# `Kombu.Utils.Retry`
[🔗](https://github.com/hacktobeer/kombu/blob/v0.1.0/lib/kombu/utils/retry.ex#L1)

Functional utilities, LRU cache, and retry helpers matching `kombu.utils.functional`
and `kombu.utils.time`.

# `dictfilter`

```elixir
@spec dictfilter(map() | keyword()) :: map()
```

Remove all keys from a map or keyword list whose value is `nil`.

# `fxrange`

```elixir
@spec fxrange(number(), number() | nil, number(), boolean()) :: Enumerable.t()
```

Generate floating-point range (`kombu.utils.functional.fxrange`).

# `fxrangemax`

```elixir
@spec fxrangemax(number(), number() | nil, number(), number()) :: Enumerable.t()
```

Generate floating-point range bounded by cumulative sum `max` (`kombu.utils.functional.fxrangemax`).

# `maybe_list`

```elixir
@spec maybe_list(term()) :: list() | nil
```

Wrap a scalar in a single-element list unless it is `nil` or already a list.

# `maybe_s_to_ms`

```elixir
@spec maybe_s_to_ms(number() | nil) :: integer() | nil
```

Convert seconds to milliseconds (`int(float(v) * 1000.0)`), or `nil` if `nil`.

# `retry_over_time`

```elixir
@spec retry_over_time((-> term()), module() | [module()], keyword()) :: term()
```

Retry `fun` when an exception in `catch_list` is raised (`kombu.utils.functional.retry_over_time`).

Options:
- `:max_retries` - maximum number of retries before re-raising (`nil` for unlimited)
- `:interval_start` - initial backoff in seconds (default `2`)
- `:interval_step` - backoff increment in seconds (default `2`)
- `:interval_max` - maximum sleep interval in seconds (default `30`)
- `:errback` - `fn exc, interval_list, retries -> sleep_seconds`
- `:callback` - `fn -> :ok` called between retries and each 1s sleep tick
- `:timeout` - overall timeout in seconds (`nil` for none)
- `:sleep_fn` - custom sleep function `fn seconds -> :ok` (defaults to `Process.sleep(trunc(s * 1000))`)

---

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