R Debug Plugin Created by Andrey "Rarst" Savchenko

r-debug.php

<?php

/*
Plugin Name: R Debug
Description: Set of dump helpers for debug.
Author: Andrey "Rarst" Savchenko
Author URI: https://www.rarst.net/
License: MIT
 */

/**
 * Class with static dump methods
 */
class R_Debug
{

	/**
	 * List basic performance stats
	 *
	 * @param bool $visible display or only include in source
	 */
	static function list_performance($visible = false)
	{

		if (defined('DOING_AJAX')) {
			return;
		}

		$stat = sprintf(
			'%d queries in %s seconds, using %.2fMB memory',
			get_num_queries(),
			timer_stop(0, 3),
			memory_get_peak_usage() / 1024 / 1024
		);

		echo $visible ? $stat : "<!-- {$stat} -->";
	}

	/**
	 * List defined constants
	 *
	 * @param bool|string $filter limit to matching names or values
	 */
	static function list_constants($filter = false)
	{

		$constants = get_defined_constants();

		if (false !== $filter) {
			$temp = array();

			foreach ($constants as $key => $constant) {
				if (false !== stripos($key, $filter) || false !== stripos($constant, $filter)) {
					$temp[$key] = $constant;
				}
			}

			$constants = $temp;
		}

		ksort($constants);
		self::dump($constants);
	}

	/**
	 * Concatenate print_r of all input and echo in pre tags.
	 */
	static function dump()
	{
		ob_start();
		$output = '';

		foreach (func_get_args() as $arg) {
			$output .= print_r($arg, true);
		}

		echo '<pre>' . $output . '</pre>';

		$buffer = ob_get_clean();
		if (isset($_GET['save_debug_to_file']) && filter_var($_GET['save_debug_to_file'])) {
			error_log($buffer, 3, WP_CONTENT_DIR . '/r-debug.html');
		} else {
			echo $buffer;
		}
	}

	/**
	 * List cron entries with time remaining till next run
	 */
	static function list_cron()
	{

		ob_start();
		$cron = _get_cron_array();

		echo '<pre>';

		$offset = get_option('gmt_offset') * 3600;

		foreach ($cron as $time => $entry) {

			$when = '<strong>In ' . human_time_diff($time) . '</strong> (' . $time . ' ' . date_i18n(DATE_RSS, $time + $offset) . ')';
			echo "<br />&gt;&gt;&gt;&gt;&gt;\t{$when}<br />";

			foreach (array_keys($entry) as $function) {
				echo "\t{$function}<br />";
				self::list_hooks($function);
			}
		}

		echo '</pre>';

		$buffer = ob_get_clean();

		if (isset($_GET['save_debug_to_file']) && filter_var($_GET['save_debug_to_file'])) {
			error_log($buffer, 3, WP_CONTENT_DIR . '/r-debug.html');
		} else {
			echo $buffer;
		}
	}

	/**
	 * List hooks as currently defined
	 *
	 * @param bool|string $filter limit to matching names
	 */
	static function list_hooks($filter = false)
	{

		global $wp_filter;

		$skip_filter = empty($filter);
		$hooks       = $wp_filter;
		ksort($hooks);

		foreach ($hooks as $tag => $hook) {
			if ($skip_filter || false !== strpos($tag, $filter)) {
				self::dump_hook($tag, $hook);
			}
		}
	}

	/**
	 * Output hook info
	 *
	 * @param string        $tag  hook name
	 * @param WP_Hook|array $hook hook data
	 */
	static function dump_hook($tag, $hook)
	{

		static $counter = 0;

		if ($hook instanceof WP_Hook) {
			$hook = $hook->callbacks;
		}

		ksort($hook);
		ob_start();
		$counter = $counter + 1;
		echo "<pre>&gt;&gt;&gt;&gt;&gt;\t<strong>{$counter} - {$tag}</strong><br />";

		foreach ($hook as $priority => $functions) {
			echo $priority;

			foreach ($functions as $function) {
				echo "\t";

