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[lhc/web/wiklou.git] / includes / db / Database.php
1 <?php
2 /**
3 * @defgroup Database Database
4 *
5 * @file
6 * @ingroup Database
7 * This file deals with database interface functions
8 * and query specifics/optimisations
9 */
10
11 /** Number of times to re-try an operation in case of deadlock */
12 define( 'DEADLOCK_TRIES', 4 );
13 /** Minimum time to wait before retry, in microseconds */
14 define( 'DEADLOCK_DELAY_MIN', 500000 );
15 /** Maximum time to wait before retry */
16 define( 'DEADLOCK_DELAY_MAX', 1500000 );
17
18 /**
19 * Base interface for all DBMS-specific code. At a bare minimum, all of the
20 * following must be implemented to support MediaWiki
21 *
22 * @file
23 * @ingroup Database
24 */
25 interface DatabaseType {
26 /**
27 * Get the type of the DBMS, as it appears in $wgDBtype.
28 *
29 * @return string
30 */
31 function getType();
32
33 /**
34 * Open a connection to the database. Usually aborts on failure
35 *
36 * @param $server String: database server host
37 * @param $user String: database user name
38 * @param $password String: database user password
39 * @param $dbName String: database name
40 * @return bool
41 * @throws DBConnectionError
42 */
43 function open( $server, $user, $password, $dbName );
44
45 /**
46 * The DBMS-dependent part of query()
47 * @todo Fixme: Make this private someday
48 *
49 * @param $sql String: SQL query.
50 * @return Result object to feed to fetchObject, fetchRow, ...; or false on failure
51 * @private
52 */
53 function doQuery( $sql );
54
55 /**
56 * Fetch the next row from the given result object, in object form.
57 * Fields can be retrieved with $row->fieldname, with fields acting like
58 * member variables.
59 *
60 * @param $res SQL result object as returned from DatabaseBase::query(), etc.
61 * @return Row object
62 * @throws DBUnexpectedError Thrown if the database returns an error
63 */
64 function fetchObject( $res );
65
66 /**
67 * Fetch the next row from the given result object, in associative array
68 * form. Fields are retrieved with $row['fieldname'].
69 *
70 * @param $res SQL result object as returned from DatabaseBase::query(), etc.
71 * @return Row object
72 * @throws DBUnexpectedError Thrown if the database returns an error
73 */
74 function fetchRow( $res );
75
76 /**
77 * Get the number of rows in a result object
78 *
79 * @param $res Mixed: A SQL result
80 * @return int
81 */
82 function numRows( $res );
83
84 /**
85 * Get the number of fields in a result object
86 * @see http://www.php.net/mysql_num_fields
87 *
88 * @param $res Mixed: A SQL result
89 * @return int
90 */
91 function numFields( $res );
92
93 /**
94 * Get a field name in a result object
95 * @see http://www.php.net/mysql_field_name
96 *
97 * @param $res Mixed: A SQL result
98 * @param $n Integer
99 * @return string
100 */
101 function fieldName( $res, $n );
102
103 /**
104 * Get the inserted value of an auto-increment row
105 *
106 * The value inserted should be fetched from nextSequenceValue()
107 *
108 * Example:
109 * $id = $dbw->nextSequenceValue('page_page_id_seq');
110 * $dbw->insert('page',array('page_id' => $id));
111 * $id = $dbw->insertId();
112 *
113 * @return int
114 */
115 function insertId();
116
117 /**
118 * Change the position of the cursor in a result object
119 * @see http://www.php.net/mysql_data_seek
120 *
121 * @param $res Mixed: A SQL result
122 * @param $row Mixed: Either MySQL row or ResultWrapper
123 */
124 function dataSeek( $res, $row );
125
126 /**
127 * Get the last error number
128 * @see http://www.php.net/mysql_errno
129 *
130 * @return int
131 */
132 function lastErrno();
133
134 /**
135 * Get a description of the last error
136 * @see http://www.php.net/mysql_error
137 *
138 * @return string
139 */
140 function lastError();
141
142 /**
143 * mysql_fetch_field() wrapper
144 * Returns false if the field doesn't exist
145 *
146 * @param $table string: table name
147 * @param $field string: field name
148 *
149 * @return Field
150 */
151 function fieldInfo( $table, $field );
152
153 /**
154 * Get information about an index into an object
155 * @param $table string: Table name
156 * @param $index string: Index name
157 * @param $fname string: Calling function name
158 * @return Mixed: Database-specific index description class or false if the index does not exist
159 */
160 function indexInfo( $table, $index, $fname = 'Database::indexInfo' );
161
162 /**
163 * Get the number of rows affected by the last write query
164 * @see http://www.php.net/mysql_affected_rows
165 *
166 * @return int
167 */
168 function affectedRows();
169
170 /**
171 * Wrapper for addslashes()
172 *
173 * @param $s string: to be slashed.
174 * @return string: slashed string.
175 */
176 function strencode( $s );
177
178 /**
179 * Returns a wikitext link to the DB's website, e.g.,
180 * return "[http://www.mysql.com/ MySQL]";
181 * Should at least contain plain text, if for some reason
182 * your database has no website.
183 *
184 * @return string: wikitext of a link to the server software's web site
185 */
186 static function getSoftwareLink();
187
188 /**
189 * A string describing the current software version, like from
190 * mysql_get_server_info().
191 *
192 * @return string: Version information from the database server.
193 */
194 function getServerVersion();
195
196 /**
197 * A string describing the current software version, and possibly
198 * other details in a user-friendly way. Will be listed on Special:Version, etc.
199 * Use getServerVersion() to get machine-friendly information.
200 *
201 * @return string: Version information from the database server
202 */
203 function getServerInfo();
204 }
205
206 /**
207 * Database abstraction object
208 * @ingroup Database
209 */
210 abstract class DatabaseBase implements DatabaseType {
211
212 # ------------------------------------------------------------------------------
213 # Variables
214 # ------------------------------------------------------------------------------
215
216 protected $mLastQuery = '';
217 protected $mDoneWrites = false;
218 protected $mPHPError = false;
219
220 protected $mServer, $mUser, $mPassword, $mConn = null, $mDBname;
221 protected $mOpened = false;
222
223 protected $mTablePrefix;
224 protected $mFlags;
225 protected $mTrxLevel = 0;
226 protected $mErrorCount = 0;
227 protected $mLBInfo = array();
228 protected $mFakeSlaveLag = null, $mFakeMaster = false;
229 protected $mDefaultBigSelects = null;
230 protected $mSchemaVars = false;
231
232 # ------------------------------------------------------------------------------
233 # Accessors
234 # ------------------------------------------------------------------------------
235 # These optionally set a variable and return the previous state
236
237 /**
238 * A string describing the current software version, and possibly
239 * other details in a user-friendly way. Will be listed on Special:Version, etc.
240 * Use getServerVersion() to get machine-friendly information.
241 *
242 * @return string: Version information from the database server
243 */
244 public function getServerInfo() {
245 return $this->getServerVersion();
246 }
247
248 /**
249 * Boolean, controls output of large amounts of debug information
250 */
251 function debug( $debug = null ) {
252 return wfSetBit( $this->mFlags, DBO_DEBUG, $debug );
253 }
254
255 /**
256 * Turns buffering of SQL result sets on (true) or off (false).
257 * Default is "on" and it should not be changed without good reasons.
258 */
259 function bufferResults( $buffer = null ) {
260 if ( is_null( $buffer ) ) {
261 return !(bool)( $this->mFlags & DBO_NOBUFFER );
262 } else {
263 return !wfSetBit( $this->mFlags, DBO_NOBUFFER, !$buffer );
264 }
265 }
266
267 /**
268 * Turns on (false) or off (true) the automatic generation and sending
269 * of a "we're sorry, but there has been a database error" page on
270 * database errors. Default is on (false). When turned off, the
271 * code should use lastErrno() and lastError() to handle the
272 * situation as appropriate.
273 */
274 function ignoreErrors( $ignoreErrors = null ) {
275 return wfSetBit( $this->mFlags, DBO_IGNORE, $ignoreErrors );
276 }
277
278 /**
279 * The current depth of nested transactions
280 * @param $level Integer: , default NULL.
281 */
282 function trxLevel( $level = null ) {
283 return wfSetVar( $this->mTrxLevel, $level );
284 }
285
286 /**
287 * Number of errors logged, only useful when errors are ignored
288 */
289 function errorCount( $count = null ) {
290 return wfSetVar( $this->mErrorCount, $count );
291 }
292
293 function tablePrefix( $prefix = null ) {
294 return wfSetVar( $this->mTablePrefix, $prefix, true );
295 }
296
297 /**
298 * Properties passed down from the server info array of the load balancer
299 */
300 function getLBInfo( $name = null ) {
301 if ( is_null( $name ) ) {
302 return $this->mLBInfo;
303 } else {
304 if ( array_key_exists( $name, $this->mLBInfo ) ) {
305 return $this->mLBInfo[$name];
306 } else {
307 return null;
308 }
309 }
310 }
311
312 function setLBInfo( $name, $value = null ) {
313 if ( is_null( $value ) ) {
314 $this->mLBInfo = $name;
315 } else {
316 $this->mLBInfo[$name] = $value;
317 }
318 }
319
320 /**
321 * Set lag time in seconds for a fake slave
322 */
323 function setFakeSlaveLag( $lag ) {
324 $this->mFakeSlaveLag = $lag;
325 }
326
327 /**
328 * Make this connection a fake master
329 */
330 function setFakeMaster( $enabled = true ) {
331 $this->mFakeMaster = $enabled;
332 }
333
334 /**
335 * Returns true if this database supports (and uses) cascading deletes
336 */
337 function cascadingDeletes() {
338 return false;
339 }
340
341 /**
342 * Returns true if this database supports (and uses) triggers (e.g. on the page table)
343 */
344 function cleanupTriggers() {
345 return false;
346 }
347
348 /**
349 * Returns true if this database is strict about what can be put into an IP field.
350 * Specifically, it uses a NULL value instead of an empty string.
351 */
352 function strictIPs() {
353 return false;
354 }
355
356 /**
357 * Returns true if this database uses timestamps rather than integers
358 */
359 function realTimestamps() {
360 return false;
361 }
362
363 /**
364 * Returns true if this database does an implicit sort when doing GROUP BY
365 */
366 function implicitGroupby() {
367 return true;
368 }
369
370 /**
371 * Returns true if this database does an implicit order by when the column has an index
372 * For example: SELECT page_title FROM page LIMIT 1
373 */
374 function implicitOrderby() {
375 return true;
376 }
377
378 /**
379 * Returns true if this database requires that SELECT DISTINCT queries require that all
380 ORDER BY expressions occur in the SELECT list per the SQL92 standard
381 */
382 function standardSelectDistinct() {
383 return true;
384 }
385
386 /**
387 * Returns true if this database can do a native search on IP columns
388 * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
389 */
390 function searchableIPs() {
391 return false;
392 }
393
394 /**
395 * Returns true if this database can use functional indexes
396 */
397 function functionalIndexes() {
398 return false;
399 }
400
401 /**
402 * Return the last query that went through DatabaseBase::query()
403 * @return String
404 */
405 function lastQuery() { return $this->mLastQuery; }
406
407
408 /**
409 * Returns true if the connection may have been used for write queries.
410 * Should return true if unsure.
411 */
412 function doneWrites() { return $this->mDoneWrites; }
413
414 /**
415 * Is a connection to the database open?
416 * @return Boolean
417 */
418 function isOpen() { return $this->mOpened; }
419
420 /**
421 * Set a flag for this connection
422 *
423 * @param $flag Integer: DBO_* constants from Defines.php:
424 * - DBO_DEBUG: output some debug info (same as debug())
425 * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
426 * - DBO_IGNORE: ignore errors (same as ignoreErrors())
427 * - DBO_TRX: automatically start transactions
428 * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
429 * and removes it in command line mode
430 * - DBO_PERSISTENT: use persistant database connection
431 */
432 function setFlag( $flag ) {
433 $this->mFlags |= $flag;
434 }
435
436 /**
437 * Clear a flag for this connection
438 *
439 * @param $flag: same as setFlag()'s $flag param
440 */
441 function clearFlag( $flag ) {
442 $this->mFlags &= ~$flag;
443 }
444
445 /**
446 * Returns a boolean whether the flag $flag is set for this connection
447 *
448 * @param $flag: same as setFlag()'s $flag param
449 * @return Boolean
450 */
451 function getFlag( $flag ) {
452 return !!( $this->mFlags & $flag );
453 }
454
455 /**
456 * General read-only accessor
457 */
458 function getProperty( $name ) {
459 return $this->$name;
460 }
461
462 function getWikiID() {
463 if ( $this->mTablePrefix ) {
464 return "{$this->mDBname}-{$this->mTablePrefix}";
465 } else {
466 return $this->mDBname;
467 }
468 }
469
470 /**
471 * Return a path to the DBMS-specific schema, otherwise default to tables.sql
472 */
473 public function getSchema() {
474 global $IP;
475 if ( file_exists( "$IP/maintenance/" . $this->getType() . "/tables.sql" ) ) {
476 return "$IP/maintenance/" . $this->getType() . "/tables.sql";
477 } else {
478 return "$IP/maintenance/tables.sql";
479 }
480 }
481
482 # ------------------------------------------------------------------------------
483 # Other functions
484 # ------------------------------------------------------------------------------
485
486 /**
487 * Constructor.
