Implement basic integration with Query Monitor

Author: JanJakes

wp-includes/sqlite/class-wp-sqlite-db.php

@@ -427,6 +427,9 @@ public function query( $query ) {
 		// Keep track of the last query for debug.
 		$this->last_query = $query;
 
+		// Save the query count before running another query.
+		$last_query_count = count( $this->queries ?? array() );
+
 		/*
 		 * @TODO: WPDB uses "$this->check_current_query" to check table/column
 		 *        charset and strip all invalid characters from the query.
@@ -478,6 +481,13 @@ public function query( $query ) {
 			$return_val     = $num_rows;
 		}
 
+		// When Query Monitor is active, let's add the Query Monitor backtrace,
+		// so it can display extended query information in the developer panel.
+		$query_index = $last_query_count;
+		if ( class_exists( 'QM_Backtrace' ) && isset( $this->queries[ $query_index ] ) ) {
+			$this->queries[ $query_index ]['trace'] = new QM_Backtrace();
+		}
+
 		return $return_val;
 	}
 

wp-includes/sqlite/db.php

@@ -61,10 +61,57 @@
  * that are present in the GitHub repository
  * but not the plugin published on WordPress.org.
  */
+global $wpdb;
 $crosscheck_tests_file_path = dirname( __DIR__, 2 ) . '/tests/class-wp-sqlite-crosscheck-db.php';
 if ( defined( 'SQLITE_DEBUG_CROSSCHECK' ) && SQLITE_DEBUG_CROSSCHECK && file_exists( $crosscheck_tests_file_path ) ) {
 	require_once $crosscheck_tests_file_path;
-	$GLOBALS['wpdb'] = new WP_SQLite_Crosscheck_DB( DB_NAME );
+	$wpdb = new WP_SQLite_Crosscheck_DB( DB_NAME );
 } else {
-	$GLOBALS['wpdb'] = new WP_SQLite_DB( defined( 'DB_NAME' ) ? DB_NAME : '' );
+	// Allow plugins to wrap the wpdb object.
+	$wpdb = new WP_SQLite_DB( defined( 'DB_NAME' ) ? DB_NAME : '' );
+
+	/*
+	 * Query Monitor integration:
+	 *
+	 * When the Query Monitor plugin exists in its standard location, let's check
+	 * if it is active, so we can load it eagerly. This is a workaround to avoid
+	 * SQLite and Query Monitor competing for the "wp-content/db.php" file.
+	 */
+	global $table_prefix;
+	$plugins_dir = defined( 'WP_PLUGIN_DIR' ) ? WP_PLUGIN_DIR : WP_CONTENT_DIR . '/plugins';
+	$qm_db_file  = $plugins_dir . '/query-monitor/wp-content/db.php';
+	if ( isset( $table_prefix ) && file_exists( $qm_db_file ) ) {
+		// Check if Query Monitor is active.
+		$wpdb->set_prefix( $table_prefix );
+		$value = $wpdb->get_row(
+			$wpdb->prepare(
+				"SELECT option_value FROM $wpdb->options WHERE option_name = %s LIMIT 1",
+				'active_plugins'
+			)
+		);
+
+		$query_monitor_active = in_array(
+			'query-monitor/query-monitor.php',
+			unserialize( $value->option_value ),
+			true
+		);
+
+		if ( $query_monitor_active ) {
+			// Load Query Monitor's "db.php" file. This overrides the global $wpdb
+			// object, so we need to back it up before and restore after loading.
+			$_wpdb = $wpdb;
+			require_once $qm_db_file;
+			$wpdb = $_wpdb;
+
+			// Remove Query Monitor's deactivation hook so that it doesn't delete
+			// the "db.php" file. Currently, it attempts so when QM_DB is defined.
+			add_action(
+				'deactivate_query-monitor/query-monitor.php',
+				function () {
+					remove_all_actions( 'deactivate_query-monitor/query-monitor.php' );
+				},
+				0
+			);
+		}
+	}
 }