1 files changed, 73 insertions, 0 deletions
diff --git a/includes/libs/ScopedCallback.php b/includes/libs/ScopedCallback.php
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+++ b/includes/libs/ScopedCallback.php
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+<?php
+/**
+ * This file deals with RAII style scoped callbacks.
+ *
+ * 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
+ */
+
+/**
+ * Class for asserting that a callback happens when an dummy object leaves scope
+ *
+ * @since 1.21
+ */
+class ScopedCallback {
+	/** @var callable */
+	protected $callback;
+
+	/**
+	 * @param callable $callback
+	 * @throws Exception
+	 */
+	public function __construct( $callback ) {
+		if ( !is_callable( $callback ) ) {
+			throw new InvalidArgumentException( "Provided callback is not valid." );
+		}
+		$this->callback = $callback;
+	}
+
+	/**
+	 * Trigger a scoped callback and destroy it.
+	 * This is the same is just setting it to null.
+	 *
+	 * @param ScopedCallback $sc
+	 */
+	public static function consume( ScopedCallback &$sc = null ) {
+		$sc = null;
+	}
+
+	/**
+	 * Destroy a scoped callback without triggering it
+	 *
+	 * @param ScopedCallback $sc
+	 */
+	public static function cancel( ScopedCallback &$sc = null ) {
+		if ( $sc ) {
+			$sc->callback = null;
+		}
+		$sc = null;
+	}
+
+	/**
+	 * Trigger the callback when this leaves scope
+	 */
+	function __destruct() {
+		if ( $this->callback !== null ) {
+			call_user_func( $this->callback );
+		}
+	}
+}