488 * @param $server String: database server host
489 * @param $user String: database user name
490 * @param $password String: database user password
491 * @param $dbName String: database name
492 * @param $flags
493 * @param $tablePrefix String: database table prefixes. By default use the prefix gave in LocalSettings.php
494 */
495 function __construct( $server = false, $user = false, $password = false, $dbName = false,
496 $flags = 0, $tablePrefix = 'get from global'
497 ) {
498 global $wgDBprefix, $wgCommandLineMode;
499
500 $this->mFlags = $flags;
501
502 if ( $this->mFlags & DBO_DEFAULT ) {
503 if ( $wgCommandLineMode ) {
504 $this->mFlags &= ~DBO_TRX;
505 } else {
506 $this->mFlags |= DBO_TRX;
507 }
508 }
509
510 /** Get the default table prefix*/
511 if ( $tablePrefix == 'get from global' ) {
512 $this->mTablePrefix = $wgDBprefix;
513 } else {
514 $this->mTablePrefix = $tablePrefix;
515 }
516
517 if ( $user ) {
518 $this->open( $server, $user, $password, $dbName );
519 }
520 }
521
522 /**
523 * Same as new DatabaseMysql( ... ), kept for backward compatibility
524 * @deprecated
525 */
526 static function newFromParams( $server, $user, $password, $dbName, $flags = 0 ) {
527 wfDeprecated( __METHOD__ );
528 return new DatabaseMysql( $server, $user, $password, $dbName, $flags );
529 }
530
531 /**
532 * Given a DB type, construct the name of the appropriate child class of
533 * DatabaseBase. This is designed to replace all of the manual stuff like:
534 * $class = 'Database' . ucfirst( strtolower( $type ) );
535 * as well as validate against the canonical list of DB types we have
536 *
537 * This factory function is mostly useful for when you need to connect to a
538 * database other than the MediaWiki default (such as for external auth,
539 * an extension, et cetera). Do not use this to connect to the MediaWiki
540 * database. Example uses in core:
541 * @see LoadBalancer::reallyOpenConnection()
542 * @see ExternalUser_MediaWiki::initFromCond()
543 * @see ForeignDBRepo::getMasterDB()
544 * @see WebInstaller_DBConnect::execute()
545 *
546 * @param $dbType String A possible DB type
547 * @param $p Array An array of options to pass to the constructor.
548 * Valid options are: host, user, password, dbname, flags, tableprefix
549 * @return DatabaseBase subclass or null
550 */
551 public final static function newFromType( $dbType, $p = array() ) {
552 $canonicalDBTypes = array(
553 'mysql', 'postgres', 'sqlite', 'oracle', 'mssql', 'ibm_db2'
554 );
555 $dbType = strtolower( $dbType );
556
557 if( in_array( $dbType, $canonicalDBTypes ) ) {
558 $class = 'Database' . ucfirst( $dbType );
559 return new $class(
560 isset( $p['host'] ) ? $p['host'] : false,
561 isset( $p['user'] ) ? $p['user'] : false,
562 isset( $p['password'] ) ? $p['password'] : false,
563 isset( $p['dbname'] ) ? $p['dbname'] : false,
564 isset( $p['flags'] ) ? $p['flags'] : 0,
565 isset( $p['tableprefix'] ) ? $p['tableprefix'] : 'get from global'
566 );
567 } else {
568 return null;
569 }
570 }
571
572 protected function installErrorHandler() {
573 $this->mPHPError = false;
574 $this->htmlErrors = ini_set( 'html_errors', '0' );
575 set_error_handler( array( $this, 'connectionErrorHandler' ) );
576 }
577
578 protected function restoreErrorHandler() {
579 restore_error_handler();
580 if ( $this->htmlErrors !== false ) {
581 ini_set( 'html_errors', $this->htmlErrors );
582 }
583 if ( $this->mPHPError ) {
584 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->mPHPError );
585 $error = preg_replace( '!^.*?:(.*)$!', '$1', $error );
586 return $error;
587 } else {
588 return false;
589 }
590 }
591
592 protected function connectionErrorHandler( $errno, $errstr ) {
593 $this->mPHPError = $errstr;
594 }
595
596 /**
597 * Closes a database connection.
598 * if it is open : commits any open transactions
599 *
600 * @return Bool operation success. true if already closed.
601 */
602 function close() {
603 # Stub, should probably be overridden
604 return true;
605 }
606
607 /**
608 * @param $error String: fallback error message, used if none is given by DB
609 */
610 function reportConnectionError( $error = 'Unknown error' ) {
611 $myError = $this->lastError();
612 if ( $myError ) {
613 $error = $myError;
614 }
615
616 # New method
617 throw new DBConnectionError( $this, $error );
618 }
619
620 /**
621 * Determine whether a query writes to the DB.
622 * Should return true if unsure.
623 */
624 function isWriteQuery( $sql ) {
625 return !preg_match( '/^(?:SELECT|BEGIN|COMMIT|SET|SHOW|\(SELECT)\b/i', $sql );
626 }
627
628 /**
629 * Usually aborts on failure. If errors are explicitly ignored, returns success.
630 *
631 * @param $sql String: SQL query
632 * @param $fname String: Name of the calling function, for profiling/SHOW PROCESSLIST
633 * comment (you can use __METHOD__ or add some extra info)
634 * @param $tempIgnore Boolean: Whether to avoid throwing an exception on errors...
635 * maybe best to catch the exception instead?
636 * @return boolean or ResultWrapper. true for a successful write query, ResultWrapper object for a successful read query,
637 * or false on failure if $tempIgnore set
638 * @throws DBQueryError Thrown when the database returns an error of any kind
639 */
640 public function query( $sql, $fname = '', $tempIgnore = false ) {
641 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
642 if ( !Profiler::instance()->isStub() ) {
643 # generalizeSQL will probably cut down the query to reasonable
644 # logging size most of the time. The substr is really just a sanity check.
645
646 # Who's been wasting my precious column space? -- TS
647 # $profName = 'query: ' . $fname . ' ' . substr( DatabaseBase::generalizeSQL( $sql ), 0, 255 );
648
649 if ( $isMaster ) {
650 $queryProf = 'query-m: ' . substr( DatabaseBase::generalizeSQL( $sql ), 0, 255 );
651 $totalProf = 'DatabaseBase::query-master';
652 } else {
653 $queryProf = 'query: ' . substr( DatabaseBase::generalizeSQL( $sql ), 0, 255 );
654 $totalProf = 'DatabaseBase::query';
655 }
656
657 wfProfileIn( $totalProf );
658 wfProfileIn( $queryProf );
659 }
660
661 $this->mLastQuery = $sql;
662 if ( !$this->mDoneWrites && $this->isWriteQuery( $sql ) ) {
663 // Set a flag indicating that writes have been done
664 wfDebug( __METHOD__ . ": Writes done: $sql\n" );
665 $this->mDoneWrites = true;
666 }
667
668 # Add a comment for easy SHOW PROCESSLIST interpretation
669 # if ( $fname ) {
670 global $wgUser;
671 if ( is_object( $wgUser ) && $wgUser->isItemLoaded( 'name' ) ) {
672 $userName = $wgUser->getName();
673 if ( mb_strlen( $userName ) > 15 ) {
674 $userName = mb_substr( $userName, 0, 15 ) . '...';
675 }
676 $userName = str_replace( '/', '', $userName );
677 } else {
678 $userName = '';
679 }
680 $commentedSql = preg_replace( '/\s/', " /* $fname $userName */ ", $sql, 1 );
681 # } else {
682 # $commentedSql = $sql;
683 # }
684
685 # If DBO_TRX is set, start a transaction
686 if ( ( $this->mFlags & DBO_TRX ) && !$this->trxLevel() &&
687 $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK' ) {
688 // avoid establishing transactions for SHOW and SET statements too -
689 // that would delay transaction initializations to once connection
690 // is really used by application
691 $sqlstart = substr( $sql, 0, 10 ); // very much worth it, benchmark certified(tm)
692 if ( strpos( $sqlstart, "SHOW " ) !== 0 and strpos( $sqlstart, "SET " ) !== 0 )
693 $this->begin();
694 }
695
696 if ( $this->debug() ) {
697 static $cnt = 0;
698
699 $cnt++;
700 $sqlx = substr( $commentedSql, 0, 500 );
701 $sqlx = strtr( $sqlx, "\t\n", ' ' );
702
703 if ( $isMaster ) {
704 wfDebug( "Query $cnt (master): $sqlx\n" );
705 } else {
706 wfDebug( "Query $cnt (slave): $sqlx\n" );
707 }
708 }
709
710 if ( istainted( $sql ) & TC_MYSQL ) {
711 throw new MWException( 'Tainted query found' );
712 }
713
714 # Do the query and handle errors
715 $ret = $this->doQuery( $commentedSql );
716
717 # Try reconnecting if the connection was lost
718 if ( false === $ret && $this->wasErrorReissuable() ) {
719 # Transaction is gone, like it or not
720 $this->mTrxLevel = 0;
721 wfDebug( "Connection lost, reconnecting...\n" );
722
723 if ( $this->ping() ) {
724 wfDebug( "Reconnected\n" );
725 $sqlx = substr( $commentedSql, 0, 500 );
726 $sqlx = strtr( $sqlx, "\t\n", ' ' );
727 global $wgRequestTime;
728 $elapsed = round( microtime( true ) - $wgRequestTime, 3 );
729 if ( $elapsed < 300 ) {
730 # Not a database error to lose a transaction after a minute or two
731 wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
732 }
733 $ret = $this->doQuery( $commentedSql );
734 } else {
735 wfDebug( "Failed\n" );
736 }
737 }
738
739 if ( false === $ret ) {
740 $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
741 }
742
743 if ( !Profiler::instance()->isStub() ) {
744 wfProfileOut( $queryProf );
745 wfProfileOut( $totalProf );
746 }
747
748 return $this->resultObject( $ret );
749 }
750
751 /**
752 * @param $error String
753 * @param $errno Integer
754 * @param $sql String
755 * @param $fname String
756 * @param $tempIgnore Boolean
757 */
758 function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
759 # Ignore errors during error handling to avoid infinite recursion
760 $ignore = $this->ignoreErrors( true );
761 ++$this->mErrorCount;
762
763 if ( $ignore || $tempIgnore ) {
764 wfDebug( "SQL ERROR (ignored): $error\n" );
765 $this->ignoreErrors( $ignore );
766 } else {
767 $sql1line = str_replace( "\n", "\\n", $sql );
768 wfLogDBError( "$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n" );
769 wfDebug( "SQL ERROR: " . $error . "\n" );
770 throw new DBQueryError( $this, $error, $errno, $sql, $fname );
771 }
772 }
773
774
775 /**
776 * Intended to be compatible with the PEAR::DB wrapper functions.
777 * http://pear.php.net/manual/en/package.database.db.intro-execute.php
778 *
779 * ? = scalar value, quoted as necessary
780 * ! = raw SQL bit (a function for instance)
781 * & = filename; reads the file and inserts as a blob
782 * (we don't use this though...)
783 */
784 function prepare( $sql, $func = 'DatabaseBase::prepare' ) {
785 /* MySQL doesn't support prepared statements (yet), so just
786 pack up the query for reference. We'll manually replace
787 the bits later. */
788 return array( 'query' => $sql, 'func' => $func );
789 }
790
791 function freePrepared( $prepared ) {
792 /* No-op by default */
793 }
794
795 /**
796 * Execute a prepared query with the various arguments
797 * @param $prepared String: the prepared sql
798 * @param $args Mixed: Either an array here, or put scalars as varargs
799 */
800 function execute( $prepared, $args = null ) {
801 if ( !is_array( $args ) ) {
802 # Pull the var args
803 $args = func_get_args();
804 array_shift( $args );
805 }
806
807 $sql = $this->fillPrepared( $prepared['query'], $args );
808
809 return $this->query( $sql, $prepared['func'] );
810 }
811
812 /**
813 * Prepare & execute an SQL statement, quoting and inserting arguments
814 * in the appropriate places.
815 * @param $query String
816 * @param $args ...
817 */
818 function safeQuery( $query, $args = null ) {
819 $prepared = $this->prepare( $query, 'DatabaseBase::safeQuery' );
820
821 if ( !is_array( $args ) ) {
822 # Pull the var args
823 $args = func_get_args();
824 array_shift( $args );
825 }
826
827 $retval = $this->execute( $prepared, $args );
828 $this->freePrepared( $prepared );
829
830 return $retval;
831 }
832
833 /**
834 * For faking prepared SQL statements on DBs that don't support
835 * it directly.
836 * @param $preparedQuery String: a 'preparable' SQL statement
837 * @param $args Array of arguments to fill it with
838 * @return string executable SQL
839 */
840 function fillPrepared( $preparedQuery, $args ) {
841 reset( $args );
842 $this->preparedArgs =& $args;
843
844 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
845 array( &$this, 'fillPreparedArg' ), $preparedQuery );
846 }
847
848 /**
849 * preg_callback func for fillPrepared()
850 * The arguments should be in $this->preparedArgs and must not be touched
851 * while we're doing this.
