1 files changed, 134 insertions, 0 deletions
diff --git a/includes/cache/UserCache.php b/includes/cache/UserCache.php
new file mode 100644
index 00000000..6ec23669
--- /dev/null
+++ b/includes/cache/UserCache.php
@@ -0,0 +1,134 @@
+<?php
+/**
+ * Caches current user names and other info based on user IDs.
+ *
+ * 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
+ * @ingroup Cache
+ */
+
+/**
+ * @since 1.20
+ */
+class UserCache {
+	protected $cache = array(); // (uid => property => value)
+	protected $typesCached = array(); // (uid => cache type => 1)
+
+	/**
+	 * @return UserCache
+	 */
+	public static function singleton() {
+		static $instance = null;
+		if ( $instance === null ) {
+			$instance = new self();
+		}
+		return $instance;
+	}
+
+	protected function __construct() {}
+
+	/**
+	 * Get a property of a user based on their user ID
+	 *
+	 * @param $userId integer User ID
+	 * @param $prop string User property
+	 * @return mixed The property or false if the user does not exist
+	 */
+	public function getProp( $userId, $prop ) {
+		if ( !isset( $this->cache[$userId][$prop] ) ) {
+			wfDebug( __METHOD__ . ": querying DB for prop '$prop' for user ID '$userId'.\n" );
+			$this->doQuery( array( $userId ) ); // cache miss
+		}
+		return isset( $this->cache[$userId][$prop] )
+			? $this->cache[$userId][$prop]
+			: false; // user does not exist?
+	}
+
+	/**
+	 * Preloads user names for given list of users.
+	 * @param $userIds Array List of user IDs
+	 * @param $options Array Option flags; include 'userpage' and 'usertalk'
+	 * @param $caller String: the calling method
+	 */
+	public function doQuery( array $userIds, $options = array(), $caller = '' ) {
+		wfProfileIn( __METHOD__ );
+
+		$usersToCheck = array();
+		$usersToQuery = array();
+
+		foreach ( $userIds as $userId ) {
+			$userId = (int)$userId;
+			if ( $userId <= 0 ) {
+				continue; // skip anons
+			}
+			if ( isset( $this->cache[$userId]['name'] ) ) {
+				$usersToCheck[$userId] = $this->cache[$userId]['name']; // already have name
+			} else {
+				$usersToQuery[] = $userId; // we need to get the name
+			}
+		}
+
+		// Lookup basic info for users not yet loaded...
+		if ( count( $usersToQuery ) ) {
+			$dbr = wfGetDB( DB_SLAVE );
+			$table = array( 'user' );
+			$conds = array( 'user_id' => $usersToQuery );
+			$fields = array( 'user_name', 'user_real_name', 'user_registration', 'user_id' );
+
+			$comment = __METHOD__;
+			if ( strval( $caller ) !== '' ) {
+				$comment .= "/$caller";
+			}
+
+			$res = $dbr->select( $table, $fields, $conds, $comment );
+			foreach ( $res as $row ) { // load each user into cache
+				$userId = (int)$row->user_id;
+				$this->cache[$userId]['name'] = $row->user_name;
+				$this->cache[$userId]['real_name'] = $row->user_real_name;
+				$this->cache[$userId]['registration'] = $row->user_registration;
+				$usersToCheck[$userId] = $row->user_name;
+			}
+		}
+
+		$lb = new LinkBatch();
+		foreach ( $usersToCheck as $userId => $name ) {
+			if ( $this->queryNeeded( $userId, 'userpage', $options ) ) {
+				$lb->add( NS_USER, str_replace( ' ', '_', $row->user_name ) );
+				$this->typesCached[$userId]['userpage'] = 1;
+			}
+			if ( $this->queryNeeded( $userId, 'usertalk', $options ) ) {
+				$lb->add( NS_USER_TALK, str_replace( ' ', '_', $row->user_name ) );
+				$this->typesCached[$userId]['usertalk'] = 1;
+			}
+		}
+		$lb->execute();
+
+		wfProfileOut( __METHOD__ );
+	}
+
+	/**
+	 * Check if a cache type is in $options and was not loaded for this user
+	 *
+	 * @param $uid integer user ID
+	 * @param $type string Cache type
+	 * @param $options Array Requested cache types
+	 * @return bool
+	 */
+	protected function queryNeeded( $uid, $type, array $options ) {
+		return ( in_array( $type, $options ) && !isset( $this->typesCached[$uid][$type] ) );
+	}
+}