includes/db/ORMTable.php

   1 <?php
   2 /**
   3  * Abstract base class for representing a single database table.
   4  * Documentation inline and at https://www.mediawiki.org/wiki/Manual:ORMTable
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  19  * http://www.gnu.org/copyleft/gpl.html
  20  *
  21  * @since 1.20
  22  *
  23  * @file ORMTable.php
  24  * @ingroup ORM
  25  *
  26  * @license GNU GPL v2 or later
  27  * @author Jeroen De Dauw < jeroendedauw@gmail.com >
  28  */
  29
  30 abstract class ORMTable extends DBAccessBase implements IORMTable {
  31
  32         /**
  33          * Gets the db field prefix.
  34          *
  35          * @since 1.20
  36          *
  37          * @return string
  38          */
  39         protected abstract function getFieldPrefix();
  40
  41         /**
  42          * Cache for instances, used by the singleton method.
  43          *
  44          * @since 1.20
  45          * @var array of DBTable
  46          */
  47         protected static $instanceCache = array();
  48
  49         /**
  50          * ID of the database connection to use for read operations.
  51          * Can be changed via @see setReadDb.
  52          *
  53          * @since 1.20
  54          * @var integer DB_ enum
  55          */
  56         protected $readDb = DB_SLAVE;
  57
  58         /**
  59          * Returns a list of default field values.
  60          * field name => field value
  61          *
  62          * @since 1.20
  63          *
  64          * @return array
  65          */
  66         public function getDefaults() {
  67                 return array();
  68         }
  69
  70         /**
  71          * Returns a list of the summary fields.
  72          * These are fields that cache computed values, such as the amount of linked objects of $type.
  73          * This is relevant as one might not want to do actions such as log changes when these get updated.
  74          *
  75          * @since 1.20
  76          *
  77          * @return array
  78          */
  79         public function getSummaryFields() {
  80                 return array();
  81         }
  82
  83         /**
  84          * Selects the the specified fields of the records matching the provided
  85          * conditions and returns them as DBDataObject. Field names get prefixed.
  86          *
  87          * @since 1.20
  88          *
  89          * @param array|string|null $fields
  90          * @param array $conditions
  91          * @param array $options
  92          * @param string|null $functionName
  93          *
  94          * @return ORMResult
  95          */
  96         public function select( $fields = null, array $conditions = array(),
  97                                                         array $options = array(), $functionName  = null ) {
  98                 return new ORMResult( $this, $this->rawSelect( $fields, $conditions, $options, $functionName ) );
  99         }
 100
 101         /**
 102          * Selects the the specified fields of the records matching the provided
 103          * conditions and returns them as DBDataObject. Field names get prefixed.
 104          *
 105          * @since 1.20
 106          *
 107          * @param array|string|null $fields
 108          * @param array $conditions
 109          * @param array $options
 110          * @param string|null $functionName
 111          *
 112          * @return array of self
 113          */
 114         public function selectObjects( $fields = null, array $conditions = array(),
 115                                                                    array $options = array(), $functionName  = null ) {
 116                 $result = $this->selectFields( $fields, $conditions, $options, false, $functionName );
 117
 118                 $objects = array();
 119
 120                 foreach ( $result as $record ) {
 121                         $objects[] = $this->newRow( $record );
 122                 }
 123
 124                 return $objects;
 125         }
 126
 127         /**
 128          * Do the actual select.
 129          *
 130          * @since 1.20
 131          *
 132          * @param null|string|array $fields
 133          * @param array $conditions
 134          * @param array $options
 135          * @param null|string $functionName
 136          *
 137          * @return ResultWrapper
 138          */
 139         public function rawSelect( $fields = null, array $conditions = array(),
 140                                                            array $options = array(), $functionName  = null ) {
 141                 if ( is_null( $fields ) ) {
 142                         $fields = array_keys( $this->getFields() );
 143                 }
 144                 else {
 145                         $fields = (array)$fields;
 146                 }
 147
 148                 $dbr = $this->getReadDbConnection();
 149                 $result = $dbr->select(
 150                         $this->getName(),
 151                         $this->getPrefixedFields( $fields ),
 152                         $this->getPrefixedValues( $conditions ),
 153                         is_null( $functionName ) ? __METHOD__ : $functionName,
 154                         $options
 155                 );
 156
 157                 $this->releaseConnection( $dbr );
 158                 return $result;
 159         }
 160
 161         /**
 162          * Selects the the specified fields of the records matching the provided
 163          * conditions and returns them as associative arrays.
 164          * Provided field names get prefixed.
 165          * Returned field names will not have a prefix.
