MediaWiki  1.33.0
BatchRowIterator.php
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1 <?php
2 
4 
29 class BatchRowIterator implements RecursiveIterator {
30 
34  protected $db;
35 
39  protected $table;
40 
44  protected $primaryKey;
45 
49  protected $batchSize;
50 
55  protected $conditions = [];
56 
60  protected $joinConditions = [];
61 
66  protected $fetchColumns;
67 
71  protected $orderBy;
72 
76  private $current = [];
77 
81  private $key;
82 
86  protected $options = [];
87 
96  if ( $batchSize < 1 ) {
97  throw new InvalidArgumentException( 'Batch size must be at least 1 row.' );
98  }
99  $this->db = $db;
100  $this->table = $table;
101  $this->primaryKey = (array)$primaryKey;
102  $this->fetchColumns = $this->primaryKey;
103  $this->orderBy = implode( ' ASC,', $this->primaryKey ) . ' ASC';
104  $this->batchSize = $batchSize;
105  }
106 
111  public function addConditions( array $conditions ) {
112  $this->conditions = array_merge( $this->conditions, $conditions );
113  }
114 
119  public function addOptions( array $options ) {
120  $this->options = array_merge( $this->options, $options );
121  }
122 
127  public function addJoinConditions( array $conditions ) {
128  $this->joinConditions = array_merge( $this->joinConditions, $conditions );
129  }
130 
135  public function setFetchColumns( array $columns ) {
136  // If it's not the all column selector merge in the primary keys we need
137  if ( count( $columns ) === 1 && reset( $columns ) === '*' ) {
138  $this->fetchColumns = $columns;
139  } else {
140  $this->fetchColumns = array_unique( array_merge(
141  $this->primaryKey,
142  $columns
143  ) );
144  }
145  }
146 
153  public function extractPrimaryKeys( $row ) {
154  $pk = [];
155  foreach ( $this->primaryKey as $alias => $column ) {
156  $name = is_numeric( $alias ) ? $column : $alias;
157  $pk[$name] = $row->{$name};
158  }
159  return $pk;
160  }
161 
165  public function current() {
166  return $this->current;
167  }
168 
172  public function key() {
173  return $this->key;
174  }
175 
179  public function rewind() {
180  $this->key = -1; // self::next() will turn this into 0
181  $this->current = [];
182  $this->next();
183  }
184 
188  public function valid() {
189  return (bool)$this->current;
190  }
191 
195  public function hasChildren() {
196  return $this->current && count( $this->current );
197  }
198 
202  public function getChildren() {
203  return new NotRecursiveIterator( new ArrayIterator( $this->current ) );
204  }
205 
209  public function next() {
210  $res = $this->db->select(
211  $this->table,
212  $this->fetchColumns,
213  $this->buildConditions(),
214  __METHOD__,
215  [
216  'LIMIT' => $this->batchSize,
217  'ORDER BY' => $this->orderBy,
218  ] + $this->options,
219  $this->joinConditions
220  );
221 
222  // The iterator is converted to an array because in addition to
223  // returning it in self::current() we need to use the end value
224  // in self::buildConditions()
225  $this->current = iterator_to_array( $res );
226  $this->key++;
227  }
228 
241  protected function buildConditions() {
242  if ( !$this->current ) {
243  return $this->conditions;
244  }
245 
246  $maxRow = end( $this->current );
247  $maximumValues = [];
248  foreach ( $this->primaryKey as $alias => $column ) {
249  $name = is_numeric( $alias ) ? $column : $alias;
250  $maximumValues[$column] = $this->db->addQuotes( $maxRow->{$name} );
251  }
252 
253  $pkConditions = [];
254  // For example: If we have 3 primary keys
255  // first run through will generate
256  // col1 = 4 AND col2 = 7 AND col3 > 1
257  // second run through will generate
258  // col1 = 4 AND col2 > 7
259  // and the final run through will generate
260  // col1 > 4
261  while ( $maximumValues ) {
262  $pkConditions[] = $this->buildGreaterThanCondition( $maximumValues );
263  array_pop( $maximumValues );
264  }
265 
266  $conditions = $this->conditions;
267  $conditions[] = sprintf( '( %s )', implode( ' ) OR ( ', $pkConditions ) );
268 
269  return $conditions;
270  }
271 
284  protected function buildGreaterThanCondition( array $quotedMaximumValues ) {
285  $keys = array_keys( $quotedMaximumValues );
286  $lastColumn = end( $keys );
287  $lastValue = array_pop( $quotedMaximumValues );
288  $conditions = [];
289  foreach ( $quotedMaximumValues as $column => $value ) {
290  $conditions[] = "$column = $value";
291  }
292  $conditions[] = "$lastColumn > $lastValue";
293 
294  return implode( ' AND ', $conditions );
295  }
296 }
BatchRowIterator\$conditions
$conditions
Definition: BatchRowIterator.php:55
captcha-old.count
count
Definition: captcha-old.py:249
conditions
and give any other recipients of the Program a copy of this License along with the Program You may charge a fee for the physical act of transferring a and you may at your option offer warranty protection in exchange for a fee You may modify your copy or copies of the Program or any portion of thus forming a work based on the and copy and distribute such modifications or work under the terms of Section provided that you also meet all of these conditions
Definition: COPYING.txt:87
BatchRowIterator\$joinConditions
$joinConditions
Definition: BatchRowIterator.php:60
BatchRowIterator\setFetchColumns
setFetchColumns(array $columns)
Definition: BatchRowIterator.php:135
BatchRowIterator\rewind
rewind()
Reset the iterator to the begining of the table.