852 *
853 * @param $matches Array
854 * @return String
855 * @private
856 */
857 function fillPreparedArg( $matches ) {
858 switch( $matches[1] ) {
859 case '\\?': return '?';
860 case '\\!': return '!';
861 case '\\&': return '&';
862 }
863
864 list( /* $n */ , $arg ) = each( $this->preparedArgs );
865
866 switch( $matches[1] ) {
867 case '?': return $this->addQuotes( $arg );
868 case '!': return $arg;
869 case '&':
870 # return $this->addQuotes( file_get_contents( $arg ) );
871 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
872 default:
873 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
874 }
875 }
876
877 /**
878 * Free a result object
879 * @param $res Mixed: A SQL result
880 */
881 function freeResult( $res ) {
882 # Stub. Might not really need to be overridden, since results should
883 # be freed by PHP when the variable goes out of scope anyway.
884 }
885
886 /**
887 * Simple UPDATE wrapper
888 * Usually aborts on failure
889 * If errors are explicitly ignored, returns success
890 *
891 * This function exists for historical reasons, DatabaseBase::update() has a more standard
892 * calling convention and feature set
893 */
894 function set( $table, $var, $value, $cond, $fname = 'DatabaseBase::set' ) {
895 $table = $this->tableName( $table );
896 $sql = "UPDATE $table SET $var = '" .
897 $this->strencode( $value ) . "' WHERE ($cond)";
898
899 return (bool)$this->query( $sql, $fname );
900 }
901
902 /**
903 * Simple SELECT wrapper, returns a single field, input must be encoded
904 * Usually aborts on failure
905 * If errors are explicitly ignored, returns FALSE on failure
906 */
907 function selectField( $table, $var, $cond = '', $fname = 'DatabaseBase::selectField', $options = array() ) {
908 if ( !is_array( $options ) ) {
909 $options = array( $options );
910 }
911
912 $options['LIMIT'] = 1;
913
914 $res = $this->select( $table, $var, $cond, $fname, $options );
915
916 if ( $res === false || !$this->numRows( $res ) ) {
917 return false;
918 }
919
920 $row = $this->fetchRow( $res );
921
922 if ( $row !== false ) {
923 return reset( $row );
924 } else {
925 return false;
926 }
927 }
928
929 /**
930 * Returns an optional USE INDEX clause to go after the table, and a
931 * string to go at the end of the query
932 *
933 * @private
934 *
935 * @param $options Array: associative array of options to be turned into
936 * an SQL query, valid keys are listed in the function.
937 * @return Array
938 */
939 function makeSelectOptions( $options ) {
940 $preLimitTail = $postLimitTail = '';
941 $startOpts = '';
942
943 $noKeyOptions = array();
944
945 foreach ( $options as $key => $option ) {
946 if ( is_numeric( $key ) ) {
947 $noKeyOptions[$option] = true;
948 }
949 }
950
951 if ( isset( $options['GROUP BY'] ) ) {
952 $gb = is_array( $options['GROUP BY'] )
953 ? implode( ',', $options['GROUP BY'] )
954 : $options['GROUP BY'];
955 $preLimitTail .= " GROUP BY {$gb}";
956 }
957
958 if ( isset( $options['HAVING'] ) ) {
959 $preLimitTail .= " HAVING {$options['HAVING']}";
960 }
961
962 if ( isset( $options['ORDER BY'] ) ) {
963 $ob = is_array( $options['ORDER BY'] )
964 ? implode( ',', $options['ORDER BY'] )
965 : $options['ORDER BY'];
966 $preLimitTail .= " ORDER BY {$ob}";
967 }
968
969 // if (isset($options['LIMIT'])) {
970 // $tailOpts .= $this->limitResult('', $options['LIMIT'],
971 // isset($options['OFFSET']) ? $options['OFFSET']
972 // : false);
973 // }
974
975 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
976 $postLimitTail .= ' FOR UPDATE';
977 }
978
979 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
980 $postLimitTail .= ' LOCK IN SHARE MODE';
981 }
982
983 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
984 $startOpts .= 'DISTINCT';
985 }
986
987 # Various MySQL extensions
988 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
989 $startOpts .= ' /*! STRAIGHT_JOIN */';
990 }
991
992 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
993 $startOpts .= ' HIGH_PRIORITY';
994 }
995
996 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
997 $startOpts .= ' SQL_BIG_RESULT';
998 }
999
1000 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1001 $startOpts .= ' SQL_BUFFER_RESULT';
1002 }
1003
1004 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1005 $startOpts .= ' SQL_SMALL_RESULT';
1006 }
1007
1008 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1009 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1010 }
1011
1012 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1013 $startOpts .= ' SQL_CACHE';
1014 }
1015
1016 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1017 $startOpts .= ' SQL_NO_CACHE';
1018 }
1019
1020 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
1021 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1022 } else {
1023 $useIndex = '';
1024 }
1025
1026 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1027 }
1028
1029 /**
1030 * SELECT wrapper
1031 *
1032 * @param $table Mixed: Array or string, table name(s) (prefix auto-added)
1033 * @param $vars Mixed: Array or string, field name(s) to be retrieved
1034 * @param $conds Mixed: Array or string, condition(s) for WHERE
1035 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
1036 * @param $options Array: Associative array of options (e.g. array('GROUP BY' => 'page_title')),
1037 * see DatabaseBase::makeSelectOptions code for list of supported stuff
1038 * @param $join_conds Array: Associative array of table join conditions (optional)
1039 * (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
1040 * @return ResultWrapper|Bool Database result resource (feed to DatabaseBase::fetchObject
1041 * or whatever), or false on failure
1042 */
1043 function select( $table, $vars, $conds = '', $fname = 'DatabaseBase::select', $options = array(), $join_conds = array() ) {
1044 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1045
1046 return $this->query( $sql, $fname );
1047 }
1048
1049 /**
1050 * SELECT wrapper
1051 *
1052 * @param $table Mixed: Array or string, table name(s) (prefix auto-added). Array keys are table aliases (optional)
1053 * @param $vars Mixed: Array or string, field name(s) to be retrieved
1054 * @param $conds Mixed: Array or string, condition(s) for WHERE
1055 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
1056 * @param $options Array: Associative array of options (e.g. array('GROUP BY' => 'page_title')),
1057 * see DatabaseBase::makeSelectOptions code for list of supported stuff
1058 * @param $join_conds Array: Associative array of table join conditions (optional)
1059 * (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
1060 * @return string, the SQL text
1061 */
1062 function selectSQLText( $table, $vars, $conds = '', $fname = 'DatabaseBase::select', $options = array(), $join_conds = array() ) {
1063 if ( is_array( $vars ) ) {
1064 $vars = implode( ',', $vars );
1065 }
1066
1067 if ( !is_array( $options ) ) {
1068 $options = array( $options );
1069 }
1070
1071 if ( is_array( $table ) ) {
1072 if ( !empty( $join_conds ) || ( isset( $options['USE INDEX'] ) && is_array( @$options['USE INDEX'] ) ) ) {
1073 $from = ' FROM ' . $this->tableNamesWithUseIndexOrJOIN( $table, @$options['USE INDEX'], $join_conds );
1074 } else {
1075 $from = ' FROM ' . implode( ',', $this->tableNamesWithAlias( $table ) );
1076 }
1077 } elseif ( $table != '' ) {
1078 if ( $table { 0 } == ' ' ) {
1079 $from = ' FROM ' . $table;
1080 } else {
1081 $from = ' FROM ' . $this->tableName( $table );
1082 }
1083 } else {
1084 $from = '';
1085 }
1086
1087 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
1088
1089 if ( !empty( $conds ) ) {
1090 if ( is_array( $conds ) ) {
1091 $conds = $this->makeList( $conds, LIST_AND );
1092 }
1093 $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
1094 } else {
1095 $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
1096 }
1097
1098 if ( isset( $options['LIMIT'] ) )
1099 $sql = $this->limitResult( $sql, $options['LIMIT'],
1100 isset( $options['OFFSET'] ) ? $options['OFFSET'] : false );
1101 $sql = "$sql $postLimitTail";
1102
1103 if ( isset( $options['EXPLAIN'] ) ) {
1104 $sql = 'EXPLAIN ' . $sql;
1105 }
1106
1107 return $sql;
1108 }
1109
1110 /**
1111 * Single row SELECT wrapper
1112 * Aborts or returns FALSE on error
1113 *
1114 * @param $table String: table name
1115 * @param $vars String: the selected variables
1116 * @param $conds Array: a condition map, terms are ANDed together.
1117 * Items with numeric keys are taken to be literal conditions
1118 * Takes an array of selected variables, and a condition map, which is ANDed
1119 * e.g: selectRow( "page", array( "page_id" ), array( "page_namespace" =>
1120 * NS_MAIN, "page_title" => "Astronomy" ) ) would return an object where
1121 * $obj- >page_id is the ID of the Astronomy article
1122 * @param $fname String: Calling function name
1123 * @param $options Array
1124 * @param $join_conds Array
1125 *
1126 * @return ResultWrapper|Bool
1127 */
1128 function selectRow( $table, $vars, $conds, $fname = 'DatabaseBase::selectRow', $options = array(), $join_conds = array() ) {
1129 $options['LIMIT'] = 1;
1130 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1131
1132 if ( $res === false ) {
1133 return false;
1134 }
1135
1136 if ( !$this->numRows( $res ) ) {
1137 return false;
1138 }
1139
1140 $obj = $this->fetchObject( $res );
1141
1142 return $obj;
1143 }
1144
1145 /**
1146 * Estimate rows in dataset
1147 * Returns estimated count - not necessarily an accurate estimate across different databases,
1148 * so use sparingly
1149 * Takes same arguments as DatabaseBase::select()
1150 *
1151 * @param $table String: table name
1152 * @param $vars Array: unused
1153 * @param $conds Array: filters on the table
1154 * @param $fname String: function name for profiling
1155 * @param $options Array: options for select
1156 * @return Integer: row count
1157 */
1158 public function estimateRowCount( $table, $vars = '*', $conds = '', $fname = 'DatabaseBase::estimateRowCount', $options = array() ) {
1159 $rows = 0;
1160 $res = $this->select ( $table, 'COUNT(*) AS rowcount', $conds, $fname, $options );
1161
1162 if ( $res ) {
1163 $row = $this->fetchRow( $res );
1164 $rows = ( isset( $row['rowcount'] ) ) ? $row['rowcount'] : 0;
1165 }
1166
1167 return $rows;
1168 }
1169
1170 /**
1171 * Removes most variables from an SQL query and replaces them with X or N for numbers.
1172 * It's only slightly flawed. Don't use for anything important.
1173 *
1174 * @param $sql String: A SQL Query
1175 */
1176 static function generalizeSQL( $sql ) {
1177 # This does the same as the regexp below would do, but in such a way
1178 # as to avoid crashing php on some large strings.
1179 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
1180
1181 $sql = str_replace ( "\\\\", '', $sql );
1182 $sql = str_replace ( "\\'", '', $sql );
1183 $sql = str_replace ( "\\\"", '', $sql );
1184 $sql = preg_replace ( "/'.*'/s", "'X'", $sql );
1185 $sql = preg_replace ( '/".*"/s', "'X'", $sql );
1186
1187 # All newlines, tabs, etc replaced by single space
1188 $sql = preg_replace ( '/\s+/', ' ', $sql );
1189
1190 # All numbers => N
1191 $sql = preg_replace ( '/-?[0-9]+/s', 'N', $sql );
1192
1193 return $sql;
1194 }
1195
1196 /**
1197 * Determines whether a field exists in a table
1198 *
1199 * @param $table String: table name
1200 * @param $field String: filed to check on that table
1201 * @param $fname String: calling function name (optional)
1202 * @return Boolean: whether $table has filed $field
1203 */
1204 function fieldExists( $table, $field, $fname = 'DatabaseBase::fieldExists' ) {
1205 $info = $this->fieldInfo( $table, $field );
1206
1207 return (bool)$info;
1208 }
1209
1210 /**
1211 * Determines whether an index exists
1212 * Usually aborts on failure
1213 * If errors are explicitly ignored, returns NULL on failure
1214 */
1215 function indexExists( $table, $index, $fname = 'DatabaseBase::indexExists' ) {
1216 $info = $this->indexInfo( $table, $index, $fname );
1217 if ( is_null( $info ) ) {
1218 return null;
1219 } else {
1220 return $info !== false;
1221 }
1222 }
1223
1224 /**
1225 * Query whether a given table exists
1226 */
1227 function tableExists( $table ) {
1228 $table = $this->tableName( $table );
1229 $old = $this->ignoreErrors( true );
1230 $res = $this->query( "SELECT 1 FROM $table LIMIT 1", __METHOD__ );
1231 $this->ignoreErrors( $old );
1232
1233 return (bool)$res;
1234 }
1235
1236 /**
1237 * mysql_field_type() wrapper
1238 */
1239 function fieldType( $res, $index ) {
1240 if ( $res instanceof ResultWrapper ) {
1241 $res = $res->result;
1242 }
1243
1244 return mysql_field_type( $res, $index );
1245 }
1246
1247 /**
1248 * Determines if a given index is unique
1249 */
1250 function indexUnique( $table, $index ) {
1251 $indexInfo = $this->indexInfo( $table, $index );
1252
1253 if ( !$indexInfo ) {
1254 return null;
1255 }
1256
1257 return !$indexInfo[0]->Non_unique;
1258 }
1259
1260 /**
1261 * INSERT wrapper, inserts an array into a table
1262 *
1263 * $a may be a single associative array, or an array of these with numeric keys, for
1264 * multi-row insert.
