From 9590795b91988a5901379bb49f4a43eb5eb5db26 Mon Sep 17 00:00:00 2001
From: Ori Livneh <ori@wikimedia.org>
Date: Sun, 25 Aug 2013 23:46:21 -0700
Subject: [PATCH] Add 'RedisPubSubFeedEngine' feed engine

This patch adds a class which implements the RCFeedEngine interface by
publishing recent change notifications to Redis. The class handles the
'redis://' URI scheme. Recent changes are PUBLISHed to the channel 'rc'; a
different channel name may be specified as a path component.

Change-Id: I846036c091c45059a8947245a1efe92c9800dcf4
---
 includes/AutoLoader.php                   |  1 +
 includes/DefaultSettings.php              |  1 +
 includes/rcfeed/RedisPubSubFeedEngine.php | 41 +++++++++++++++++++++++
 3 files changed, 43 insertions(+)
 create mode 100644 includes/rcfeed/RedisPubSubFeedEngine.php

diff --git a/includes/AutoLoader.php b/includes/AutoLoader.php
index 2e8244158a..0706fe3f5c 100644
--- a/includes/AutoLoader.php
+++ b/includes/AutoLoader.php
@@ -851,6 +851,7 @@ $wgAutoloadLocalClasses = array(
 
 	# includes/rcfeed
 	'RCFeedEngine' => 'includes/rcfeed/RCFeedEngine.php',
+	'RedisPubSubFeedEngine' => 'includes/rcfeed/RedisPubSubFeedEngine.php',
 	'UDPRCFeedEngine' => 'includes/rcfeed/UDPRCFeedEngine.php',
 	'RCFeedFormatter' => 'includes/rcfeed/RCFeedFormatter.php',
 	'IRCColourfulRCFeedFormatter' => 'includes/rcfeed/IRCColourfulRCFeedFormatter.php',
diff --git a/includes/DefaultSettings.php b/includes/DefaultSettings.php
index 880f05a348..cc694a346d 100644
--- a/includes/DefaultSettings.php
+++ b/includes/DefaultSettings.php
@@ -5559,6 +5559,7 @@ $wgRCFeeds = array();
  * Keys are scheme names, values are names of engine classes.
  */
 $wgRCEngines = array(
+	'redis' => 'RedisPubSubFeedEngine',
 	'udp' => 'UDPRCFeedEngine',
 );
 
diff --git a/includes/rcfeed/RedisPubSubFeedEngine.php b/includes/rcfeed/RedisPubSubFeedEngine.php
new file mode 100644
index 0000000000..4bcc13375b
--- /dev/null
+++ b/includes/rcfeed/RedisPubSubFeedEngine.php
@@ -0,0 +1,41 @@
+<?php
+class RedisPubSubFeedEngine implements RCFeedEngine {
+	/**
+	 * Emit a recent change notification via Redis Pub/Sub
+	 *
+	 * If the feed URI contains a path component, it will be used to generate a
+	 * channel name by stripping the leading slash and replacing any remaining
+	 * slashes with '.'. If no path component is present, the channel is set to
+	 * 'rc'. If the URI contains a query string, its parameters will be parsed
+	 * as RedisConnectionPool options.
+	 *
+	 * @example $wgRCFeeds['redis'] = array(
+	 *      'formatter' => 'JSONRCFeedFormatter',
+	 *      'uri'       => "redis://127.0.0.1:6379/rc.$wgDBname",
+	 * );
+	 *
+	 * @since 1.22
+	 */
+	public function send( array $feed, $line ) {
+		$parsed = parse_url( $feed['uri'] );
+		$server = $parsed['host'];
+		$options = array( 'serializer' => 'none' );
+		$channel = 'rc';
+
+		if ( isset( $parsed['port'] ) ) {
+			$server .= ":{$parsed['port']}";
+		}
+		if ( isset( $parsed['query'] ) ) {
+			parse_str( $parsed['query'], $options );
+		}
+		if ( isset( $parsed['pass'] ) ) {
+			$options['password'] = $parsed['pass'];
+		}
+		if ( isset( $parsed['path'] ) ) {
+			$channel = str_replace( '/', '.', ltrim( $parsed['path'], '/' ) );
+		}
+		$pool = RedisConnectionPool::singleton( $options );
+		$conn = $pool->getConnection( $server );
+		$conn->publish( $channel, $line );
+	}
+}
-- 
2.20.1