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Refactor stat functions in readdir code #3006

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Merged
harendra-kumar merged 1 commit into from
Mar 25, 2025
Merged

Refactor stat functions in readdir code #3006

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150 changes: 69 additions & 81 deletions core/src/Streamly/Internal/FileSystem/Posix/ReadDir.hsc
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Original file line number Diff line number Diff line change
Expand Up @@ -273,72 +273,64 @@ isMetaDir dname = do
then return True
else return False

data GStatRes
= GSIsMetaDir
| GSIsRegDir
| GSIsNotDir
| GSIgnoreError Errno

{-# NOINLINE gstatDname #-}
gstatDname
:: ReadOptions -> PosixPath -> Ptr CChar -> IO GStatRes
gstatDname conf parent dname = do
isMeta <- liftIO $ isMetaDir dname
if isMeta
then pure GSIsMetaDir
else do
-- XXX We can create a pinned array right here since the next call pins
-- it anyway.
path <- appendCString parent dname
Array.asCStringUnsafe (Path.toChunk path) $ \cStr -> do
res <- stat (_followSymlinks conf) cStr
case res of
Right mode -> pure $
if (mode == s_IFDIR)
then GSIsRegDir
else GSIsNotDir
Left errno -> do
if errno == eNOENT
then unless (_ignoreNonExistingFiles conf) $
throwErrno (errMsg path)
else if errno == eACCES
then unless (_ignoreInAccessibleFiles conf) $
throwErrno (errMsg path)
else if errno == eLOOP
then unless (_ignoreSymlinkLoopErrors conf) $
throwErrno (errMsg path)
else throwErrno (errMsg path)
pure $ GSIgnoreError errno
data EntryType = EntryIsDir | EntryIsNotDir | EntryIgnored

{-# NOINLINE statEntryType #-}
statEntryType
:: ReadOptions -> PosixPath -> Ptr CChar -> IO EntryType
statEntryType conf parent dname = do
-- XXX We can create a pinned array right here since the next call pins
-- it anyway.
path <- appendCString parent dname
Array.asCStringUnsafe (Path.toChunk path) $ \cStr -> do
res <- stat (_followSymlinks conf) cStr
case res of
Right mode -> pure $
if (mode == s_IFDIR)
then EntryIsDir
else EntryIsNotDir
Left errno -> do
if errno == eNOENT
then unless (_ignoreNonExistingFiles conf) $
throwErrno (errMsg path)
else if errno == eACCES
then unless (_ignoreInAccessibleFiles conf) $
throwErrno (errMsg path)
else if errno == eLOOP
then unless (_ignoreSymlinkLoopErrors conf) $
throwErrno (errMsg path)
else throwErrno (errMsg path)
pure $ EntryIgnored
where

errMsg path =
let pathStr = Path.toString_ path
in "statDname: " ++ pathStr
in "statEntryType: " ++ pathStr

-- | Checks if dname is a directory and additionaly returns if dname is a meta
-- directory.
{-# INLINE checkDirStatus #-}
checkDirStatus
-- | Checks if dname is a directory, not dir or should be ignored.
{-# INLINE getEntryType #-}
getEntryType
:: ReadOptions
-> PosixPath -> Ptr CChar -> #{type unsigned char} -> IO GStatRes
-> PosixPath -> Ptr CChar -> #{type unsigned char} -> IO EntryType
getEntryType conf parent dname dtype = do
let needStat =
#ifdef FORCE_LSTAT_READDIR
checkDirStatus conf parent dname _ =
gstatDname conf parent dname
True
#else
checkDirStatus conf parent dname dtype =
if dtype == (#const DT_DIR)
then do
isMeta <- liftIO $ isMetaDir dname
pure $ if isMeta then GSIsMetaDir else GSIsRegDir
else if dtype == (#const DT_LNK)
then
if _followSymlinks conf
then gstatDname conf parent dname
else pure GSIsNotDir
else if dtype /= #const DT_UNKNOWN
then pure GSIsNotDir
else gstatDname conf parent dname
(dtype == (#const DT_LNK) && _followSymlinks conf)
|| dtype == #const DT_UNKNOWN
#endif

if dtype /= (#const DT_DIR) && not needStat
then pure EntryIsNotDir
else do
isMeta <- liftIO $ isMetaDir dname
if isMeta
then pure EntryIgnored
else if dtype == (#const DT_DIR)
then pure EntryIsDir
else statEntryType conf parent dname

