Cachex has get, put, fetch, clear, etc.
getreturns value if it is present in cache, nil if its a cache missfetchexecutes fallback function on cache miss.
For example - lets have a fallback function which returns same value after delay of 5 seconds.
iex(1)> import Cachex.Spec
iex(2)> Cachex.start_link(:my_cache, [ fallback: fallback(default: fn x -> :timer.sleep(5000)
...(2)> x end) ])
iex(3)> Cachex.get(:my_cache, 1) #get will return nil as there is no entry
{:ok, nil}
fetch will invoke fallback function when there is a miss - fallback function is executed and value is put into the cache after delay of 5 seconds.
iex(4)> Cachex.fetch(:my_cache, 1) # 5 sec delay due to timer.sleep in fallback function
{:commit, 1}
iex(5)> Cachex.get(:my_cache, 1) # get will return value as it exists in cache
{:ok, 1}
Now fetch will return value from cache without executing fallback function
iex(6)> Cachex.fetch(:my_cache, 1) # returns immediately, fallback not invoked
{:ok, 1}