 166          *
 167          * When $collapse is true:
 168          * If one field is selected, each item in the result array will be this field.
 169          * If two fields are selected, each item in the result array will have as key
 170          * the first field and as value the second field.
 171          * If more then two fields are selected, each item will be an associative array.
 172          *
 173          * @since 1.20
 174          *
 175          * @param array|string|null $fields
 176          * @param array $conditions
 177          * @param array $options
 178          * @param boolean $collapse Set to false to always return each result row as associative array.
 179          * @param string|null $functionName
 180          *
 181          * @return array of array
 182          */
 183         public function selectFields( $fields = null, array $conditions = array(),
 184                                                                   array $options = array(), $collapse = true, $functionName  = null ) {
 185                 $objects = array();
 186
 187                 $result = $this->rawSelect( $fields, $conditions, $options, $functionName );
 188
 189                 foreach ( $result as $record ) {
 190                         $objects[] = $this->getFieldsFromDBResult( $record );
 191                 }
 192
 193                 if ( $collapse ) {
 194                         if ( count( $fields ) === 1 ) {
 195                                 $objects = array_map( 'array_shift', $objects );
 196                         }
 197                         elseif ( count( $fields ) === 2 ) {
 198                                 $o = array();
 199
 200                                 foreach ( $objects as $object ) {
 201                                         $o[array_shift( $object )] = array_shift( $object );
 202                                 }
 203
 204                                 $objects = $o;
 205                         }
 206                 }
 207
 208                 return $objects;
 209         }
 210
 211         /**
 212          * Selects the the specified fields of the first matching record.
 213          * Field names get prefixed.
 214          *
 215          * @since 1.20
 216          *
 217          * @param array|string|null $fields
 218          * @param array $conditions
 219          * @param array $options
 220          * @param string|null $functionName
 221          *
 222          * @return IORMRow|bool False on failure
 223          */
 224         public function selectRow( $fields = null, array $conditions = array(),
 225                                                            array $options = array(), $functionName = null ) {
 226                 $options['LIMIT'] = 1;
 227
 228                 $objects = $this->select( $fields, $conditions, $options, $functionName );
 229
 230                 return $objects->isEmpty() ? false : $objects->current();
 231         }
 232
 233         /**
 234          * Selects the the specified fields of the records matching the provided
 235          * conditions. Field names do NOT get prefixed.
 236          *
 237          * @since 1.20
 238          *
 239          * @param array $fields
 240          * @param array $conditions
 241          * @param array $options
 242          * @param string|null $functionName
 243          *
 244          * @return ResultWrapper
 245          */
 246         public function rawSelectRow( array $fields, array $conditions = array(),
 247                                                                   array $options = array(), $functionName = null ) {
 248                 $dbr = $this->getReadDbConnection();
 249
 250                 $result = $dbr->selectRow(
 251                         $this->getName(),
 252                         $fields,
 253                         $conditions,
 254                         is_null( $functionName ) ? __METHOD__ : $functionName,
 255                         $options
 256                 );
 257
 258                 $this->releaseConnection( $dbr );
 259                 return $result;
 260         }
 261
 262         /**
 263          * Selects the the specified fields of the first record matching the provided
 264          * conditions and returns it as an associative array, or false when nothing matches.
 265          * This method makes use of selectFields and expects the same parameters and
 266          * returns the same results (if there are any, if there are none, this method returns false).
 267          * @see ORMTable::selectFields
 268          *
 269          * @since 1.20
 270          *
 271          * @param array|string|null $fields
 272          * @param array $conditions
 273          * @param array $options
 274          * @param boolean $collapse Set to false to always return each result row as associative array.
 275          * @param string|null $functionName
 276          *
 277          * @return mixed|array|bool False on failure
 278          */
 279         public function selectFieldsRow( $fields = null, array $conditions = array(),
 280                                                                          array $options = array(), $collapse = true, $functionName = null ) {
 281                 $options['LIMIT'] = 1;
 282
 283                 $objects = $this->selectFields( $fields, $conditions, $options, $collapse, $functionName );
 284
 285                 return empty( $objects ) ? false : $objects[0];
 286         }
 287
 288         /**
 289          * Returns if there is at least one record matching the provided conditions.
 290          * Condition field names get prefixed.
