LRUCache

It's a simple in-memory cache that expires the least recently used item in the cache when the count of items in the cache reaches a fixed limit.

$ gem install lru_cache

require "lru_cache"

# create a new cache with a 1,000 item limit
cache = LRUCache.new(1_000)

# get or set item in cache
cache["some key"] ||= expensive_operation

By default the LRUCache is not thread-safe. If you intend to access the cache in multi-threaded code, use LRUCache::ThreadSafe.

require "lru_cache/thread_safe"

# create a new thread-safe cache with a 1,000 item limit
cache = LRUCache::ThreadSafe.new(1_000)

# get or set item in cache
cache["some key"] ||= expensive_operation

• #clear empties the cache
• #count returns the number of items currently in cache
• #delete(key) removes an item from the cache
• #get(key) returns the cached value or nil
• #limit returns the cache limit (defaults to 1)
• #limit=value sets the cache limit to value
• #set(key, value) stores the value in the cache
• #[key] alias for #get(key)
• #[key]=value alias for #set(key, value)

This code is released under the MIT license, and is copyright 2012 by Brendan Baldwin. Please see the accompanying LICENSE file for the full text of the license.