|
| 1 | +# CLAUDE.md |
| 2 | + |
| 3 | +This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository. |
| 4 | + |
| 5 | +## Project Overview |
| 6 | + |
| 7 | +Nette Caching is a PHP library providing flexible caching with multiple storage backends and advanced dependency tracking. It's part of the Nette Framework ecosystem. |
| 8 | + |
| 9 | +**Key features:** |
| 10 | +- Multiple storage backends (FileStorage, MemcachedStorage, SQLiteStorage, MemoryStorage) |
| 11 | +- Advanced dependency tracking (tags, priorities, file changes, callbacks) |
| 12 | +- Cache stampede prevention in FileStorage |
| 13 | +- Atomic operations with file locking |
| 14 | +- PSR-16 SimpleCache adapter |
| 15 | +- Latte template integration with `{cache}` tag |
| 16 | +- Nette DI integration |
| 17 | + |
| 18 | +**Requirements:** PHP 8.1-8.5 |
| 19 | + |
| 20 | +## Essential Commands |
| 21 | + |
| 22 | +### Testing |
| 23 | + |
| 24 | +```bash |
| 25 | +# Run all tests |
| 26 | +vendor/bin/tester tests -C -s -C |
| 27 | + |
| 28 | +# Run specific test directory |
| 29 | +vendor/bin/tester tests/Caching -C -s -C |
| 30 | +vendor/bin/tester tests/Storages -C -s -C |
| 31 | + |
| 32 | +# Run single test file |
| 33 | +php tests/Caching/Cache.bulkLoad.phpt |
| 34 | + |
| 35 | +# Flags used: |
| 36 | +# -C = Use system-wide php.ini |
| 37 | +# -s -C = Show skipped tests |
| 38 | +``` |
| 39 | + |
| 40 | +### Static Analysis |
| 41 | + |
| 42 | +```bash |
| 43 | +# Run PHPStan (level 5) |
| 44 | +composer run phpstan |
| 45 | + |
| 46 | +# Or directly |
| 47 | +vendor/bin/phpstan analyse |
| 48 | +``` |
| 49 | + |
| 50 | +### Linting |
| 51 | + |
| 52 | +```bash |
| 53 | +# Nette coding standard checks |
| 54 | +composer run tester |
| 55 | +``` |
| 56 | + |
| 57 | +## Architecture Overview |
| 58 | + |
| 59 | +### Core Layering |
| 60 | + |
| 61 | +The library follows a clean separation of concerns: |
| 62 | + |
| 63 | +``` |
| 64 | +Cache (high-level API) |
| 65 | + ↓ |
| 66 | +Storage interface (abstraction) |
| 67 | + ↓ |
| 68 | +Storage implementations (FileStorage, MemcachedStorage, etc.) |
| 69 | + ↓ |
| 70 | +Journal interface (for tags/priorities) |
| 71 | + ↓ |
| 72 | +SQLiteJournal implementation |
| 73 | +``` |
| 74 | + |
| 75 | +**Cache** (`src/Caching/Cache.php`): Primary API for caching operations. Provides namespace isolation, dependency tracking, memoization (`wrap()`, `call()`), and output capturing (`capture()`, was `start()` in v3.0). |
| 76 | + |
| 77 | +**Storage interface** (`src/Caching/Storage.php`): Defines the contract all storage backends must implement: |
| 78 | +- `read(string $key): mixed` |
| 79 | +- `write(string $key, $data, array $dependencies): void` |
| 80 | +- `remove(string $key): void` |
| 81 | +- `clean(array $conditions): void` |
| 82 | +- `lock(string $key): void` - Prevents concurrent writes |
| 83 | + |
| 84 | +**Journal interface** (`src/Caching/Storages/Journal.php`): Tracks metadata for tags and priorities. Required for: |
| 85 | +- `Cache::Tags` - Tag-based invalidation |
| 86 | +- `Cache::Priority` - Priority-based cleanup |
| 87 | + |
| 88 | +Default implementation: SQLiteJournal using SQLite database at `{tempDir}/journal.s3db`. |
| 89 | + |
| 90 | +### Storage Implementations |
| 91 | + |
| 92 | +All in `src/Caching/Storages/`: |
| 93 | + |
| 94 | +- **FileStorage** - Production default. Files stored in temp directory with atomic operations via file locking (LOCK_SH for reads, LOCK_EX for writes). Implements cache stampede prevention: when cache miss occurs with concurrent requests, only first thread generates value, others wait. File format: 6-byte header with meta size + serialized metadata + data. |
| 95 | + |
| 96 | +- **SQLiteStorage** - Single-file database storage. Good for shared hosting environments. |
| 97 | + |
| 98 | +- **MemcachedStorage** - Distributed caching via Memcached server. Requires `memcached` PHP extension. |
| 99 | + |
| 100 | +- **MemoryStorage** - In-memory array storage, lost after request. Used for testing or request-scoped caching. |
