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          *
  90          * @return Array mapping PDBK to ID
  91          */
  92         public function execute() {
  93                 $linkCache = LinkCache::singleton();
  94                 return $this->executeInto( $linkCache );
  95         }
  96
  97         /**
  98          * Do the query and add the results to a given LinkCache object
  99          * Return an array mapping PDBK to ID
 100          *
 101          * @param $cache LinkCache
 102          * @return Array remaining IDs
 103          */
 104         protected function executeInto( &$cache ) {
 105                 wfProfileIn( __METHOD__ );
 106                 $res = $this->doQuery();
 107                 $ids = $this->addResultToCache( $cache, $res );
 108                 $this->doGenderQuery();
 109                 wfProfileOut( __METHOD__ );
 110                 return $ids;
 111         }
 112
 113         /**
 114          * Add a ResultWrapper containing IDs and titles to a LinkCache object.
 115          * As normal, titles will go into the static Title cache field.
 116          * This function *also* stores extra fields of the title used for link
 117          * parsing to avoid extra DB queries.
 118          *
 119          * @param $cache LinkCache
 120          * @param $res
 121          * @return Array of remaining titles
 122          */
 123         public function addResultToCache( $cache, $res ) {
 124                 if ( !$res ) {
 125                         return array();
 126                 }
 127
 128                 // For each returned entry, add it to the list of good links, and remove it from $remaining
 129
 130                 $ids = array();
 131                 $remaining = $this->data;
 132                 foreach ( $res as $row ) {
 133                         $title = Title::makeTitle( $row->page_namespace, $row->page_title );
 134                         $cache->addGoodLinkObjFromRow( $title, $row );
 135                         $ids[$title->getPrefixedDBkey()] = $row->page_id;
 136                         unset( $remaining[$row->page_namespace][$row->page_title] );
 137                 }
 138
 139                 // The remaining links in $data are bad links, register them as such
 140                 foreach ( $remaining as $ns => $dbkeys ) {
 141                         foreach ( $dbkeys as $dbkey => $unused ) {
 142                                 $title = Title::makeTitle( $ns, $dbkey );
 143                                 $cache->addBadLinkObj( $title );
 144                                 $ids[$title->getPrefixedDBkey()] = 0;
 145                         }
 146                 }
 147                 return $ids;
 148         }
 149
 150         /**
 151          * Perform the existence test query, return a ResultWrapper with page_id fields
 152          * @return Bool|ResultWrapper
 153          */
 154         public function doQuery() {
 155                 if ( $this->isEmpty() ) {
 156                         return false;
 157                 }
 158                 wfProfileIn( __METHOD__ );
 159
 160                 // This is similar to LinkHolderArray::replaceInternal
 161                 $dbr = wfGetDB( DB_SLAVE );
 162                 $table = 'page';
 163                 $fields = array( 'page_id', 'page_namespace', 'page_title', 'page_len',
 164                         'page_is_redirect', 'page_latest' );
 165                 $conds = $this->constructSet( 'page', $dbr );
 166
 167                 // Do query
 168                 $caller = __METHOD__;
 169                 if ( strval( $this->caller ) !== '' ) {
 170                         $caller .= " (for {$this->caller})";
 171                 }
 172                 $res = $dbr->select( $table, $fields, $conds, $caller );
 173                 wfProfileOut( __METHOD__ );
 174                 return $res;
 175         }
 176
 177         /**
 178          * Do (and cache) {{GENDER:...}} information for userpages in this LinkBatch
 179          *
 180          * @return bool whether the query was successful
 181          */
 182         public function doGenderQuery() {
 183                 if ( $this->isEmpty() ) {
 184                         return false;
 185                 }
 186
 187                 global $wgContLang;
 188                 if ( !$wgContLang->needsGenderDistinction() ) {
 189                         return false;
 190                 }
 191
 192                 $genderCache = GenderCache::singleton();
 193                 $genderCache->dolinkBatch( $this->data, $this->caller );
 194                 return true;
 195         }
 196
 197         /**
 198          * Construct a WHERE clause which will match all the given titles.
 199          *
 200          * @param $prefix String: the appropriate table's field name prefix ('page', 'pl', etc)
 201          * @param $db DatabaseBase object to use
 202          * @return mixed string with SQL where clause fragment, or false if no items.
 203          */
 204         public function constructSet( $prefix, $db ) {
 205                 return $db->makeWhereFrom2d( $this->data, "{$prefix}_namespace", "{$prefix}_title" );
 206         }
 207 }