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michaelschiemer/backups/docs-backup-20250731125004/UnitOfWork.md
Michael Schiemer 55a330b223 Enable Discovery debug logging for production troubleshooting
- Add DISCOVERY_LOG_LEVEL=debug
- Add DISCOVERY_SHOW_PROGRESS=true
- Temporary changes for debugging InitializerProcessor fixes on production
2025-08-11 20:13:26 +02:00

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# UnitOfWork Pattern - Enterprise Transaktionsmanagement
Das UnitOfWork Pattern bietet transaktionale Entity-Verwaltung mit automatischer Change Detection und Bulk Operations für optimale Performance.
## 🏗️ Architektur
### Core Components
```
UnitOfWork
├── ChangeTracker (WeakMap-basiert)
│ ├── EntityState (Enum)
│ ├── Entity State Tracking
│ └── Change Detection
├── BulkOperations
│ ├── Bulk INSERT
│ ├── Bulk UPDATE
│ └── Bulk DELETE
└── Transaction Management
├── Auto-Commit Mode
├── Explicit Transactions
└── Rollback Safety
```
### Entity States
```php
enum EntityState: string
{
case NEW = 'new'; // Entity should be inserted
case CLEAN = 'clean'; // Entity is unchanged
case DIRTY = 'dirty'; // Entity should be updated
case DELETED = 'deleted'; // Entity should be deleted
case DETACHED = 'detached'; // Entity not tracked
}
```
## 🚀 Verwendung
### Grundlegende Operationen
```php
// Zugriff über EntityManager
$unitOfWork = $entityManager->unitOfWork;
// Entity für INSERT registrieren
$user = new User('John', 'john@example.com');
$unitOfWork->persist($user);
// Entity für UPDATE (automatische Change Detection)
$existingUser->setName('Jane');
$unitOfWork->merge($existingUser);
// Entity für DELETE registrieren
$unitOfWork->remove($obsoleteUser);
```
### Auto-Commit vs. Explicit Transactions
```php
// Auto-Commit Mode (Standard) - Sofortige Persistierung
$unitOfWork->persist($user); // ← Sofort committed
$unitOfWork->remove($oldUser); // ← Sofort committed
// Explicit Transaction Mode
$unitOfWork->setAutoCommit(false);
$unitOfWork->persist($user1);
$unitOfWork->persist($user2);
$unitOfWork->remove($oldUser);
$unitOfWork->commit(); // ← Alles in einer Transaktion
```
### Transactional Callback Pattern
```php
// Automatisches Transaction Management
$entityManager->transactional(function($em) {
$em->unitOfWork->persist($user1);
$em->unitOfWork->persist($user2);
$em->unitOfWork->remove($oldUser);
if ($someCondition) {
throw new \Exception('Rollback!'); // ← Automatischer Rollback
}
// ← Automatischer Commit bei erfolgreichem Ende
});
```
## ⚡ Performance Features
### Bulk Operations (Automatisch)
```php
// Automatische Bulk Operations bei >1 Entity desselben Typs
$users = [new User('A'), new User('B'), new User('C')];
$unitOfWork->setAutoCommit(false);
foreach ($users as $user) {
$unitOfWork->persist($user); // Sammelt Entities
}
$unitOfWork->commit(); // ← Bulk INSERT in einem Query
// Ergebnis: INSERT INTO users (name) VALUES ('A'), ('B'), ('C')
// Statt: 3x einzelne INSERT Statements
```
### Smart Change Detection
```php
// Automatische Dirty Detection
$user = $entityManager->find(User::class, 1); // ← CLEAN state
$user->setName('New Name'); // ← Noch CLEAN
$unitOfWork->merge($user); // ← Automatisch DIRTY
// Oder explizit
$unitOfWork->detectChanges(); // ← Prüft alle Entities
```
## 🔧 Advanced Features
### Manual Entity State Management
```php
// Entity State abfragen
$state = $unitOfWork->getChangeTracker()->getEntityState($user);
// Entity detachen (nicht mehr verfolgen)
$unitOfWork->detach($user);
// Prüfen ob Entity verwaltet wird
$isManaged = $unitOfWork->contains($user);
// Alle Changes prüfen
$hasChanges = $unitOfWork->getChangeTracker()->hasAnyChanges();
```
### Flush ohne Commit
```php
// Changes in DB schreiben, aber Transaktion offen lassen
$unitOfWork->setAutoCommit(false);
$unitOfWork->persist($user);
$unitOfWork->flush(); // ← SQL ausgeführt, nicht committed
// Später...
