# `Licet.GC`
[🔗](https://github.com/netoum/licet/blob/v0.1.0/lib/licet/gc.ex#L1)

Garbage collection of old relationship history.

Licet keeps deleted and expired relationships, and the snapshots of past
writes, for `gc_window` seconds, so that tokens from that window can still be
read exactly. Every instance runs a collector that removes older history
every `gc_interval` milliseconds, in batches of `gc_batch` rows.

On several nodes, each pass takes a Postgres advisory lock, so only one node
collects at a time. Set `gc_interval: false` to disable automatic passes, for
example in tests or to trigger them from your own scheduler with `collect/1`.

# `collect`

```elixir
@spec collect(atom()) :: :ok | :locked | {:error, Licet.Error.t()}
```

Runs one collection pass on `instance` now and waits for it.

Returns `:locked` when another node holds the lock and is collecting, and
`{:error, %Licet.Error{reason: :not_started}}` when no instance with that
name is running.

## Examples

    Licet.GC.collect(MyApp.Licet)
    #=> :ok

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*Consult [api-reference.md](api-reference.md) for complete listing*