1265 *
1266 * Usually aborts on failure
1267 * If errors are explicitly ignored, returns success
1268 *
1269 * @param $table String: table name (prefix auto-added)
1270 * @param $a Array: Array of rows to insert
1271 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
1272 * @param $options Mixed: Associative array of options
1273 *
1274 * @return bool
1275 */
1276 function insert( $table, $a, $fname = 'DatabaseBase::insert', $options = array() ) {
1277 # No rows to insert, easy just return now
1278 if ( !count( $a ) ) {
1279 return true;
1280 }
1281
1282 $table = $this->tableName( $table );
1283
1284 if ( !is_array( $options ) ) {
1285 $options = array( $options );
1286 }
1287
1288 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1289 $multi = true;
1290 $keys = array_keys( $a[0] );
1291 } else {
1292 $multi = false;
1293 $keys = array_keys( $a );
1294 }
1295
1296 $sql = 'INSERT ' . implode( ' ', $options ) .
1297 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1298
1299 if ( $multi ) {
1300 $first = true;
1301 foreach ( $a as $row ) {
1302 if ( $first ) {
1303 $first = false;
1304 } else {
1305 $sql .= ',';
1306 }
1307 $sql .= '(' . $this->makeList( $row ) . ')';
1308 }
1309 } else {
1310 $sql .= '(' . $this->makeList( $a ) . ')';
1311 }
1312
1313 return (bool)$this->query( $sql, $fname );
1314 }
1315
1316 /**
1317 * Make UPDATE options for the DatabaseBase::update function
1318 *
1319 * @private
1320 * @param $options Array: The options passed to DatabaseBase::update
1321 * @return string
1322 */
1323 function makeUpdateOptions( $options ) {
1324 if ( !is_array( $options ) ) {
1325 $options = array( $options );
1326 }
1327
1328 $opts = array();
1329
1330 if ( in_array( 'LOW_PRIORITY', $options ) ) {
1331 $opts[] = $this->lowPriorityOption();
1332 }
1333
1334 if ( in_array( 'IGNORE', $options ) ) {
1335 $opts[] = 'IGNORE';
1336 }
1337
1338 return implode( ' ', $opts );
1339 }
1340
1341 /**
1342 * UPDATE wrapper, takes a condition array and a SET array
1343 *
1344 * @param $table String: The table to UPDATE
1345 * @param $values Array: An array of values to SET
1346 * @param $conds Array: An array of conditions (WHERE). Use '*' to update all rows.
1347 * @param $fname String: The Class::Function calling this function
1348 * (for the log)
1349 * @param $options Array: An array of UPDATE options, can be one or
1350 * more of IGNORE, LOW_PRIORITY
1351 * @return Boolean
1352 */
1353 function update( $table, $values, $conds, $fname = 'DatabaseBase::update', $options = array() ) {
1354 $table = $this->tableName( $table );
1355 $opts = $this->makeUpdateOptions( $options );
1356 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET );
1357
1358 if ( $conds != '*' ) {
1359 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
1360 }
1361
1362 return $this->query( $sql, $fname );
1363 }
1364
1365 /**
1366 * Makes an encoded list of strings from an array
1367 * @param $a Array
1368 * @param $mode
1369 * LIST_COMMA - comma separated, no field names
1370 * LIST_AND - ANDed WHERE clause (without the WHERE)
1371 * LIST_OR - ORed WHERE clause (without the WHERE)
1372 * LIST_SET - comma separated with field names, like a SET clause
1373 * LIST_NAMES - comma separated field names
1374 *
1375 * @return string
1376 */
1377 function makeList( $a, $mode = LIST_COMMA ) {
1378 if ( !is_array( $a ) ) {
1379 throw new DBUnexpectedError( $this, 'DatabaseBase::makeList called with incorrect parameters' );
1380 }
1381
1382 $first = true;
1383 $list = '';
1384
1385 foreach ( $a as $field => $value ) {
1386 if ( !$first ) {
1387 if ( $mode == LIST_AND ) {
1388 $list .= ' AND ';
1389 } elseif ( $mode == LIST_OR ) {
1390 $list .= ' OR ';
1391 } else {
1392 $list .= ',';
1393 }
1394 } else {
1395 $first = false;
1396 }
1397
1398 if ( ( $mode == LIST_AND || $mode == LIST_OR ) && is_numeric( $field ) ) {
1399 $list .= "($value)";
1400 } elseif ( ( $mode == LIST_SET ) && is_numeric( $field ) ) {
1401 $list .= "$value";
1402 } elseif ( ( $mode == LIST_AND || $mode == LIST_OR ) && is_array( $value ) ) {
1403 if ( count( $value ) == 0 ) {
1404 throw new MWException( __METHOD__ . ': empty input' );
1405 } elseif ( count( $value ) == 1 ) {
1406 // Special-case single values, as IN isn't terribly efficient
1407 // Don't necessarily assume the single key is 0; we don't
1408 // enforce linear numeric ordering on other arrays here.
1409 $value = array_values( $value );
1410 $list .= $field . " = " . $this->addQuotes( $value[0] );
1411 } else {
1412 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
1413 }
1414 } elseif ( $value === null ) {
1415 if ( $mode == LIST_AND || $mode == LIST_OR ) {
1416 $list .= "$field IS ";
1417 } elseif ( $mode == LIST_SET ) {
1418 $list .= "$field = ";
1419 }
1420 $list .= 'NULL';
1421 } else {
1422 if ( $mode == LIST_AND || $mode == LIST_OR || $mode == LIST_SET ) {
1423 $list .= "$field = ";
1424 }
1425 $list .= $mode == LIST_NAMES ? $value : $this->addQuotes( $value );
1426 }
1427 }
1428
1429 return $list;
1430 }
1431
1432 /**
1433 * Build a partial where clause from a 2-d array such as used for LinkBatch.
1434 * The keys on each level may be either integers or strings.
1435 *
1436 * @param $data Array: organized as 2-d array(baseKeyVal => array(subKeyVal => <ignored>, ...), ...)
1437 * @param $baseKey String: field name to match the base-level keys to (eg 'pl_namespace')
1438 * @param $subKey String: field name to match the sub-level keys to (eg 'pl_title')
1439 * @return Mixed: string SQL fragment, or false if no items in array.
1440 */
1441 function makeWhereFrom2d( $data, $baseKey, $subKey ) {
1442 $conds = array();
1443
1444 foreach ( $data as $base => $sub ) {
1445 if ( count( $sub ) ) {
1446 $conds[] = $this->makeList(
1447 array( $baseKey => $base, $subKey => array_keys( $sub ) ),
1448 LIST_AND );
1449 }
1450 }
1451
1452 if ( $conds ) {
1453 return $this->makeList( $conds, LIST_OR );
1454 } else {
1455 // Nothing to search for...
1456 return false;
1457 }
1458 }
1459
1460 /**
1461 * Bitwise operations
1462 */
1463
1464 function bitNot( $field ) {
1465 return "(~$field)";
1466 }
1467
1468 function bitAnd( $fieldLeft, $fieldRight ) {
1469 return "($fieldLeft & $fieldRight)";
1470 }
1471
1472 function bitOr( $fieldLeft, $fieldRight ) {
1473 return "($fieldLeft | $fieldRight)";
1474 }
1475
1476 /**
1477 * Change the current database
1478 *
1479 * @todo Explain what exactly will fail if this is not overridden.
1480 * @return bool Success or failure
1481 */
1482 function selectDB( $db ) {
1483 # Stub. Shouldn't cause serious problems if it's not overridden, but
1484 # if your database engine supports a concept similar to MySQL's
1485 # databases you may as well.
1486 $this->mDBname = $db;
1487 return true;
1488 }
1489
1490 /**
1491 * Get the current DB name
1492 */
1493 function getDBname() {
1494 return $this->mDBname;
1495 }
1496
1497 /**
1498 * Get the server hostname or IP address
1499 */
1500 function getServer() {
1501 return $this->mServer;
1502 }
1503
1504 /**
1505 * Format a table name ready for use in constructing an SQL query
1506 *
1507 * This does two important things: it quotes the table names to clean them up,
1508 * and it adds a table prefix if only given a table name with no quotes.
1509 *
1510 * All functions of this object which require a table name call this function
1511 * themselves. Pass the canonical name to such functions. This is only needed
1512 * when calling query() directly.
1513 *
1514 * @param $name String: database table name
1515 * @param $quoted Boolean: Automatically pass the table name through
1516 * addIdentifierQuotes() so that it can be used in a query.
1517 * @return String: full database name
1518 */
1519 function tableName( $name, $quoted = true ) {
1520 global $wgSharedDB, $wgSharedPrefix, $wgSharedTables;
1521 # Skip the entire process when we have a string quoted on both ends.
1522 # Note that we check the end so that we will still quote any use of
1523 # use of `database`.table. But won't break things if someone wants
1524 # to query a database table with a dot in the name.
1525 if ( $this->isQuotedIdentifier( $name ) ) {
1526 return $name;
1527 }
1528
1529 # Lets test for any bits of text that should never show up in a table
1530 # name. Basically anything like JOIN or ON which are actually part of
1531 # SQL queries, but may end up inside of the table value to combine
1532 # sql. Such as how the API is doing.
1533 # Note that we use a whitespace test rather than a \b test to avoid
1534 # any remote case where a word like on may be inside of a table name
1535 # surrounded by symbols which may be considered word breaks.
1536 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
1537 return $name;
1538 }
1539
1540 # Split database and table into proper variables.
1541 # We reverse the explode so that database.table and table both output
1542 # the correct table.
1543 $dbDetails = array_reverse( explode( '.', $name, 2 ) );
1544 if ( isset( $dbDetails[1] ) ) {
1545 @list( $table, $database ) = $dbDetails;
1546 } else {
1547 @list( $table ) = $dbDetails;
1548 }
1549 $prefix = $this->mTablePrefix; # Default prefix
1550
1551 # Note that we use the long format because php will complain in in_array if
1552 # the input is not an array, and will complain in is_array if it is not set.
1553 if ( !isset( $database ) # Don't use shared database if pre selected.
1554 && isset( $wgSharedDB ) # We have a shared database
1555 && !$this->isQuotedIdentifier( $table ) # Paranoia check to prevent shared tables listing '`table`'
1556 && isset( $wgSharedTables )
1557 && is_array( $wgSharedTables )
1558 && in_array( $table, $wgSharedTables ) ) { # A shared table is selected
1559 $database = $wgSharedDB;
1560 $prefix = isset( $wgSharedPrefix ) ? $wgSharedPrefix : $prefix;
1561 }
1562
1563 # Quote the $database and $table and apply the prefix if not quoted.
1564 if ( isset( $database ) ) {
1565 $database = ( !$quoted || $this->isQuotedIdentifier( $database ) ? $database : $this->addIdentifierQuotes( $database ) );
1566 $prefix = '';
1567 }
1568
1569 $table = "{$prefix}{$table}";
1570 if ( $quoted && !$this->isQuotedIdentifier( $table ) ) {
1571 $table = $this->addIdentifierQuotes( "{$table}" );
1572 }
1573
1574 # Merge our database and table into our final table name.
1575 $tableName = ( isset( $database ) ? "{$database}.{$table}" : "{$table}" );
1576
1577 return $tableName;
1578 }
1579
1580 /**
1581 * Fetch a number of table names into an array
1582 * This is handy when you need to construct SQL for joins
1583 *
1584 * Example:
1585 * extract($dbr->tableNames('user','watchlist'));
1586 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1587 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1588 */
1589 public function tableNames() {
1590 $inArray = func_get_args();
1591 $retVal = array();
1592
1593 foreach ( $inArray as $name ) {
1594 $retVal[$name] = $this->tableName( $name );
1595 }
1596
1597 return $retVal;
1598 }
1599
1600 /**
1601 * Fetch a number of table names into an zero-indexed numerical array
1602 * This is handy when you need to construct SQL for joins
1603 *
1604 * Example:
1605 * list( $user, $watchlist ) = $dbr->tableNamesN('user','watchlist');
1606 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1607 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1608 */
1609 public function tableNamesN() {
1610 $inArray = func_get_args();
1611 $retVal = array();
1612
1613 foreach ( $inArray as $name ) {
1614 $retVal[] = $this->tableName( $name );
1615 }
1616
1617 return $retVal;
1618 }
1619
1620 /**
1621 * Get an aliased table name
1622 * e.g. tableName AS newTableName
1623 *
1624 * @param $name string Table name, see tableName()
1625 * @param $alias string Alias (optional)
1626 * @return string SQL name for aliased table. Will not alias a table to its own name
1627 */
1628 public function tableNameWithAlias( $name, $alias = false ) {
1629 if ( !$alias || $alias == $name ) {
1630 return $this->tableName( $name );
1631 } else {
1632 return $this->tableName( $name ) . ' ' . $this->addIdentifierQuotes( $alias );
1633 }
1634 }
1635
1636 /**
1637 * Gets an array of aliased table names
1638 *
1639 * @param $tables array( [alias] => table )
1640 * @return array of strings, see tableNameWithAlias()
1641 */
1642 public function tableNamesWithAlias( $tables ) {
1643 $retval = array();
1644 foreach ( $tables as $alias => $table ) {
1645 if ( is_numeric( $alias ) ) {
1646 $alias = $table;
1647 }
1648 $retval[] = $this->tableNameWithAlias( $table, $alias );
1649 }
1650 return $retval;
1651 }
1652
1653 /**
1654 * @return string
1655 */
1656 function tableNamesWithUseIndexOrJOIN( $tables, $use_index = array(), $join_conds = array() ) {
1657 $ret = array();
1658 $retJOIN = array();
1659 $use_index_safe = is_array( $use_index ) ? $use_index : array();
1660 $join_conds_safe = is_array( $join_conds ) ? $join_conds : array();
1661
1662 foreach ( $tables as $alias => $table ) {
1663 if ( !is_string( $alias ) ) {
1664 // No alias? Set it equal to the table name
1665 $alias = $table;
1666 }
1667 // Is there a JOIN and INDEX clause for this table?
