<?php
/**
- * Category objects are immutable, strictly speaking. If you call methods that change the database,
- * like to refresh link counts, the objects will be appropriately reinitialized.
- * Member variables are lazy-initialized.
+ * Representation for a category.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
*
- * TODO: Move some stuff from CategoryPage.php to here, and use that.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
*
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
* @author Simetrical
*/
+/**
+ * Category objects are immutable, strictly speaking. If you call methods that change the database,
+ * like to refresh link counts, the objects will be appropriately reinitialized.
+ * Member variables are lazy-initialized.
+ *
+ * @todo Move some stuff from CategoryPage.php to here, and use that.
+ */
class Category {
/** Name of the category, normalized to DB-key form */
private $mName = null;
private $mID = null;
- /** Category page title */
+ /**
+ * Category page title
+ * @var Title
+ */
private $mTitle = null;
/** Counts of membership (cat_pages, cat_subcats, cat_files) */
private $mPages = null, $mSubcats = null, $mFiles = null;
- private function __construct() { }
+ const LOAD_ONLY = 0;
+ const LAZY_INIT_ROW = 1;
+
+ private function __construct() {
+ }
/**
* Set up all member variables using a database query.
+ * @param int $mode
+ * @throws MWException
* @return bool True on success, false on failure.
*/
- protected function initialize() {
+ protected function initialize( $mode = self::LOAD_ONLY ) {
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 );
+ $where = [ 'cat_title' => $this->mName ];
} elseif ( $this->mName === null ) {
- $where = array( 'cat_id' => $this->mID );
+ $where = [ 'cat_id' => $this->mID ];
} else {
# Already initialized
return true;
}
- $dbr = wfGetDB( DB_SLAVE );
+
+ $dbr = wfGetDB( DB_REPLICA );
$row = $dbr->selectRow(
'category',
- array( 'cat_id', 'cat_title', 'cat_pages', 'cat_subcats', 'cat_files' ),
+ [ 'cat_id', 'cat_title', 'cat_pages', 'cat_subcats', 'cat_files' ],
$where,
__METHOD__
);
if ( !$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;
+ # 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;
+ $this->mFiles = 0;
+
+ # If the title exists, call refreshCounts to add a row for it.
+ if ( $mode === self::LAZY_INIT_ROW && $this->mTitle->exists() ) {
+ DeferredUpdates::addCallableUpdate( [ $this, 'refreshCounts' ] );
+ }
return true;
} else {
}
}
- $this->mID = $row->cat_id;
- $this->mName = $row->cat_title;
- $this->mPages = $row->cat_pages;
+ $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;
+ $this->mFiles = $row->cat_files;
- # (bug 13683) If the count is negative, then 1) it's obviously wrong
+ # (T15683) 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();
+ $this->mPages = max( $this->mPages, 0 );
+ $this->mSubcats = max( $this->mSubcats, 0 );
+ $this->mFiles = max( $this->mFiles, 0 );
+
+ if ( $mode === self::LAZY_INIT_ROW ) {
+ DeferredUpdates::addCallableUpdate( [ $this, 'refreshCounts' ] );
+ }
}
return true;
/**
* Factory function.
*
- * @param $name Array: A category name (no "Category:" prefix). It need
+ * @param array $name A category name (no "Category:" prefix). It need
* not be normalized, with spaces replaced by underscores.
* @return mixed Category, or false on a totally invalid name
*/
/**
* Factory function.
*
- * @param $title Title for the category page
- * @return Mixed: category, or false on a totally invalid name
+ * @param Title $title Title for the category page
+ * @return Category|bool On a totally invalid name
*/
public static function newFromTitle( $title ) {
$cat = new self();
/**
* Factory function.
*
- * @param $id Integer: a category id
+ * @param int $id A category id
* @return Category
*/
public static function newFromID( $id ) {
/**
* Factory function, for constructing a Category object from a result set
*
- * @param $row result set row, must contain the cat_xxx fields. If the fields are null,
- * the resulting Category object will represent an empty category if a title object
- * was given. If the fields are null and no title was given, this method fails and returns false.
- * @param $title optional title object for the category represented by the given row.
- * May be provided if it is already known, to avoid having to re-create a title object later.
- * @return Category
+ * @param object $row Result set row, must contain the cat_xxx fields. If the
+ * fields are null, the resulting Category object will represent an empty
+ * category if a title object was given. If the fields are null and no
+ * title was given, this method fails and returns false.