| 101 | + |
| 102 | +- **DevNullStorage** - No-op storage for testing when you want to disable caching. |
| 103 | + |
| 104 | +### Dependency System |
| 105 | + |
| 106 | +Cache dependencies control expiration and invalidation. All use Cache class constants: |
| 107 | + |
| 108 | +- `Cache::Expire` - Time-based expiration (timestamp, seconds, or string like "20 minutes") |
| 109 | +- `Cache::Sliding` - Extends expiration on each read |
| 110 | +- `Cache::Files` - Invalidate when file(s) modified (checks filemtime) |
| 111 | +- `Cache::Items` - Invalidate when other cache items expire |
| 112 | +- `Cache::Tags` - Tag-based invalidation (requires Journal) |
| 113 | +- `Cache::Priority` - Priority-based cleanup (requires Journal) |
| 114 | +- `Cache::Callbacks` - Custom validation callbacks |
| 115 | +- `Cache::Constants` - Invalidate when PHP constants change |
| 116 | + |
| 117 | +Dependencies can be combined; cache expires when ANY criterion fails. |
| 118 | + |
| 119 | +### Bridge Components |
| 120 | + |
| 121 | +**Nette DI Bridge** (`src/Bridges/CacheDI/CacheExtension.php`): |
| 122 | +- Auto-registers Storage service (FileStorage by default) |
| 123 | +- Auto-registers Journal service (SQLiteJournal if pdo_sqlite available) |
| 124 | +- Validates and creates temp directory |
| 125 | +- Services registered: `cache.storage`, `cache.journal` |
| 126 | + |
| 127 | +**Latte Bridge** (`src/Bridges/CacheLatte/`): |
| 128 | +- Provides `{cache}` tag for template caching |
| 129 | +- Runtime in `Runtime.php` manages cache lifecycle |
| 130 | +- Node compilation in `Nodes/CacheNode.php` |
| 131 | +- Automatic invalidation when template source changes |
| 132 | +- Supports parameters: `{cache $id, expire: '20 minutes', tags: [tag1, tag2]}` |
| 133 | +- Can be conditional: `{cache $id, if: !$form->isSubmitted()}` |
| 134 | + |
| 135 | +**PSR-16 Bridge** (`src/Bridges/Psr/PsrCacheAdapter.php`): |
| 136 | +- Adapts Nette Storage to PSR-16 SimpleCache interface |
| 137 | +- Used for PSR compatibility in third-party integrations |
| 138 | + |
| 139 | +### Bulk Operations |
| 140 | + |
| 141 | +Two specialized classes enable efficient bulk operations: |
| 142 | + |
| 143 | +- **BulkReader** (`src/Caching/BulkReader.php`) - Interface for storages supporting bulk reads |
| 144 | +- **BulkWriter** (`src/Caching/BulkWriter.php`) - Interface for storages supporting bulk writes |
| 145 | + |
| 146 | +Used by `Cache::bulkLoad()` and `Cache::bulkSave()` to reduce storage round-trips. |
| 147 | + |
| 148 | +## Testing Structure |
| 149 | + |
| 150 | +Tests organized by component in `tests/`: |
| 151 | +- `Caching/` - Cache class tests |
| 152 | +- `Storages/` - Storage implementation tests |
| 153 | +- `Bridges.DI/` - Nette DI integration tests |
| 154 | +- `Bridges.Latte3/` - Latte 3.x template caching tests |
| 155 | +- `Bridges.Psr/` - PSR-16 adapter tests |
| 156 | + |
| 157 | +Test utilities: |
| 158 | +- `bootstrap.php` - Test environment setup with `test()` helper function |
| 159 | +- `getTempDir()` - Creates isolated temp directory per test process |
| 160 | +- Uses Nette Tester with `.phpt` format |
| 161 | + |
| 162 | +## Development Notes |
| 163 | + |
| 164 | +### File Locking Strategy (FileStorage) |
| 165 | + |
| 166 | +Three atomic operation types documented in FileStorage.php: |
| 167 | +1. **Reading**: open(r+b) → lock(LOCK_SH) → read → close |
| 168 | +2. **Deleting**: unlink, if fails lock(LOCK_EX) → truncate → close → unlink |
| 169 | +3. **Writing**: open(r+b or wb) → lock(LOCK_EX) → truncate → write data → write meta → close |
| 170 | + |
| 171 | +This ensures atomicity on both NTFS and ext3 filesystems. |
| 172 | + |
| 173 | +### Cache Stampede Prevention |
| 174 | + |
| 175 | +FileStorage prevents cache stampede through locking: when multiple concurrent threads request non-existent cache item, `lock()` ensures only first thread generates value while others wait. Others then use the generated result. |
