  private $deleted = 0;
20  private $reassigned = 0;
21 
22  public function __construct() {
23  parent::__construct();
24  $this->addDescription(
25  'Clean up duplicate ar_rev_id, both within archive and between archive and revision.'
26  );
27  $this->setBatchSize( 10000 );
28  }
29 
30  protected function getUpdateKey() {
31  return __CLASS__;
32  }
33 
34  protected function doDBUpdates() {
35  $this->output( "Deduplicating ar_rev_id...\n" );
36  $dbw = $this->getDB( DB_MASTER );
37  // Sanity check. If this is a new install, we don't need to do anything here.
38  if ( PopulateArchiveRevId::isNewInstall( $dbw ) ) {
39  $this->output( "New install, nothing to do here.\n" );
40  return true;
41  }
42 
44 
45  $minId = $dbw->selectField( 'archive', 'MIN(ar_rev_id)', [], __METHOD__ );
46  $maxId = $dbw->selectField( 'archive', 'MAX(ar_rev_id)', [], __METHOD__ );
47  $batchSize = $this->getBatchSize();
48 
49  $this->arActorQuery = ActorMigration::newMigration()->getJoin( 'ar_user' );
50  $revActorQuery = ActorMigration::newMigration()->getJoin( 'rev_user' );
51 
52  for ( $id = $minId; $id <= $maxId; $id += $batchSize ) {
53  $endId = min( $maxId, $id + $batchSize - 1 );
54 
55  $this->beginTransaction( $dbw, __METHOD__ );
56 
57  // Lock the archive and revision table rows for the IDs we're checking
58  // to try to prevent deletions or undeletions from confusing things.
59  $dbw->selectRowCount(
60  'archive',
61  1,
62  [ 'ar_rev_id >= ' . (int)$id, 'ar_rev_id <= ' . (int)$endId ],
63  __METHOD__,
64  [ 'FOR UPDATE' ]
65  );
66  $dbw->selectRowCount(
67  'revision',
68  1,
69  [ 'rev_id >= ' . (int)$id, 'rev_id <= ' . (int)$endId ],
70  __METHOD__,
71  [ 'LOCK IN SHARE MODE' ]
72  );
73 
74  // Figure out the ar_rev_ids we actually need to look at
75  $res = $dbw->select(
76  [ 'archive', 'revision' ] + $revActorQuery['tables'],
77  [ 'rev_id', 'rev_timestamp', 'rev_sha1' ] + $revActorQuery['fields'],
78  [ 'ar_rev_id >= ' . (int)$id, 'ar_rev_id <= ' . (int)$endId ],
79  __METHOD__,
80  [ 'DISTINCT' ],
81  [ 'revision' => [ 'JOIN', 'ar_rev_id = rev_id' ] ] + $revActorQuery['joins']
82  );
83  $revRows = [];
84  foreach ( $res as $row ) {
85  $revRows[$row->rev_id] = $row;
86  }
87 
88  $arRevIds = $dbw->selectFieldValues(
89  [ 'archive' ],
90  'ar_rev_id',
91  [ 'ar_rev_id >= ' . (int)$id, 'ar_rev_id <= ' . (int)$endId ],
92  __METHOD__,
93  [ 'GROUP BY' => 'ar_rev_id', 'HAVING' => 'COUNT(*) > 1' ]
94  );
95  $arRevIds = array_values( array_unique( array_merge( $arRevIds, array_keys( $revRows ) ) ) );
96 
97  if ( $arRevIds ) {
98  $this->processArRevIds( $dbw, $arRevIds, $revRows );
99  }
100 
101  $this->output( "... $id-$endId\n" );
102  $this->commitTransaction( $dbw, __METHOD__ );
103  }
104 
105  $this->output(
106  "Finished deduplicating ar_rev_id. $this->deleted rows deleted, "
107  . "$this->reassigned assigned new IDs.\n"
108  );
109  return true;
110  }
111 
118  private function processArRevIds( IDatabase $dbw, array $arRevIds, array $revRows ) {
119  // Select all the data we need for deduplication
120  $res = $dbw->select(
121  [ 'archive' ] + $this->arActorQuery['tables'],
122  [ 'ar_id', 'ar_rev_id', 'ar_namespace', 'ar_title', 'ar_timestamp', 'ar_sha1' ]
123  + $this->arActorQuery['fields'],
124  [ 'ar_rev_id' => $arRevIds ],
125  __METHOD__,
126  [],
127  $this->arActorQuery['joins']
128  );
129 
130  // Determine which rows we need to delete or reassign
131  $seen = [];
132  $toDelete = [];
133  $toReassign = [];
134  foreach ( $res as $row ) {
135  // Revision-table row exists?
