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diff --git a/www/wiki/includes/PageProps.php b/www/wiki/includes/PageProps.php
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+<?php
+/**
+ * Access to properties of a page.
+ *
+ * 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.
+ *
+ * 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
+ */
+use Wikimedia\ScopedCallback;
+
+/**
+ * Gives access to properties of a page.
+ *
+ * @since 1.27
+ */
+class PageProps {
+
+	/**
+	 * @var PageProps
+	 */
+	private static $instance;
+
+	/**
+	 * Overrides the default instance of this class
+	 * This is intended for use while testing and will fail if MW_PHPUNIT_TEST is not defined.
+	 *
+	 * If this method is used it MUST also be called with null after a test to ensure a new
+	 * default instance is created next time getInstance is called.
+	 *
+	 * @since 1.27
+	 *
+	 * @param PageProps|null $store
+	 *
+	 * @return ScopedCallback to reset the overridden value
+	 * @throws MWException
+	 */
+	public static function overrideInstance( PageProps $store = null ) {
+		if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
+			throw new MWException(
+				'Cannot override ' . __CLASS__ . 'default instance in operation.'
+			);
+		}
+		$previousValue = self::$instance;
+		self::$instance = $store;
+		return new ScopedCallback( function () use ( $previousValue ) {
+			self::$instance = $previousValue;
+		} );
+	}
+
+	/**
+	 * @return PageProps
+	 */
+	public static function getInstance() {
+		if ( self::$instance === null ) {
+			self::$instance = new self();
+		}
+		return self::$instance;
+	}
+
+	/** Cache parameters */
+	const CACHE_TTL = 10; // integer; TTL in seconds
+	const CACHE_SIZE = 100; // integer; max cached pages
+
+	/** Property cache */
+	private $cache = null;
+
+	/**
+	 * Create a PageProps object
+	 */
+	private function __construct() {
+		$this->cache = new ProcessCacheLRU( self::CACHE_SIZE );
+	}
+
+	/**
+	 * Ensure that cache has at least this size
+	 * @param int $size
+	 */
+	public function ensureCacheSize( $size ) {
+		if ( $this->cache->getSize() < $size ) {
+			$this->cache->resize( $size );
+		}
+	}
+
+	/**
+	 * Given one or more Titles and one or more names of properties,
+	 * returns an associative array mapping page ID to property value.
+	 * Pages in the provided set of Titles that do not have a value for
+	 * the given properties will not appear in the returned array. If a
+	 * single Title is provided, it does not need to be passed in an array,
+	 * but an array will always be returned. If a single property name is
+	 * provided, it does not need to be passed in an array. In that case,
+	 * an associative array mapping page ID to property value will be
+	 * returned; otherwise, an associative array mapping page ID to
+	 * an associative array mapping property name to property value will be
+	 * returned. An empty array will be returned if no matching properties
+	 * were found.
+	 *
+	 * @param Title[]|Title $titles
+	 * @param string[]|string $propertyNames
+	 * @return array associative array mapping page ID to property value
+	 */
+	public function getProperties( $titles, $propertyNames ) {
+		if ( is_array( $propertyNames ) ) {
+			$gotArray = true;
+		} else {
+			$propertyNames = [ $propertyNames ];
+			$gotArray = false;
+		}
+
+		$values = [];
+		$goodIDs = $this->getGoodIDs( $titles );
+		$queryIDs = [];
+		foreach ( $goodIDs as $pageID ) {
+			foreach ( $propertyNames as $propertyName ) {
+				$propertyValue = $this->getCachedProperty( $pageID, $propertyName );
+				if ( $propertyValue === false ) {
+					$queryIDs[] = $pageID;
+					break;
+				} else {
+					if ( $gotArray ) {
+						$values[$pageID][$propertyName] = $propertyValue;
+					} else {
+						$values[$pageID] = $propertyValue;
+					}
+				}
+			}
+		}
+
+		if ( $queryIDs ) {
+			$dbr = wfGetDB( DB_REPLICA );
+			$result = $dbr->select(
+				'page_props',
+				[
+					'pp_page',
+					'pp_propname',
+					'pp_value'
+				],
+				[
+					'pp_page' => $queryIDs,
+					'pp_propname' => $propertyNames
+				],
+				__METHOD__
+			);
+
+			foreach ( $result as $row ) {
+				$pageID = $row->pp_page;
+				$propertyName = $row->pp_propname;
+				$propertyValue = $row->pp_value;
+				$this->cacheProperty( $pageID, $propertyName, $propertyValue );
+				if ( $gotArray ) {
+					$values[$pageID][$propertyName] = $propertyValue;
+				} else {
+					$values[$pageID] = $propertyValue;
+				}
+			}
+		}
+
+		return $values;
+	}
+
+	/**
+	 * Get all page property values.
