58 lines
1.3 KiB
Elixir
58 lines
1.3 KiB
Elixir
defmodule Todo.DatabaseWorker do
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use GenServer
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def start_link({_db_folder, worker_id} = state) do
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GenServer.start_link(__MODULE__, state, name: via_tuple(worker_id))
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end
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def store(worker_id, key, data) do
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worker_id
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|> via_tuple()
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|> GenServer.cast({:store, key, data})
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end
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def get(worker_id, key) do
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worker_id
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|> via_tuple()
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|> GenServer.call({:get, key})
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end
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defp via_tuple(worker_id) do
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Todo.ProcessRegistry.via_tuple({__MODULE__, worker_id})
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end
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@impl GenServer
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def init({db_folder, worker_id} = state) do
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IO.puts("Starting #{__MODULE__} #{worker_id} with db folder #{db_folder}.")
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{:ok, state}
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end
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@impl GenServer
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def handle_cast({:store, key, data}, {db_folder, _worker_id} = state) do
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{db_folder, key}
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|> file_name()
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|> File.write!(:erlang.term_to_binary(data))
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{:noreply, state}
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end
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@impl GenServer
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def handle_call({:get, key}, _, {db_folder, _worker_id} = state) do
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data =
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case File.read(file_name({db_folder, key})) do
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{:ok, contents} ->
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:erlang.binary_to_term(contents)
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{:error, :enoent} ->
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nil
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end
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{:reply, data, state}
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end
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def file_name({db_folder, key}) do
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Path.join(db_folder, to_string(key))
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end
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end
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