# Grim

Grim is a pruning library that periodically destroys stale records that are no longer useful.

After installing Grim, add the `Grim.ReaperSupervisor` to your supervision tree with a list of schemas or queries
that you would like to delete.


```elixir
      grim_config = [
        repo: MyApp.Repo,
        reapers: [Soul, Chaff, Spirit]
      ]

      children =
      [
        {Grim.ReaperSupervisor, grim_config}
      ]
```


The reaper supervisor can be initialized in 4 different ways.

1. A list of Schemas, if you would like to use the default pruning values

```elixir
      grim_config = [
        repo: Repo,
        reapers: [Soul, Chaff, Spirit]
      ]
```

2. A list of Schema tuples with configuration options
```elixir
      grim_config = [
        repo: Repo,
        reapers: [{Soul, [ttl: 10_000]}, {Chaff, [poll_interval: 100]}, {Spirit, [batch_size: 10_000]}]
      ]
```

3. With explicit reaper child specs
```elixir
      grim_config = [
        repo: Repo,
        reapers: [{Reaper, [query: Soul, poll_interval: 100]}, {Reaper, [query: Chaff]}, {Reaper, [batch_size: 100]}]
      ]
```

4. Or a combination of all of the above
```elixir
      grim_config = [
        repo: Repo,
        reapers: [{Reaper, [query: Soul, poll_interval: 100]}, Chaff, {Spirit, [batch_size: 10_000]}]
      ]
```


The following configurations are available
```
:batch_size -> Number of records deleted at a time
:poll_interval -> How often grim should check for records to delete
:ttl -> How old should records be before they are deleted
:query -> An ecto Schema module name or an ecto query
```




## Installation

Install by adding `grim` to your list of dependencies in `mix.exs`:

```elixir
def deps do
  [
    {:grim, "~> 0.1.0"}
  ]
end
```



Documentation can be generated with [ExDoc](https://github.com/elixir-lang/ex_doc)
and published on [HexDocs](https://hexdocs.pm). Once published, the docs can
be found at <https://hexdocs.pm/grim>.