Performance Profiling

WP Dumper includes a powerful profiling system that helps you identify performance bottlenecks in your WordPress application.

📊 Basic Profiling

Starting and Stopping Profiling

// Start profiling
start_wp_profiling();

// Your code to profile
do_some_heavy_operations();

// Stop profiling and view results
stop_wp_profiling();

Adding Checkpoints

Checkpoints help you track performance at specific points in your code:

start_wp_profiling();

wp_checkpoint('Plugin initialization');
// Plugin init code...

wp_checkpoint('Database queries');
// Database operations...

wp_checkpoint('Template rendering');
// Template code...

stop_wp_profiling();

🎯 What Gets Profiled

The profiler automatically tracks:

• Execution time between checkpoints
• Memory usage and memory differences
• Database queries executed
• WordPress hooks called (with call counts)
• Overall performance metrics

📈 Profiling Output

When you call stop_wp_profiling(), you’ll see:

Execution Summary

execution_summary: {
  total_time: "2.1234s"
  memory_used: "15.2 MB"
  peak_memory: "32.1 MB"
  total_queries: 47
}

Checkpoints

checkpoints: [
  {
    label: "Plugin initialization"
    elapsed_time: "0.0123s"
    memory_diff: "2.1 MB"
    queries_diff: 5
    total_time: "0.0123s"
    total_memory: "12.3 MB"
  },
  {
    label: "Database queries"
    elapsed_time: "0.0456s"
    memory_diff: "1.8 MB"
    queries_diff: 12
    total_time: "0.0579s"
    total_memory: "14.1 MB"
  }
]

Top Hooks

top_hooks: {
  "wp_head": 23
  "wp_enqueue_scripts": 15
  "init": 12
  "wp_footer": 8
}

Query Analysis

query_summary: {
  total_queries: 47
  select_queries: 42
  insert_queries: 3
  update_queries: 2
  delete_queries: 0
}

slow_queries: [
  {
    query: "SELECT * FROM wp_posts WHERE..."
    backtrace: "wp-includes/post.php:123"
  }
]

🔧 Advanced Profiling

Profiling Specific Code Blocks

// Profile a specific function
function my_heavy_function() {
    start_wp_profiling();
    
    wp_checkpoint('Start heavy operation');
    
    // Heavy code here
    for ($i = 0; $i < 1000; $i++) {
        // Some operation
    }
    
    wp_checkpoint('End heavy operation');
    
    stop_wp_profiling();
}

Profiling WordPress Hooks

// Profile what happens during wp_head
add_action('wp_head', function() {
    start_wp_profiling();
    wp_checkpoint('wp_head start');
}, 1);

add_action('wp_head', function() {
    wp_checkpoint('wp_head end');
    stop_wp_profiling();
}, 999);

Profiling Page Load

// In your theme's functions.php
add_action('init', function() {
    start_wp_profiling();
    wp_checkpoint('WordPress init');
});

add_action('wp_footer', function() {
    wp_checkpoint('Before footer');
    stop_wp_profiling();
}, 999);

📊 Performance Metrics

Quick Performance Check

// Quick performance snapshot
dump_performance();

/* Shows:
- Execution time
- Memory usage (current, peak, limit)
- Database queries
- Loaded plugins count
*/

Using the perf() Shortcut

// Same as dump_performance()
perf();

🎯 Common Profiling Scenarios

1. Plugin Performance Analysis

// Profile plugin activation
register_activation_hook(__FILE__, function() {
    start_wp_profiling();
    wp_checkpoint('Plugin activation start');
    
    // Plugin activation code
    create_database_tables();
    wp_checkpoint('Database tables created');
    
    setup_default_options();
    wp_checkpoint('Default options set');
    
    stop_wp_profiling();
});

2. Theme Performance Analysis

// In functions.php
add_action('after_setup_theme', function() {
    start_wp_profiling();
    wp_checkpoint('Theme setup start');
});

add_action('wp_enqueue_scripts', function() {
    wp_checkpoint('Scripts enqueued');
});

add_action('wp_footer', function() {
    wp_checkpoint('Footer rendered');
    stop_wp_profiling();
}, 999);

3. Custom Query Performance

function get_featured_products() {
    start_wp_profiling();
    wp_checkpoint('Query start');
    
    $products = new WP_Query([
        'post_type' => 'product',
        'meta_query' => [
            [
                'key' => 'featured',
                'value' => 'yes'
            ]
        ]
    ]);
    
    wp_checkpoint('Query executed');
    
    $processed = process_products($products->posts);
    wp_checkpoint('Products processed');
    
    stop_wp_profiling();
    
    return $processed;
}

4. AJAX Performance Analysis

add_action('wp_ajax_my_action', function() {
    start_wp_profiling();
    wp_checkpoint('AJAX start');
    
    // AJAX processing
    $data = process_ajax_request();
    wp_checkpoint('Request processed');
    
    wp_send_json_success($data);
    wp_checkpoint('Response sent');
    
    stop_wp_profiling();
});

🚀 Performance Optimization Tips

Based on Profiling Results

1. High Memory Usage: Look for memory leaks in loops or large data structures
2. Many Database Queries: Consider caching or query optimization
3. Slow Checkpoints: Identify bottleneck functions
4. High Hook Counts: Review unnecessary hook callbacks

Example Optimization

// Before optimization
function get_user_posts($user_id) {
    start_wp_profiling();
    
    $posts = get_posts(['author' => $user_id]);
    wp_checkpoint('Posts retrieved');
    
    foreach ($posts as $post) {
        $meta = get_post_meta($post->ID); // N+1 problem!
        wp_checkpoint("Meta for post {$post->ID}");
    }
    
    stop_wp_profiling();
}

// After optimization
function get_user_posts_optimized($user_id) {
    start_wp_profiling();
    
    $posts = get_posts(['author' => $user_id]);
    wp_checkpoint('Posts retrieved');
    
    // Get all meta in one query
    $post_ids = wp_list_pluck($posts, 'ID');
    $all_meta = get_post_meta($post_ids);
    wp_checkpoint('All meta retrieved');
    
    stop_wp_profiling();
}

🔍 Analyzing Results

Reading Checkpoint Data

• elapsed_time: Time since last checkpoint
• memory_diff: Memory change since last checkpoint
• queries_diff: Queries executed since last checkpoint
• total_time: Total time since profiling started
• total_memory: Total memory usage at this point

Identifying Bottlenecks

1. Look for checkpoints with high elapsed_time
2. Check for large memory_diff values
3. Watch for high queries_diff numbers
4. Review the top_hooks for unexpected high counts

💡 Best Practices

1. Use descriptive checkpoint labels
2. Profile in development environment first
3. Remove profiling code from production
4. Focus on the biggest bottlenecks first
5. Profile before and after optimizations
6. Use profiling with query analysis for complete picture

🔗 Related Documentation

• Query Analysis - Database query debugging
• WordPress Debugging - WordPress-specific debugging