 291          *
 292          * @since 1.20
 293          *
 294          * @param array $conditions
 295          *
 296          * @return boolean
 297          */
 298         public function has( array $conditions = array() ) {
 299                 return $this->selectRow( array( 'id' ), $conditions ) !== false;
 300         }
 301
 302         /**
 303          * Checks if the table exists
 304          *
 305          * @since 1.21
 306          *
 307          * @return boolean
 308          */
 309         public function exists() {
 310                 $dbr = $this->getReadDbConnection();
 311                 $exists = $dbr->tableExists( $this->getName() );
 312                 $this->releaseConnection( $dbr );
 313
 314                 return $exists;
 315         }
 316
 317         /**
 318          * Returns the amount of matching records.
 319          * Condition field names get prefixed.
 320          *
 321          * Note that this can be expensive on large tables.
 322          * In such cases you might want to use DatabaseBase::estimateRowCount instead.
 323          *
 324          * @since 1.20
 325          *
 326          * @param array $conditions
 327          * @param array $options
 328          *
 329          * @return integer
 330          */
 331         public function count( array $conditions = array(), array $options = array() ) {
 332                 $res = $this->rawSelectRow(
 333                         array( 'rowcount' => 'COUNT(*)' ),
 334                         $this->getPrefixedValues( $conditions ),
 335                         $options
 336                 );
 337
 338                 return $res->rowcount;
 339         }
 340
 341         /**
 342          * Removes the object from the database.
 343          *
 344          * @since 1.20
 345          *
 346          * @param array $conditions
 347          * @param string|null $functionName
 348          *
 349          * @return boolean Success indicator
 350          */
 351         public function delete( array $conditions, $functionName = null ) {
 352                 $dbw = $this->getWriteDbConnection();
 353
 354                 $result = $dbw->delete(
 355                         $this->getName(),
 356                         $conditions === array() ? '*' : $this->getPrefixedValues( $conditions ),
 357                         $functionName
 358                 ) !== false; // DatabaseBase::delete does not always return true for success as documented...
 359
 360                 $this->releaseConnection( $dbw );
 361                 return $result;
 362         }
 363
 364         /**
 365          * Get API parameters for the fields supported by this object.
 366          *
 367          * @since 1.20
 368          *
 369          * @param boolean $requireParams
 370          * @param boolean $setDefaults
 371          *
 372          * @return array
 373          */
 374         public function getAPIParams( $requireParams = false, $setDefaults = false ) {
 375                 $typeMap = array(
 376                         'id' => 'integer',
 377                         'int' => 'integer',
 378                         'float' => 'NULL',
 379                         'str' => 'string',
 380                         'bool' => 'integer',
 381                         'array' => 'string',
 382                         'blob' => 'string',
 383                 );
 384
 385                 $params = array();
 386                 $defaults = $this->getDefaults();
 387
 388                 foreach ( $this->getFields() as $field => $type ) {
 389                         if ( $field == 'id' ) {
 390                                 continue;
 391                         }
 392
 393                         $hasDefault = array_key_exists( $field, $defaults );
 394
 395                         $params[$field] = array(
 396                                 ApiBase::PARAM_TYPE => $typeMap[$type],
 397                                 ApiBase::PARAM_REQUIRED => $requireParams && !$hasDefault
 398                         );
 399
 400                         if ( $type == 'array' ) {
 401                                 $params[$field][ApiBase::PARAM_ISMULTI] = true;
 402                         }
 403
 404                         if ( $setDefaults && $hasDefault ) {
 405                                 $default = is_array( $defaults[$field] ) ? implode( '|', $defaults[$field] ) : $defaults[$field];
 406                                 $params[$field][ApiBase::PARAM_DFLT] = $default;
 407                         }
 408                 }
 409
 410                 return $params;
 411         }
 412
 413         /**
 414          * Returns an array with the fields and their descriptions.
 415          *
 416          * field name => field description
 417          *
 418          * @since 1.20
 419          *
 420          * @return array
 421          */
 422         public function getFieldDescriptions() {
 423                 return array();
 424         }
 425
 426         /**
 427          * Get the database ID used for read operations.
 428          *
 429          * @since 1.20
 430          *
 431          * @return integer DB_ enum
 432          */
 433         public function getReadDb() {
 434                 return $this->readDb;
 435         }
 436
 437         /**
 438          * Set the database ID to use for read operations, use DB_XXX constants or an index to the load balancer setup.
