Profiler Class

The Profiler class renders a fixed, collapsible debug toolbar at the bottom of every page during development. It displays execution benchmarks, memory usage, database queries, request data, session state, HTTP headers, and application configuration — all without touching your view files.

Loading

Load the library inside your controller or base controller constructor:

<?php
$this->call->library('profiler');

Once loaded, the profiler registers a PHP shutdown function automatically. The toolbar is injected into the page at the end of every request — you do not need to call anything in your views.

Warning

Only enable the Profiler in development environments. It exposes database queries, session data, config values, and POST/GET payloads. Never load it on a production server.

<?php
if (config_item('environment') === 'development')
{
    $this->call->library('profiler');
}

Toolbar Overview

The toolbar sits fixed at the bottom of the browser window and shows a summary bar at all times. Clicking the bar toggles the full panel open or closed.

Summary bar chips

Chip	Contents
MEM	Current PHP memory usage (e.g. 2.40 MB)
⏱ 0.0821s	Total page execution time
4 queries	Number of database queries executed
GET / POST	HTTP request method

Panel tabs

Tab	Contents
Benchmarks	LavaLust execution time, custom timers, and total page time. Rows exceeding 0.5 s are highlighted in red.
Memory	Current memory usage, peak memory usage, and the PHP memory limit.
Queries	All database queries with bound values interpolated for readability. Queries exceeding 100 ms are highlighted in red.
POST	All $_POST key-value pairs for the current request.
GET	All $_GET key-value pairs for the current request.
URI	Full REQUEST_URI of the current request.
Session	All $_SESSION key-value pairs (only shown when a session is active).
Headers	All incoming HTTP request headers.
Config	All key-value pairs from the LavaLust config class.
PHP Info	PHP version, OS, SAPI, max execution time, upload limits, and loaded extensions. Disabled by default — enable via set_sections().

Enabling and Disabling Sections

Use set_sections() to show or hide individual tabs. Pass an associative array of section names mapped to TRUE or FALSE:

<?php
$this->call->library('profiler');

// Disable sections you do not need
$this->profiler->set_sections([
    'config'   => FALSE,
    'session'  => FALSE,
    'php_info' => FALSE,
]);

// Enable the PHP Info tab (disabled by default)
$this->profiler->set_sections([
    'php_info' => TRUE,
]);

All available section keys and their defaults:

Section key	Default	Description
benchmarks	TRUE	Execution timers and total page time
memory	TRUE	PHP memory usage and peak
queries	TRUE	Database queries executed this request
post_data	TRUE	$_POST key-value pairs
get_data	TRUE	$_GET key-value pairs
uri_string	TRUE	Full request URI
session	TRUE	$_SESSION data (when a session is active)
headers	TRUE	Incoming HTTP request headers
config	TRUE	LavaLust application config values
php_info	FALSE	PHP version, extensions, and ini settings

Note

Unknown section keys are silently ignored — only keys listed in the table above are recognised.

Custom Benchmark Timers

You can add your own named timers to the Benchmarks tab using mark_start() and mark_end():

<?php
$this->profiler->mark_start('render_template');

// ... some code to measure ...

$this->profiler->mark_end('render_template');

The elapsed time appears in the Benchmarks panel alongside the built-in LavaLust and total-page timers.

Multiple timers

<?php
$this->profiler->mark_start('db_fetch');
$users = $this->user_model->get_all();
$this->profiler->mark_end('db_fetch');

$this->profiler->mark_start('build_csv');
$csv = $this->csv_service->from_array($users);
$this->profiler->mark_end('build_csv');

Note

If mark_end() is never called for a timer (e.g. an early return in your code), the Benchmarks panel shows (running) for that entry rather than a time value.

Method	Signature	Returns
mark_start()	mark_start($name)	void
mark_end()	mark_end($name)	void

Manually Rendering the Toolbar

The profiler renders itself automatically via a PHP shutdown function, so you normally do not need to call display() at all. If you need to force output at a specific point (for example, before a die() call or in a custom error page), call it explicitly:

<?php
$this->profiler->display();

display() is idempotent — calling it more than once outputs the toolbar only on the first call. The shutdown function will not output it a second time.

Method	Signature	Description
display()	display()	Render and echo the toolbar immediately
set_sections()	set_sections(array $sections)	Show or hide individual tabs

Queries Tab

The Queries tab shows every database query executed during the request. Bound parameter values are interpolated inline for readability so you can see the actual data being queried — not just placeholder ? markers.

Rows exceeding 100 ms are highlighted in red to make slow queries immediately visible.

Note

Query logging requires the LavaLust Database class to expose a get_query_log() method that returns an array of entries in the form:

[
    'query'    => 'SELECT * FROM users WHERE id = ?',
    'bindings' => [42],
    'time'     => 0.00123,
]

If the database is not loaded or does not implement get_query_log(), the tab shows “No queries executed — or DB not loaded.”

Slow Threshold Reference

Panel	Threshold	Visual indicator
Benchmarks	> 0.5 s	Row background turns red with a left red border
Queries	> 0.1 s (100 ms)	Row background turns red with a left red border

Method Reference

Method	Signature	Returns
set_sections()	set_sections(array $sections)	void
mark_start()	mark_start($name)	void
mark_end()	mark_end($name)	void
display()	display()	void

Complete Example

<?php
// app/controllers/Dashboard.php
class Dashboard extends Controller
{
    public function __construct()
    {
        parent::__construct();
        $this->call->model('Report_model', 'report_model');

        if (config_item('environment') === 'development')
        {
            $this->call->library('profiler');

            $this->profiler->set_sections([
                'php_info' => TRUE,
                'config'   => FALSE,
            ]);
        }
    }

    public function index()
    {
        // Time the data-fetch phase
        $this->profiler->mark_start('fetch_reports');
        $reports = $this->report_model->get_latest(50);
        $this->profiler->mark_end('fetch_reports');

        // Time the processing phase
        $this->profiler->mark_start('process_reports');
        $summary = $this->_build_summary($reports);
        $this->profiler->mark_end('process_reports');

        $data['summary'] = $summary;
        $this->call->view('dashboard/index', $data);

        // Toolbar renders automatically at shutdown —
        // no need to call display() here
    }
}

The Benchmarks tab will show four rows for the above request:

Label	Time
LavaLust Execution	0.0041s
fetch_reports	0.0218s
process_reports	0.0093s
Total Page Time	0.0482s

Tips and Best Practices

• Load the Profiler inside an environment === 'development' guard so it can never accidentally run in production.

• Use mark_start() / mark_end() around any code path you suspect is slow — database calls, file reads, external API requests, or view rendering.

• Use the Queries tab to catch N+1 problems: if the query count grows with the number of items on a page, you likely need eager loading or a JOIN.

• Disable sections you are not actively investigating (set_sections(['config' => FALSE, 'headers' => FALSE])) to keep the toolbar focused and fast to scan.

• The PHP Info tab is disabled by default because it exposes loaded extension names and ini settings. Only enable it when you specifically need to verify the server environment.

• If mark_end() is never reached for a timer, the entry shows (running) as a reminder that the measurement is incomplete.

• The toolbar CSS is injected only once per page (tracked with a static variable) so loading the library multiple times does not duplicate the styles.