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
#clearempties the cache#countreturns the number of items currently in cache#delete(key)removes an item from the cache#get(key)returns the cached value or nil#limitreturns the cache limit (defaults to 1)#limit=valuesets the cache limit to value#set(key, value)stores the value in the cache#[key]alias for#get(key)#[key]=valuealias 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.