-{-# OPTIONS -fno-implicit-prelude -#include "HsBase.h" #-}
+{-# OPTIONS_GHC -fno-implicit-prelude -#include "HsBase.h" #-}
#undef DEBUG_DUMP
--
-----------------------------------------------------------------------------
+-- #hide
module GHC.IO (
hWaitForInput, hGetChar, hGetLine, hGetContents, hPutChar, hPutStr,
commitBuffer', -- hack, see below
hGetcBuffered, -- needed by ghc/compiler/utils/StringBuffer.lhs
- hGetBuf, hPutBuf, slurpFile,
+ hGetBuf, hGetBufNonBlocking, hPutBuf, hPutBufNonBlocking, slurpFile,
memcpy_ba_baoff,
memcpy_ptr_baoff,
memcpy_baoff_ba,
import GHC.Show
import GHC.List
import GHC.Exception ( ioError, catch )
+
+#ifdef mingw32_HOST_OS
import GHC.Conc
+#endif
-- ---------------------------------------------------------------------------
-- Simple input operations
-- It returns 'True' as soon as input is available on @hdl@,
-- or 'False' if no input is available within @t@ milliseconds.
--
+-- If @t@ is less than zero, then @hWaitForInput@ waits indefinitely.
+--
-- This operation may fail with:
--
-- * 'isEOFError' if the end of file has been reached.
+--
+-- NOTE for GHC users: unless you use the @-threaded@ flag,
+-- @hWaitForInput t@ where @t >= 0@ will block all other Haskell
+-- threads for the duration of the call. It behaves like a
+-- @safe@ foreign call in this respect.
hWaitForInput :: Handle -> Int -> IO Bool
hWaitForInput h msecs = do
then return True
else do
- r <- throwErrnoIfMinus1Retry "hWaitForInput"
- (inputReady (fromIntegral (haFD handle_)) (fromIntegral msecs) (haIsStream handle_))
- return (r /= 0)
-
-foreign import ccall unsafe "inputReady"
+ if msecs < 0
+ then do buf' <- fillReadBuffer (haFD handle_) True
+ (haIsStream handle_) buf
+ writeIORef ref buf'
+ return True
+ else do r <- throwErrnoIfMinus1Retry "hWaitForInput" $
+ inputReady (fromIntegral (haFD handle_))
+ (fromIntegral msecs) (haIsStream handle_)
+ return (r /= 0)
+
+foreign import ccall safe "inputReady"
inputReady :: CInt -> CInt -> Bool -> IO CInt
-- ---------------------------------------------------------------------------
Nothing -> hGetLineUnBuffered h
Just l -> return l
-
+hGetLineBuffered :: Handle__ -> IO String
hGetLineBuffered handle_ = do
let ref = haBuffer handle_
buf <- readIORef ref
hGetLineBufferedLoop handle_ ref buf []
-
-hGetLineBufferedLoop handle_ ref
- buf@Buffer{ bufRPtr=r, bufWPtr=w, bufBuf=raw } xss =
- let
- -- find the end-of-line character, if there is one
- loop raw r
- | r == w = return (False, w)
- | otherwise = do
- (c,r') <- readCharFromBuffer raw r
- if c == '\n'
- then return (True, r) -- NB. not r': don't include the '\n'
- else loop raw r'
+hGetLineBufferedLoop :: Handle__ -> IORef Buffer -> Buffer -> [String]
+ -> IO String
+hGetLineBufferedLoop handle_ ref
+ buf@Buffer{ bufRPtr=r, bufWPtr=w, bufBuf=raw } xss =
+ let
+ -- find the end-of-line character, if there is one
+ loop raw r
+ | r == w = return (False, w)
+ | otherwise = do
+ (c,r') <- readCharFromBuffer raw r
+ if c == '\n'
+ then return (True, r) -- NB. not r': don't include the '\n'
+ else loop raw r'
in do
(eol, off) <- loop raw r
-- if eol == True, then off is the offset of the '\n'
-- otherwise off == w and the buffer is now empty.
if eol
- then do if (w == off + 1)
- then writeIORef ref buf{ bufRPtr=0, bufWPtr=0 }
- else writeIORef ref buf{ bufRPtr = off + 1 }
- return (concat (reverse (xs:xss)))
- else do
- maybe_buf <- maybeFillReadBuffer (haFD handle_) True (haIsStream handle_)
- buf{ bufWPtr=0, bufRPtr=0 }
- case maybe_buf of
- -- Nothing indicates we caught an EOF, and we may have a
- -- partial line to return.