+	 * Given one or more Titles, returns an associative array mapping page
+	 * ID to an associative array mapping property names to property
+	 * values. Pages in the provided set of Titles that do not have any
+	 * properties will not appear in the returned array. If a single Title
+	 * is provided, it does not need to be passed in an array, but an array
+	 * will always be returned. An empty array will be returned if no
+	 * matching properties were found.
+	 *
+	 * @param Title[]|Title $titles
+	 * @return array associative array mapping page ID to property value array
+	 */
+	public function getAllProperties( $titles ) {
+		$values = [];
+		$goodIDs = $this->getGoodIDs( $titles );
+		$queryIDs = [];
+		foreach ( $goodIDs as $pageID ) {
+			$pageProperties = $this->getCachedProperties( $pageID );
+			if ( $pageProperties === false ) {
+				$queryIDs[] = $pageID;
+			} else {
+				$values[$pageID] = $pageProperties;
+			}
+		}
+
+		if ( $queryIDs != [] ) {
+			$dbr = wfGetDB( DB_REPLICA );
+			$result = $dbr->select(
+				'page_props',
+				[
+					'pp_page',
+					'pp_propname',
+					'pp_value'
+				],
+				[
+					'pp_page' => $queryIDs,
+				],
+				__METHOD__
+			);
+
+			$currentPageID = 0;
+			$pageProperties = [];
+			foreach ( $result as $row ) {
+				$pageID = $row->pp_page;
+				if ( $currentPageID != $pageID ) {
+					if ( $pageProperties != [] ) {
+						$this->cacheProperties( $currentPageID, $pageProperties );
+						$values[$currentPageID] = $pageProperties;
+					}
+					$currentPageID = $pageID;
+					$pageProperties = [];
+				}
+				$pageProperties[$row->pp_propname] = $row->pp_value;
+			}
+			if ( $pageProperties != [] ) {
+				$this->cacheProperties( $pageID, $pageProperties );
+				$values[$pageID] = $pageProperties;
+			}
+		}
+
+		return $values;
+	}
+
+	/**
+	 * @param Title[]|Title $titles
+	 * @return array array of good page IDs
+	 */
+	private function getGoodIDs( $titles ) {
+		$result = [];
+		if ( is_array( $titles ) ) {
+			( new LinkBatch( $titles ) )->execute();
+
+			foreach ( $titles as $title ) {
+				$pageID = $title->getArticleID();
+				if ( $pageID > 0 ) {
+					$result[] = $pageID;
+				}
+			}
+		} else {
+			$pageID = $titles->getArticleID();
+			if ( $pageID > 0 ) {
+				$result[] = $pageID;
+			}
+		}
+		return $result;
+	}
+
+	/**
+	 * Get a property from the cache.
+	 *
+	 * @param int $pageID page ID of page being queried
+	 * @param string $propertyName name of property being queried
+	 * @return string|bool property value array or false if not found
+	 */
+	private function getCachedProperty( $pageID, $propertyName ) {
+		if ( $this->cache->has( $pageID, $propertyName, self::CACHE_TTL ) ) {
+			return $this->cache->get( $pageID, $propertyName );
+		}
+		if ( $this->cache->has( 0, $pageID, self::CACHE_TTL ) ) {
+			$pageProperties = $this->cache->get( 0, $pageID );
+			if ( isset( $pageProperties[$propertyName] ) ) {
+				return $pageProperties[$propertyName];
+			}
+		}
+		return false;
+	}
+
+	/**
+	 * Get properties from the cache.
+	 *
+	 * @param int $pageID page ID of page being queried
+	 * @return string|bool property value array or false if not found
+	 */
+	private function getCachedProperties( $pageID ) {
+		if ( $this->cache->has( 0, $pageID, self::CACHE_TTL ) ) {
+			return $this->cache->get( 0, $pageID );
+		}
+		return false;
+	}
+
+	/**
+	 * Save a property to the cache.
+	 *
+	 * @param int $pageID page ID of page being cached
+	 * @param string $propertyName name of property being cached
+	 * @param mixed $propertyValue value of property
+	 */
+	private function cacheProperty( $pageID, $propertyName, $propertyValue ) {
+		$this->cache->set( $pageID, $propertyName, $propertyValue );
+	}
+
+	/**
+	 * Save properties to the cache.
+	 *
+	 * @param int $pageID page ID of page being cached
+	 * @param string[] $pageProperties associative array of page properties to be cached
+	 */
+	private function cacheProperties( $pageID, $pageProperties ) {
+		$this->cache->clear( $pageID );
+		$this->cache->set( 0, $pageID, $pageProperties );
+	}
+}