Learn how driver wraps around regular ruby drivers.
Driver
Driver is a wrapper class that persists and retrieves values from backend. It needs to implement:
inc(keys=List, values=Map)
method increment values for keysset(keys=List, values=Map)
method set values for keysget(keys=List)
method to retrieve values for keys
The keys list is used to build identifiers for objects that needs to modify or retrieve values for. Driver then decides on the optimal way to implement these actions.
Packer Class
Some databases cannot store nested maps/values. Or they cannot perform increment on nested values that does not exist. For this reason you can use Packer class that helps you convert values to dot notation.
iex(1)> values = %{ a: 1, b: %{ c: 22, d: 33 } }
%{a: 1, b: %{c: 22, d: 33}}
iex(2)> packed = Trifle.Stats.Packer.pack(values)
%{"a" => 1, "b.c" => 22, "b.d" => 33}
iex(3)> Trifle.Stats.Packer.unpack(packed)
%{"a" => 1, "b" => %{"c" => 22, "d" => 33}}