Wordpress: Print hooks

wp-print-hooks.php

<?php
/*
Plugin Name: Instrument Hooks for WordPress
Description: Instruments Hooks for a Page. Outputs during the Shutdown Hook.
Version: 0.1
Author: Mike Schinkel
Author URI: http://mikeschinkel.com
*/

if ($_GET['instrument']=='hooks') {

    add_action('shutdown','instrument_hooks');
    function instrument_hooks() {
        global $wpdb;
        $hooks = $wpdb->get_results("SELECT * FROM wp_hook_list ORDER BY first_call");
        $html = array();
        $html[] = '<style>#instrumented-hook-list table,#instrumented-hook-list th,#instrumented-hook-list td {border:1px solid gray;padding:2px 5px;}</style>
<div align="center" id="instrumented-hook-list">
    <table>
        <tr>
        <th>First Call</th>
        <th>Hook Name</th>
        <th>Hook Type</th>
        <th>Arg Count</th>
        <th>Called By</th>
        <th>Line #</th>
        <th>File Name</th>
        </tr>';
        foreach($hooks as $hook) {
            $html[] = "<tr>
            <td>{$hook->first_call}</td>
            <td>{$hook->hook_name}</td>
            <td>{$hook->hook_type}</td>
            <td>{$hook->arg_count}</td>
            <td>{$hook->called_by}</td>
            <td>{$hook->line_num}</td>
            <td>{$hook->file_name}</td>
            </tr>";
        }
        $html[] = '</table></div>';
        echo implode("\n",$html);
    }

    add_action('all','record_hook_usage');
    function record_hook_usage($hook){
        global $wpdb;
        static $in_hook = false;
        static $first_call = 1;
        static $doc_root;
        $callstack = debug_backtrace();
        if (!$in_hook) {
            $in_hook = true;
            if ($first_call==1) {
                $doc_root = $_SERVER['DOCUMENT_ROOT'];
                $results = $wpdb->get_results("SHOW TABLE STATUS LIKE 'wp_hook_list'");
                if (count($results)==1) {
                    $wpdb->query("TRUNCATE TABLE wp_hook_list");
                } else {
                    $wpdb->query("CREATE TABLE wp_hook_list (
                    called_by varchar(96) NOT NULL,
                    hook_name varchar(96) NOT NULL,
                    hook_type varchar(15) NOT NULL,
                    first_call int(11) NOT NULL,
                    arg_count tinyint(4) NOT NULL,
                    file_name varchar(128) NOT NULL,
                    line_num smallint NOT NULL,
                    PRIMARY KEY (first_call,hook_name))"
                    );
                }
            }
            $args = func_get_args();
            $arg_count = count($args)-1;
            $hook_type = str_replace('do_','',
                str_replace('apply_filters','filter',
                    str_replace('_ref_array','[]',
                        $callstack[3]['function'])));
            $file_name = str_replace($doc_root,'',$callstack[3]['file']);
            $line_num = $callstack[3]['line'];
            $called_by = $callstack[4]['function'];
            $wpdb->query("INSERT wp_hook_list
                (first_call,called_by,hook_name,hook_type,arg_count,file_name,line_num)
                VALUES ($first_call,'$called_by()','$hook','$hook_type',$arg_count,'$file_name',$line_num)");
            $first_call++;
            $in_hook = false;
        }
    }
}
?>