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         /**
  49          * @param $ns int
  50          * @param $dbkey string
  51          * @return mixed
  52          */
  53         public function add( $ns, $dbkey ) {
  54                 if ( $ns < 0 ) {
  55                         return;
  56                 }
  57                 if ( !array_key_exists( $ns, $this->data ) ) {
  58                         $this->data[$ns] = array();
  59                 }
  60
  61                 $this->data[$ns][str_replace( ' ', '_', $dbkey )] = 1;
  62         }
  63
  64         /**
  65          * Set the link list to a given 2-d array
  66          * First key is the namespace, second is the DB key, value arbitrary
  67          *
  68          * @param $array array
  69          */
  70         public function setArray( $array ) {
  71                 $this->data = $array;
  72         }
  73
  74         /**
  75          * Returns true if no pages have been added, false otherwise.
  76          *
  77          * @return bool
  78          */
  79         public function isEmpty() {
  80                 return ($this->getSize() == 0);
  81         }
  82
  83         /**
  84          * Returns the size of the batch.
  85          *
  86          * @return int
  87          */
  88         public function getSize() {
  89                 return count( $this->data );
  90         }
  91
  92         /**
  93          * Do the query and add the results to the LinkCache object
  94          *
  95          * @return Array mapping PDBK to ID
  96          */
  97         public function execute() {
  98                 $linkCache = LinkCache::singleton();
  99                 return $this->executeInto( $linkCache );
 100         }
 101
 102         /**
 103          * Do the query and add the results to a given LinkCache object
 104          * Return an array mapping PDBK to ID
 105          *
 106          * @param $cache LinkCache
 107          * @return Array remaining IDs
 108          */
 109         protected function executeInto( &$cache ) {
 110                 wfProfileIn( __METHOD__ );
 111                 $res = $this->doQuery();
 112                 $this->doGenderQuery();
 113                 $ids = $this->addResultToCache( $cache, $res );
 114                 wfProfileOut( __METHOD__ );
 115                 return $ids;
 116         }
 117
 118         /**
 119          * Add a ResultWrapper containing IDs and titles to a LinkCache object.
 120          * As normal, titles will go into the static Title cache field.
 121          * This function *also* stores extra fields of the title used for link
 122          * parsing to avoid extra DB queries.
 123          *
 124          * @param $cache LinkCache
 125          * @param $res
 126          * @return Array of remaining titles
 127          */
 128         public function addResultToCache( $cache, $res ) {
 129                 if ( !$res ) {
 130                         return array();
 131                 }
 132
 133                 // For each returned entry, add it to the list of good links, and remove it from $remaining
 134
 135                 $ids = array();
 136                 $remaining = $this->data;
 137                 foreach ( $res as $row ) {
 138                         $title = Title::makeTitle( $row->page_namespace, $row->page_title );
 139                         $cache->addGoodLinkObjFromRow( $title, $row );
 140                         $ids[$title->getPrefixedDBkey()] = $row->page_id;
 141                         unset( $remaining[$row->page_namespace][$row->page_title] );
 142                 }
 143
 144                 // The remaining links in $data are bad links, register them as such
 145                 foreach ( $remaining as $ns => $dbkeys ) {
 146                         foreach ( $dbkeys as $dbkey => $unused ) {
 147                                 $title = Title::makeTitle( $ns, $dbkey );
 148                                 $cache->addBadLinkObj( $title );
 149                                 $ids[$title->getPrefixedDBkey()] = 0;
 150                         }
 151                 }
 152                 return $ids;
 153         }
 154
 155         /**
 156          * Perform the existence test query, return a ResultWrapper with page_id fields
 157          * @return Bool|ResultWrapper
 158          */
 159         public function doQuery() {
 160                 if ( $this->isEmpty() ) {
 161                         return false;
 162                 }
 163                 wfProfileIn( __METHOD__ );
 164
 165                 // This is similar to LinkHolderArray::replaceInternal
 166                 $dbr = wfGetDB( DB_SLAVE );
 167                 $table = 'page';
 168                 $fields = array( 'page_id', 'page_namespace', 'page_title', 'page_len',
 169                         'page_is_redirect', 'page_latest' );
 170                 $conds = $this->constructSet( 'page', $dbr );
 171
 172                 // Do query
 173                 $caller = __METHOD__;
 174                 if ( strval( $this->caller ) !== '' ) {
 175                         $caller .= " (for {$this->caller})";
 176                 }
 177                 $res = $dbr->select( $table, $fields, $conds, $caller );
 178                 wfProfileOut( __METHOD__ );
 179                 return $res;
 180         }
 181
 182         /**
 183          * Do (and cache) {{GENDER:...}} information for userpages in this LinkBatch
 184          *
 185          * @return bool whether the query was successful
 186          */
 187         public function doGenderQuery() {
 188                 if ( $this->isEmpty() ) {
 189                         return false;
 190                 }
 191
 192                 global $wgContLang;
 193                 if ( !$wgContLang->needsGenderDistinction() ) {
 194                         return false;
 195                 }
 196
 197                 $genderCache = GenderCache::singleton();
 198                 $genderCache->doLinkBatch( $this->data, $this->caller );
 199                 return true;
 200         }
 201
 202         /**
 203          * Construct a WHERE clause which will match all the given titles.
 204          *
 205          * @param $prefix String: the appropriate table's field name prefix ('page', 'pl', etc)
 206          * @param $db DatabaseBase object to use
 207          * @return mixed string with SQL where clause fragment, or false if no items.
 208          */
 209         public function constructSet( $prefix, $db ) {
 210                 return $db->makeWhereFrom2d( $this->data, "{$prefix}_namespace", "{$prefix}_title" );
 211         }
 212 }