GenStage is a specification for exchanging events between producers and consumers. It also provides a mechanism to specify the computational flow between stages.
This project currently provides the following functionality:
-
Experimental.GenStage
(docs) - a behaviour for implementing producer and consumer stages -
Experimental.Flow
(docs) -Flow
allows developers to express computations on collections, similar to theEnum
andStream
modules, although computations will be executed in parallel using multipleGenStage
s -
Experimental.DynamicSupervisor
(docs) - a supervisor designed for starting children dynamically. Besides being a replacement for the:simple_one_for_one
strategy in the regularSupervisor
, aDynamicSupervisor
can also be used as a stage consumer, making it straight-forward to spawn a new process for every event in a stage pipeline
The module names are marked as Experimental
to avoid conflicts as they are meant to be included in future Elixir releases. In your code, you may add alias Experimental.{DynamicSupervisor, Flow, GenStage}
to the top of your files and use the relative names from then on.
You can find examples on how to use the modules above in the examples directory:
-
ProducerConsumer - a simple example of setting up a pipeline of
A -> B -> C
stages and having events flowing through -
DynamicSupervisor - an example of how to use one or more
DynamicSupervisor
as a consumer to a producer that works as a counter -
GenEvent - an example of how to use
GenStage
to implement aGenEvent
replacement that leverages concurrency and provides more flexibility regarding buffer size and back-pressure
GenStage requires Elixir v1.3.
-
Add
:gen_stage
to your list of dependencies in mix.exs:def deps do [{:gen_stage, "~> 0.4"}] end
-
Ensure
:gen_stage
is started before your application:def application do [applications: [:gen_stage]] end
Here is a list of potential topics to be explored by this project (in no particular order or guarantee):
- Consider using DynamicSupervisor to implement Task.Supervisor (as a consumer)
Same as Elixir.