| 176 | + |
| 177 | +### Namespace Handling |
| 178 | + |
| 179 | +Cache uses internal null byte separator (`Cache::NamespaceSeparator = "\x00"`) to isolate namespaces. Keys are prefixed with `{namespace}\x00{key}`. |
| 180 | + |
| 181 | +### Constants Naming |
| 182 | + |
| 183 | +Library uses modern PascalCase constants (e.g., `Cache::Expire`) with deprecated UPPERCASE aliases (e.g., `Cache::EXPIRATION`) for backward compatibility. |
| 184 | + |
| 185 | +**Version 3.0 compatibility note:** In version 3.0, the Storage interface was named `IStorage` (with `I` prefix) and constants were UPPERCASE (e.g., `Cache::EXPIRE` instead of `Cache::Expire`). |
| 186 | + |
| 187 | +## Using Cache in Code |
| 188 | + |
| 189 | +Two approaches for dependency injection: |
| 190 | + |
| 191 | +**Approach 1: Inject Storage, create Cache manually** |
| 192 | +```php |
| 193 | +class ClassOne |
| 194 | +{ |
| 195 | + private Nette\Caching\Cache $cache; |
| 196 | + |
| 197 | + public function __construct(Nette\Caching\Storage $storage) |
| 198 | + { |
| 199 | + $this->cache = new Nette\Caching\Cache($storage, 'my-namespace'); |
| 200 | + } |
| 201 | +} |
| 202 | +``` |
| 203 | + |
| 204 | +**Approach 2: Inject Cache directly** |
| 205 | +```php |
| 206 | +class ClassTwo |
| 207 | +{ |
| 208 | + public function __construct( |
| 209 | + private Nette\Caching\Cache $cache, |
| 210 | + ) { |
| 211 | + } |
| 212 | +} |
| 213 | +``` |
| 214 | + |
| 215 | +Configuration for Approach 2: |
| 216 | +```neon |
| 217 | +services: |
| 218 | + - ClassTwo( Nette\Caching\Cache(namespace: 'my-namespace') ) |
| 219 | +``` |
| 220 | + |
| 221 | +## DI Services |
| 222 | + |
| 223 | +Services automatically registered by CacheExtension: |
| 224 | + |
| 225 | +| Service Name | Type | Description | |
| 226 | +|--------------|------|-------------| |
| 227 | +| `cache.storage` | `Nette\Caching\Storage` | Primary cache storage (FileStorage by default) | |
| 228 | +| `cache.journal` | `Nette\Caching\Storages\Journal` | Journal for tags/priorities (SQLiteJournal, requires pdo_sqlite) | |
| 229 | + |
| 230 | +## Configuration Examples |
| 231 | + |
| 232 | +### Change Storage Backend |
| 233 | + |
| 234 | +```neon |
| 235 | +services: |
| 236 | + cache.storage: Nette\Caching\Storages\DevNullStorage |
| 237 | +``` |
| 238 | + |
| 239 | +### Use MemcachedStorage |
| 240 | + |
| 241 | +```neon |
| 242 | +services: |
| 243 | + cache.storage: Nette\Caching\Storages\MemcachedStorage('10.0.0.5') |
| 244 | +``` |
| 245 | + |
| 246 | +### Use SQLiteStorage |
| 247 | + |
| 248 | +```neon |
| 249 | +services: |
| 250 | + cache.storage: Nette\Caching\Storages\SQLiteStorage('%tempDir%/cache.db') |
| 251 | +``` |
| 252 | + |
| 253 | +### Custom Journal |
| 254 | + |
| 255 | +```neon |
| 256 | +services: |
| 257 | + cache.journal: MyJournal |
| 258 | +``` |
| 259 | + |
| 260 | +### Disable Caching (for testing) |
| 261 | + |
| 262 | +```neon |
| 263 | +services: |
| 264 | + cache.storage: Nette\Caching\Storages\DevNullStorage |
| 265 | +``` |
| 266 | + |
| 267 | +**Note:** This doesn't affect Latte template caching or DI container caching, as those are managed independently and [don't need to be disabled during development](https://doc.nette.org/troubleshooting#How-to-Disable-Cache-During-Development). |
| 268 | + |
| 269 | +## PSR-16 Usage |
| 270 | + |
| 271 | +The `PsrCacheAdapter` provides PSR-16 SimpleCache compatibility (available since v3.3.1): |
| 272 | + |
| 273 | +```php |
| 274 | +$psrCache = new Nette\Bridges\Psr\PsrCacheAdapter($storage); |
| 275 | + |
| 276 | +// PSR-16 interface |
| 277 | +$psrCache->set('key', 'value', 3600); |
| 278 | +$value = $psrCache->get('key', 'default'); |
| 279 | + |
| 280 | +// Supports all PSR-16 methods |
| 281 | +$psrCache->getMultiple(['key1', 'key2']); |
| 282 | +$psrCache->setMultiple(['key1' => 'val1', 'key2' => 'val2']); |
| 283 | +$psrCache->deleteMultiple(['key1', 'key2']); |
| 284 | +``` |
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