@lostboy you should realistically be able to receive a { :purge, _opts } message... but I just checked and it appears it's not working. Let me take a quick look at it!

Edit: ha, I knew that this was broken previously but for different reasons... I fixed it but only ever tested it with the internal Stats hook so I totally missed that it wouldn't fire the rest of the hooks. Fix incoming!

Ok, this is now resolved in the main branch so you can pick it up from here.

The next version will be released on Hex pretty soon, just gotta review a few things. For what it's worth, I always intend master to be stable enough to use (otherwise I keep changes in PR until it is stable), so it should be ok to just point your projects to the GitHub.

For reference, here's the test case I used to make sure the hooks were receiving:

Erlang/OTP 18 [erts-7.3] [source] [64-bit] [smp:8:8] [async-threads:10] [hipe] [kernel-poll:false] [dtrace]

Interactive Elixir (1.2.4) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)> defmodule MyModule.PostPurgeHook do
...(1)>   use Cachex.Hook
...(1)> 
...(1)>   def handle_notify({ :purge, _opts }, state) do
...(1)>     IO.puts("Purge received!")
...(1)>     { :ok, state }
...(1)>   end
...(1)> 
...(1)>   def handle_notify(_action, state) do
...(1)>     { :ok, state }
...(1)>   end
...(1)> end
{:module, MyModule.PostPurgeHook,
 <<70, 79, 82, 49, 0, 0, 13, 96, 66, 69, 65, 77, 69, 120, 68, 99, 0, 0, 2, 221, 131, 104, 2, 100, 0, 14, 101, 108, 105, 120, 105, 114, 95, 100, 111, 99, 115, 95, 118, 49, 108, 0, 0, 0, 4, 104, 2, ...>>,
 {:handle_notify, 2}}
iex(2)> Cachex.start_link([ name: :my_cache, hooks: %Cachex.Hook { module: MyModule.PostPurgeHook, type: :post }, default_ttl: :timer.seconds(3), ttl_interval: :timer.seconds(5) ])
{:ok, #PID<0.149.0>}
iex(3)> Cachex.set(:my_cache, "key", "value")
{:ok, true}
Purge received!
iex(4)> 

If you want to know how many were purged, you need to add results: true to the hook declaration, and change your handler to def handle_notify({ :purge, _opts }, { :ok, count }, state).

I hope this solves your issue, and thank you very much for the kind words 😃 Please let me know if you come across anything else, or have further questions about this!