136  if ( isset( $revRows[$row->ar_rev_id] ) ) {
137  $revRow = $revRows[$row->ar_rev_id];
138 
139  // Record the rev_id as seen, so the code below will always delete or reassign.
140  if ( !isset( $seen[$revRow->rev_id] ) ) {
141  $seen[$revRow->rev_id] = [
142  'first' => "revision row",
143  ];
144  }
145 
146  // Delete the archive row if it seems to be the same regardless
147  // of page, because moves can change IDs and titles.
148  if ( $row->ar_timestamp === $revRow->rev_timestamp &&
149  $row->ar_sha1 === $revRow->rev_sha1 &&
150  $row->ar_user === $revRow->rev_user &&
151  $row->ar_user_text === $revRow->rev_user_text
152  ) {
153  $this->output(
154  "Row $row->ar_id duplicates revision row for rev_id $revRow->rev_id, deleting\n"
155  );
156  $toDelete[] = $row->ar_id;
157  continue;
158  }
159  }
160 
161  $key = $this->getSeenKey( $row );
162  if ( !isset( $seen[$row->ar_rev_id] ) ) {
163  // This rev_id hasn't even been seen yet, nothing to do besides record it.
164  $seen[$row->ar_rev_id] = [
165  'first' => "archive row $row->ar_id",
166  $key => $row->ar_id,
167  ];
168  } elseif ( !isset( $seen[$row->ar_rev_id][$key] ) ) {
169  // The rev_id was seen, but not this particular change. Reassign it.
170  $seen[$row->ar_rev_id][$key] = $row->ar_id;
171  $this->output(
172  "Row $row->ar_id conflicts with {$seen[$row->ar_rev_id]['first']} "
173  . "for rev_id $row->ar_rev_id, reassigning\n"
174  );
175  $toReassign[] = $row->ar_id;
176  } else {
177  // The rev_id was seen with a row that matches this change. Delete it.
178  $this->output(
179  "Row $row->ar_id duplicates archive row {$seen[$row->ar_rev_id][$key]} "
180  . "for rev_id $row->ar_rev_id, deleting\n"
181  );
182  $toDelete[] = $row->ar_id;
183  }
184  }
185 
186  // Perform the updates
187  if ( $toDelete ) {
188  $dbw->delete( 'archive', [ 'ar_id' => $toDelete ], __METHOD__ );
189  $this->deleted += $dbw->affectedRows();
190  }
191  if ( $toReassign ) {
192  $this->reassigned += PopulateArchiveRevId::reassignArRevIds( $dbw, $toReassign );
193  }
194  }
195 
201  private function getSeenKey( $row ) {
202  return implode( "\n", [
203  $row->ar_namespace,
204  $row->ar_title,
205  $row->ar_timestamp,
206  $row->ar_sha1,
207  $row->ar_user,
208  $row->ar_user_text,
209  ] );
210  }
211 
212 }
213 
214 $maintClass = "DeduplicateArchiveRevId";
215 require_once RUN_MAINTENANCE_IF_MAIN;
commitTransaction(IDatabase $dbw, $fname)
Commit the transcation on a DB handle and wait for replica DBs to catch up.
const RUN_MAINTENANCE_IF_MAIN
Definition: Maintenance.php:39
affectedRows()
Get the number of rows affected by the last write query.
setBatchSize( $s=0)
Set the batch size.
Maintenance script that cleans up archive rows with duplicated ar_rev_id, both within archive and bet...
const DB_MASTER
Definition: defines.php:26
processArRevIds(IDatabase $dbw, array $arRevIds, array $revRows)
Process a set of ar_rev_ids.
static checkMysqlAutoIncrementBug(IDatabase $dbw)
Check for (and work around) a MySQL auto-increment bug.
static newMigration()
Static constructor.
static reassignArRevIds(IDatabase $dbw, array $arIds, array $conds=[])
Assign new ar_rev_ids to a set of ar_ids.
addDescription( $text)
Set the description text.
output( $out, $channel=null)
Throw some output to the user.
Class for scripts that perform database maintenance and want to log the update in updatelog so we can...
Basic database interface for live and lazy-loaded relation database handles.
Definition: IDatabase.php:38
getBatchSize()
Returns batch size.
select( $table, $vars, $conds='', $fname=__METHOD__, $options=[], $join_conds=[])
Execute a SELECT query constructed using the various parameters provided.
delete( $table, $conds, $fname=__METHOD__)
DELETE query wrapper.
getDB( $db, $groups=[], $dbDomain=false)
Returns a database to be used by current maintenance script.
beginTransaction(IDatabase $dbw, $fname)
Begin a transcation on a DB.
static isNewInstall(IDatabase $dbw)
getSeenKey( $row)
Make a key identifying a "unique" change from a row.