Merge branch 'master' of git.ethitter.com:wp-plugins/redis-page-cache

redis-page-cache/redis-page-cache.php

@@ -23,10 +23,18 @@ along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
 
+// Version cache keys to support plugin upgrades that modify data structures
+if ( ! defined( 'REDIS_PAGE_CACHE_CACHE_VERSION' ) ) {
+	define( 'REDIS_PAGE_CACHE_CACHE_VERSION', 0 );
+}
+
 class Redis_Page_Cache {
 	// Hold singleton instance
 	private static $__instance = null;
 
+	// Maintain a single instance of the Redis library, on demand via redis()
+	private static $__redis = null;
+
 	// Regular class variables
 	private $ns = 'redis-page-cache';
 
@@ -47,9 +55,87 @@ class Redis_Page_Cache {
 	 * @return null
 	 */
 	private function __construct() {
+		// UI
 		add_action( 'admin_init', array( $this, 'register_options' ) );
 		add_action( 'admin_menu', array( $this, 'register_ui' ) );
+
+		// Automated invalidations
 		add_action( 'transition_post_status', array( $this, 'flush_cache' ), 10, 3 );
+
+		// Manual invalidations
+		add_action( 'admin_bar_menu', array( $this, 'admin_bar_menu' ), 999 );
+		add_action( 'post_row_actions', array( $this, 'quick_edit' ), 999, 2 );
+		add_action( 'page_row_actions', array( $this, 'quick_edit' ), 999, 2 );
+		add_action( 'wp_ajax_redis_page_cache_purge', array( $this, 'ajax_purge' ) );
+	}
+
+	/**
+	 * Create an instance of the Predis library as needed
+	 *
+	 * @return object
+	 */
+	private function redis() {
+		if ( is_null( self::$__redis ) ) {
+			// Default connection settings
+			$redis_settings = array(
+				'host'     => '127.0.0.1',
+				'port'     => 6379,
+			);
+
+			// Override default connection settings with global values, when present
+			if ( defined( 'REDIS_PAGE_CACHE_REDIS_HOST' ) && REDIS_PAGE_CACHE_REDIS_HOST ) {
+				$redis_settings['host'] = REDIS_PAGE_CACHE_REDIS_HOST;
+			}
+			if ( defined( 'REDIS_PAGE_CACHE_REDIS_PORT' ) && REDIS_PAGE_CACHE_REDIS_PORT ) {
+				$redis_settings['port'] = REDIS_PAGE_CACHE_REDIS_PORT;
+			}
+			if ( defined( 'REDIS_PAGE_CACHE_REDIS_DB' ) && REDIS_PAGE_CACHE_REDIS_DB ) {
+				$redis_settings['database'] = REDIS_PAGE_CACHE_REDIS_DB;
+			}
+
+			// Connect to Redis using either the PHP PECL extension of the bundled Predis library
+			if ( class_exists( 'Redis' ) ) {
+				self::$redis = new Redis();
+
+				self::$redis->connect( $redis_settings['host'], $redis_settings['port'] );
+
+				// Default DB is 0, so only need to SELECT if other
+				if ( isset( $redis_settings['database'] ) ) {
+					self::$redis->select( $redis_settings['database'] );
+				}
+			} else {
+				// Load the Predis library and return an instance of it
+				include_once dirname( __FILE__ ) . '/predis5.2.php';
+				self::$__redis = new Predis_Client( $redis_settings );
+			}
+		}
+
+		return self::$__redis;
+	}
+
+	/**
+	 * Turn URL into corresponding Redis cache key
+	 *
+	 * @param string $url
+	 * @return string
+	 */
+	private function build_key( $url ) {
+		return md5( 'v' . REDIS_PAGE_CACHE_CACHE_VERSION . '-' . $url );
+	}
+
+	/**
+	 * Remove a specific URL from the Redis cache
+	 *
+	 * @param string $url
+	 * @return null
+	 */
+	private function purge( $url ) {
+		$redis = $this->redis();
+
+		$redis_key = $this->build_key( $url );
+		foreach ( array( '', 'M-', 'T-', ) as $prefix ) {
+			$redis->del( $prefix . $redis_key );
+		}
 	}
 
