Doumi.Port

Doumi.Port is a helper library that makes it easier to use Python, Ruby in Elixir powered by Erlport, NimblePool.

도우미(Doumi) means "helper" in Korean.

Why pool?

https://medium.com/stuart-engineering/how-we-use-python-within-elixir-486eb4d266f9

Every time we run Python code through ErlPort, ErlPort starts an OS process, this is rather inefficient and expensive. To avoid this trap, we went looking for some pooling mechanism ...

Why NimblePool?

https://github.com/dashbitco/nimble_pool#nimblepool

You should consider using NimblePool whenever you have to manage sockets, ports, or NIF resources and you want the client to perform one-off operations on them. For example, NimblePool is a good solution to manage HTTP/1 connections, ports that need to communicate with long-running programs, etc.

Usage

Call Python function via Pool

defmodule MyApp.PythonPool do
  use Doumi.Port,
    adapter: Doumi.Port.Adapter.Python,
    pool_size: 4
end

defmodule MyApp.Application do
  ...

  @impl true
  def start(_type, _args) do
    children = [
      ...
      MyApp.PythonPool
    ]

    Supervisor.start_link(children, strategy: :one_for_one, name: MyApp.Supervisor)
  end
end

defmodule MyApp.Native do
  def add(a, b) do
    {:ok, result} = MyApp.PythonPool.command(:operator, :add, [a, b])

    result
  end
end

Init and Setup Python in Elixir application

# Create requirements.txt, .gitignores to ./priv/python
mix doumi.port.init --port python

# Add Python dependency
echo "pypdf2==3.0.1" >> ./priv/python/requirements.txt

# Install Python dependecies
mix doumi.port.setup --port python

You can install Python dependencies to your release with mix doumi.port.setup.

defmodule MyApp.MixProject do
  defp aliases do
    [
      ...,
      "release.setup": ["doumi.port.setup --port python", ...]
    ]
  end
end

...

# release setup (ex. install Python dependencies, compile assets)
RUN mix release.setup

...

Installation

The package can be installed by adding doumi_port to your list of dependencies in mix.exs:

def deps do
  [
    {:doumi_port, "~> 0.6.0"},
    # To support Python >= 3.11, erlport should be overridden
    # https://github.com/erlport/erlport/pull/13
    {:erlport, github: "nallwhy/erlport", ref: "6f5cb45", override: true}
  ]
end

TODO

• Support use macro
• Support Ruby
• Support mix tasks that help setup Python in applications
• Support mix tasks that help setup Ruby in applications
• Pool 이 위치를 알게하고, compile 시에 빌드를 하도록
• Documentation
• Write blog posts

Doumi*

All Doumi libraries:

• Doumi.Phoenix.SVG: A helper library that generates Phoenix function components from SVG files.
• Doumi.Phoenix.Params: A helper library that supports converting form to params and params to form
• Doumi.URI.Query: A helper library that encode complicated query of URI.

Copyright and License

Copyright (c) 2023 Jinkyou Son (Json)

This work is free. You can redistribute it and/or modify it under the terms of the MIT License. See the LICENSE.md file for more details.