+ * @param Title $title Optional title object for the category represented by
+ * the given row. May be provided if it is already known, to avoid having
+ * to re-create a title object later.
+ * @return Category|false
*/
public static function newFromRow( $row, $title = null ) {
$cat = new self();
# 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 linke an empty
+ # was ever added to the category. This case should be treated link an empty
# category, if possible.
if ( $row->cat_title === null ) {
# but we can't know that here...
return false;
} else {
- $cat->mName = $title->getDBkey(); # if we have a title object, fetch the category name from there
+ # if we have a title object, fetch the category name from there
+ $cat->mName = $title->getDBkey();
}
- $cat->mID = false;
+ $cat->mID = false;
$cat->mSubcats = 0;
- $cat->mPages = 0;
- $cat->mFiles = 0;
+ $cat->mPages = 0;
+ $cat->mFiles = 0;
} else {
- $cat->mName = $row->cat_title;
- $cat->mID = $row->cat_id;
+ $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;
+ $cat->mPages = $row->cat_pages;
+ $cat->mFiles = $row->cat_files;
}
return $cat;
}
- /** @return mixed DB key name, or false on failure */
- public function getName() { return $this->getX( 'mName' ); }
+ /**
+ * @return mixed DB key name, or false on failure
+ */
+ public function getName() {
+ return $this->getX( 'mName' );
+ }
- /** @return mixed Category ID, or false on failure */
- public function getID() { return $this->getX( 'mID' ); }
+ /**
+ * @return mixed Category ID, or false on failure
+ */
+ public function getID() {
+ return $this->getX( 'mID' );
+ }
- /** @return mixed Total number of member pages, or false on failure */
- public function getPageCount() { return $this->getX( 'mPages' ); }
+ /**
+ * @return mixed Total number of member pages, or false on failure
+ */
+ public function getPageCount() {
+ return $this->getX( 'mPages' );
+ }
- /** @return mixed Number of subcategories, or false on failure */
- public function getSubcatCount() { return $this->getX( 'mSubcats' ); }
+ /**
+ * @return mixed Number of subcategories, or false on failure
+ */
+ public function getSubcatCount() {
+ return $this->getX( 'mSubcats' );
+ }
- /** @return mixed Number of member files, or false on failure */
- public function getFileCount() { return $this->getX( 'mFiles' ); }
+ /**
+ * @return mixed Number of member files, or false on failure
+ */
+ public function getFileCount() {
+ return $this->getX( 'mFiles' );
+ }
/**
- * @return mixed The Title for this category, or false on failure.
+ * @return Title|bool Title for this category, or false on failure.
*/
public function getTitle() {
- if ( $this->mTitle ) return $this->mTitle;
+ if ( $this->mTitle ) {
+ return $this->mTitle;
+ }
- if ( !$this->initialize() ) {
+ if ( !$this->initialize( self::LAZY_INIT_ROW ) ) {
return false;
}
/**
* Fetch a TitleArray of up to $limit category members, beginning after the
* category sort key $offset.
- * @param $limit integer
- * @param $offset string
- * @return TitleArray object for category members.
+ * @param int|bool $limit
+ * @param string $offset
+ * @return TitleArray TitleArray object for category members.
*/
public function getMembers( $limit = false, $offset = '' ) {
- $dbr = wfGetDB( DB_SLAVE );
+ $dbr = wfGetDB( DB_REPLICA );
- $conds = array( 'cl_to' => $this->getName(), 'cl_from = page_id' );
- $options = array( 'ORDER BY' => 'cl_sortkey' );
+ $conds = [ 'cl_to' => $this->getName(), 'cl_from = page_id' ];
+ $options = [ 'ORDER BY' => 'cl_sortkey' ];
if ( $limit ) {
- $options[ 'LIMIT' ] = $limit;
+ $options['LIMIT'] = $limit;
}
if ( $offset !== '' ) {
$conds[] = 'cl_sortkey > ' . $dbr->addQuotes( $offset );
}
- return TitleArray::newFromResult(
+ $result = TitleArray::newFromResult(
$dbr->select(
- array( 'page', 'categorylinks' ),
- array( 'page_id', 'page_namespace', 'page_title', 'page_len',
- 'page_is_redirect', 'page_latest' ),
+ [ 'page', 'categorylinks' ],
+ [ 'page_id', 'page_namespace', 'page_title', 'page_len',
+ 'page_is_redirect', 'page_latest' ],
$conds,
__METHOD__,
$options
)
);
+
+ return $result;
}
- /** Generic accessor */
+ /**
+ * Generic accessor
+ * @param string $key
+ * @return bool
+ */
private function getX( $key ) {
- if ( !$this->initialize() ) {
+ if ( !$this->initialize( self::LAZY_INIT_ROW ) ) {
return false;
}
- return $this-> { $key } ;
+ return $this->{$key};
}
/**
return false;
}
- # Note, we must use names for this, since categorylinks does.
