Fix inotify preview polling

3 files changed, 35 insertions, 47 deletions

diff --git a/src/Hakyll.hs b/src/Hakyll.hs
index aaf36d4..1fe6147 100644
--- a/src/Hakyll.hs
+++ b/src/Hakyll.hs
@@ -12,7 +12,6 @@ module Hakyll
     , module Hakyll.Core.Util.File
     , module Hakyll.Core.Writable
     , module Hakyll.Main
-    , module Hakyll.Web
     , module Hakyll.Web.CompressCss
     , module Hakyll.Web.Feed
     , module Hakyll.Web.FileType
@@ -37,7 +36,6 @@ import Hakyll.Core.Util.Arrow
 import Hakyll.Core.Util.File
 import Hakyll.Core.Writable
 import Hakyll.Main
-import Hakyll.Web
 import Hakyll.Web.CompressCss
 import Hakyll.Web.Feed
 import Hakyll.Web.FileType
diff --git a/src/Hakyll/Main.hs b/src/Hakyll/Main.hs
index 74097f7..8cec42e 100644
--- a/src/Hakyll/Main.hs
+++ b/src/Hakyll/Main.hs
@@ -6,10 +6,9 @@ module Hakyll.Main
     ) where
 
 import Control.Concurrent (forkIO)
-import Control.Monad (when, forM_)
+import Control.Monad (when)
 import System.Environment (getProgName, getArgs)
 import System.Directory (doesDirectoryExist, removeDirectoryRecursive)
-import qualified Data.Set as S
 
 import Hakyll.Core.Configuration
 import Hakyll.Core.Run
@@ -87,16 +86,15 @@ preview configuration rules port = do
     -- Build once, keep the rule set
     ruleSet <- run configuration rules
 
-    -- Debug: show the resources used
-    forM_ (S.toList $ rulesResources ruleSet) $ putStrLn . show
+    -- Get the resource list and a callback for the preview poll
+    let resources = rulesResources ruleSet
+        callback = build configuration rules
 
-    {-
     -- Fork a thread polling for changes
-    _ <- forkIO $ previewPoll configuration "." $ build configuration rules
+    _ <- forkIO $ previewPoll configuration resources callback
     
     -- Run the server in the main thread
     server configuration port
-    -}
 
 -- | Rebuild the site
 --
diff --git a/src/Hakyll/Web/Preview/INotify.hs b/src/Hakyll/Web/Preview/INotify.hs
index fb3a7de..5bee981 100644
--- a/src/Hakyll/Web/Preview/INotify.hs
+++ b/src/Hakyll/Web/Preview/INotify.hs
@@ -4,57 +4,49 @@ module Hakyll.Web.Preview.INotify
     ( previewPoll
     ) where
 
-import Control.Monad (forM_, when, unless)
-import System.Directory (doesDirectoryExist)
-import System.FilePath ((</>))
-import Data.List (isPrefixOf)
+import Control.Monad (forM_, when)
+import Data.Set (Set)
+import qualified Data.Set as S
+import System.FilePath (takeDirectory)
 
 import System.INotify
 
-import Hakyll.Core.Util.File
 import Hakyll.Core.Configuration
+import Hakyll.Core.ResourceProvider
+import Hakyll.Core.Identifier
 
 -- | Calls the given callback when the directory tree changes
 --
 previewPoll :: HakyllConfiguration  -- ^ Configuration
-            -> FilePath             -- ^ Root directory
+            -> Set Resource         -- ^ Resources to watch
             -> IO ()                -- ^ Action called when something changes
             -> IO ()                -- ^ Can block forever
-previewPoll conf directory callback = do
+previewPoll _ resources callback = do
     -- Initialize inotify
     inotify <- initINotify
 
-    -- Start by watching all directories
-    contents <- getRecursiveContents True directory
-    forM_ contents $ \file -> do
-        isDir <- doesDirectoryExist file
-        when isDir $ watchDirectory conf inotify file callback
+    let -- A set of file paths
+        paths = S.map (toFilePath . unResource) resources
 
--- | Start watching a directory recursively: when another directory is created
--- inside this directory, start watching that one as well...
---
-watchDirectory :: HakyllConfiguration  -- ^ Configuration
-               -> INotify              -- ^ INotify handle
-               -> FilePath             -- ^ Directory to watch
-               -> IO ()                -- ^ Callback
-               -> IO ()                -- ^ No result
-watchDirectory conf inotify path callback =
-    unless (isFileInternal conf path) $ do
-        _ <- addWatch inotify interesting path $ \event -> do
-            putStrLn $ "Triggered: " ++ show event
-            callback' inotify path event
+        -- A list of directories
+        directories = S.toList $ S.map (notEmpty . takeDirectory) paths
+
+        -- Make sure a directory name is not empty
+        notEmpty "" = "."
+        notEmpty x  = x
+
+        -- Execute the callback when path is known
+        ifResource path = when (path `S.member` paths) $ do
+            putStrLn $ "Changed: " ++ path
+            callback
+
+    -- Add a watcher for every directory
+    forM_ directories $ \directory -> do
+        putStrLn $ "Adding watch for " ++ directory
+        _ <- addWatch inotify interesting directory $ \e -> case e of
+            (Modified _ (Just p)) -> ifResource p
+            _                     -> return ()
         return ()
   where
-    callback' i p (Created True n) = watchDirectory conf i (p </> n) callback
-    callback' _ _ (Created _ p)    = whenProper $ Just p
-    callback' _ _ (Modified _ p)   = whenProper p
-    callback' _ _ (MovedOut _ p _) = whenProper $ Just p
-    callback' _ _ (MovedIn _ p _)  = whenProper $ Just p
-    callback' _ _ (Deleted _ p)    = whenProper $ Just p
-    callback' _ _ _                = return ()
-
-    interesting = [Modify, Create, Move, Delete]
-
-    -- Call the callback only for proper files
-    whenProper Nothing  = return ()
-    whenProper (Just f) = unless ("." `isPrefixOf` f) callback
+    -- Interesting events
+    interesting = [Modify]