module IdempotentRequest class RedisStorage attr_reader :redis, :namespace, :expire_time def initialize(redis, config = {}) @redis = redis @namespace = config.fetch(:namespace, 'idempotency_keys') @expire_time = config[:expire_time] end def lock(key) setnx_with_expiration(lock_key(key), true) end def read(key) redis.get(namespaced_key(key)) end def write(key, payload) setnx_with_expiration(namespaced_key(key), payload) end private def setnx_with_expiration(key, data) redis.set( key, data, {}.tap do |options| options[:nx] = true options[:ex] = expire_time.to_i if expire_time.to_i > 0 end ) end def lock_key(key) namespaced_key("lock:#{key}") end def namespaced_key(key) [namespace, key.strip] .compact .join(':') .downcase end end end