- if ( $this->mName === null ) {
- if ( !$this->initialize() ) {
- return false;
- }
+ # If we have just a category name, find out whether there is an
+ # existing row. Or if we have just an ID, get the name, because
+ # that's what categorylinks uses.
+ if ( !$this->initialize( self::LOAD_ONLY ) ) {
+ return false;
}
$dbw = wfGetDB( DB_MASTER );
- $dbw->begin();
-
- # 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'
- );
+ # Avoid excess contention on the same category (T162121)
+ $name = __METHOD__ . ':' . md5( $this->mName );
+ $scopedLock = $dbw->getScopedLockAndFlush( $name, __METHOD__, 1 );
+ if ( !$scopedLock ) {
+ return false;
+ }
- $cond1 = $dbw->conditional( 'page_namespace=' . NS_CATEGORY, 1, 'NULL' );
- $cond2 = $dbw->conditional( 'page_namespace=' . NS_FILE, 1, 'NULL' );
+ $dbw->startAtomic( __METHOD__ );
+
+ $cond1 = $dbw->conditional( [ 'page_namespace' => NS_CATEGORY ], 1, 'NULL' );
+ $cond2 = $dbw->conditional( [ 'page_namespace' => NS_FILE ], 1, 'NULL' );
$result = $dbw->selectRow(
- array( 'categorylinks', 'page' ),
- array( 'COUNT(*) AS pages',
- "COUNT($cond1) AS subcats",
- "COUNT($cond2) AS files"
- ),
- array( 'cl_to' => $this->mName, 'page_id = cl_from' ),
+ [ 'categorylinks', 'page' ],
+ [ 'pages' => 'COUNT(*)',
+ 'subcats' => "COUNT($cond1)",
+ 'files' => "COUNT($cond2)"
+ ],
+ [ 'cl_to' => $this->mName, 'page_id = cl_from' ],
__METHOD__,
- '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__
+ [ 'LOCK IN SHARE MODE' ]
);
- $dbw->commit();
+
+ $shouldExist = $result->pages > 0 || $this->getTitle()->exists();
+
+ if ( $this->mID ) {
+ if ( $shouldExist ) {
+ # The category row already exists, so do a plain UPDATE instead
+ # of INSERT...ON DUPLICATE KEY UPDATE to avoid creating a gap
+ # in the cat_id sequence. The row may or may not be "affected".
+ $dbw->update(
+ 'category',
+ [
+ 'cat_pages' => $result->pages,
+ 'cat_subcats' => $result->subcats,
+ 'cat_files' => $result->files
+ ],
+ [ 'cat_title' => $this->mName ],
+ __METHOD__
+ );
+ } else {
+ # The category is empty and has no description page, delete it
+ $dbw->delete(
+ 'category',
+ [ 'cat_title' => $this->mName ],
+ __METHOD__
+ );
+ $this->mID = false;
+ }
+ } elseif ( $shouldExist ) {
+ # The category row doesn't exist but should, so create it. Use
+ # upsert in case of races.
+ $dbw->upsert(
+ 'category',
+ [
+ 'cat_title' => $this->mName,
+ 'cat_pages' => $result->pages,
+ 'cat_subcats' => $result->subcats,
+ 'cat_files' => $result->files
+ ],
+ [ 'cat_title' ],
+ [
+ 'cat_pages' => $result->pages,
+ 'cat_subcats' => $result->subcats,
+ 'cat_files' => $result->files
+ ],
+ __METHOD__
+ );
+ // @todo: Should we update $this->mID here? Or not since Category
+ // objects tend to be short lived enough to not matter?
+ }
+
+ $dbw->endAtomic( __METHOD__ );
# Now we should update our local counts.
- $this->mPages = $result->pages;
+ $this->mPages = $result->pages;
$this->mSubcats = $result->subcats;
- $this->mFiles = $result->files;
+ $this->mFiles = $result->files;
- return $ret;
+ return true;
}
}
scripts.mit.edu / autoinstallsdev / mediawiki.git / blobdiff