a149336a59
This gets it building on Windows again, with 1 test suite failure (addurl). Sponsored-by: Kevin Mueller
122 lines
3.1 KiB
Haskell
122 lines
3.1 KiB
Haskell
{- streaming directory reading
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-
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- Copyright 2011-2025 Joey Hess <id@joeyh.name>
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-
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- License: BSD-2-clause
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-}
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{-# LANGUAGE CPP #-}
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{-# LANGUAGE LambdaCase #-}
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{-# LANGUAGE OverloadedStrings #-}
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{-# OPTIONS_GHC -fno-warn-tabs #-}
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module Utility.Directory.Stream (
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DirectoryHandle,
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openDirectory,
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closeDirectory,
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readDirectory,
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isDirectoryPopulated,
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) where
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import Control.Monad
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import Control.Concurrent
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import Data.Maybe
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import Prelude
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#ifdef mingw32_HOST_OS
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import qualified System.Win32 as Win32
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#else
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import qualified Data.ByteString as B
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import qualified System.Posix.Directory.ByteString as Posix
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#endif
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import Utility.Directory
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import Utility.Exception
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import Utility.FileSystemEncoding
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import Utility.OsPath
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#ifndef mingw32_HOST_OS
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data DirectoryHandle = DirectoryHandle IsOpen Posix.DirStream
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#else
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data DirectoryHandle = DirectoryHandle IsOpen Win32.HANDLE Win32.FindData (MVar ())
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#endif
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type IsOpen = MVar () -- full when the handle is open
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openDirectory :: RawFilePath -> IO DirectoryHandle
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openDirectory path = do
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#ifndef mingw32_HOST_OS
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dirp <- Posix.openDirStream path
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isopen <- newMVar ()
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return (DirectoryHandle isopen dirp)
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#else
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(h, fdat) <- Win32.findFirstFile (fromOsPath (toOsPath path </> literalOsPath "*"))
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-- Indicate that the fdat contains a filename that readDirectory
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-- has not yet returned, by making the MVar be full.
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-- (There's always at least a "." entry.)
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alreadyhave <- newMVar ()
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isopen <- newMVar ()
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return (DirectoryHandle isopen h fdat alreadyhave)
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#endif
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closeDirectory :: DirectoryHandle -> IO ()
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#ifndef mingw32_HOST_OS
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closeDirectory (DirectoryHandle isopen dirp) =
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whenOpen isopen $
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Posix.closeDirStream dirp
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#else
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closeDirectory (DirectoryHandle isopen h _ alreadyhave) =
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whenOpen isopen $ do
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_ <- tryTakeMVar alreadyhave
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Win32.findClose h
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#endif
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where
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whenOpen :: IsOpen -> IO () -> IO ()
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whenOpen mv f = do
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v <- tryTakeMVar mv
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when (isJust v) f
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-- | Reads the next entry from the handle. Once the end of the directory
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-- is reached, returns Nothing and automatically closes the handle.
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readDirectory :: DirectoryHandle -> IO (Maybe RawFilePath)
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#ifndef mingw32_HOST_OS
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readDirectory hdl@(DirectoryHandle _ dirp) = do
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e <- Posix.readDirStream dirp
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if B.null e
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then do
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closeDirectory hdl
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return Nothing
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else return (Just e)
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#else
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readDirectory hdl@(DirectoryHandle _ h fdat mv) = do
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-- If the MVar is full, then the filename in fdat has
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-- not yet been returned. Otherwise, need to find the next
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-- file.
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r <- tryTakeMVar mv
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case r of
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Just () -> getfn
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Nothing -> do
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more <- Win32.findNextFile h fdat
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if more
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then getfn
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else do
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closeDirectory hdl
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return Nothing
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where
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getfn = do
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filename <- Win32.getFindDataFileName fdat
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return (Just (toRawFilePath filename))
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#endif
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-- | True only when directory exists and is not empty.
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isDirectoryPopulated :: RawFilePath -> IO Bool
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isDirectoryPopulated d = bracket (openDirectory d) closeDirectory check
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`catchIO` const (return False)
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where
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check h = do
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v <- readDirectory h
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case v of
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Nothing -> return False
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Just f
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| not (toOsPath f `elem` dirCruft) -> return True
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| otherwise -> check h
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