1 files changed, 92 insertions, 0 deletions
diff --git a/includes/poolcounter/PoolCounterWorkViaCallback.php b/includes/poolcounter/PoolCounterWorkViaCallback.php
new file mode 100644
index 00000000..af83d2e0
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+++ b/includes/poolcounter/PoolCounterWorkViaCallback.php
@@ -0,0 +1,92 @@
+<?php
+/**
+ * Provides of semaphore semantics for restricting the number
+ * of workers that may be concurrently performing the same task.
+ *
+ * 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
+ */
+
+/**
+ * Convenience class for dealing with PoolCounters using callbacks
+ * @since 1.22
+ */
+class PoolCounterWorkViaCallback extends PoolCounterWork {
+	/** @var callable */
+	protected $doWork;
+	/** @var callable|null */
+	protected $doCachedWork;
+	/** @var callable|null */
+	protected $fallback;
+	/** @var callable|null */
+	protected $error;
+
+	/**
+	 * Build a PoolCounterWork class from a type, key, and callback map.
+	 *
+	 * The callback map must at least have a callback for the 'doWork' method.
+	 * Additionally, callbacks can be provided for the 'doCachedWork', 'fallback',
+	 * and 'error' methods. Methods without callbacks will be no-ops that return false.
+	 * If a 'doCachedWork' callback is provided, then execute() may wait for any prior
+	 * process in the pool to finish and reuse its cached result.
+	 *
+	 * @param string $type
+	 * @param string $key
+	 * @param array $callbacks Map of callbacks
+	 * @throws MWException
+	 */
+	public function __construct( $type, $key, array $callbacks ) {
+		parent::__construct( $type, $key );
+		foreach ( array( 'doWork', 'doCachedWork', 'fallback', 'error' ) as $name ) {
+			if ( isset( $callbacks[$name] ) ) {
+				if ( !is_callable( $callbacks[$name] ) ) {
+					throw new MWException( "Invalid callback provided for '$name' function." );
+				}
+				$this->$name = $callbacks[$name];
+			}
+		}
+		if ( !isset( $this->doWork ) ) {
+			throw new MWException( "No callback provided for 'doWork' function." );
+		}
+		$this->cacheable = isset( $this->doCachedWork );
+	}
+
+	public function doWork() {
+		return call_user_func_array( $this->doWork, array() );
+	}
+
+	public function getCachedWork() {
+		if ( $this->doCachedWork ) {
+			return call_user_func_array( $this->doCachedWork, array() );
+		}
+		return false;
+	}
+
+	public function fallback() {
+		if ( $this->fallback ) {
+			return call_user_func_array( $this->fallback, array() );
+		}
+		return false;
+	}
+
+	public function error( $status ) {
+		if ( $this->error ) {
+			return call_user_func_array( $this->error, array( $status ) );
+		}
+		return false;
+	}
+}