CacheMoney

Simple caching for Elixir using ETS or Redis

Installation

The package can be installed by adding :cache_money to your list of dependencies in mix.exs:

def deps do
  [
    {:cache_money, "~> 0.6.2"}
  ]
end

Basic Usage

Create your cache by calling CacheMoney.start_link/3:

alias CacheMoney.Adapters.Redis

{:ok, cache} = CacheMoney.start_link(:my_cache, %{adapter: Redis})

The first argument is your cache name, in most implementations the cache name will simply be prepended to your keys in order to keep your caches separate. The second argument is a map that contains an :adapter, which should be from CacheMoney.Adapters, or anything that implements the CacheMoney.Adapter behaviour. The rest of the values of this map are passed to the adapter, and are specified by the adapter. The third argument is a keyword list of options that are passed to the underlying genserver, should you need to customize the genserver further.

Now you can put stuff in the cache, and retrieve it later!

CacheMoney.set(cache, :foo, "bar")
CacheMoney.get(cache, :foo)
# "bar"

set also includes an expiry param, should you want the value in the cache to expire (expiry is in milliseconds, however some adapters can't handle an expiration less than one second (such as redis). In these cases, the expiry will be set to 1 second.)

CacheMoney.set(cache, :foo, "bar", 10_000)
CacheMoney.get(cache, :foo)
# More than 10 seconds later
CacheMoney.get(cache, :foo)
# nil

get_lazy/3 and get_lazy/4 (with an expiry) are also available, which allows you to provide a function that will get the value. The value will be saved, and then returned.

CacheMoney.get_lazy(cache, :foo, fn -> "expensive to get data" end)
# "expensive to get data"
CacheMoney.get_lazy(cache, :foo, fn -> "I don't get executed" end)
# "expensive to get data"

Testing

The CacheMoney.Adapters.Sandbox adapter has been provided to help with testing. To use it, set your cache's adapter to Sandbox in your test env config, then in your test module do:

setup do
  Sandbox.checkout(YourCache)
  on_exit(fn -> Sandbox.checkin(YourCache) end)
  :ok
end

A good

Copyright and License

Copyright (c) 2018 Trevor Fenn

This work is free. You can redistribute it and/or modify it under the terms of the MIT License. See the LICENSE.md file for more details.