# Barenboim

# Conejo

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 `Barenboim` is prepared to tackle with data streaming dependencies in concurrent flows.

  If your application works with a data streaming and your incoming events could have dependencies between them, the app can have problems about when the
  dependency data is ready. Reasons:
  * The Application which is sending the data is not sending the data in the right order
  * Your Application is treating the data concurrently therefore the order is not ensured.

## Installation
  * Add `barenboim` to your list of dependencies in `mix.exs`:

    ```elixir
    def deps do
       [{:barenboim, "~> 0.1.0"}]
    end
    ```
    
## Configuration    
  * Barenboim uses [poolboy](https://github.com/devinus/poolboy) and you can configure it depending on your needs:

    ```elixir
    config :barenboim,
      pool_domain: :global,     # default :local
      pool_size: 20,            # default 10
      max_overflow: 3           # default 5
    ```
    
  You can also configure a delay for a reminder notification. A reminder notification is sent in order to
  avoid corner cases (notification between the data access and the registration of a dependency). 
  This time (milliseconds) should be defined depending on your data access function time (see next section).
  
    ```elixir
    config :barenboim,
      reminder_time: 50     # default 100
    ```

## How to use it
  Define the function that will retrieve the dependency data where `dependency_id` is the id of your data
  and call `Barenboim.get_data`. You can also specify a time out in milliseconds.
  ```elixir
  fun = fn(dependency_id) -> MyDataModule.get(dependency_id) end
  {:ok, data} = Barenboim.get_data(dependency_id, fun)
  ```

  Meanwhile, the flow that is processing a new event has to `notify` when the data is available for others.
  ```elixir
    Barenboim.notify(dependency_id)
  ```
  Or you can even attach the data:
  ```elixir
    Barenboim.notify({dependency_id, dependency_data})
  ```
## Test
  * Run the tests.
  ```bash
  mix test 
  ```
  
## In honor of
  [Daniel Barenboim](https://en.wikipedia.org/wiki/Daniel_Barenboim)