Preserve outbound backlog across outages, fix backoff quiet period

src/HomeAssistant/Runtime/Supervisor.hs

@@ -42,7 +42,7 @@ defaultBackoff = Backoff 0.1 30 30
 
 -- | Delay before the @attempt@-th restart: doubles from base, clamped at cap.
 backoffDelay :: Backoff -> Int -> NominalDiffTime
-backoffDelay (Backoff base cap _) attempt = go (attempt - 1) base
+backoffDelay (Backoff base cap _) attempt = go (max 0 (attempt - 1)) base
   where
     go 0 d = d
     go n d = go (n - 1) (min cap (d * 2))
@@ -68,13 +68,13 @@ supervised name backoff action = go 1
         [ Handler $ \(f :: Fatal) -> pure (Just (Left f))
         , Handler $ \(e :: SomeException) -> pure (Just (Right e))
         ]
+      end <- getCurrentTime
       case outcome of
         Nothing -> error "unreachable: supervised action returned"
         Just (Left f) -> throw f
         Just (Right e) -> do
           putStrLn $ "[" <> T.unpack name <> "] attempt " <> show attempt <> " crashed: " <> displayException e
           let delay = backoffDelay backoff attempt
-          putStrLn $ "[" <> T.unpack name <> "] restarting in " <> show delay <> "s"
+          putStrLn $ "[" <> T.unpack name <> "] restarting in " <> show delay
           threadDelay (round (realToFrac delay * 1000000 :: Double))
-          end <- getCurrentTime
           go (nextAttempt backoff (diffUTCTime end start) attempt)