Definition: BatchRowIterator.php:179
BatchRowIterator\valid
valid()
Definition: BatchRowIterator.php:188
BatchRowIterator\addConditions
addConditions(array $conditions)
Definition: BatchRowIterator.php:111
BatchRowIterator
Definition: BatchRowIterator.php:29
BatchRowIterator\buildGreaterThanCondition
buildGreaterThanCondition(array $quotedMaximumValues)
Given an array of column names and their maximum value generate an SQL condition where all keys excep...
Definition: BatchRowIterator.php:284
BatchRowIterator\extractPrimaryKeys
extractPrimaryKeys( $row)
Extracts the primary key(s) from a database row.
Definition: BatchRowIterator.php:153
$res
$res
Definition: database.txt:21
php
injection txt This is an overview of how MediaWiki makes use of dependency injection The design described here grew from the discussion of RFC T384 The term dependency this means that anything an object needs to operate should be injected from the the object itself should only know narrow no concrete implementation of the logic it relies on The requirement to inject everything typically results in an architecture that based on two main types of and essentially stateless service objects that use other service objects to operate on the value objects As of the beginning MediaWiki is only starting to use the DI approach Much of the code still relies on global state or direct resulting in a highly cyclical dependency which acts as the top level factory for services in MediaWiki which can be used to gain access to default instances of various services MediaWikiServices however also allows new services to be defined and default services to be redefined Services are defined or redefined by providing a callback the instantiator that will return a new instance of the service When it will create an instance of MediaWikiServices and populate it with the services defined in the files listed by thereby bootstrapping the DI framework Per $wgServiceWiringFiles lists includes ServiceWiring php
Definition: injection.txt:35
BatchRowIterator\$orderBy
$orderBy
Definition: BatchRowIterator.php:71
Wikimedia\Rdbms\IDatabase
Basic database interface for live and lazy-loaded relation database handles.
Definition: IDatabase.php:38
BatchRowIterator\hasChildren
hasChildren()
Definition: BatchRowIterator.php:195
BatchRowIterator\$table
$table
Definition: BatchRowIterator.php:39
BatchRowIterator\next
next()
Fetch the next set of rows from the database.
Definition: BatchRowIterator.php:209
table
deferred txt A few of the database updates required by various functions here can be deferred until after the result page is displayed to the user For updating the view updating the linked to tables after a etc PHP does not yet have any way to tell the server to actually return and disconnect while still running these but it might have such a feature in the future We handle these by creating a deferred update object and putting those objects on a global then executing the whole list after the page is displayed We don t do anything smart like collating updates to the same table or such because the list is almost always going to have just one item on if so it s not worth the trouble Since there is a job queue in the jobs table
Definition: deferred.txt:11
BatchRowIterator\$current
$current
Definition: BatchRowIterator.php:76
BatchRowIterator\key
key()
Definition: BatchRowIterator.php:172
BatchRowIterator\buildConditions
buildConditions()
Uses the primary key list and the maximal result row from the previous iteration to build an SQL cond...
Definition: BatchRowIterator.php:241
use
as see the revision history and available at free of to any person obtaining a copy of this software and associated documentation to deal in the Software without including without limitation the rights to use
Definition: MIT-LICENSE.txt:10
BatchRowIterator\addOptions
addOptions(array $options)
Definition: BatchRowIterator.php:119
NotRecursiveIterator
Definition: NotRecursiveIterator.php:27
array
The wiki should then use memcached to cache various data To use multiple just add more items to the array To increase the weight of a make its entry a array("192.168.0.1:11211", 2))
BatchRowIterator\__construct
__construct(IDatabase $db, $table, $primaryKey, $batchSize)
Definition: BatchRowIterator.php:95
$name
Allows to change the fields on the form that will be generated $name
Definition: hooks.txt:271
key
either a unescaped string or a HtmlArmor object after in associative array form externallinks including delete and has completed for all link tables whether this was an auto creation use $formDescriptor instead default is conds Array Extra conditions for the No matching items in log is displayed if loglist is empty msgKey Array If you want a nice box with a set this to the key of the message First element is the message key
Definition: hooks.txt:2154
BatchRowIterator\$batchSize
$batchSize
Definition: BatchRowIterator.php:49
BatchRowIterator\$db
$db
Definition: BatchRowIterator.php:34
$value
$value
Definition: styleTest.css.php:49
BatchRowIterator\$primaryKey
$primaryKey
Definition: BatchRowIterator.php:44
BatchRowIterator\$key
int $key
key 0-indexed number of pages fetched since self::reset()
Definition: BatchRowIterator.php:81
BatchRowIterator\addJoinConditions
addJoinConditions(array $conditions)
Definition: BatchRowIterator.php:127
BatchRowIterator\$fetchColumns
$fetchColumns
Definition: BatchRowIterator.php:66
as
This document is intended to provide useful advice for parties seeking to redistribute MediaWiki to end users It s targeted particularly at maintainers for Linux since it s been observed that distribution packages of MediaWiki often break We ve consistently had to recommend that users seeking support use official tarballs instead of their distribution s and this often solves whatever problem the user is having It would be nice if this could such as
Definition: distributors.txt:9
$keys
$keys
Definition: testCompression.php:67
BatchRowIterator\current
current()
Definition: BatchRowIterator.php:165
options
Using a hook running we can avoid having all this option specific stuff in our mainline code Using the function We ve cleaned up the code here by removing clumps of infrequently used code and moving them off somewhere else It s much easier for someone working with this code to see what s _really_ going and make changes or fix bugs In we can take all the code that deals with the little used title reversing options(say) and put it in one place. Instead of having little title-reversing if-blocks spread all over the codebase in showAnArticle
BatchRowIterator\getChildren
getChildren()
Definition: BatchRowIterator.php:202
BatchRowIterator\$options
array $options
Additional query options.
Definition: BatchRowIterator.php:86