1668 if ( isset( $join_conds_safe[$alias] ) && isset( $use_index_safe[$alias] ) ) {
1669 $tableClause = $join_conds_safe[$alias][0] . ' ' . $this->tableNameWithAlias( $table, $alias );
1670 $tableClause .= ' ' . $this->useIndexClause( implode( ',', (array)$use_index_safe[$alias] ) );
1671 $on = $this->makeList( (array)$join_conds_safe[$alias][1], LIST_AND );
1672 if ( $on != '' ) {
1673 $tableClause .= ' ON (' . $on . ')';
1674 }
1675
1676 $retJOIN[] = $tableClause;
1677 // Is there an INDEX clause?
1678 } else if ( isset( $use_index_safe[$alias] ) ) {
1679 $tableClause = $this->tableNameWithAlias( $table, $alias );
1680 $tableClause .= ' ' . $this->useIndexClause( implode( ',', (array)$use_index_safe[$alias] ) );
1681 $ret[] = $tableClause;
1682 // Is there a JOIN clause?
1683 } else if ( isset( $join_conds_safe[$alias] ) ) {
1684 $tableClause = $join_conds_safe[$alias][0] . ' ' . $this->tableNameWithAlias( $table, $alias );
1685 $on = $this->makeList( (array)$join_conds_safe[$alias][1], LIST_AND );
1686 if ( $on != '' ) {
1687 $tableClause .= ' ON (' . $on . ')';
1688 }
1689
1690 $retJOIN[] = $tableClause;
1691 } else {
1692 $tableClause = $this->tableNameWithAlias( $table, $alias );
1693 $ret[] = $tableClause;
1694 }
1695 }
1696
1697 // We can't separate explicit JOIN clauses with ',', use ' ' for those
1698 $straightJoins = !empty( $ret ) ? implode( ',', $ret ) : "";
1699 $otherJoins = !empty( $retJOIN ) ? implode( ' ', $retJOIN ) : "";
1700
1701 // Compile our final table clause
1702 return implode( ' ', array( $straightJoins, $otherJoins ) );
1703 }
1704
1705 /**
1706 * Get the name of an index in a given table
1707 */
1708 function indexName( $index ) {
1709 // Backwards-compatibility hack
1710 $renamed = array(
1711 'ar_usertext_timestamp' => 'usertext_timestamp',
1712 'un_user_id' => 'user_id',
1713 'un_user_ip' => 'user_ip',
1714 );
1715
1716 if ( isset( $renamed[$index] ) ) {
1717 return $renamed[$index];
1718 } else {
1719 return $index;
1720 }
1721 }
1722
1723 /**
1724 * If it's a string, adds quotes and backslashes
1725 * Otherwise returns as-is
1726 */
1727 function addQuotes( $s ) {
1728 if ( $s === null ) {
1729 return 'NULL';
1730 } else {
1731 # This will also quote numeric values. This should be harmless,
1732 # and protects against weird problems that occur when they really
1733 # _are_ strings such as article titles and string->number->string
1734 # conversion is not 1:1.
1735 return "'" . $this->strencode( $s ) . "'";
1736 }
1737 }
1738
1739 /**
1740 * Quotes an identifier using `backticks` or "double quotes" depending on the database type.
1741 * MySQL uses `backticks` while basically everything else uses double quotes.
1742 * Since MySQL is the odd one out here the double quotes are our generic
1743 * and we implement backticks in DatabaseMysql.
1744 */
1745 public function addIdentifierQuotes( $s ) {
1746 return '"' . str_replace( '"', '""', $s ) . '"';
1747 }
1748
1749 /**
1750 * Returns if the given identifier looks quoted or not according to
1751 * the database convention for quoting identifiers .
1752 * @return boolean
1753 */
1754 public function isQuotedIdentifier( $name ) {
1755 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
1756 }
1757
1758 /**
1759 * Backwards compatibility, identifier quoting originated in DatabasePostgres
1760 * which used quote_ident which does not follow our naming conventions
1761 * was renamed to addIdentifierQuotes.
1762 * @deprecated use addIdentifierQuotes
1763 */
1764 function quote_ident( $s ) {
1765 wfDeprecated( __METHOD__ );
1766 return $this->addIdentifierQuotes( $s );
1767 }
1768
1769 /**
1770 * Escape string for safe LIKE usage.
1771 * WARNING: you should almost never use this function directly,
1772 * instead use buildLike() that escapes everything automatically
1773 * Deprecated in 1.17, warnings in 1.17, removed in ???
1774 */
1775 public function escapeLike( $s ) {
1776 wfDeprecated( __METHOD__ );
1777 return $this->escapeLikeInternal( $s );
1778 }
1779
1780 protected function escapeLikeInternal( $s ) {
1781 $s = str_replace( '\\', '\\\\', $s );
1782 $s = $this->strencode( $s );
1783 $s = str_replace( array( '%', '_' ), array( '\%', '\_' ), $s );
1784
1785 return $s;
1786 }
1787
1788 /**
1789 * LIKE statement wrapper, receives a variable-length argument list with parts of pattern to match
1790 * containing either string literals that will be escaped or tokens returned by anyChar() or anyString().
1791 * Alternatively, the function could be provided with an array of aforementioned parameters.
1792 *
1793 * Example: $dbr->buildLike( 'My_page_title/', $dbr->anyString() ) returns a LIKE clause that searches
1794 * for subpages of 'My page title'.
1795 * Alternatively: $pattern = array( 'My_page_title/', $dbr->anyString() ); $query .= $dbr->buildLike( $pattern );
1796 *
1797 * @since 1.16
1798 * @return String: fully built LIKE statement
1799 */
1800 function buildLike() {
1801 $params = func_get_args();
1802
1803 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
1804 $params = $params[0];
1805 }
1806
1807 $s = '';
1808
1809 foreach ( $params as $value ) {
1810 if ( $value instanceof LikeMatch ) {
1811 $s .= $value->toString();
1812 } else {
1813 $s .= $this->escapeLikeInternal( $value );
1814 }
1815 }
1816
1817 return " LIKE '" . $s . "' ";
1818 }
1819
1820 /**
1821 * Returns a token for buildLike() that denotes a '_' to be used in a LIKE query
1822 */
1823 function anyChar() {
1824 return new LikeMatch( '_' );
1825 }
1826
1827 /**
1828 * Returns a token for buildLike() that denotes a '%' to be used in a LIKE query
1829 */
1830 function anyString() {
1831 return new LikeMatch( '%' );
1832 }
1833
1834 /**
1835 * Returns an appropriately quoted sequence value for inserting a new row.
1836 * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
1837 * subclass will return an integer, and save the value for insertId()
1838 */
1839 function nextSequenceValue( $seqName ) {
1840 return null;
1841 }
1842
1843 /**
1844 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
1845 * is only needed because a) MySQL must be as efficient as possible due to
1846 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
1847 * which index to pick. Anyway, other databases might have different
1848 * indexes on a given table. So don't bother overriding this unless you're
1849 * MySQL.
1850 */
1851 function useIndexClause( $index ) {
1852 return '';
1853 }
1854
1855 /**
1856 * REPLACE query wrapper
1857 * PostgreSQL simulates this with a DELETE followed by INSERT
1858 * $row is the row to insert, an associative array
1859 * $uniqueIndexes is an array of indexes. Each element may be either a
1860 * field name or an array of field names
1861 *
1862 * It may be more efficient to leave off unique indexes which are unlikely to collide.
1863 * However if you do this, you run the risk of encountering errors which wouldn't have
1864 * occurred in MySQL
1865 *
1866 * @param $table String: The table to replace the row(s) in.
1867 * @param $uniqueIndexes Array: An associative array of indexes
1868 * @param $rows Array: Array of rows to replace
1869 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
1870 */
1871 function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseBase::replace' ) {
1872 $table = $this->tableName( $table );
1873
1874 # Single row case
1875 if ( !is_array( reset( $rows ) ) ) {
1876 $rows = array( $rows );
1877 }
1878
1879 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
1880 $first = true;
1881
1882 foreach ( $rows as $row ) {
1883 if ( $first ) {
1884 $first = false;
1885 } else {
1886 $sql .= ',';
1887 }
1888
1889 $sql .= '(' . $this->makeList( $row ) . ')';
1890 }
1891
1892 return $this->query( $sql, $fname );
1893 }
1894
1895 /**
1896 * DELETE where the condition is a join
1897 * MySQL does this with a multi-table DELETE syntax, PostgreSQL does it with sub-selects
1898 *
1899 * For safety, an empty $conds will not delete everything. If you want to delete all rows where the
1900 * join condition matches, set $conds='*'
1901 *
1902 * DO NOT put the join condition in $conds
1903 *
1904 * @param $delTable String: The table to delete from.
1905 * @param $joinTable String: The other table.
1906 * @param $delVar String: The variable to join on, in the first table.
1907 * @param $joinVar String: The variable to join on, in the second table.
1908 * @param $conds Array: Condition array of field names mapped to variables, ANDed together in the WHERE clause
1909 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
1910 */
1911 function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'DatabaseBase::deleteJoin' ) {
1912 if ( !$conds ) {
1913 throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
1914 }
1915
1916 $delTable = $this->tableName( $delTable );
1917 $joinTable = $this->tableName( $joinTable );
1918 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1919
1920 if ( $conds != '*' ) {
1921 $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
1922 }
1923
1924 return $this->query( $sql, $fname );
1925 }
1926
1927 /**
1928 * Returns the size of a text field, or -1 for "unlimited"
1929 */
1930 function textFieldSize( $table, $field ) {
1931 $table = $this->tableName( $table );
1932 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
1933 $res = $this->query( $sql, 'DatabaseBase::textFieldSize' );
1934 $row = $this->fetchObject( $res );
1935
1936 $m = array();
1937
1938 if ( preg_match( '/\((.*)\)/', $row->Type, $m ) ) {
1939 $size = $m[1];
1940 } else {
1941 $size = -1;
1942 }
1943
1944 return $size;
1945 }
1946
1947 /**
1948 * A string to insert into queries to show that they're low-priority, like
1949 * MySQL's LOW_PRIORITY. If no such feature exists, return an empty
1950 * string and nothing bad should happen.
1951 *
1952 * @return string Returns the text of the low priority option if it is supported, or a blank string otherwise
1953 */
1954 function lowPriorityOption() {
1955 return '';
1956 }
1957
1958 /**
1959 * DELETE query wrapper
1960 *
1961 * Use $conds == "*" to delete all rows
1962 */
1963 function delete( $table, $conds, $fname = 'DatabaseBase::delete' ) {
1964 if ( !$conds ) {
1965 throw new DBUnexpectedError( $this, 'DatabaseBase::delete() called with no conditions' );
1966 }
1967
1968 $table = $this->tableName( $table );
1969 $sql = "DELETE FROM $table";
1970
1971 if ( $conds != '*' ) {
1972 $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1973 }
1974
1975 return $this->query( $sql, $fname );
1976 }
1977
1978 /**
1979 * INSERT SELECT wrapper
1980 * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
1981 * Source items may be literals rather than field names, but strings should be quoted with DatabaseBase::addQuotes()
1982 * $conds may be "*" to copy the whole table
1983 * srcTable may be an array of tables.
1984 */
1985 function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'DatabaseBase::insertSelect',
1986 $insertOptions = array(), $selectOptions = array() )
1987 {
1988 $destTable = $this->tableName( $destTable );
1989
1990 if ( is_array( $insertOptions ) ) {
1991 $insertOptions = implode( ' ', $insertOptions );
1992 }
1993
1994 if ( !is_array( $selectOptions ) ) {
1995 $selectOptions = array( $selectOptions );
1996 }
1997
1998 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
1999
2000 if ( is_array( $srcTable ) ) {
2001 $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
2002 } else {
2003 $srcTable = $this->tableName( $srcTable );
2004 }
2005
2006 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
2007 " SELECT $startOpts " . implode( ',', $varMap ) .
2008 " FROM $srcTable $useIndex ";
2009
2010 if ( $conds != '*' ) {
2011 $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
2012 }
2013
2014 $sql .= " $tailOpts";
2015
2016 return $this->query( $sql, $fname );
2017 }
2018
2019 /**
2020 * Construct a LIMIT query with optional offset. This is used for query
2021 * pages. The SQL should be adjusted so that only the first $limit rows
2022 * are returned. If $offset is provided as well, then the first $offset
2023 * rows should be discarded, and the next $limit rows should be returned.
2024 * If the result of the query is not ordered, then the rows to be returned
2025 * are theoretically arbitrary.
