Elixir Application Config performance

kloak.exs

defmodule Kloak do
  use GenServer

  @normal_table :"#{__MODULE__}.Config"
  @concurrent_table :"#{__MODULE__}.ConfigConcurrent"

  @config [json_library: Jason,
  ciphers: [
    default:
      {Cloak.Ciphers.AES.GCM,
       tag: "AES.GCM.V1", key: Base.decode64!("3Jnb0hZiHIzHTOih7t2cTEPEpY98Tu1wvQkPfq/XwqE=")},
    secondary:
      {Cloak.Ciphers.AES.CTR,
       tag: "AES.CTR.V1", key: Base.decode64!("o5IzV8xlunc0m0/8HNHzh+3MCBBvYZa0mv4CsZic5qI=")}
  ]]

  def init(args) do
    {:ok, args}
  end

  def start_link() do
    {:ok, pid} = GenServer.start_link(__MODULE__, [], name: __MODULE__)

    :ets.new(@normal_table, [:named_table, :protected])
    :ets.new(@concurrent_table, [:named_table, :protected, read_concurrency: true])

    :ets.insert(@normal_table, {:config, @config})
    :ets.insert(@concurrent_table, {:config, @config})

    {:ok, pid}
  end

  def read_config() do
    :ets.lookup(@normal_table, :config)
  end

  def read_concurrent_config() do
    :ets.lookup(@concurrent_table, :config)
  end

  def read_application_env() do
    Application.get_env(:myapp, MyVault)
  end
end

Application.put_env(:myapp, MyVault, [json_library: Jason,
ciphers: [
  default:
    {Cloak.Ciphers.AES.GCM,
     tag: "AES.GCM.V1", key: Base.decode64!("3Jnb0hZiHIzHTOih7t2cTEPEpY98Tu1wvQkPfq/XwqE=")},
  secondary:
    {Cloak.Ciphers.AES.CTR,
     tag: "AES.CTR.V1", key: Base.decode64!("o5IzV8xlunc0m0/8HNHzh+3MCBBvYZa0mv4CsZic5qI=")}
]])

Kloak.start_link()

# Benchee.run(
#   %{
#     "Kloak.read_config/0" => fn ->
#       for _i <- 1..1000 do
#         Kloak.read_config()
#       end
#     end,
#     "Kloak.read_concurrent_config/0" => fn ->
#       for _i <- 1..1000 do
#         Kloak.read_concurrent_config()
#       end
#     end,
#     "Kloak.read_application_env/0" => fn ->
#       for _i <- 1..1000 do
#         Kloak.read_application_env()
#       end
#     end
#   },
#   warmup: 5,
#   time: 10,
#   memory_time: 1
# )
# Operating System: macOS
# CPU Information: Intel(R) Core(TM) i7-8750H CPU @ 2.20GHz
# Number of Available Cores: 12
# Available memory: 16 GB
# Elixir 1.8.1
# Erlang 21.1
#
# Benchmark suite executing with the following configuration:
# warmup: 5 s
# time: 10 s
# memory time: 1 s
# parallel: 1
# inputs: none specified
# Estimated total run time: 48 s
#
# Benchmarking Kloak.read_application_env/0...
# Benchmarking Kloak.read_concurrent_config/0...
# Benchmarking Kloak.read_config/0...
#
# Name                                     ips        average  deviation         median         99th %
# Kloak.read_config/0                   3.99 K      250.40 μs    ±24.17%      290.99 μs      373.99 μs
# Kloak.read_concurrent_config/0        3.36 K      297.81 μs    ±25.47%      325.99 μs      510.99 μs
# Kloak.read_application_env/0          2.16 K      463.02 μs    ±17.43%      433.99 μs      783.99 μs
#
# Comparison:
# Kloak.read_config/0                   3.99 K
# Kloak.read_concurrent_config/0        3.36 K - 1.19x slower +47.42 μs
# Kloak.read_application_env/0          2.16 K - 1.85x slower +212.62 μs
#
# Memory usage statistics:
#
# Name                              Memory usage
# Kloak.read_config/0                  578.22 KB
# Kloak.read_concurrent_config/0       578.22 KB - 1.00x memory usage +0 KB
# Kloak.read_application_env/0         664.30 KB - 1.15x memory usage +86.09 KB
#
# **All measurements for memory usage were the same**

Benchee.run(
  %{
    "Kloak.read_config/0" => fn ->
      for _i <- 1..1000 do
        Kloak.read_config()
      end
    end,
    "Kloak.read_concurrent_config/0" => fn ->
      for _i <- 1..1000 do
        Kloak.read_concurrent_config()
      end
    end,
    "Kloak.read_application_env/0" => fn ->
      for _i <- 1..1000 do
        Kloak.read_application_env()
      end
    end
  },
  warmup: 5,
  parallel: 12,
  time: 10,
  memory_time: 1
)
#
# Operating System: macOS
# CPU Information: Intel(R) Core(TM) i7-8750H CPU @ 2.20GHz
# Number of Available Cores: 12
# Available memory: 16 GB
# Elixir 1.8.1
# Erlang 21.1
#
# Benchmark suite executing with the following configuration:
# warmup: 5 s
# time: 10 s
# memory time: 1 s
# parallel: 12
# inputs: none specified
# Estimated total run time: 48 s
#
# Benchmarking Kloak.read_application_env/0...
# Benchmarking Kloak.read_concurrent_config/0...
# Benchmarking Kloak.read_config/0...
#
# Name                                     ips        average  deviation         median         99th %
# Kloak.read_concurrent_config/0       1081.08        0.92 ms    ±32.31%        0.91 ms        1.70 ms
# Kloak.read_config/0                   738.80        1.35 ms    ±27.82%        1.36 ms        2.21 ms
# Kloak.read_application_env/0          633.68        1.58 ms    ±37.28%        1.45 ms        4.09 ms
#
# Comparison:
# Kloak.read_concurrent_config/0       1081.08
# Kloak.read_config/0                   738.80 - 1.46x slower +0.43 ms
# Kloak.read_application_env/0          633.68 - 1.71x slower +0.65 ms
#
# Memory usage statistics:
#
# Name                              Memory usage
# Kloak.read_concurrent_config/0       578.22 KB
# Kloak.read_config/0                  578.22 KB - 1.00x memory usage +0 KB
# Kloak.read_application_env/0         664.30 KB - 1.15x memory usage +86.09 KB
#
# **All measurements for memory usage were the same**