-------------------------------------------------------------------------------
-- streaming reads
-------------------------------------------------------------------------------
Expand Down Expand Up @@ -376,12 +368,11 @@ readDirStreamEither confMod (curdir, (DirStream dirp)) = loop
-- fromPtrN, but it is not straightforward because the reclen is
-- padded to 8-byte boundary.
name <- Array.fromCString (castPtr dname)
gsRes <- checkDirStatus conf curdir dname dtype
case gsRes of
GSIsRegDir -> return (Just (Left (mkPath name)))
GSIsNotDir -> return (Just (Right (mkPath name)))
-- Loop if it's a meta directory or an error that we can ignore
_ -> loop
etype <- getEntryType conf curdir dname dtype
case etype of
EntryIsDir -> return (Just (Left (mkPath name)))
EntryIsNotDir -> return (Just (Right (mkPath name)))
EntryIgnored -> loop
else do
errno <- getErrno
if (errno == eINTR)
Expand Down Expand Up @@ -515,9 +506,9 @@ readEitherChunks confMod alldirs =
dtype :: #{type unsigned char} <-
liftIO $ #{peek struct dirent, d_type} dentPtr

gsRes <- liftIO $ checkDirStatus conf curdir dname dtype
case gsRes of
GSIsRegDir -> do
etype <- liftIO $ getEntryType conf curdir dname dtype
case etype of
EntryIsDir -> do
path <- liftIO $ appendCString curdir dname
let dirs1 = path : dirs
ndirs1 = ndirs + 1
Expand All @@ -526,7 +517,7 @@ readEitherChunks confMod alldirs =
(ChunkStreamLoop curdir xs dirp [] 0 files nfiles)
else return $ Skip
(ChunkStreamLoop curdir xs dirp dirs1 ndirs1 files nfiles)
GSIsNotDir -> do
EntryIsNotDir -> do
path <- liftIO $ appendCString curdir dname
let files1 = path : files
nfiles1 = nfiles + 1
Expand All @@ -535,8 +526,7 @@ readEitherChunks confMod alldirs =
(ChunkStreamLoop curdir xs dirp dirs ndirs [] 0)
else return $ Skip
(ChunkStreamLoop curdir xs dirp dirs ndirs files1 nfiles1)
-- Loop if it's a meta directory or an error that we can ignore
_ -> return $ Skip st
EntryIgnored -> return $ Skip st
else do
errno <- liftIO getErrno
if (errno == eINTR)
Expand Down Expand Up @@ -684,9 +674,9 @@ readEitherByteChunks confMod alldirs =
-- because it has a StreamK in the middle.
-- Keep the file check first as it is more likely

gsRes <- liftIO $ checkDirStatus conf curdir dname dtype
case gsRes of
GSIsNotDir -> do
etype <- liftIO $ getEntryType conf curdir dname dtype
case etype of
EntryIsNotDir -> do
r <- copyToBuf mbarr pos curdir dname
case r of
Just pos1 ->
Expand All @@ -703,7 +693,7 @@ readEitherByteChunks confMod alldirs =
else
return $ Skip
(ChunkStreamByteLoopPending dname curdir xs dirp mbarr pos)
GSIsRegDir -> do
EntryIsDir -> do
path <- liftIO $ appendCString curdir dname
let dirs1 = path : dirs
ndirs1 = ndirs + 1
Expand All @@ -718,8 +708,7 @@ readEitherByteChunks confMod alldirs =
-- otherwise skip.
return $ Yield (Left dirs1)
(ChunkStreamByteLoopPending dname curdir xs dirp mbarr pos)
-- Loop if it's a meta directory or an error that we can ignore
_ -> return $ Skip st
EntryIgnored -> return $ Skip st
else do
errno <- liftIO getErrno
if (errno == eINTR)
Expand Down Expand Up @@ -843,9 +832,9 @@ readEitherByteChunksAt confMod (ppath, alldirs) =
liftIO $ #{peek struct dirent, d_type} dentPtr

-- Keep the file check first as it is more likely
gsRes <- liftIO $ checkDirStatus conf curdir dname dtype
case gsRes of
GSIsNotDir -> do
etype <- liftIO $ getEntryType conf curdir dname dtype
case etype of
EntryIsNotDir -> do
r <- copyToBuf mbarr pos curdir dname
case r of
Just pos1 ->
Expand All @@ -856,7 +845,7 @@ readEitherByteChunksAt confMod (ppath, alldirs) =
return $ Skip
(ByteChunksAtRealloc
dname pfd dirp curdir xs dirs ndirs mbarr pos)
GSIsRegDir -> do
EntryIsDir -> do
arr <- Array.fromCString (castPtr dname)
let path = Path.unsafeFromChunk arr
let dirs1 = path : dirs
Expand All @@ -882,8 +871,7 @@ readEitherByteChunksAt confMod (ppath, alldirs) =
return $ Skip
(ByteChunksAtRealloc
dname pfd dirp curdir xs dirs1 ndirs1 mbarr pos)
-- Loop if it's a meta directory or an error that we can ignore
_ -> return $ Skip st
EntryIgnored -> return $ Skip st
else do
errno <- liftIO getErrno
if (errno == eINTR)
Expand Down
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