Package io.github.dhruv1110.jcachex

Class CacheEntry<V>

  • Type Parameters:
    V - the type of the cached value
    public class CacheEntry<V>
extends Object
    Represents a cache entry containing a value along with metadata for cache management.

    This class encapsulates both the cached value and important metadata such as creation time, last access time, access count, weight, and expiration information. This metadata is used by eviction strategies, expiration policies, and statistics collection.

    Key Features:

    • Value Storage: Holds the actual cached value
    • Access Tracking: Maintains access count and last access time for LRU/LFU eviction
    • Weight Support: Stores entry weight for weight-based eviction strategies
    • Expiration: Tracks creation time and expiration time for TTL policies
    • Thread Safety: Access count updates are atomic and thread-safe

    Usage in Cache Operations:

    
 // Cache entries are created internally when putting values
 cache.put("user123", user); // Creates CacheEntry<User> internally

 // Eviction strategies use entry metadata
 // LRU strategy checks lastAccessTime
 // LFU strategy checks accessCount
 // Weight-based strategy checks weight

 // Expiration policies use creation and expiration times
 if (entry.isExpired()) {
     cache.remove(key); // Entry is automatically removed
 }

    Integration with Eviction Strategies:

    
 // Custom eviction strategy example
 public class CustomEvictionStrategy<K, V> implements EvictionStrategy<K, V> { @Override
     public K selectEvictionCandidate(Map<K, CacheEntry<V>> entries) {
         return entries.entrySet().stream()
                 .min((e1, e2) -> {
                     CacheEntry<V> entry1 = e1.getValue();
                     CacheEntry<V> entry2 = e2.getValue();

                     // Evict entry with lowest access count
                     return Long.compare(entry1.getAccessCount(), entry2.getAccessCount());
                 })
                 .map(Map.Entry::getKey)
                 .orElse(null);
     }
     // ... other methods
 }
    Since:
    1.0.0
    See Also:
    EvictionStrategy, CacheConfig

    • Constructor Detail

      • CacheEntry

        public CacheEntry​(V value,
                  long weight,
                  Instant expirationTime)

    • Method Detail

      • getValue

        public V getValue()

      • getWeight

        public long getWeight()

      • isExpired

        public boolean isExpired()

      • getExpirationTime

        public Instant getExpirationTime()

      • getAccessCount

        public long getAccessCount()

      • incrementAccessCount

        public void incrementAccessCount()

      • getLastAccessTime

        public Instant getLastAccessTime()

      • getCreationTime

        public Instant getCreationTime()