Weaver

A graph streaming engine written in Elixir

Installation

Add weaver to your list of dependencies in mix.exs:

def deps do
  [
    {:weaver, github: "weaver-engine/weaver"}
  ]
end

To use Loom, also add the forked version of GenStage:

def deps do
  [
    {:weaver, github: "weaver-engine/weaver"},
    {:gen_stage, github: "weaver-engine/gen_stage", branch: "prosumer"}
  ]
end

The fork is equivalent to GenStage, except some checks are removed to allow for producer modules to also subscribe to other Producers (see diff and issue comment by José Valim).

Loom

While Weaver.weave only runs a single step at a time and returns the results, Loom helps to run all required steps and streams the results. Under the hood it supervises a topology of GenStage workers that you can run as part of your supervision tree:

defmodule MyApp.Application do
  ...

  def start(_type, _args) do
    children = [
      ...

      Weaver.Loom
    ]

    opts = [strategy: :one_for_one, name: MyApp.Supervisor]
    Supervisor.start_link(children, opts)
  end
end

To stream a query, call Weaver.Loom.weave.