2026 *
2027 * $sql is expected to be a SELECT, if that makes a difference. For
2028 * UPDATE, limitResultForUpdate should be used.
2029 *
2030 * The version provided by default works in MySQL and SQLite. It will very
2031 * likely need to be overridden for most other DBMSes.
2032 *
2033 * @param $sql String: SQL query we will append the limit too
2034 * @param $limit Integer: the SQL limit
2035 * @param $offset Integer the SQL offset (default false)
2036 */
2037 function limitResult( $sql, $limit, $offset = false ) {
2038 if ( !is_numeric( $limit ) ) {
2039 throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
2040 }
2041
2042 return "$sql LIMIT "
2043 . ( ( is_numeric( $offset ) && $offset != 0 ) ? "{$offset}," : "" )
2044 . "{$limit} ";
2045 }
2046
2047 function limitResultForUpdate( $sql, $num ) {
2048 return $this->limitResult( $sql, $num, 0 );
2049 }
2050
2051 /**
2052 * Returns true if current database backend supports ORDER BY or LIMIT for separate subqueries
2053 * within the UNION construct.
2054 * @return Boolean
2055 */
2056 function unionSupportsOrderAndLimit() {
2057 return true; // True for almost every DB supported
2058 }
2059
2060 /**
2061 * Construct a UNION query
2062 * This is used for providing overload point for other DB abstractions
2063 * not compatible with the MySQL syntax.
2064 * @param $sqls Array: SQL statements to combine
2065 * @param $all Boolean: use UNION ALL
2066 * @return String: SQL fragment
2067 */
2068 function unionQueries( $sqls, $all ) {
2069 $glue = $all ? ') UNION ALL (' : ') UNION (';
2070 return '(' . implode( $glue, $sqls ) . ')';
2071 }
2072
2073 /**
2074 * Returns an SQL expression for a simple conditional. This doesn't need
2075 * to be overridden unless CASE isn't supported in your DBMS.
2076 *
2077 * @param $cond String: SQL expression which will result in a boolean value
2078 * @param $trueVal String: SQL expression to return if true
2079 * @param $falseVal String: SQL expression to return if false
2080 * @return String: SQL fragment
2081 */
2082 function conditional( $cond, $trueVal, $falseVal ) {
2083 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
2084 }
2085
2086 /**
2087 * Returns a comand for str_replace function in SQL query.
2088 * Uses REPLACE() in MySQL
2089 *
2090 * @param $orig String: column to modify
2091 * @param $old String: column to seek
2092 * @param $new String: column to replace with
2093 */
2094 function strreplace( $orig, $old, $new ) {
2095 return "REPLACE({$orig}, {$old}, {$new})";
2096 }
2097
2098 /**
2099 * Determines if the last failure was due to a deadlock
2100 * STUB
2101 */
2102 function wasDeadlock() {
2103 return false;
2104 }
2105
2106 /**
2107 * Determines if the last query error was something that should be dealt
2108 * with by pinging the connection and reissuing the query.
2109 * STUB
2110 */
2111 function wasErrorReissuable() {
2112 return false;
2113 }
2114
2115 /**
2116 * Determines if the last failure was due to the database being read-only.
2117 * STUB
2118 */
2119 function wasReadOnlyError() {
2120 return false;
2121 }
2122
2123 /**
2124 * Perform a deadlock-prone transaction.
2125 *
2126 * This function invokes a callback function to perform a set of write
2127 * queries. If a deadlock occurs during the processing, the transaction
2128 * will be rolled back and the callback function will be called again.
2129 *
2130 * Usage:
2131 * $dbw->deadlockLoop( callback, ... );
2132 *
2133 * Extra arguments are passed through to the specified callback function.
2134 *
2135 * Returns whatever the callback function returned on its successful,
2136 * iteration, or false on error, for example if the retry limit was
2137 * reached.
2138 */
2139 function deadlockLoop() {
2140 $myFname = 'DatabaseBase::deadlockLoop';
2141
2142 $this->begin();
2143 $args = func_get_args();
2144 $function = array_shift( $args );
2145 $oldIgnore = $this->ignoreErrors( true );
2146 $tries = DEADLOCK_TRIES;
2147
2148 if ( is_array( $function ) ) {
2149 $fname = $function[0];
2150 } else {
2151 $fname = $function;
2152 }
2153
2154 do {
2155 $retVal = call_user_func_array( $function, $args );
2156 $error = $this->lastError();
2157 $errno = $this->lastErrno();
2158 $sql = $this->lastQuery();
2159
2160 if ( $errno ) {
2161 if ( $this->wasDeadlock() ) {
2162 # Retry
2163 usleep( mt_rand( DEADLOCK_DELAY_MIN, DEADLOCK_DELAY_MAX ) );
2164 } else {
2165 $this->reportQueryError( $error, $errno, $sql, $fname );
2166 }
2167 }
2168 } while ( $this->wasDeadlock() && --$tries > 0 );
2169
2170 $this->ignoreErrors( $oldIgnore );
2171
2172 if ( $tries <= 0 ) {
2173 $this->rollback( $myFname );
2174 $this->reportQueryError( $error, $errno, $sql, $fname );
2175 return false;
2176 } else {
2177 $this->commit( $myFname );
2178 return $retVal;
2179 }
2180 }
2181
2182 /**
2183 * Do a SELECT MASTER_POS_WAIT()
2184 *
2185 * @param $pos MySQLMasterPos object
2186 * @param $timeout Integer: the maximum number of seconds to wait for synchronisation
2187 */
2188 function masterPosWait( MySQLMasterPos $pos, $timeout ) {
2189 $fname = 'DatabaseBase::masterPosWait';
2190 wfProfileIn( $fname );
2191
2192 # Commit any open transactions
2193 if ( $this->mTrxLevel ) {
2194 $this->commit();
2195 }
2196
2197 if ( !is_null( $this->mFakeSlaveLag ) ) {
2198 $wait = intval( ( $pos->pos - microtime( true ) + $this->mFakeSlaveLag ) * 1e6 );
2199
2200 if ( $wait > $timeout * 1e6 ) {
2201 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
2202 wfProfileOut( $fname );
2203 return -1;
2204 } elseif ( $wait > 0 ) {
2205 wfDebug( "Fake slave waiting $wait us\n" );
2206 usleep( $wait );
2207 wfProfileOut( $fname );
2208 return 1;
2209 } else {
2210 wfDebug( "Fake slave up to date ($wait us)\n" );
2211 wfProfileOut( $fname );
2212 return 0;
2213 }
2214 }
2215
2216 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
2217 $encFile = $this->addQuotes( $pos->file );
2218 $encPos = intval( $pos->pos );
2219 $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
2220 $res = $this->doQuery( $sql );
2221
2222 if ( $res && $row = $this->fetchRow( $res ) ) {
2223 wfProfileOut( $fname );
2224 return $row[0];
2225 } else {
2226 wfProfileOut( $fname );
2227 return false;
2228 }
2229 }
2230
2231 /**
2232 * Get the position of the master from SHOW SLAVE STATUS
2233 */
2234 function getSlavePos() {
2235 if ( !is_null( $this->mFakeSlaveLag ) ) {
2236 $pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag );
2237 wfDebug( __METHOD__ . ": fake slave pos = $pos\n" );
2238 return $pos;
2239 }
2240
2241 $res = $this->query( 'SHOW SLAVE STATUS', 'DatabaseBase::getSlavePos' );
2242 $row = $this->fetchObject( $res );
2243
2244 if ( $row ) {
2245 $pos = isset( $row->Exec_master_log_pos ) ? $row->Exec_master_log_pos : $row->Exec_Master_Log_Pos;
2246 return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos );
2247 } else {
2248 return false;
2249 }
2250 }
2251
2252 /**
2253 * Get the position of the master from SHOW MASTER STATUS
2254 */
2255 function getMasterPos() {
2256 if ( $this->mFakeMaster ) {
2257 return new MySQLMasterPos( 'fake', microtime( true ) );
2258 }
2259
2260 $res = $this->query( 'SHOW MASTER STATUS', 'DatabaseBase::getMasterPos' );
2261 $row = $this->fetchObject( $res );
2262
2263 if ( $row ) {
2264 return new MySQLMasterPos( $row->File, $row->Position );
2265 } else {
2266 return false;
2267 }
2268 }
2269
2270 /**
2271 * Begin a transaction, committing any previously open transaction
2272 */
2273 function begin( $fname = 'DatabaseBase::begin' ) {
2274 $this->query( 'BEGIN', $fname );
2275 $this->mTrxLevel = 1;
2276 }
2277
2278 /**
2279 * End a transaction
2280 */
2281 function commit( $fname = 'DatabaseBase::commit' ) {
2282 if ( $this->mTrxLevel ) {
2283 $this->query( 'COMMIT', $fname );
2284 $this->mTrxLevel = 0;
2285 }
2286 }
2287
2288 /**
2289 * Rollback a transaction.
2290 * No-op on non-transactional databases.
2291 */
2292 function rollback( $fname = 'DatabaseBase::rollback' ) {
2293 if ( $this->mTrxLevel ) {
2294 $this->query( 'ROLLBACK', $fname, true );
2295 $this->mTrxLevel = 0;
2296 }
2297 }
2298
2299 /**
2300 * Begin a transaction, committing any previously open transaction
2301 * @deprecated use begin()
2302 */
2303 function immediateBegin( $fname = 'DatabaseBase::immediateBegin' ) {
2304 wfDeprecated( __METHOD__ );
2305 $this->begin();
2306 }
2307
2308 /**
2309 * Commit transaction, if one is open
2310 * @deprecated use commit()
2311 */
2312 function immediateCommit( $fname = 'DatabaseBase::immediateCommit' ) {
2313 wfDeprecated( __METHOD__ );
2314 $this->commit();
2315 }
2316
2317 /**
2318 * Creates a new table with structure copied from existing table
2319 * Note that unlike most database abstraction functions, this function does not
2320 * automatically append database prefix, because it works at a lower
2321 * abstraction level.
2322 * The table names passed to this function shall not be quoted (this
2323 * function calls addIdentifierQuotes when needed).
2324 *
2325 * @param $oldName String: name of table whose structure should be copied
2326 * @param $newName String: name of table to be created
2327 * @param $temporary Boolean: whether the new table should be temporary
2328 * @param $fname String: calling function name
2329 * @return Boolean: true if operation was successful
2330 */
2331 function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabaseBase::duplicateTableStructure' ) {
2332 throw new MWException( 'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
2333 }
2334
2335 /**
2336 * List all tables on the database
2337 *
2338 * @param $prefix Only show tables with this prefix, e.g. mw_
2339 * @param $fname String: calling function name
2340 */
2341 function listTables( $prefix = null, $fname = 'DatabaseBase::listTables' ) {
2342 throw new MWException( 'DatabaseBase::listTables is not implemented in descendant class' );
2343 }
2344
2345 /**
2346 * Return MW-style timestamp used for MySQL schema
2347 */
2348 function timestamp( $ts = 0 ) {
2349 return wfTimestamp( TS_MW, $ts );
2350 }
2351
2352 /**
2353 * Local database timestamp format or null
2354 */
2355 function timestampOrNull( $ts = null ) {
2356 if ( is_null( $ts ) ) {
2357 return null;
2358 } else {
2359 return $this->timestamp( $ts );
2360 }
2361 }
2362
2363 /**
2364 * @todo document
2365 */
2366 function resultObject( $result ) {
2367 if ( empty( $result ) ) {
2368 return false;
2369 } elseif ( $result instanceof ResultWrapper ) {
2370 return $result;
2371 } elseif ( $result === true ) {
2372 // Successful write query
2373 return $result;
2374 } else {
2375 return new ResultWrapper( $this, $result );
2376 }
2377 }
2378
2379 /**
2380 * Return aggregated value alias
2381 */
2382 function aggregateValue ( $valuedata, $valuename = 'value' ) {
2383 return $valuename;
2384 }
2385
2386 /**
2387 * Ping the server and try to reconnect if it there is no connection
2388 *
2389 * @return bool Success or failure
2390 */
2391 function ping() {
2392 # Stub. Not essential to override.
2393 return true;
2394 }
2395
2396 /**
2397 * Get slave lag.
2398 * Currently supported only by MySQL
2399 * @return Database replication lag in seconds
2400 */
2401 function getLag() {
2402 return intval( $this->mFakeSlaveLag );
2403 }
2404
2405 /**
2406 * Get status information from SHOW STATUS in an associative array
2407 */
2408 function getStatus( $which = "%" ) {
2409 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
2410 $status = array();
2411
2412 foreach ( $res as $row ) {
2413 $status[$row->Variable_name] = $row->Value;
2414 }
2415
2416 return $status;
2417 }
2418
2419 /**
2420 * Return the maximum number of items allowed in a list, or 0 for unlimited.
2421 */
2422 function maxListLen() {
2423 return 0;
2424 }
2425
2426 function encodeBlob( $b ) {
2427 return $b;
2428 }
2429
2430 function decodeBlob( $b ) {
2431 return $b;
2432 }
2433
2434 /**
2435 * Override database's default connection timeout. May be useful for very
2436 * long batch queries such as full-wiki dumps, where a single query reads
2437 * out over hours or days. May or may not be necessary for non-MySQL
2438 * databases. For most purposes, leaving it as a no-op should be fine.