				$callback = $function['function'];

				if (is_string($callback)) {
					echo $callback;
				} elseif (is_a($callback, 'Closure')) {
					$closure = new ReflectionFunction($callback);
					echo 'closure from ' . $closure->getFileName() . '::' . $closure->getStartLine();
				} elseif (is_object($callback)) {
					$class = new ReflectionClass($callback);
					$name  = $class->getName();
					if (0 === strpos($name, 'class@anonymous')) {
						echo 'anonymous class from ' . $class->getFileName() . '::' . $class->getStartLine();
					} else {
						echo $name;
					}
				} elseif (is_string($callback[0])) { // static method call
					echo $callback[0] . '::' . $callback[1];
				} elseif (is_object($callback[0])) {
					echo get_class($callback[0]) . '->' . $callback[1];
				}

				echo (1 == $function['accepted_args']) ? '<br />' : " ({$function['accepted_args']}) <br />";
			}
		}

		echo '</pre>';
		$buffer = ob_get_clean();

		if (isset($_GET['save_debug_to_file']) && filter_var($_GET['save_debug_to_file'])) {
			error_log($buffer, 3, WP_CONTENT_DIR . '/r-debug.html');
		} else {
			echo $buffer;
		}
	}

	/**
	 * Enable live listing of hooks as they run
	 *
	 * @param bool|string $hook limit to matching names
	 */
	static function list_live_hooks($hook = false)
	{

		if (false === $hook) {
			$hook = 'all';
		}

		add_action($hook, array(__CLASS__, 'list_hook_details'), -1);
	}

	/**
	 * Handler for live hooks output
	 *
	 * @param mixed $input
	 *
	 * @return mixed
	 */
	static function list_hook_details($input = null)
	{

		global $wp_filter;

		$tag = current_filter();

		if (isset($wp_filter[$tag])) {
			self::dump_hook($tag, $wp_filter[$tag]);
		}

		return $input;
	}

	/**
	 * List active plugins
	 */
	static function list_plugins()
	{

		self::dump(get_option('active_plugins'));
	}

	/**
	 * List post's fields, custom fields, and terms
	 *
	 * @param int $post_id
	 */
	static function list_post($post_id = null)
	{

		if (empty($post_id)) {
			$post_id = get_the_ID();
		}

		self::dump(
			get_post($post_id),
			get_post_custom($post_id),
			wp_get_post_terms($post_id, get_post_taxonomies($post_id))
		);
	}

	/**
	 * List performed MySQL queries
	 */
	static function list_queries()
	{

		global $wpdb;

		if (!defined('SAVEQUERIES') || !SAVEQUERIES) {

			trigger_error('SAVEQUERIES needs to be defined', E_USER_NOTICE);

			return;
		}

		ob_start();
		echo '<pre>';

		foreach ($wpdb->queries as $query) {

			list($request, $duration, $backtrace) = $query;
			$duration  = sprintf('%f', $duration);
			$backtrace = explode(',', $backtrace);
			$backtrace = trim(array_pop($backtrace));

			if ('get_option' == $backtrace) {

				preg_match_all('/\option_name.*?=.*?\'(.+?)\'/', $request, $matches);
				$backtrace .= "({$matches[1][0]})";
			}

			echo "<br /><code>{$request}</code><br />{$backtrace} in {$duration}s<br />";
		}

		echo '<br /></pre>';
		$buffer = ob_get_clean();

		if (isset($_GET['save_debug_to_file']) && filter_var($_GET['save_debug_to_file'])) {
			error_log($buffer, 3, WP_CONTENT_DIR . '/r-debug.html');
		} else {
			echo $buffer;
		}
	}

	/**
	 * Run EXPLAIN on provided MySQL query or last query performed.
	 *
	 * @param string $query
	 */
	static function explain_query($query = '')
	{

		/** @var wpdb $wpdb */
		global $wpdb;

		if (empty($query)) {
			$query = $wpdb->last_query;
		}

		self::dump(
			$query,
			$wpdb->get_results('EXPLAIN EXTENDED ' . $query),
			$wpdb->get_results('SHOW WARNINGS')
		);
	}
}


// In Debug Mode, save list of hooks being executed on current page in wp-content/r-debug.log
// Enable below block, only during debugging.
// if (isset($_GET['debugging']) && filter_var($_GET['debugging'], FILTER_VALIDATE_BOOLEAN)) {
$_GET['save_debug_to_file'] = true;
$_GET['empty_old_log_in_debug_file'] = true;
R_Debug::list_live_hooks();
// }


if (isset($_GET['empty_old_log_in_debug_file']) && filter_var($_GET['empty_old_log_in_debug_file'])) {
	$fp = fopen(WP_CONTENT_DIR . '/r-debug.html', "w");
	if ($fp !== false) {
		ftruncate($fp, 0);
		fclose($fp);
	}
}