includes/cache/LinkBatch.php

   1 <?php
   2
   3 /**
   4  * Class representing a list of titles
   5  * The execute() method checks them all for existence and adds them to a LinkCache object
   6  *
   7  * @ingroup Cache
   8  */
   9 class LinkBatch {
  10         /**
  11          * 2-d array, first index namespace, second index dbkey, value arbitrary
  12          */
  13         var $data = array();
  14
  15         /**
  16          * For debugging which method is using this class.
  17          */
  18         protected $caller;
  19
  20         function __construct( $arr = array() ) {
  21                 foreach( $arr as $item ) {
  22                         $this->addObj( $item );
  23                 }
  24         }
  25
  26         /**
  27          * Use ->setCaller( __METHOD__ ) to indicate which code is using this
  28          * class. Only used in debugging output.
  29          * @since 1.17
  30          *
  31          * @param $caller
  32          */
  33         public function setCaller( $caller ) {
  34                 $this->caller = $caller;
  35         }
  36
  37         /**
  38          * @param $title Title
  39          */
  40         public function addObj( $title ) {
  41                 if ( is_object( $title ) ) {
  42                         $this->add( $title->getNamespace(), $title->getDBkey() );
  43                 } else {
  44                         wfDebug( "Warning: LinkBatch::addObj got invalid title object\n" );
  45                 }
  46         }
  47
  48         public function add( $ns, $dbkey ) {
  49                 if ( $ns < 0 ) {
  50                         return;
  51                 }
  52                 if ( !array_key_exists( $ns, $this->data ) ) {
  53                         $this->data[$ns] = array();
  54                 }
  55
  56                 $this->data[$ns][str_replace( ' ', '_', $dbkey )] = 1;
  57         }
  58
  59         /**
  60          * Set the link list to a given 2-d array
  61          * First key is the namespace, second is the DB key, value arbitrary
  62          *
  63          * @param $array array
  64          */
  65         public function setArray( $array ) {
  66                 $this->data = $array;
  67         }
  68
  69         /**
  70          * Returns true if no pages have been added, false otherwise.
  71          *
  72          * @return bool
  73          */
  74         public function isEmpty() {
  75                 return ($this->getSize() == 0);
  76         }
  77
  78         /**
  79          * Returns the size of the batch.
  80          *
  81          * @return int
  82          */
  83         public function getSize() {
  84                 return count( $this->data );
  85         }
  86
  87         /**
  88          * Do the query and add the results to the LinkCache object
  89          * Return an array mapping PDBK to ID
  90          */
  91         public function execute() {
  92                 $linkCache = LinkCache::singleton();
  93                 return $this->executeInto( $linkCache );
  94         }
  95
  96         /**
  97          * Do the query and add the results to a given LinkCache object
  98          * Return an array mapping PDBK to ID
  99          */
 100         protected function executeInto( &$cache ) {
 101                 wfProfileIn( __METHOD__ );
 102                 $res = $this->doQuery();
 103                 $ids = $this->addResultToCache( $cache, $res );
 104                 $this->doGenderQuery();
 105                 wfProfileOut( __METHOD__ );
 106                 return $ids;
 107         }
 108
 109         /**
 110          * Add a ResultWrapper containing IDs and titles to a LinkCache object.
 111          * As normal, titles will go into the static Title cache field.
 112          * This function *also* stores extra fields of the title used for link
 113          * parsing to avoid extra DB queries.
 114          *
 115          * @param $cache
 116          * @param $res
 117          */
 118         public function addResultToCache( $cache, $res ) {
 119                 if ( !$res ) {
 120                         return array();
 121                 }
 122
 123                 // For each returned entry, add it to the list of good links, and remove it from $remaining
 124
 125                 $ids = array();
 126                 $remaining = $this->data;
 127                 foreach ( $res as $row ) {
 128                         $title = Title::makeTitle( $row->page_namespace, $row->page_title );
 129                         $cache->addGoodLinkObjFromRow( $title, $row );
 130                         $ids[$title->getPrefixedDBkey()] = $row->page_id;
 131                         unset( $remaining[$row->page_namespace][$row->page_title] );
 132                 }
 133
 134                 // The remaining links in $data are bad links, register them as such
 135                 foreach ( $remaining as $ns => $dbkeys ) {
 136                         foreach ( $dbkeys as $dbkey => $unused ) {
 137                                 $title = Title::makeTitle( $ns, $dbkey );
 138                                 $cache->addBadLinkObj( $title );
 139                                 $ids[$title->getPrefixedDBkey()] = 0;
 140                         }
 141                 }
 142                 return $ids;
 143         }
 144
 145         /**
 146          * Perform the existence test query, return a ResultWrapper with page_id fields
 147          */
 148         public function doQuery() {
 149                 if ( $this->isEmpty() ) {
 150                         return false;
 151                 }
 152                 wfProfileIn( __METHOD__ );
 153
 154                 // This is similar to LinkHolderArray::replaceInternal
 155                 $dbr = wfGetDB( DB_SLAVE );
 156                 $table = 'page';
 157                 $fields = array( 'page_id', 'page_namespace', 'page_title', 'page_len',
 158                         'page_is_redirect', 'page_latest' );
 159                 $conds = $this->constructSet( 'page', $dbr );
 160
 161                 // Do query
 162                 $caller = __METHOD__;
 163                 if ( strval( $this->caller ) !== '' ) {
 164                         $caller .= " (for {$this->caller})";
 165                 }
 166                 $res = $dbr->select( $table, $fields, $conds, $caller );
 167                 wfProfileOut( __METHOD__ );
 168                 return $res;
 169         }
 170
 171         public function doGenderQuery() {
 172                 if ( $this->isEmpty() ) {
 173                         return false;
 174                 }
 175
 176                 global $wgContLang;
 177                 if ( !$wgContLang->needsGenderDistinction() ) {
 178                         return false;
 179                 }
 180
 181                 $genderCache = GenderCache::singleton();
 182                 $genderCache->dolinkBatch( $this->data, $this->caller );
 183         }
 184
 185         /**
 186          * Construct a WHERE clause which will match all the given titles.
 187          *
 188          * @param $prefix String: the appropriate table's field name prefix ('page', 'pl', etc)
 189          * @param $db DatabaseBase object to use
 190          * @return mixed string with SQL where clause fragment, or false if no items.
 191          */
 192         public function constructSet( $prefix, $db ) {
 193                 return $db->makeWhereFrom2d( $this->data, "{$prefix}_namespace", "{$prefix}_title" );
 194         }
 195 }