2439 *
2440 * @param $timeout Integer in seconds
2441 */
2442 public function setTimeout( $timeout ) {}
2443
2444 /**
2445 * Read and execute SQL commands from a file.
2446 * Returns true on success, error string or exception on failure (depending on object's error ignore settings)
2447 * @param $filename String: File name to open
2448 * @param $lineCallback Callback: Optional function called before reading each line
2449 * @param $resultCallback Callback: Optional function called for each MySQL result
2450 * @param $fname String: Calling function name or false if name should be generated dynamically
2451 * using $filename
2452 */
2453 function sourceFile( $filename, $lineCallback = false, $resultCallback = false, $fname = false ) {
2454 wfSuppressWarnings();
2455 $fp = fopen( $filename, 'r' );
2456 wfRestoreWarnings();
2457
2458 if ( false === $fp ) {
2459 throw new MWException( "Could not open \"{$filename}\".\n" );
2460 }
2461
2462 if ( !$fname ) {
2463 $fname = __METHOD__ . "( $filename )";
2464 }
2465
2466 try {
2467 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback, $fname );
2468 }
2469 catch ( MWException $e ) {
2470 fclose( $fp );
2471 throw $e;
2472 }
2473
2474 fclose( $fp );
2475
2476 return $error;
2477 }
2478
2479 /**
2480 * Get the full path of a patch file. Originally based on archive()
2481 * from updaters.inc. Keep in mind this always returns a patch, as
2482 * it fails back to MySQL if no DB-specific patch can be found
2483 *
2484 * @param $patch String The name of the patch, like patch-something.sql
2485 * @return String Full path to patch file
2486 */
2487 public function patchPath( $patch ) {
2488 global $IP;
2489
2490 $dbType = $this->getType();
2491 if ( file_exists( "$IP/maintenance/$dbType/archives/$patch" ) ) {
2492 return "$IP/maintenance/$dbType/archives/$patch";
2493 } else {
2494 return "$IP/maintenance/archives/$patch";
2495 }
2496 }
2497
2498 /**
2499 * Set variables to be used in sourceFile/sourceStream, in preference to the
2500 * ones in $GLOBALS. If an array is set here, $GLOBALS will not be used at
2501 * all. If it's set to false, $GLOBALS will be used.
2502 *
2503 * @param $vars False, or array mapping variable name to value.
2504 */
2505 function setSchemaVars( $vars ) {
2506 $this->mSchemaVars = $vars;
2507 }
2508
2509 /**
2510 * Read and execute commands from an open file handle
2511 * Returns true on success, error string or exception on failure (depending on object's error ignore settings)
2512 * @param $fp Resource: File handle
2513 * @param $lineCallback Callback: Optional function called before reading each line
2514 * @param $resultCallback Callback: Optional function called for each MySQL result
2515 * @param $fname String: Calling function name
2516 */
2517 function sourceStream( $fp, $lineCallback = false, $resultCallback = false, $fname = 'DatabaseBase::sourceStream' ) {
2518 $cmd = "";
2519 $done = false;
2520 $dollarquote = false;
2521
2522 while ( ! feof( $fp ) ) {
2523 if ( $lineCallback ) {
2524 call_user_func( $lineCallback );
2525 }
2526
2527 $line = trim( fgets( $fp, 1024 ) );
2528 $sl = strlen( $line ) - 1;
2529
2530 if ( $sl < 0 ) {
2531 continue;
2532 }
2533
2534 if ( '-' == $line { 0 } && '-' == $line { 1 } ) {
2535 continue;
2536 }
2537
2538 # # Allow dollar quoting for function declarations
2539 if ( substr( $line, 0, 4 ) == '$mw$' ) {
2540 if ( $dollarquote ) {
2541 $dollarquote = false;
2542 $done = true;
2543 }
2544 else {
2545 $dollarquote = true;
2546 }
2547 }
2548 else if ( !$dollarquote ) {
2549 if ( ';' == $line { $sl } && ( $sl < 2 || ';' != $line { $sl - 1 } ) ) {
2550 $done = true;
2551 $line = substr( $line, 0, $sl );
2552 }
2553 }
2554
2555 if ( $cmd != '' ) {
2556 $cmd .= ' ';
2557 }
2558
2559 $cmd .= "$line\n";
2560
2561 if ( $done ) {
2562 $cmd = str_replace( ';;', ";", $cmd );
2563 $cmd = $this->replaceVars( $cmd );
2564 $res = $this->query( $cmd, $fname );
2565
2566 if ( $resultCallback ) {
2567 call_user_func( $resultCallback, $res, $this );
2568 }
2569
2570 if ( false === $res ) {
2571 $err = $this->lastError();
2572 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
2573 }
2574
2575 $cmd = '';
2576 $done = false;
2577 }
2578 }
2579
2580 return true;
2581 }
2582
2583 /**
2584 * Database independent variable replacement, replaces a set of variables
2585 * in a sql statement with their contents as given by $this->getSchemaVars().
2586 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables
2587 *
2588 * '{$var}' should be used for text and is passed through the database's addQuotes method
2589 * `{$var}` should be used for identifiers (eg: table and database names), it is passed through
2590 * the database's addIdentifierQuotes method which can be overridden if the database
2591 * uses something other than backticks.
2592 * / *$var* / is just encoded, besides traditional dbprefix and tableoptions it's use should be avoided
2593 *
2594 * @param $ins String: SQL statement to replace variables in
2595 * @return String The new SQL statement with variables replaced
2596 */
2597 protected function replaceSchemaVars( $ins ) {
2598 $vars = $this->getSchemaVars();
2599 foreach ( $vars as $var => $value ) {
2600 // replace '{$var}'
2601 $ins = str_replace( '\'{$' . $var . '}\'', $this->addQuotes( $value ), $ins );
2602 // replace `{$var}`
2603 $ins = str_replace( '`{$' . $var . '}`', $this->addIdentifierQuotes( $value ), $ins );
2604 // replace /*$var*/
2605 $ins = str_replace( '/*$' . $var . '*/', $this->strencode( $value ) , $ins );
2606 }
2607 return $ins;
2608 }
2609
2610 /**
2611 * Replace variables in sourced SQL
2612 */
2613 protected function replaceVars( $ins ) {
2614 $ins = $this->replaceSchemaVars( $ins );
2615
2616 // Table prefixes
2617 $ins = preg_replace_callback( '!/\*(?:\$wgDBprefix|_)\*/([a-zA-Z_0-9]*)!',
2618 array( $this, 'tableNameCallback' ), $ins );
2619
2620 // Index names
2621 $ins = preg_replace_callback( '!/\*i\*/([a-zA-Z_0-9]*)!',
2622 array( $this, 'indexNameCallback' ), $ins );
2623
2624 return $ins;
2625 }
2626
2627 /**
2628 * Get schema variables. If none have been set via setSchemaVars(), then
2629 * use some defaults from the current object.
2630 */
2631 protected function getSchemaVars() {
2632 if ( $this->mSchemaVars ) {
2633 return $this->mSchemaVars;
2634 } else {
2635 return $this->getDefaultSchemaVars();
2636 }
2637 }
2638
2639 /**
2640 * Get schema variables to use if none have been set via setSchemaVars().
2641 * Override this in derived classes to provide variables for tables.sql
2642 * and SQL patch files.
2643 */
2644 protected function getDefaultSchemaVars() {
2645 return array();
2646 }
2647
2648 /**
2649 * Table name callback
2650 * @private
2651 */
2652 protected function tableNameCallback( $matches ) {
2653 return $this->tableName( $matches[1] );
2654 }
2655
2656 /**
2657 * Index name callback
2658 */
2659 protected function indexNameCallback( $matches ) {
2660 return $this->indexName( $matches[1] );
2661 }
2662
2663 /**
2664 * Build a concatenation list to feed into a SQL query
2665 * @param $stringList Array: list of raw SQL expressions; caller is responsible for any quoting
2666 * @return String
2667 */
2668 function buildConcat( $stringList ) {
2669 return 'CONCAT(' . implode( ',', $stringList ) . ')';
2670 }
2671
2672 /**
2673 * Acquire a named lock
2674 *
2675 * Abstracted from Filestore::lock() so child classes can implement for
2676 * their own needs.
2677 *
2678 * @param $lockName String: name of lock to aquire
2679 * @param $method String: name of method calling us
2680 * @param $timeout Integer: timeout
2681 * @return Boolean
2682 */
2683 public function lock( $lockName, $method, $timeout = 5 ) {
2684 return true;
2685 }
2686
2687 /**
2688 * Release a lock.
2689 *
2690 * @param $lockName String: Name of lock to release
2691 * @param $method String: Name of method calling us
2692 *
2693 * @return Returns 1 if the lock was released, 0 if the lock was not established
2694 * by this thread (in which case the lock is not released), and NULL if the named
2695 * lock did not exist
2696 */
2697 public function unlock( $lockName, $method ) {
2698 return true;
2699 }
2700
2701 /**
2702 * Lock specific tables
2703 *
2704 * @param $read Array of tables to lock for read access
2705 * @param $write Array of tables to lock for write access
2706 * @param $method String name of caller
2707 * @param $lowPriority bool Whether to indicate writes to be LOW PRIORITY
2708 */
2709 public function lockTables( $read, $write, $method, $lowPriority = true ) {
2710 return true;
2711 }
2712
2713 /**
2714 * Unlock specific tables
2715 *
2716 * @param $method String the caller
2717 */
2718 public function unlockTables( $method ) {
2719 return true;
2720 }
2721
2722 /**
2723 * Delete a table
2724 */
2725 public function dropTable( $tableName, $fName = 'DatabaseBase::dropTable' ) {
2726 if( !$this->tableExists( $tableName ) ) {
2727 return false;
2728 }
2729 $sql = "DROP TABLE " . $this->tableName( $tableName );
2730 if( $this->cascadingDeletes() ) {
2731 $sql .= " CASCADE";
2732 }
2733 return $this->query( $sql, $fName );
2734 }
2735
2736 /**
2737 * Get search engine class. All subclasses of this need to implement this
2738 * if they wish to use searching.
2739 *
2740 * @return String
2741 */
2742 public function getSearchEngine() {
2743 return 'SearchEngineDummy';
2744 }
2745
2746 /**
2747 * Find out when 'infinity' is. Most DBMSes support this. This is a special
2748 * keyword for timestamps in PostgreSQL, and works with CHAR(14) as well
2749 * because "i" sorts after all numbers.
2750 *
2751 * @return String
2752 */
2753 public function getInfinity() {
2754 return 'infinity';
2755 }
2756
2757 /**
2758 * Encode an expiry time
2759 *
2760 * @param $expiry String: timestamp for expiry, or the 'infinity' string
2761 * @return String
2762 */
2763 public function encodeExpiry( $expiry ) {
2764 if ( $expiry == '' || $expiry == $this->getInfinity() ) {
2765 return $this->getInfinity();
2766 } else {
2767 return $this->timestamp( $expiry );
2768 }
2769 }
2770
2771 /**
2772 * Allow or deny "big selects" for this session only. This is done by setting
2773 * the sql_big_selects session variable.
2774 *
2775 * This is a MySQL-specific feature.
2776 *
2777 * @param $value Mixed: true for allow, false for deny, or "default" to restore the initial value
2778 */
2779 public function setBigSelects( $value = true ) {
2780 // no-op
2781 }
2782 }
2783
2784 /******************************************************************************
2785 * Utility classes
2786 *****************************************************************************/
2787
2788 /**
2789 * Utility class.
