lift types from IO to Annex

Some remotes like External need to run store and retrieve actions in Annex,
not IO. In order to do that lift, I had to dive pretty deep into the
utilities, making Utility.Gpg and Utility.Tmp be partly converted to using
MonadIO, and Control.Monad.Catch for exception handling.

There should be no behavior changes in this commit.

This commit was sponsored by Michael Barabanov.

Utility/Gpg.hs

@@ -11,14 +11,15 @@ module Utility.Gpg where
 
 import Control.Applicative
 import Control.Concurrent
+import Control.Monad.IO.Class
 import qualified Data.Map as M
+import Control.Monad.Catch (bracket, MonadMask)
 
 import Common
 import qualified Build.SysConfig as SysConfig
 
 #ifndef mingw32_HOST_OS
 import System.Posix.Types
-import Control.Exception (bracket)
 import System.Path
 import Utility.Env
 #else
@@ -104,18 +105,18 @@ pipeStrict params input = do
  -
  - Note that to avoid deadlock with the cleanup stage,
  - the reader must fully consume gpg's input before returning. -}
-feedRead :: [CommandParam] -> String -> (Handle -> IO ()) -> (Handle -> IO a) -> IO a
+feedRead :: (MonadIO m, MonadMask m) => [CommandParam] -> String -> (Handle -> IO ()) -> (Handle -> m a) -> m a
 feedRead params passphrase feeder reader = do
 #ifndef mingw32_HOST_OS
 	-- pipe the passphrase into gpg on a fd
-	(frompipe, topipe) <- createPipe
-	void $ forkIO $ do
+	(frompipe, topipe) <- liftIO createPipe
+	liftIO $ void $ forkIO $ do
 		toh <- fdToHandle topipe
 		hPutStrLn toh passphrase
 		hClose toh
 	let Fd pfd = frompipe
 	let passphrasefd = [Param "--passphrase-fd", Param $ show pfd]
-	closeFd frompipe `after` go (passphrasefd ++ params)
+	liftIO (closeFd frompipe) `after` go (passphrasefd ++ params)
 #else
 	-- store the passphrase in a temp file for gpg
 	withTmpFile "gpg" $ \tmpfile h -> do
@@ -128,15 +129,24 @@ feedRead params passphrase feeder reader = do
 	go params' = pipeLazy params' feeder reader
 
 {- Like feedRead, but without passphrase. -}
-pipeLazy :: [CommandParam] -> (Handle -> IO ()) -> (Handle -> IO a) -> IO a
+pipeLazy :: (MonadIO m, MonadMask m) => [CommandParam] -> (Handle -> IO ()) -> (Handle -> m a) -> m a
 pipeLazy params feeder reader = do
-	params' <- stdParams $ Param "--batch" : params
-	withBothHandles createProcessSuccess (proc gpgcmd params')
-		$ \(to, from) -> do
-			void $ forkIO $ do
-				feeder to
-				hClose to
-			reader from
+	params' <- liftIO $ stdParams $ Param "--batch" : params
+	let p = (proc gpgcmd params')
+		{ std_in = CreatePipe
+		, std_out = CreatePipe
+		, std_err = Inherit
+		}
+	bracket (setup p) (cleanup p) go
+  where
+	setup = liftIO . createProcess
+	cleanup p (_, _, _, pid) = liftIO $ forceSuccessProcess p pid
+	go p = do
+		let (to, from) = bothHandles p
+		liftIO $ void $ forkIO $ do
+			feeder to
+			hClose to
+		reader from
 
 {- Finds gpg public keys matching some string. (Could be an email address,
  - a key id, or a name; See the section 'HOW TO SPECIFY A USER ID' of

Utility/Process.hs

@@ -31,6 +31,7 @@ module Utility.Process (
 	stdinHandle,
 	stdoutHandle,
 	stderrHandle,
+	bothHandles,
 	processHandle,
 	devNull,
 ) where

Utility/Tmp.hs

@@ -9,11 +9,12 @@
 
 module Utility.Tmp where
 
-import Control.Exception (bracket)
 import System.IO
 import System.Directory
 import Control.Monad.IfElse
 import System.FilePath
+import Control.Monad.IO.Class
+import Control.Monad.Catch (bracket, MonadMask)
 
 import Utility.Exception
 import Utility.FileSystemEncoding
@@ -42,18 +43,18 @@ viaTmp a file content = bracket setup cleanup use
 
 {- Runs an action with a tmp file located in the system's tmp directory
  - (or in "." if there is none) then removes the file. -}
-withTmpFile :: Template -> (FilePath -> Handle -> IO a) -> IO a
+withTmpFile :: (MonadIO m, MonadMask m) => Template -> (FilePath -> Handle -> m a) -> m a
 withTmpFile template a = do
-	tmpdir <- catchDefaultIO "." getTemporaryDirectory
+	tmpdir <- liftIO $ catchDefaultIO "." getTemporaryDirectory
 	withTmpFileIn tmpdir template a
 
 {- Runs an action with a tmp file located in the specified directory,
  - then removes the file. -}
-withTmpFileIn :: FilePath -> Template -> (FilePath -> Handle -> IO a) -> IO a
+withTmpFileIn :: (MonadIO m, MonadMask m) => FilePath -> Template -> (FilePath -> Handle -> m a) -> m a
 withTmpFileIn tmpdir template a = bracket create remove use
   where
-	create = openTempFile tmpdir template
-	remove (name, handle) = do
+	create = liftIO $ openTempFile tmpdir template
+	remove (name, handle) = liftIO $ do
 		hClose handle
 		catchBoolIO (removeFile name >> return True)
 	use (name, handle) = a name handle