Cache Management System

The objective of this system is to enable user to utilise a generic framework and define their own flavour of cache (customised cacheStorage and eviction policies).

Current Implementation:

• A generic class Cache.java which can be initialised using a cacheStorage class (eg: SingleTierStorage.java) and an eviction policy class (eg: LRUEvictionPolicy.java, FIFOCacheEvictionPolicy.java)

• CacheStorage.java is an interface with generic <K, V> and every implementation must implement:

  • void add(K k, V v)
  • V get(K k)
  • List<K> getAll()
  • V remove(K k)

• CacheEvictionPolicy.java is an interface with generic <K> and every implementation much implement:

  • void include(K k)
  • void access(K k)
  • K evict()

Future use cases can include (but not limited to):

• Multi Tier Cache Storage with overall storage capacity
• Multi Tier Cache Storage with different storage capacities
• Least Frequently Used (LFU) eviction policy

Examples:

• Single Tier Cache with initial capacity = 5, eviction policy = FIFO

put("Key1", "Value1");
put("Key2", "Value2");
put("Key3", "Value3");
put("Key4", "Value4");
get("Key1"); // Key1 accessed, makes no difference in eviction
get("Key3"); // Key3 accessed, makes no difference in eviction
put("Key5", "Value5");
put("Key6", "Value6"); // Key1 will be removed to put Key6
put("Key7", "Value7"); // Key2 will be removed to put Key7

Cache Contents: [Key3, Key4, Key5, Key6, Key 7]

• Single Tier Cache with initial capacity = 5, eviction policy = LRU

put("Key1", "Value1");
put("Key2", "Value2");
put("Key3", "Value3");
put("Key4", "Value4");
get("Key1"); // Key1 accessed, makes it most recently used
get("Key3"); // Key3 accessed, makes it most recently used
put("Key5", "Value5");
put("Key6", "Value6"); // Key2 will be removed to put Key6
put("Key7", "Value7"); // Key4 will be removed to put Key7

Cache Contents: [Key1, Key3, Key5, Key6, Key 7]