 	/**
@@ -58,8 +144,8 @@ class Redis_Page_Cache {
 	 * @return null
 	 */
 	public function register_options() {
-		register_setting( $this->ns, 'redis-page-cache-seconds', 'absint' );
-		register_setting( $this->ns, 'redis-page-cache-unlimited', 'absint' );
+		register_setting( $this->ns, $this->ns . '-seconds', 'absint' );
+		register_setting( $this->ns, $this->ns . '-unlimited', 'absint' );
 	}
 
 	/**
@@ -97,7 +183,7 @@ class Redis_Page_Cache {
 				<tr>
 					<th scope="row"><label for="duration-seconds"><?php _e( 'Duration of Caching in Seconds:', 'redis-page-cache' ); ?></label></td>
 					<td>
-						<input type="text" name="redis-page-cache-seconds" id="duration-seconds" size="15" value="<?php echo (int) get_option( 'redis-page-cache-seconds', 43200 ); ?>" />
+						<input type="text" name="<?php echo esc_attr( $this->ns ); ?>-seconds" id="duration-seconds" size="15" value="<?php echo (int) get_option( $this->ns . '-seconds', 43200 ); ?>" />
 
 						<p class="description"><?php _e( 'How many seconds would you like to cache individual pages? <strong>Recommended 12 hours or 43200 seconds</strong>.', 'redis-page-cache' ); ?></p>
 					</td>
@@ -105,7 +191,7 @@ class Redis_Page_Cache {
 				<tr>
 					<th scope="row"><label for="unlimited-cache"><?php _e( 'Cache Without Expiration?', 'redis-page-cache' ); ?></label></th>
 					<td>
-						<input type="checkbox" name="redis-page-cache-unlimited" id="unlimited-cache" value="1" <?php checked( true, (bool) get_option( 'redis-page-cache-unlimited', false ) ); ?>/>
+						<input type="checkbox" name="<?php echo esc_attr( $this->ns ); ?>-unlimited" id="unlimited-cache" value="1" <?php checked( true, (bool) get_option( $this->ns . '-unlimited', false ) ); ?>/>
 
 						<p class="description"><?php _e( 'If this option is set, the cache never expire. This option overides the setting <em>Duration of Caching in Seconds</em>.', 'redis-page-cache' ); ?></p>
 					</td>
@@ -129,40 +215,105 @@ class Redis_Page_Cache {
 	 */
 	public function flush_cache( $new_status, $old_status, $post ) {
 		if ( in_array( 'publish', array( $new_status, $old_status ) ) ) {
-			// Default connection settings
-			$redis_settings = array(
-				'host'     => '127.0.0.1',
-				'port'     => 6379,
-			);
+			$this->purge( get_permalink( $post->ID ) );
+			$this->purge( trailingslashit( get_home_url() ) );
+		}
+	}
 
-			// Override default connection settings with global values, when present
-			if ( defined( 'REDIS_PAGE_CACHE_REDIS_HOST' ) && REDIS_PAGE_CACHE_REDIS_HOST ) {
-				$redis_settings['host'] = REDIS_PAGE_CACHE_REDIS_HOST;
-			}
-			if ( defined( 'REDIS_PAGE_CACHE_REDIS_PORT' ) && REDIS_PAGE_CACHE_REDIS_PORT ) {
-				$redis_settings['port'] = REDIS_PAGE_CACHE_REDIS_PORT;
-			}
-			if ( defined( 'REDIS_PAGE_CACHE_REDIS_DB' ) && REDIS_PAGE_CACHE_REDIS_DB ) {
-				$redis_settings['database'] = REDIS_PAGE_CACHE_REDIS_DB;
-			}
+	/**
+	 * Add a single-page purge option to the admin bar for those with proper capabilities
+	 *
+	 * @action admin_bar_menu
+	 * @return null
+	 */
+	public function admin_bar_menu() {
+		global $wp_admin_bar;
+
+		// In the admin, only show on the post editor
+		if ( is_admin() && 'post' !== get_current_screen()->base ) {
+			return;
+		}
 