 439          *
 440          * @param integer $db
 441          *
 442          * @since 1.20
 443          */
 444         public function setReadDb( $db ) {
 445                 $this->readDb = $db;
 446         }
 447
 448         /**
 449          * Get the ID of the any foreign wiki to use as a target for database operations
 450          *
 451          * @since 1.20
 452          *
 453          * @return String|bool The target wiki, in a form that  LBFactory understands (or false if the local wiki is used)
 454          */
 455         public function getTargetWiki() {
 456                 return $this->wiki;
 457         }
 458
 459         /**
 460          * Set the ID of the any foreign wiki to use as a target for database operations
 461          *
 462          * @param String|bool $wiki The target wiki, in a form that  LBFactory understands (or false if the local wiki shall be used)
 463          *
 464          * @since 1.20
 465          */
 466         public function setTargetWiki( $wiki ) {
 467                 $this->wiki = $wiki;
 468         }
 469
 470         /**
 471          * Get the database type used for read operations.
 472          * This is to be used instead of wfGetDB.
 473          *
 474          * @see LoadBalancer::getConnection
 475          *
 476          * @since 1.20
 477          *
 478          * @return DatabaseBase The database object
 479          */
 480         public function getReadDbConnection() {
 481                 return $this->getConnection( $this->getReadDb(), array() );
 482         }
 483
 484         /**
 485          * Get the database type used for read operations.
 486          * This is to be used instead of wfGetDB.
 487          *
 488          * @see LoadBalancer::getConnection
 489          *
 490          * @since 1.20
 491          *
 492          * @return DatabaseBase The database object
 493          */
 494         public function getWriteDbConnection() {
 495                 return $this->getConnection( DB_MASTER, array() );
 496         }
 497
 498         /**
 499          * Releases the lease on the given database connection. This is useful mainly
 500          * for connections to a foreign wiki. It does nothing for connections to the local wiki.
 501          *
 502          * @see LoadBalancer::reuseConnection
 503          *
 504          * @param DatabaseBase $db the database
 505          *
 506          * @since 1.20
 507          */
 508         public function releaseConnection( DatabaseBase $db ) {
 509                 parent::releaseConnection( $db ); // just make it public
 510         }
 511
 512         /**
 513          * Update the records matching the provided conditions by
 514          * setting the fields that are keys in the $values param to
 515          * their corresponding values.
 516          *
 517          * @since 1.20
 518          *
 519          * @param array $values
 520          * @param array $conditions
 521          *
 522          * @return boolean Success indicator
 523          */
 524         public function update( array $values, array $conditions = array() ) {
 525                 $dbw = $this->getWriteDbConnection();
 526
 527                 $result = $dbw->update(
 528                         $this->getName(),
 529                         $this->getPrefixedValues( $values ),
 530                         $this->getPrefixedValues( $conditions ),
 531                         __METHOD__
 532                 ) !== false; // DatabaseBase::update does not always return true for success as documented...
 533
 534                 $this->releaseConnection( $dbw );
 535                 return $result;
 536         }
 537
 538         /**
 539          * Computes the values of the summary fields of the objects matching the provided conditions.
 540          *
 541          * @since 1.20
 542          *
 543          * @param array|string|null $summaryFields
 544          * @param array $conditions
 545          */
 546         public function updateSummaryFields( $summaryFields = null, array $conditions = array() ) {
 547                 $slave = $this->getReadDb();
 548                 $this->setReadDb( DB_MASTER );
 549
 550                 /**
 551                  * @var IORMRow $item
 552                  */
 553                 foreach ( $this->select( null, $conditions ) as $item ) {
 554                         $item->loadSummaryFields( $summaryFields );
 555                         $item->setSummaryMode( true );
 556                         $item->save();
 557                 }
 558
 559                 $this->setReadDb( $slave );
 560         }
 561
 562         /**
 563          * Takes in an associative array with field names as keys and
 564          * their values as value. The field names are prefixed with the
 565          * db field prefix.
 566          *
 567          * @since 1.20
 568          *
 569          * @param array $values
 570          *
 571          * @return array
 572          */
 573         public function getPrefixedValues( array $values ) {
 574                 $prefixedValues = array();
 575
 576                 foreach ( $values as $field => $value ) {
 577                         if ( is_integer( $field ) ) {
 578                                 if ( is_array( $value ) ) {
 579                                         $field = $value[0];
 580                                         $value = $value[1];
 581                                 }
 582                                 else {
 583                                         $value = explode( ' ', $value, 2 );
 584                                         $value[0] = $this->getPrefixedField( $value[0] );
 585                                         $prefixedValues[] = implode( ' ', $value );
 586                                         continue;
 587                                 }
 588                         }
 589
 590                         $prefixedValues[$this->getPrefixedField( $field )] = $value;
 591                 }
 592
 593                 return $prefixedValues;
 594         }
 595
 596         /**
 597          * Takes in a field or array of fields and returns an
 598          * array with their prefixed versions, ready for db usage.
