I verified that the DeltaCrdt.Storage Behavior used for persistence is specifying a type called storage_format with the following representation:
defmodule DeltaCrdt.Storage do
@moduledoc """
This behaviour can be used to enable persistence of the CRDT.
This can be helpful in the event of crashes.
To use, implement this behaviour in a module, and pass it to your CRDT with the `storage_module` option.
"""
@type t :: module()
@opaque storage_format ::
{node_id :: term(), sequence_number :: integer(), crdt_state :: term()}
@callback write(name :: term(), storage_format()) :: :ok
@callback read(name :: term()) :: storage_format() | nil
endNote that the type is basically composed of {node_id :: term(), sequence_number :: integer(), crdt_state :: term()} but checking where this behavior is called I noticed that actually the expected return pattern of the read function is different from the type specified in the behavior. See in DeltaCrdt.CausalCrd:
defp read_from_storage(state) do
case state.storage_module.read(state.name) do
nil ->
state
{node_id, sequence_number, crdt_state, merkle_map} ->
Map.put(state, :sequence_number, sequence_number)
|> Map.put(:crdt_state, crdt_state)
|> Map.put(:merkle_map, merkle_map)
|> Map.put(:node_id, node_id)
|> remove_crdt_state_keys()
end
endIn this case the expected return type pattern is {node_id, sequence_number, crdt_state, merkle_map}.
My first question is what is the correct format?
I verified that the DeltaCrdt.Storage Behavior used for persistence is specifying a type called storage_format with the following representation:
Note that the type is basically composed of {node_id :: term(), sequence_number :: integer(), crdt_state :: term()} but checking where this behavior is called I noticed that actually the expected return pattern of the read function is different from the type specified in the behavior. See in DeltaCrdt.CausalCrd:
In this case the expected return type pattern is {node_id, sequence_number, crdt_state, merkle_map}.
My first question is what is the correct format?