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         public function setArray( $array ) {
  64                 $this->data = $array;
  65         }
  66
  67         /**
  68          * Returns true if no pages have been added, false otherwise.
  69          */
  70         public function isEmpty() {
  71                 return ($this->getSize() == 0);
  72         }
  73
  74         /**
  75          * Returns the size of the batch.
  76          */
  77         public function getSize() {
  78                 return count( $this->data );
  79         }
  80
  81         /**
  82          * Do the query and add the results to the LinkCache object
  83          * Return an array mapping PDBK to ID
  84          */
  85          public function execute() {
  86                 $linkCache = LinkCache::singleton();
  87                 return $this->executeInto( $linkCache );
  88          }
  89
  90         /**
  91          * Do the query and add the results to a given LinkCache object
  92          * Return an array mapping PDBK to ID
  93          */
  94         protected function executeInto( &$cache ) {
  95                 wfProfileIn( __METHOD__ );
  96                 $res = $this->doQuery();
  97                 $ids = $this->addResultToCache( $cache, $res );
  98                 $this->doGenderQuery();
  99                 wfProfileOut( __METHOD__ );
 100                 return $ids;
 101         }
 102
 103         /**
 104          * Add a ResultWrapper containing IDs and titles to a LinkCache object.
 105          * As normal, titles will go into the static Title cache field.
 106          * This function *also* stores extra fields of the title used for link
 107          * parsing to avoid extra DB queries.
 108          */
 109         public function addResultToCache( $cache, $res ) {
 110                 if ( !$res ) {
 111                         return array();
 112                 }
 113
 114                 // For each returned entry, add it to the list of good links, and remove it from $remaining
 115
 116                 $ids = array();
 117                 $remaining = $this->data;
 118                 foreach ( $res as $row ) {
 119                         $title = Title::makeTitle( $row->page_namespace, $row->page_title );
 120                         $cache->addGoodLinkObj( $row->page_id, $title, $row->page_len, $row->page_is_redirect, $row->page_latest );
 121                         $ids[$title->getPrefixedDBkey()] = $row->page_id;
 122                         unset( $remaining[$row->page_namespace][$row->page_title] );
 123                 }
 124
 125                 // The remaining links in $data are bad links, register them as such
 126                 foreach ( $remaining as $ns => $dbkeys ) {
 127                         foreach ( $dbkeys as $dbkey => $unused ) {
 128                                 $title = Title::makeTitle( $ns, $dbkey );
 129                                 $cache->addBadLinkObj( $title );
 130                                 $ids[$title->getPrefixedDBkey()] = 0;
 131                         }
 132                 }
 133                 return $ids;
 134         }
 135
 136         /**
 137          * Perform the existence test query, return a ResultWrapper with page_id fields
 138          */
 139         public function doQuery() {
 140                 if ( $this->isEmpty() ) {
 141                         return false;
 142                 }
 143                 wfProfileIn( __METHOD__ );
 144
 145                 // This is similar to LinkHolderArray::replaceInternal
 146                 $dbr = wfGetDB( DB_SLAVE );
 147                 $table = 'page';
 148                 $fields = array( 'page_id', 'page_namespace', 'page_title', 'page_len',
 149                         'page_is_redirect', 'page_latest' );
 150                 $conds = $this->constructSet( 'page', $dbr );
 151
 152                 // Do query
 153                 $caller = __METHOD__;
 154                 if ( strval( $this->caller ) !== '' ) {
 155                         $caller .= " (for {$this->caller})";
 156                 }
 157                 $res = $dbr->select( $table, $fields, $conds, $caller );
 158                 wfProfileOut( __METHOD__ );
 159                 return $res;
 160         }
 161
 162         public function doGenderQuery() {
 163                 if ( $this->isEmpty() ) {
 164                         return false;
 165                 }
 166
 167                 global $wgContLang;
 168                 if ( !$wgContLang->needsGenderDistinction() ) {
 169                         return false;
 170                 }
 171
 172                 $genderCache = GenderCache::singleton();
 173                 $genderCache->dolinkBatch( $this->data, $this->caller );
 174         }
 175
 176         /**
 177          * Construct a WHERE clause which will match all the given titles.
 178          *
 179          * @param $prefix String: the appropriate table's field name prefix ('page', 'pl', etc)
 180          * @param $db DatabaseBase object to use
 181          * @return mixed string with SQL where clause fragment, or false if no items.
 182          */
 183         public function constructSet( $prefix, $db ) {
 184                 return $db->makeWhereFrom2d( $this->data, "{$prefix}_namespace", "{$prefix}_title" );
 185         }
 186 }