Discuss PHP performance optimization techniques for 2025, including OPcache configuration, JIT compilation, and memory management strategies.

PHP Performance Optimization for 2025:

1. OPcache Configuration:

; php.ini optimizations
opcache.enable=1
opcache.memory_consumption=256
opcache.interned_strings_buffer=16
opcache.max_accelerated_files=20000
opcache.validate_timestamps=0  ; Production only
opcache.save_comments=0
opcache.enable_file_override=1
opcache.huge_code_pages=1      ; Linux only

2. JIT (Just-In-Time) Compilation:

; Enable JIT in PHP 8.0+
opcache.jit_buffer_size=256M
opcache.jit=tracing           ; or "function" for function-level JIT

// Code optimization for JIT
function calculateFibonacci(int $n): int {
    if ($n <= 1) return $n;
    return calculateFibonacci($n - 1) + calculateFibonacci($n - 2);
}

3. Memory Management Strategies:

• Object Pooling: Reuse expensive objects
• Lazy Loading: Load data only when needed
• Memory Profiling: Use Xdebug or Blackfire
• Garbage Collection: Optimize gc_collect_cycles()

4. Advanced Techniques:

// Use generators for memory efficiency
function readLargeFile(string $filename): Generator {
    $handle = fopen($filename, "r");
    while (($line = fgets($handle)) !== false) {
        yield trim($line);
    }
    fclose($handle);
}

// Implement object caching
class CachedUserService {
    private array $cache = [];
    
    public function getUser(int $id): User {
        return $this->cache[$id] ??= $this->userRepository->find($id);
    }
}

5. Database Optimization:

• Connection pooling with persistent connections
• Query optimization and indexing
• Database result caching
• Read/write splitting

Monitoring: Use APM tools like New Relic, Datadog, or open-source alternatives like Jaeger for distributed tracing.