 599          *
 600          * @since 1.20
 601          *
 602          * @param array|string $fields
 603          *
 604          * @return array
 605          */
 606         public function getPrefixedFields( array $fields ) {
 607                 foreach ( $fields as &$field ) {
 608                         $field = $this->getPrefixedField( $field );
 609                 }
 610
 611                 return $fields;
 612         }
 613
 614         /**
 615          * Takes in a field and returns an it's prefixed version, ready for db usage.
 616          *
 617          * @since 1.20
 618          *
 619          * @param string|array $field
 620          *
 621          * @return string
 622          */
 623         public function getPrefixedField( $field ) {
 624                 return $this->getFieldPrefix() . $field;
 625         }
 626
 627         /**
 628          * Takes an array of field names with prefix and returns the unprefixed equivalent.
 629          *
 630          * @since 1.20
 631          *
 632          * @param array $fieldNames
 633          *
 634          * @return array
 635          */
 636         public function unprefixFieldNames( array $fieldNames ) {
 637                 return array_map( array( $this, 'unprefixFieldName' ), $fieldNames );
 638         }
 639
 640         /**
 641          * Takes a field name with prefix and returns the unprefixed equivalent.
 642          *
 643          * @since 1.20
 644          *
 645          * @param string $fieldName
 646          *
 647          * @return string
 648          */
 649         public function unprefixFieldName( $fieldName ) {
 650                 return substr( $fieldName, strlen( $this->getFieldPrefix() ) );
 651         }
 652
 653         /**
 654          * Get an instance of this class.
 655          *
 656          * @since 1.20
 657          *
 658          * @return IORMTable
 659          */
 660         public static function singleton() {
 661                 $class = get_called_class();
 662
 663                 if ( !array_key_exists( $class, self::$instanceCache ) ) {
 664                         self::$instanceCache[$class] = new $class;
 665                 }
 666
 667                 return self::$instanceCache[$class];
 668         }
 669
 670         /**
 671          * Get an array with fields from a database result,
 672          * that can be fed directly to the constructor or
 673          * to setFields.
 674          *
 675          * @since 1.20
 676          *
 677          * @param stdClass $result
 678          *
 679          * @return array
 680          */
 681         public function getFieldsFromDBResult( stdClass $result ) {
 682                 $result = (array)$result;
 683                 return array_combine(
 684                         $this->unprefixFieldNames( array_keys( $result ) ),
 685                         array_values( $result )
 686                 );
 687         }
 688
 689         /**
 690          * @see ORMTable::newRowFromFromDBResult
 691          *
 692          * @deprecated use newRowFromDBResult instead
 693          * @since 1.20
 694          *
 695          * @param stdClass $result
 696          *
 697          * @return IORMRow
 698          */
 699         public function newFromDBResult( stdClass $result ) {
 700                 return self::newRowFromDBResult( $result );
 701         }
 702
 703         /**
 704          * Get a new instance of the class from a database result.
 705          *
 706          * @since 1.20
 707          *
 708          * @param stdClass $result
 709          *
 710          * @return IORMRow
 711          */
 712         public function newRowFromDBResult( stdClass $result ) {
 713                 return $this->newRow( $this->getFieldsFromDBResult( $result ) );
 714         }
 715
 716         /**
 717          * @see ORMTable::newRow
 718          *
 719          * @deprecated use newRow instead
 720          * @since 1.20
 721          *
 722          * @param array $data
 723          * @param boolean $loadDefaults
 724          *
 725          * @return IORMRow
 726          */
 727         public function newFromArray( array $data, $loadDefaults = false ) {
 728                 return static::newRow( $data, $loadDefaults );
 729         }
 730
 731         /**
 732          * Get a new instance of the class from an array.
 733          *
 734          * @since 1.20
 735          *
 736          * @param array $data
 737          * @param boolean $loadDefaults
 738          *
 739          * @return IORMRow
 740          */
 741         public function newRow( array $data, $loadDefaults = false ) {
 742                 $class = $this->getRowClass();
 743                 return new $class( $this, $data, $loadDefaults );
 744         }
 745
 746         /**
 747          * Return the names of the fields.
 748          *
 749          * @since 1.20
 750          *
 751          * @return array
 752          */
 753         public function getFieldNames() {
 754                 return array_keys( $this->getFields() );
 755         }
 756
 757         /**
 758          * Gets if the object can take a certain field.
 759          *
 760          * @since 1.20
 761          *
 762          * @param string $name
 763          *
 764          * @return boolean
 765          */
 766         public function canHaveField( $name ) {
 767                 return array_key_exists( $name, $this->getFields() );
 768         }
 769
 770 }