@callback info(
  Nebulex.Adapter.adapter_meta(),
  Nebulex.Cache.info_spec(),
  Nebulex.Cache.opts()
) :: Nebulex.Cache.ok_error_tuple(Nebulex.Cache.info_data())

Returns {:ok, info} where info contains the requested cache information, as specified by the spec.

If there's an error with executing the command, {:error, reason} is returned, where reason is the cause of the error.

The spec (information specification key) can be:

• The atom :all: returns a map with all information items.
• An atom: returns the value for the requested information item.
• A list of atoms: returns a map only with the requested information items.

The adapters are free to add the information specification keys they want, however, Nebulex suggests the adapters add the following specs:

• :server - General information about the cache server (e.g., cache name, adapter, PID, etc.).
• :memory - Memory consumption information (e.g., used memory, allocated memory, etc.).
• :stats - Cache statistics (e.g., hits, misses, etc.).

See Nebulex.Cache.info/2.