2790 * @ingroup Database
2791 */
2792 class DBObject {
2793 public $mData;
2794
2795 function __construct( $data ) {
2796 $this->mData = $data;
2797 }
2798
2799 function isLOB() {
2800 return false;
2801 }
2802
2803 function data() {
2804 return $this->mData;
2805 }
2806 }
2807
2808 /**
2809 * Utility class
2810 * @ingroup Database
2811 *
2812 * This allows us to distinguish a blob from a normal string and an array of strings
2813 */
2814 class Blob {
2815 private $mData;
2816
2817 function __construct( $data ) {
2818 $this->mData = $data;
2819 }
2820
2821 function fetch() {
2822 return $this->mData;
2823 }
2824 }
2825
2826 /**
2827 * Base for all database-specific classes representing information about database fields
2828 * @ingroup Database
2829 */
2830 interface Field {
2831 /**
2832 * Field name
2833 * @return string
2834 */
2835 function name();
2836
2837 /**
2838 * Name of table this field belongs to
2839 * @return string
2840 */
2841 function tableName();
2842
2843 /**
2844 * Database type
2845 * @return string
2846 */
2847 function type();
2848
2849 /**
2850 * Whether this field can store NULL values
2851 * @return bool
2852 */
2853 function isNullable();
2854 }
2855
2856 /******************************************************************************
2857 * Error classes
2858 *****************************************************************************/
2859
2860 /**
2861 * Database error base class
2862 * @ingroup Database
2863 */
2864 class DBError extends MWException {
2865 public $db;
2866
2867 /**
2868 * Construct a database error
2869 * @param $db Database object which threw the error
2870 * @param $error String A simple error message to be used for debugging
2871 */
2872 function __construct( DatabaseBase &$db, $error ) {
2873 $this->db =& $db;
2874 parent::__construct( $error );
2875 }
2876
2877 protected function getContentMessage( $html ) {
2878 if ( $html ) {
2879 return nl2br( htmlspecialchars( $this->getMessage() ) );
2880 } else {
2881 return $this->getMessage();
2882 }
2883 }
2884
2885 function getText() {
2886 global $wgShowDBErrorBacktrace;
2887
2888 $s = $this->getContentMessage( false ) . "\n";
2889
2890 if ( $wgShowDBErrorBacktrace ) {
2891 $s .= "Backtrace:\n" . $this->getTraceAsString() . "\n";
2892 }
2893
2894 return $s;
2895 }
2896
2897 function getHTML() {
2898 global $wgShowDBErrorBacktrace;
2899
2900 $s = $this->getContentMessage( true );
2901
2902 if ( $wgShowDBErrorBacktrace ) {
2903 $s .= '<p>Backtrace:</p><p>' . nl2br( htmlspecialchars( $this->getTraceAsString() ) );
2904 }
2905
2906 return $s;
2907 }
2908 }
2909
2910 /**
2911 * @ingroup Database
2912 */
2913 class DBConnectionError extends DBError {
2914 public $error;
2915
2916 function __construct( DatabaseBase &$db, $error = 'unknown error' ) {
2917 $msg = 'DB connection error';
2918
2919 if ( trim( $error ) != '' ) {
2920 $msg .= ": $error";
2921 }
2922
2923 $this->error = $error;
2924
2925 parent::__construct( $db, $msg );
2926 }
2927
2928 function useOutputPage() {
2929 // Not likely to work
2930 return false;
2931 }
2932
2933 function msg( $key, $fallback /*[, params...] */ ) {
2934 global $wgLang;
2935
2936 $args = array_slice( func_get_args(), 2 );
2937
2938 if ( $this->useMessageCache() ) {
2939 $message = $wgLang->getMessage( $key );
2940 } else {
2941 $message = $fallback;
2942 }
2943 return wfMsgReplaceArgs( $message, $args );
2944 }
2945
2946 function getLogMessage() {
2947 # Don't send to the exception log
2948 return false;
2949 }
2950
2951 function getPageTitle() {
2952 global $wgSitename;
2953 return htmlspecialchars( $this->msg( 'dberr-header', "$wgSitename has a problem" ) );
2954 }
2955
2956 function getHTML() {
2957 global $wgUseFileCache, $wgShowDBErrorBacktrace;
2958
2959 $sorry = htmlspecialchars( $this->msg( 'dberr-problems', 'Sorry! This site is experiencing technical difficulties.' ) );
2960 $again = htmlspecialchars( $this->msg( 'dberr-again', 'Try waiting a few minutes and reloading.' ) );
2961 $info = htmlspecialchars( $this->msg( 'dberr-info', '(Can\'t contact the database server: $1)' ) );
2962
2963 # No database access
2964 MessageCache::singleton()->disable();
2965
2966 if ( trim( $this->error ) == '' ) {
2967 $this->error = $this->db->getProperty( 'mServer' );
2968 }
2969
2970 $this->error = Html::element( 'span', array( 'dir' => 'ltr' ), $this->error );
2971
2972 $noconnect = "<h1>$sorry</h1><p>$again</p><p><small>$info</small></p>";
2973 $text = str_replace( '$1', $this->error, $noconnect );
2974
2975 if ( $wgShowDBErrorBacktrace ) {
2976 $text .= '<p>Backtrace:</p><p>' . nl2br( htmlspecialchars( $this->getTraceAsString() ) );
2977 }
2978
2979 $extra = $this->searchForm();
2980
2981 if ( $wgUseFileCache ) {
2982 try {
2983 $cache = $this->fileCachedPage();
2984 # Cached version on file system?
2985 if ( $cache !== null ) {
2986 # Hack: extend the body for error messages
2987 $cache = str_replace( array( '</html>', '</body>' ), '', $cache );
2988 # Add cache notice...
2989 $cache .= '<div style="color:red;font-size:150%;font-weight:bold;">'.
2990 htmlspecialchars( $this->msg( 'dberr-cachederror',
2991 'This is a cached copy of the requested page, and may not be up to date. ' ) ) .
2992 '</div>';
2993
2994 # Output cached page with notices on bottom and re-close body
2995 return "{$cache}<hr />$text<hr />$extra</body></html>";
2996 }
2997 } catch ( MWException $e ) {
2998 // Do nothing, just use the default page
2999 }
3000 }
3001
3002 # Headers needed here - output is just the error message
3003 return $this->htmlHeader() . "$text<hr />$extra" . $this->htmlFooter();
3004 }
3005
3006 function searchForm() {
3007 global $wgSitename, $wgServer;
3008
3009 $usegoogle = htmlspecialchars( $this->msg( 'dberr-usegoogle', 'You can try searching via Google in the meantime.' ) );
3010 $outofdate = htmlspecialchars( $this->msg( 'dberr-outofdate', 'Note that their indexes of our content may be out of date.' ) );
3011 $googlesearch = htmlspecialchars( $this->msg( 'searchbutton', 'Search' ) );
3012
3013 $search = htmlspecialchars( @$_REQUEST['search'] );
3014
3015 $server = htmlspecialchars( $wgServer );
3016 $sitename = htmlspecialchars( $wgSitename );
3017
3018 $trygoogle = <<<EOT
3019 <div style="margin: 1.5em">$usegoogle<br />
3020 <small>$outofdate</small></div>
3021 <!-- SiteSearch Google -->
3022 <form method="get" action="http://www.google.com/search" id="googlesearch">
3023 <input type="hidden" name="domains" value="$server" />
3024 <input type="hidden" name="num" value="50" />
3025 <input type="hidden" name="ie" value="UTF-8" />
3026 <input type="hidden" name="oe" value="UTF-8" />
3027
3028 <input type="text" name="q" size="31" maxlength="255" value="$search" />
3029 <input type="submit" name="btnG" value="$googlesearch" />
3030 <div>
3031 <input type="radio" name="sitesearch" id="gwiki" value="$server" checked="checked" /><label for="gwiki">$sitename</label>
3032 <input type="radio" name="sitesearch" id="gWWW" value="" /><label for="gWWW">WWW</label>
3033 </div>
3034 </form>
3035 <!-- SiteSearch Google -->
3036 EOT;
3037 return $trygoogle;
3038 }
3039
3040 private function fileCachedPage() {
3041 global $wgTitle, $wgOut;
3042
3043 if ( $wgOut->isDisabled() ) {
3044 return; // Done already?
3045 }
3046
3047 if ( $wgTitle ) {
3048 $t =& $wgTitle;
3049 } else {
3050 $t = Title::newFromText( $this->msg( 'mainpage', 'Main Page' ) );
3051 }
3052
3053 $cache = new HTMLFileCache( $t );
3054 if ( $cache->isFileCached() ) {
3055 return $cache->fetchPageText();
3056 } else {
3057 return '';
3058 }
3059 }
3060
3061 function htmlBodyOnly() {
3062 return true;
3063 }
3064 }
3065
3066 /**
3067 * @ingroup Database
3068 */
3069 class DBQueryError extends DBError {
3070 public $error, $errno, $sql, $fname;
3071
3072 function __construct( DatabaseBase &$db, $error, $errno, $sql, $fname ) {
3073 $message = "A database error has occurred. Did you forget to run maintenance/update.php after upgrading? See: http://www.mediawiki.org/wiki/Manual:Upgrading#Run_the_update_script\n" .
3074 "Query: $sql\n" .
3075 "Function: $fname\n" .
3076 "Error: $errno $error\n";
3077
3078 parent::__construct( $db, $message );
3079
3080 $this->error = $error;
3081 $this->errno = $errno;
3082 $this->sql = $sql;
3083 $this->fname = $fname;
3084 }
3085
3086 function getContentMessage( $html ) {
3087 if ( $this->useMessageCache() ) {
3088 $msg = $html ? 'dberrortext' : 'dberrortextcl';
3089 $ret = wfMsg( $msg, $this->getSQL(),
3090 $this->fname, $this->errno, $this->error );
3091 if ( $html ) {
3092 $ret = htmlspecialchars( $ret );
3093 }
3094 return $ret;
3095 } else {
3096 return parent::getContentMessage( $html );
3097 }
3098 }
3099
3100 function getSQL() {
3101 global $wgShowSQLErrors;
3102
3103 if ( !$wgShowSQLErrors ) {
3104 return $this->msg( 'sqlhidden', 'SQL hidden' );
3105 } else {
3106 return $this->sql;
3107 }
3108 }
3109
3110 function getLogMessage() {
3111 # Don't send to the exception log
3112 return false;
3113 }
3114
3115 function getPageTitle() {
3116 return $this->msg( 'databaseerror', 'Database error' );
3117 }
3118 }
3119
3120 /**
3121 * @ingroup Database
3122 */
3123 class DBUnexpectedError extends DBError {}
3124
3125
3126 /**
3127 * Result wrapper for grabbing data queried by someone else
3128 * @ingroup Database
3129 */
3130 class ResultWrapper implements Iterator {
3131 var $db, $result, $pos = 0, $currentRow = null;
3132
3133 /**
3134 * Create a new result object from a result resource and a Database object
3135 *
3136 * @param DatabaseBase $database
3137 * @param resource $result
3138 */
3139 function __construct( $database, $result ) {
3140 $this->db = $database;
3141
3142 if ( $result instanceof ResultWrapper ) {
3143 $this->result = $result->result;
3144 } else {
3145 $this->result = $result;
3146 }
3147 }
3148
3149 /**
3150 * Get the number of rows in a result object
3151 *
3152 * @return integer
3153 */
3154 function numRows() {
3155 return $this->db->numRows( $this );
3156 }
3157
3158 /**
3159 * Fetch the next row from the given result object, in object form.
3160 * Fields can be retrieved with $row->fieldname, with fields acting like
3161 * member variables.
3162 *
3163 * @return object
3164 * @throws DBUnexpectedError Thrown if the database returns an error
3165 */
3166 function fetchObject() {
3167 return $this->db->fetchObject( $this );
3168 }
3169
3170 /**
3171 * Fetch the next row from the given result object, in associative array
3172 * form. Fields are retrieved with $row['fieldname'].
3173 *
3174 * @return Array
3175 * @throws DBUnexpectedError Thrown if the database returns an error
3176 */
3177 function fetchRow() {
3178 return $this->db->fetchRow( $this );
3179 }
3180
3181 /**
3182 * Free a result object
3183 */
3184 function free() {
3185 $this->db->freeResult( $this );
3186 unset( $this->result );
3187 unset( $this->db );
3188 }
3189
3190 /**
3191 * Change the position of the cursor in a result object.
3192 * See mysql_data_seek()
3193 *
3194 * @param $row integer
3195 */
3196 function seek( $row ) {
3197 $this->db->dataSeek( $this, $row );
3198 }
3199
3200 /*********************
3201 * Iterator functions
3202 * Note that using these in combination with the non-iterator functions
3203 * above may cause rows to be skipped or repeated.
3204 */
3205
3206 function rewind() {
3207 if ( $this->numRows() ) {
3208 $this->db->dataSeek( $this, 0 );
3209 }
3210 $this->pos = 0;
3211 $this->currentRow = null;
3212 }
3213
3214 function current() {
3215 if ( is_null( $this->currentRow ) ) {
3216 $this->next();
3217 }
3218 return $this->currentRow;
3219 }
3220
3221 function key() {
3222 return $this->pos;
3223 }
3224
3225 function next() {
3226 $this->pos++;
3227 $this->currentRow = $this->fetchObject();
3228 return $this->currentRow;
3229 }
3230
3231 function valid() {
3232 return $this->current() !== false;
3233 }
3234 }
3235
3236 /**
3237 * Overloads the relevant methods of the real ResultsWrapper so it
3238 * doesn't go anywhere near an actual database.
3239 */
3240 class FakeResultWrapper extends ResultWrapper {
3241 var $result = array();
3242 var $db = null; // And it's going to stay that way :D
3243 var $pos = 0;
3244 var $currentRow = null;
3245
3246 function __construct( $array ) {
3247 $this->result = $array;
3248 }
3249
3250 function numRows() {
3251 return count( $this->result );
3252 }
3253
3254 function fetchRow() {
3255 $this->currentRow = $this->result[$this->pos++];
3256 return $this->currentRow;
3257 }
3258
3259 function seek( $row ) {
3260 $this->pos = $row;
3261 }
3262
3263 function free() {}
3264
3265 // Callers want to be able to access fields with $this->fieldName
3266 function fetchObject() {
3267 $this->currentRow = $this->result[$this->pos++];
3268 return (object)$this->currentRow;
3269 }
3270
3271 function rewind() {
3272 $this->pos = 0;
3273 $this->currentRow = null;
3274 }
3275 }
3276
3277 /**
3278 * Used by DatabaseBase::buildLike() to represent characters that have special meaning in SQL LIKE clauses
3279 * and thus need no escaping. Don't instantiate it manually, use DatabaseBase::anyChar() and anyString() instead.
3280 */
3281 class LikeMatch {
3282 private $str;
3283
3284 /**
3285 * Store a string into a LikeMatch marker object.
3286 *
3287 * @param String $s
3288 */
3289 public function __construct( $s ) {
3290 $this->str = $s;
3291 }
3292
3293 /**
3294 * Return the original stored string.
3295 *
3296 * @return String
3297 */
3298 public function toString() {
3299 return $this->str;
3300 }
3301 }
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