Category.php

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<?php
class Category {
    private $mName = null;
    private $mID = null;
    private $mTitle = null;
    private $mPages = null, $mSubcats = null, $mFiles = null;
 
    private function __construct() {
    }
 
    protected function initialize() {
        if ( $this->mName === null && $this->mID === null ) {
            throw new MWException( __METHOD__ . ' has both names and IDs null' );
        } elseif ( $this->mID === null ) {
            $where = array( 'cat_title' => $this->mName );
        } elseif ( $this->mName === null ) {
            $where = array( 'cat_id' => $this->mID );
        } else {
            # Already initialized
            return true;
        }
 
        wfProfileIn( __METHOD__ );
 
        $dbr = wfGetDB( DB_SLAVE );
        $row = $dbr->selectRow(
            'category',
            array( 'cat_id', 'cat_title', 'cat_pages', 'cat_subcats', 'cat_files' ),
            $where,
            __METHOD__
        );
 
        wfProfileOut( __METHOD__ );
 
        if ( !$row ) {
            # Okay, there were no contents.  Nothing to initialize.
            if ( $this->mTitle ) {
                # If there is a title object but no record in the category table,
                # treat this as an empty category.
                $this->mID = false;
                $this->mName = $this->mTitle->getDBkey();
                $this->mPages = 0;
                $this->mSubcats = 0;
                $this->mFiles = 0;
 
                return true;
            } else {
                return false; # Fail
            }
        }
 
        $this->mID = $row->cat_id;
        $this->mName = $row->cat_title;
        $this->mPages = $row->cat_pages;
        $this->mSubcats = $row->cat_subcats;
        $this->mFiles = $row->cat_files;
 
        # (bug 13683) If the count is negative, then 1) it's obviously wrong
        # and should not be kept, and 2) we *probably* don't have to scan many
        # rows to obtain the correct figure, so let's risk a one-time recount.
        if ( $this->mPages < 0 || $this->mSubcats < 0 || $this->mFiles < 0 ) {
            $this->refreshCounts();
        }
 
        return true;
    }
 
    public static function newFromName( $name ) {
        $cat = new self();
        $title = Title::makeTitleSafe( NS_CATEGORY, $name );
 
        if ( !is_object( $title ) ) {
            return false;
        }
 
        $cat->mTitle = $title;
        $cat->mName = $title->getDBkey();
 
        return $cat;
    }
 
    public static function newFromTitle( $title ) {
        $cat = new self();
 
        $cat->mTitle = $title;
        $cat->mName = $title->getDBkey();
 
        return $cat;
    }
 
    public static function newFromID( $id ) {
        $cat = new self();
        $cat->mID = intval( $id );
        return $cat;
    }
 
    public static function newFromRow( $row, $title = null ) {
        $cat = new self();
        $cat->mTitle = $title;
 
        # NOTE: the row often results from a LEFT JOIN on categorylinks. This may result in
        #       all the cat_xxx fields being null, if the category page exists, but nothing
        #       was ever added to the category. This case should be treated link an empty
        #       category, if possible.
 
        if ( $row->cat_title === null ) {
            if ( $title === null ) {
                # the name is probably somewhere in the row, for example as page_title,
                # but we can't know that here...
                return false;
            } else {
                # if we have a title object, fetch the category name from there
                $cat->mName = $title->getDBkey();
            }
 