-			$permalink = get_permalink( $post->ID );
+		// Only for Super Admins on multisite or Administrators on single site.
+		if ( ( is_multisite() && ! is_super_admin() ) || ! current_user_can( 'manage_options' ) ) {
+			return;
+		}
 
-			include_once dirname( __FILE__ ) . '/predis5.2.php'; // we need this to use Redis inside of PHP
-			$redis = new Predis_Client( $redis_settings );
+		// What are we trying to clear?
+		$url = set_url_scheme( esc_url( $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'] ) );
 
-			$redis_key = md5( $permalink );
-			foreach ( array( '', 'M-', 'T-', ) as $prefix ) {
-				$redis->del( $prefix . $redis_key );
-			}
+		$wp_admin_bar->add_menu( array(
+			'id'     => $this->ns,
+			'parent' => false,
+			'title'  => __( 'Clear Page Cache', 'redis-page-cache' ),
+			'href'   => $this->get_ajax_purge_url( $url ),
+		) );
+	}
 
-			//refresh the front page
-			$front_page = get_home_url( '/' );
-			$redis_key = md5( $front_page );
-			foreach ( array( '', 'M-', 'T-', ) as $prefix ) {
-				$redis->del( $prefix . $redis_key );
-			}
+	/**
+	 * Add a purge link to the Quick Edit actions in post tables
+	 *
+	 * @param array $actions
+	 * @param object $post
+	 * @action post_row_actions
+	 * @action page_row_actions
+	 * @return array
+	 */
+	public function quick_edit( $actions, $post ) {
+		$actions[ $this->ns ] = '<a href="' . esc_url( $this->get_ajax_purge_url( get_permalink( $post->ID ) ) ) . '">' . __( 'Clear cache', 'redis-page-cache' ) . '</a>';
+
+		return $actions;
+	}
+
+	/**
+	 * Build URL for Ajax purge requests
+	 *
+	 * @param string $url
+	 * @return string
+	 */
+	private function get_ajax_purge_url( $url ) {
+		$url = remove_query_arg( $this->ns . '-purge', $url );
+
+		$url = add_query_arg( array(
+			'action' => 'redis_page_cache_purge',
+			'nonce'  => wp_create_nonce( $url ),
+			'url'    => urlencode( $url ),
+		), admin_url( 'admin-ajax.php' ) );
+
+		return $url;
+	}
+
+	/**
+	 * Purge a page from cache via an Ajax request
+	 *
+	 * @action wp_ajax_redis_page_cache_purge
+	 * @return null
+	 */
+	public function ajax_purge() {
+		$url = esc_url_raw( urldecode( $_GET['url'] ) );
+
+		if ( isset( $_SERVER['HTTP_REFERER'] ) ) {
+			$redirect = $_SERVER['HTTP_REFERER'];
+		} else {
+			$redirect = $url;
 		}
+		$redirect = add_query_arg( $this->ns . '-purge', 'failed', $redirect );
+
+		// Check nonce and referrer
+		if ( ! check_ajax_referer( $url, 'nonce', false ) ) {
+			wp_safe_redirect( $redirect, 302 );
+		}
+
+		// Only for Super Admins on multisite or Administrators on single site.
+		if ( ( is_multisite() && ! is_super_admin() ) || ! current_user_can( 'manage_options' ) ) {
+			wp_safe_redirect( $redirect, 302 );
+		}
+
+		// Checks passed, so we purge and redirect with success noted in the query string
+		$this->purge( $url );
+
+		$redirect = add_query_arg( $this->ns . '-purge', 'success', $redirect );
+		wp_safe_redirect( $redirect, 302 );
 	}
 }