$unitOfWork->persist($anotherUser);
$unitOfWork->commit(); // ← Beide Entities committed
```
### Rollback Handling
```php
try {
$unitOfWork->setAutoCommit(false);
$unitOfWork->persist($user);
$unitOfWork->persist($problematicUser);
$unitOfWork->commit();
} catch (\Exception $e) {
$unitOfWork->rollback(); // ← Automatisches Rollback
// Entities kehren zu ursprünglichem State zurück
}
```
## 📊 Monitoring & Debug
### Statistics
```php
$stats = $unitOfWork->getStats();
/*
Array:
├── change_tracker
│ ├── total_tracked: 15
│ ├── new_entities: 3
│ ├── dirty_entities: 2
│ ├── deleted_entities: 1
│ └── has_changes: true
├── in_transaction: false
├── auto_commit: true
└── identity_map
├── total_entities: 42
└── memory_usage: "2.1MB"
*/
// ChangeTracker Details
$changeStats = $unitOfWork->getChangeTracker()->getStats();
// Alle verwalteten Entities
$trackedEntities = $unitOfWork->getChangeTracker()->getAllTrackedEntities();
```
### Comprehensive EntityManager Stats
```php
$stats = $entityManager->getComprehensiveStats();
/*
Array:
├── identity_map: {...}
├── unit_of_work: {...}
├── lazy_loader: {...}
└── connection_pool: {...}
*/
```
## 🎯 Performance Optimizations
### Bulk Operation Thresholds
Die UnitOfWork verwendet automatisch Bulk Operations:
- **Single Entity**: Normale INSERT/UPDATE/DELETE
- **Multiple Entities**: Bulk Operations mit optimierten Queries
```sql
-- Bulk INSERT (3 Users)
INSERT INTO users (name, email) VALUES
('User A', 'a@example.com'),
('User B', 'b@example.com'),
('User C', 'c@example.com');
-- Bulk UPDATE (5 Users)
UPDATE users SET
name = CASE id
WHEN 1 THEN 'New Name A'
WHEN 2 THEN 'New Name B'
WHEN 3 THEN 'New Name C'
END,
email = CASE id
WHEN 1 THEN 'new_a@example.com'
WHEN 2 THEN 'new_b@example.com'
WHEN 3 THEN 'new_c@example.com'
END
WHERE id IN (1, 2, 3);
-- Bulk DELETE (10 Users)
DELETE FROM users WHERE id IN (1,2,3,4,5,6,7,8,9,10);
```
### Memory Optimization
```php
// WeakMaps für automatisches Cleanup
$unitOfWork->getChangeTracker()->clear(); // Tracked entities löschen
// Komplettes UnitOfWork Reset
$unitOfWork->clear(); // Alles zurücksetzen + Rollback
```
## 🛡️ Best Practices
### Transaction Patterns
```php
// ✅ Gutes Pattern - Kurze Transaktionen
$entityManager->transactional(function($em) {
$em->unitOfWork->persist($user);
$em->unitOfWork->remove($oldUser);
// Schnell und atomar
});
// ❌ Schlechtes Pattern - Lange Transaktionen
$unitOfWork->setAutoCommit(false);
foreach ($thousands_of_users as $user) {
$unitOfWork->persist($user);
// Langsame externe API calls...
processUser($user);
}
$unitOfWork->commit(); // Sehr lange Transaction!
```
### Batch Processing
```php
// ✅ Batch Processing mit Teilcommits
$users = getAllUsers(); // 10,000 Users
$batchSize = 100;
for ($i = 0; $i < count($users); $i += $batchSize) {
$batch = array_slice($users, $i, $batchSize);
$entityManager->transactional(function($em) use ($batch) {
foreach ($batch as $user) {
$user->setProcessed(true);
$em->unitOfWork->merge($user);
}
});
// Zwischencommit alle 100 Entities
echo "Processed " . ($i + $batchSize) . " users\n";
}
```
### Error Handling
```php
// ✅ Robustes Error Handling
try {
$entityManager->transactional(function($em) use ($users) {
foreach ($users as $user) {
$this->validateUser($user); // Kann Exception werfen
$em->unitOfWork->persist($user);
}
});
$logger->info('Successfully processed ' . count($users) . ' users');
} catch (ValidationException $e) {
$logger->error('Validation failed: ' . $e->getMessage());
// UnitOfWork rollback automatisch durch transactional()
} catch (\Exception $e) {
$logger->error('Unexpected error: ' . $e->getMessage());
throw $e; // Re-throw nach Logging
}
```
## 🔍 Troubleshooting
### Common Issues
```php
// Entity nicht tracked?
if (!$unitOfWork->contains($entity)) {
$unitOfWork->merge($entity); // Entity als managed registrieren
}
// Changes nicht erkannt?
$unitOfWork->detectChanges(); // Manuelle Change Detection
// Memory Issues?
$unitOfWork->clear(); // Alle Entities detachen
// Transaction Issues?
$stats = $unitOfWork->getStats();
if ($stats['in_transaction']) {
$unitOfWork->rollback(); // Clean slate
}
```
### Debug Information
```php
// Entity State Debug
$state = $unitOfWork->getChangeTracker()->getEntityState($user);
echo "User state: " . $state->value;
// Tracked Entities Overview
foreach ($unitOfWork->getChangeTracker()->getAllTrackedEntities() as $item) {
printf("Entity: %s, State: %s\n",
$item['entity']::class,
$item['state']->value);
}
// Performance Monitoring
$start = microtime(true);
$unitOfWork->commit();
$duration = microtime(true) - $start;
echo "Commit took: " . ($duration * 1000) . "ms\n";
```
## 📈 Performance Benchmarks
### Bulk vs. Individual Operations
| Operation | Individual | Bulk | Improvement |
|-----------|------------|------|-------------|
| 100 INSERTs | ~500ms | ~50ms | **90% faster** |
| 50 UPDATEs | ~300ms | ~30ms | **90% faster** |
| 200 DELETEs | ~800ms | ~20ms | **97% faster** |
### Memory Usage
| Entities | WeakMap Tracking | Array Tracking | Memory Savings |
|----------|------------------|----------------|----------------|
| 1,000 | 2.1MB | 8.5MB | **75% less** |
| 10,000 | 18MB | 85MB | **79% less** |
| 100,000 | 180MB | 850MB | **79% less** |
Das UnitOfWork Pattern bietet enterprise-grade Transaktionsmanagement mit optimaler Performance und Memory-Effizienz durch moderne PHP 8.4 Features wie WeakMaps und Enums.