            $cat->mID = false;
            $cat->mSubcats = 0;
            $cat->mPages = 0;
            $cat->mFiles = 0;
        } else {
            $cat->mName = $row->cat_title;
            $cat->mID = $row->cat_id;
            $cat->mSubcats = $row->cat_subcats;
            $cat->mPages = $row->cat_pages;
            $cat->mFiles = $row->cat_files;
        }
 
        return $cat;
    }
 
    public function getName() {
        return $this->getX( 'mName' );
    }
 
    public function getID() {
        return $this->getX( 'mID' );
    }
 
    public function getPageCount() {
        return $this->getX( 'mPages' );
    }
 
    public function getSubcatCount() {
        return $this->getX( 'mSubcats' );
    }
 
    public function getFileCount() {
        return $this->getX( 'mFiles' );
    }
 
    public function getTitle() {
        if ( $this->mTitle ) {
            return $this->mTitle;
        }
 
        if ( !$this->initialize() ) {
            return false;
        }
 
        $this->mTitle = Title::makeTitleSafe( NS_CATEGORY, $this->mName );
        return $this->mTitle;
    }
 
    public function getMembers( $limit = false, $offset = '' ) {
        wfProfileIn( __METHOD__ );
 
        $dbr = wfGetDB( DB_SLAVE );
 
        $conds = array( 'cl_to' => $this->getName(), 'cl_from = page_id' );
        $options = array( 'ORDER BY' => 'cl_sortkey' );
 
        if ( $limit ) {
            $options['LIMIT'] = $limit;
        }
 
        if ( $offset !== '' ) {
            $conds[] = 'cl_sortkey > ' . $dbr->addQuotes( $offset );
        }
 
        $result = TitleArray::newFromResult(
            $dbr->select(
                array( 'page', 'categorylinks' ),
                array( 'page_id', 'page_namespace', 'page_title', 'page_len',
                    'page_is_redirect', 'page_latest' ),
                $conds,
                __METHOD__,
                $options
            )
        );
 
        wfProfileOut( __METHOD__ );
 
        return $result;
    }
 
    private function getX( $key ) {
        if ( !$this->initialize() ) {
            return false;
        }
        return $this->{$key};
    }
 
    public function refreshCounts() {
        if ( wfReadOnly() ) {
            return false;
        }
 
        # Note, we must use names for this, since categorylinks does.
        if ( $this->mName === null ) {
            if ( !$this->initialize() ) {
                return false;
            }
        }
 
        wfProfileIn( __METHOD__ );
 
        $dbw = wfGetDB( DB_MASTER );
        $dbw->begin( __METHOD__ );
 
        # Insert the row if it doesn't exist yet (e.g., this is being run via
        # update.php from a pre-1.16 schema).  TODO: This will cause lots and
        # lots of gaps on some non-MySQL DBMSes if you run populateCategory.php
        # repeatedly.  Plus it's an extra query that's unneeded almost all the
        # time.  This should be rewritten somehow, probably.
        $seqVal = $dbw->nextSequenceValue( 'category_cat_id_seq' );
        $dbw->insert(
            'category',
            array(
                'cat_id' => $seqVal,
                'cat_title' => $this->mName
            ),
            __METHOD__,
            'IGNORE'
        );
 
        $cond1 = $dbw->conditional( array( 'page_namespace' => NS_CATEGORY ), 1, 'NULL' );
        $cond2 = $dbw->conditional( array( 'page_namespace' => NS_FILE ), 1, 'NULL' );
        $result = $dbw->selectRow(
            array( 'categorylinks', 'page' ),
            array( 'pages' => 'COUNT(*)',
                'subcats' => "COUNT($cond1)",
                'files' => "COUNT($cond2)"
            ),
            array( 'cl_to' => $this->mName, 'page_id = cl_from' ),
            __METHOD__,
            array( 'LOCK IN SHARE MODE' )
        );
        $ret = $dbw->update(
            'category',
            array(
                'cat_pages' => $result->pages,
                'cat_subcats' => $result->subcats,
                'cat_files' => $result->files
            ),
            array( 'cat_title' => $this->mName ),
            __METHOD__
        );
        $dbw->commit( __METHOD__ );
 
        wfProfileOut( __METHOD__ );
 
        # Now we should update our local counts.
        $this->mPages = $result->pages;
        $this->mSubcats = $result->subcats;
        $this->mFiles = $result->files;
 
        return $ret;
    }
}