isaacs/node-lru-cache
Node Lru Cache
node-lru-cache ist ein Key-Value-Store für Node.js, der einen speicherbegrenzten Cache implementiert. Er verhindert Speichererschöpfung durch Deckelung der Gesamtzahl der Elemente oder der Gesamt-Byte-Größe und entfernt automatisch die am wenigsten verwendeten Elemente (Least-Recently-Used), um diese Limits einzuhalten.
Das Projekt bietet spezialisierte Caching-Muster, einschließlich Time-to-Live-Dauern zur Sicherstellung der Datenfrische und einen Stale-While-Revalidate-Mechanismus, der abgelaufene Inhalte bereitstellt, während im Hintergrund asynchron Updates abgerufen werden. Es enthält zudem Diagnose-Tools zur Überwachung von Cache-Hits, Misses und Eviction-Metriken über operative Statusobjekte und Diagnose-Kanäle.
Die Implementierung deckt weiterführende Funktionen für Speichermanagement und Datenwiederherstellung ab, wie etwa das automatische Abrufen von Daten für fehlende Einträge, das manuelle Bereinigen veralteter Elemente und die Ausführung von Cleanup-Funktionen beim Ablauf von Elementen, um externe Ressourcen freizugeben.
Features
- Memory-Limited Caches - Implements a memory-limited key-value store that prevents exhaustion by capping item counts or total byte size.
- LRU Cache Eviction - Implements a memory-limited cache that automatically evicts the least-recently-used items to prevent memory exhaustion.
- Cache Eviction Policies - Implements size-based eviction algorithms to maintain memory limits by removing the oldest items.
- Least Recently Used Caches - Prevents application crashes by capping memory usage through an automatic least-recently-used eviction policy.
- Application Caching - Stores frequently accessed application data in memory to reduce latency and database load.
- Hash Maps - Utilizes a hash map to provide constant-time retrieval of cached entries and their associated tracking nodes.
- Linked-List LRU Evictions - Uses a doubly linked list to maintain access order for efficient least-recently-used item eviction.
- Time-To-Live Expirations - Implements automatic data expiration based on configurable time-to-live durations.
- Cache Memory Limits - Enforces memory constraints by blocking items that exceed a calculated size from entering the cache.
- Resource Disposal - Provides mechanisms for disposing of resources and executing cleanup functions when items are removed.
- Eviction Callbacks - Implements hooks that execute custom cleanup logic when cache entries are evicted or expire.
- Resource Lifecycle Management - Ensures the release of external system resources through cleanup logic executed upon item expiration.
- Cache Performance Monitoring - Tracks hit ratios, misses, and eviction metrics to analyze and optimize caching efficiency.
- Diagnostic Channels - Provides internal event publishing via diagnostic channels for real-time observability of cache performance metrics.
- Data Fetching - Automates data recovery by retrieving values through a specified method when a key is missing.
- Stale-While-Revalidate - Supports the stale-while-revalidate pattern to serve expired content while asynchronously updating entries.
- Caching - LRU cache implementation.
