Simple Cache

Collection of key-value pair cache implementations

Implementations

All implementations primarily utilize a hashmap to associate keys with doubly linked list nodes, and doubly linked lists to arrange entries according to the respective strategy. This structure enables a constant running time complexity for all methods, get, set, remove, and clear.

• FIFO
  • Entries are removed in order of insertion regardless of their access frequency
  • New entries are inserted at the head of the list
  • When the cache reaches its maximum capacity the last node accessed by the tail pointer is removed
• LRU
  • Least recently used entries are removed
  • Same initial insertion and removal approach as FIFO
  • Subsequent access to entries results in their relocation to the head of the list, ensuring a continuous update of access recency
• MRU
  • Shares initial insertion and update approach with LRU
  • When the cache is full, the first node accessed by the head pointer is removed
• LFU
  • Uses a nested doubly linked list, with first level for organizing entries by frequency sorted low to high and with the nested list at each frequency node storing the cache entry nodes
  • Initial insertion assigns entries to the list of the node with frequency 1, accessible via the head pointer
  • Subsequent access increments the hit count of cache entry nodes, moving them to the next list associated with that frequency
  • When the cache reaches maximum capacity, the last node in the list of the lowest frequency node accessed by the tail pointer is removed

Installation

npm i simple-kv-cache

Usage

import { FIFOCache, LRUCache, MRUCache, LFUCache } from "simple-kv-cache"

const cache = new LRUCache({
  maxCapacity: 5000, // Specify options
})

// Store value
cache.set("users", [
  {
    id: 1,
    name: "John Doe",
  },
])

// Retrieve value
cache.get("users")

// Remove value
cache.remove("users")

// Remove all values
cache.clear()

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.