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-- | A module containing various file utility functions
--
module Hakyll.Core.Util.File
( makeDirectories
, getRecursiveContents
, isFileObsolete
) where
import System.FilePath (normalise, takeDirectory, (</>))
import System.Time (ClockTime)
import Control.Monad (forM, filterM)
import System.Directory ( createDirectoryIfMissing, doesDirectoryExist
, doesFileExist, getModificationTime
, getDirectoryContents
)
-- | Given a path to a file, try to make the path writable by making
-- all directories on the path.
--
makeDirectories :: FilePath -> IO ()
makeDirectories = createDirectoryIfMissing True . takeDirectory
-- | Get all contents of a directory. Note that files starting with a dot (.)
-- will be ignored.
--
getRecursiveContents :: FilePath -> IO [FilePath]
getRecursiveContents topdir = do
topdirExists <- doesDirectoryExist topdir
if topdirExists
then do names <- getDirectoryContents topdir
let properNames = filter isProper names
paths <- forM properNames $ \name -> do
let path = topdir </> name
isDirectory <- doesDirectoryExist path
if isDirectory
then getRecursiveContents path
else return [normalise path]
return (concat paths)
else return []
where
isProper = not . (== ".") . take 1
-- | Check if a timestamp is obsolete compared to the timestamps of a number of
-- files. When they are no files, it is never obsolete.
--
isObsolete :: ClockTime -- ^ The time to check.
-> [FilePath] -- ^ Dependencies of the cached file.
-> IO Bool
isObsolete _ [] = return False
isObsolete timeStamp depends = do
depends' <- filterM doesFileExist depends
dependsModified <- mapM getModificationTime depends'
return (timeStamp < maximum dependsModified)
-- | Check if a file is obsolete, given it's dependencies. When the file does
-- not exist, it is always obsolete. Other wise, it is obsolete if any of it's
-- dependencies has a more recent modification time than the file.
--
isFileObsolete :: FilePath -- ^ The cached file
-> [FilePath] -- ^ Dependencies of the cached file
-> IO Bool
isFileObsolete file depends = do
exists <- doesFileExist file
if not exists
then return True
else do timeStamp <- getModificationTime file
isObsolete timeStamp depends
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