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{-# LANGUAGE ScopedTypeVariables #-}
module Network.WireGuard.Internal.Util
( retryWithBackoff
, ignoreSyncExceptions
, foreverWithBackoff
, catchIOExceptionAnd
, catchSomeExceptionAnd
, withJust
, dropUntilM
, zeroMemory
, copyMemory
) where
import Control.Concurrent (threadDelay)
import Control.Exception (Exception (..),
IOException,
SomeAsyncException,
SomeException, throwIO)
import Control.Monad.Catch (MonadCatch (..))
import Data.Foldable (forM_)
import System.IO (hPutStrLn, stderr)
import Foreign
import Foreign.C
import Network.WireGuard.Internal.Constant
retryWithBackoff :: IO () -> IO ()
retryWithBackoff = foreverWithBackoff . ignoreSyncExceptions
ignoreSyncExceptions :: IO () -> IO ()
ignoreSyncExceptions m = catch m handleExcept
where
handleExcept e = case fromException e of
Just asyncExcept -> throwIO (asyncExcept :: SomeAsyncException)
Nothing -> hPutStrLn stderr (displayException e) -- TODO: proper logging
foreverWithBackoff :: IO () -> IO ()
foreverWithBackoff m = loop 1
where
loop t = m >> threadDelay t >> loop (min (t * 2) retryMaxWaitTime)
catchIOExceptionAnd :: MonadCatch m => m () -> m () -> m ()
catchIOExceptionAnd what m = catch m $ \(_ :: IOException) -> what
catchSomeExceptionAnd :: MonadCatch m => m () -> m () -> m ()
catchSomeExceptionAnd what m = catch m $ \(_ :: SomeException) -> what
withJust :: Monad m => m (Maybe a) -> (a -> m ()) -> m ()
withJust mma func = do
ma <- mma
forM_ ma func
dropUntilM :: Monad m => (a -> Bool) -> m a -> m a
dropUntilM cond ma = loop
where
loop = do
a <- ma
if cond a
then return a
else loop
zeroMemory :: Ptr a -> CSize -> IO ()
zeroMemory dest nbytes = memset dest 0 (fromIntegral nbytes)
copyMemory :: Ptr a -> Ptr b -> CSize -> IO ()
copyMemory = memcpy
foreign import ccall unsafe "string.h" memset :: Ptr a -> CInt -> CSize -> IO ()
foreign import ccall unsafe "string.h" memcpy :: Ptr a -> Ptr b -> CSize -> IO ()
|
