includes/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  * @package MediaWiki
   8  * @subpackage Cache
   9  */
  10 class LinkBatch {
  11         /**
  12          * 2-d array, first index namespace, second index dbkey, value arbitrary
  13          */
  14         var $data = array();
  15
  16         function LinkBatch( $arr = array() ) {
  17                 foreach( $arr as $item ) {
  18                         $this->addObj( $item );
  19                 }
  20         }
  21
  22         function addObj( $title ) {
  23                 if ( is_object( $title ) ) {
  24                         $this->add( $title->getNamespace(), $title->getDBkey() );
  25                 } else {
  26                         wfDebug( "Warning: LinkBatch::addObj got invalid title object\n" );
  27                 }
  28         }
  29
  30         function add( $ns, $dbkey ) {
  31                 if ( $ns < 0 ) {
  32                         return;
  33                 }
  34                 if ( !array_key_exists( $ns, $this->data ) ) {
  35                         $this->data[$ns] = array();
  36                 }
  37
  38                 $this->data[$ns][$dbkey] = 1;
  39         }
  40
  41         /**
  42          * Set the link list to a given 2-d array
  43          * First key is the namespace, second is the DB key, value arbitrary
  44          */
  45         function setArray( $array ) {
  46                 $this->data = $array;
  47         }
  48
  49         /**
  50          * Do the query and add the results to the LinkCache object
  51          * Return an array mapping PDBK to ID
  52          */
  53          function execute() {
  54                 $linkCache =& LinkCache::singleton();
  55                 $this->executeInto( $linkCache );
  56          }
  57
  58         /**
  59          * Do the query and add the results to a given LinkCache object
  60          * Return an array mapping PDBK to ID
  61          */
  62         function executeInto( &$cache ) {
  63                 $fname = 'LinkBatch::executeInto';
  64                 wfProfileIn( $fname );
  65                 // Do query
  66                 $res = $this->doQuery();
  67                 if ( !$res ) {
  68                         wfProfileOut( $fname );
  69                         return array();
  70                 }
  71
  72                 // For each returned entry, add it to the list of good links, and remove it from $remaining
  73
  74                 $ids = array();
  75                 $remaining = $this->data;
  76                 while ( $row = $res->fetchObject() ) {
  77                         $title = Title::makeTitle( $row->page_namespace, $row->page_title );
  78                         $cache->addGoodLinkObj( $row->page_id, $title );
  79                         $ids[$title->getPrefixedDBkey()] = $row->page_id;
  80                         unset( $remaining[$row->page_namespace][$row->page_title] );
  81                 }
  82                 $res->free();
  83
  84                 // The remaining links in $data are bad links, register them as such
  85                 foreach ( $remaining as $ns => $dbkeys ) {
  86                         foreach ( $dbkeys as $dbkey => $nothing ) {
  87                                 $title = Title::makeTitle( $ns, $dbkey );
  88                                 $cache->addBadLinkObj( $title );
  89                                 $ids[$title->getPrefixedDBkey()] = 0;
  90                         }
  91                 }
  92                 wfProfileOut( $fname );
  93                 return $ids;
  94         }
  95
  96         /**
  97          * Perform the existence test query, return a ResultWrapper with page_id fields
  98          */
  99         function doQuery() {
 100                 $fname = 'LinkBatch::doQuery';
 101                 $namespaces = array();
 102
 103                 if ( !count( $this->data ) ) {
 104                         return false;
 105                 }
 106                 wfProfileIn( $fname );
 107
 108                 // Construct query
 109                 // This is very similar to Parser::replaceLinkHolders
 110                 $dbr =& wfGetDB( DB_SLAVE );
 111                 $page = $dbr->tableName( 'page' );
 112                 $set = $this->constructSet( 'page', $dbr );
 113                 if ( $set === false ) {
 114                         wfProfileOut( $fname );
 115                         return false;
 116                 }
 117                 $sql = "SELECT page_id, page_namespace, page_title FROM $page WHERE $set";
 118
 119                 // Do query
 120                 $res = new ResultWrapper( $dbr,  $dbr->query( $sql, $fname ) );
 121                 wfProfileOut( $fname );
 122                 return $res;
 123         }
 124
 125         /**
 126          * Construct a WHERE clause which will match all the given titles.
 127          * Give the appropriate table's field name prefix ('page', 'pl', etc).
 128          *
 129          * @param $prefix String: ??
 130          * @return string
 131          * @public
 132          */
 133         function constructSet( $prefix, &$db ) {
 134                 $first = true;
 135                 $firstTitle = true;
 136                 $sql = '';
 137                 foreach ( $this->data as $ns => $dbkeys ) {
 138                         if ( !count( $dbkeys ) ) {
 139                                 continue;
 140                         }
 141
 142                         if ( $first ) {
 143                                 $first = false;
 144                         } else {
 145                                 $sql .= ' OR ';
 146                         }
 147                         $sql .= "({$prefix}_namespace=$ns AND {$prefix}_title IN (";
 148
 149                         $firstTitle = true;
 150                         foreach( $dbkeys as $dbkey => $nothing ) {
 151                                 if ( $firstTitle ) {
 152                                         $firstTitle = false;
 153                                 } else {
 154                                         $sql .= ',';
 155                                 }
 156                                 $sql .= $db->addQuotes( $dbkey );
 157                         }
 158
 159                         $sql .= '))';
 160                 }
 161                 if ( $first && $firstTitle ) {
 162                         # No titles added
 163                         return false;
 164                 } else {
 165                         return $sql;
 166                 }
 167         }
 168 }
 169
 170 ?>