skeleton C library for calling kqueue

.gitignore

@@ -11,7 +11,7 @@ html
 *.tix
 .hpc
 Utility/Touch.hs
-Utility/libdiskfree.o
+Utility/*.o
 dist
 # Sandboxed builds
 cabal-dev

Assistant/Watcher.hs

@@ -33,12 +33,15 @@ import qualified Data.ByteString.Lazy as L
 import Utility.Inotify
 import System.INotify
 #endif
+#ifdef WITH_KQUEUE
+import Utility.Kqueue
+#endif
 
 type Handler = FilePath -> Maybe FileStatus -> DaemonStatusHandle -> Annex (Maybe Change)
 
 checkCanWatch :: Annex ()
 checkCanWatch = do
-#ifdef WITH_INOTIFY
+#if (WITH_INOTIFY || WITH_KQUEUE)
 	unlessM (liftIO (inPath "lsof") <||> Annex.getState Annex.force) $
 		needLsof
 #else
@@ -82,8 +85,13 @@ watchThread st dstatus changechan = withINotify $ \i -> do
 			, errHook = hook onErr
 			}
 #else
+#ifdef WITH_KQUEUE
+watchThread st dstatus changechan = do
+	print =<< waitChange [stdError, stdOutput]
+#else
 watchThread = undefined
-#endif
+#endif /* WITH_KQUEUE */
+#endif /* WITH_INOTIFY */
 
 ignored :: FilePath -> Bool
 ignored ".git" = True

Makefile

@@ -1,13 +1,22 @@
-OS:=$(shell uname | sed 's/[-_].*//')
+bins=git-annex
+mans=git-annex.1 git-annex-shell.1
+sources=Build/SysConfig.hs Utility/Touch.hs
+all=$(bins) $(mans) docs
 
+OS:=$(shell uname | sed 's/[-_].*//')
 ifeq ($(OS),Linux)
 BASEFLAGS_OPTS+=-DWITH_INOTIFY
+clibs=Utility/libdiskfree.o
+else
+BASEFLAGS_OPTS+=-DWITH_KQUEUE
+clibs=Utility/libdiskfree.o Utility/libkqueue.o
 endif
 
 PREFIX=/usr
 IGNORE=-ignore-package monads-fd -ignore-package monads-tf
 BASEFLAGS=-Wall $(IGNORE) -outputdir tmp -IUtility -DWITH_S3 $(BASEFLAGS_OPTS)
 GHCFLAGS=-O2 $(BASEFLAGS)
+CFLAGS=-Wall
 
 ifdef PROFILE
 GHCFLAGS=-prof -auto-all -rtsopts -caf-all -fforce-recomp $(BASEFLAGS)
@@ -15,13 +24,6 @@ endif
 
 GHCMAKE=ghc $(GHCFLAGS) --make
 
-bins=git-annex
-mans=git-annex.1 git-annex-shell.1
-sources=Build/SysConfig.hs Utility/Touch.hs
-clibs=Utility/libdiskfree.o
-
-all=$(bins) $(mans) docs
-
 # Am I typing :make in vim? Do a fast build.
 ifdef VIM
 all=fast

Utility/Kqueue.hs

@@ -0,0 +1,31 @@
+{- BSD kqueue file modification notification interface
+ -
+ - Copyright 2012 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+{-# LANGUAGE ForeignFunctionInterface #-}
+
+module Utility.Kqueue ( waitChange ) where
+
+import Common
+
+import System.Posix.Types
+import Foreign.C.Types
+import Foreign.C.Error
+import Foreign.Ptr
+import Foreign.Marshal
+
+foreign import ccall unsafe "libkqueue.h waitchange" c_waitchange
+	:: Ptr Fd -> IO Fd
+
+waitChange :: [Fd] -> IO (Maybe Fd)
+waitChange fds = withArray fds $ \c_fds -> do
+	ret <- c_waitchange c_fds
+	ifM (safeErrno <$> getErrno)
+		( return $ Just ret
+		, return Nothing
+		)
+	where
+		safeErrno (Errno v) = v == 0

Utility/libkqueue.c

@@ -0,0 +1,22 @@
+/* kqueue interface, C mini-library
+ *
+ * Copyright 2012 Joey Hess <joey@kitenet.net>
+ *
+ * Licensed under the GNU GPL version 3 or higher.
+ */
+
+#include <errno.h>
+#include <stdio.h>
+
+/* Waits for a change event on one of the array of directory fds,
+ * and returns the one that changed. */
+int waitchange(const int *fds) {
+//	if (kqueue(blah, &fds) != 0)
+//		return 0; /* errno is set */
+//	else
+		errno = 0;
+
+	printf("in waitchange!, %i %i\n", fds[0], fds[1]);
+
+	return fds[0];
+}

Utility/libkqueue.h

@@ -0,0 +1 @@
+int waitchange(const int *fds);