- Nothing -> do
- writeIORef ref buf{ bufRPtr=0, bufWPtr=0 }
- let str = concat (reverse (xs:xss))
- if not (null str)
- then return str
- else ioe_EOF
- Just new_buf ->
- hGetLineBufferedLoop handle_ ref new_buf (xs:xss)
+ then do if (w == off + 1)
+ then writeIORef ref buf{ bufRPtr=0, bufWPtr=0 }
+ else writeIORef ref buf{ bufRPtr = off + 1 }
+ return (concat (reverse (xs:xss)))
+ else do
+ maybe_buf <- maybeFillReadBuffer (haFD handle_) True (haIsStream handle_)
+ buf{ bufWPtr=0, bufRPtr=0 }
+ case maybe_buf of
+ -- Nothing indicates we caught an EOF, and we may have a
+ -- partial line to return.
+ Nothing -> do
+ writeIORef ref buf{ bufRPtr=0, bufWPtr=0 }
+ let str = concat (reverse (xs:xss))
+ if not (null str)
+ then return str
+ else ioe_EOF
+ Just new_buf ->
+ hGetLineBufferedLoop handle_ ref new_buf (xs:xss)
maybeFillReadBuffer fd is_line is_stream buf
-- * 'isPermissionError' if another system resource limit would be exceeded.
hPutChar :: Handle -> Char -> IO ()
-hPutChar handle c =
- c `seq` do -- must evaluate c before grabbing the handle lock
+hPutChar handle c = do
+ c `seq` return ()
wantWritableHandle "hPutChar" handle $ \ handle_ -> do
let fd = haFD handle_
case haBufferMode handle_ of
LineBuffering -> hPutcBuffered handle_ True c
BlockBuffering _ -> hPutcBuffered handle_ False c
NoBuffering ->
- withObject (castCharToCChar c) $ \buf -> do
+ with (castCharToCChar c) $ \buf -> do
writeRawBufferPtr "hPutChar" (fromIntegral fd) (haIsStream handle_) buf 0 1
return ()
commitBuffer hdl raw sz@(I# _) count@(I# _) flush release = do
wantWritableHandle "commitAndReleaseBuffer" hdl $
- commitBuffer' hdl raw sz count flush release
+ commitBuffer' raw sz count flush release
-- Explicitly lambda-lift this function to subvert GHC's full laziness
-- optimisations, which otherwise tends to float out subexpressions
--
-- This hack is a fairly big win for hPutStr performance. --SDM 18/9/2001
--
-commitBuffer' hdl raw sz@(I# _) count@(I# _) flush release
+commitBuffer' raw sz@(I# _) count@(I# _) flush release
handle_@Handle__{ haFD=fd, haBuffer=ref, haBuffers=spare_buf_ref } = do
#ifdef DEBUG_DUMP
-> Ptr a -- address of buffer
-> Int -- number of bytes of data in buffer
-> IO ()
-hPutBuf handle ptr count
- | count == 0 = return ()
+hPutBuf h ptr count = do hPutBuf' h ptr count True; return ()
+
+hPutBufNonBlocking
+ :: Handle -- handle to write to
+ -> Ptr a -- address of buffer
+ -> Int -- number of bytes of data in buffer
+ -> IO Int -- returns: number of bytes written
+hPutBufNonBlocking h ptr count = hPutBuf' h ptr count False
+
+hPutBuf':: Handle -- handle to write to
+ -> Ptr a -- address of buffer
+ -> Int -- number of bytes of data in buffer
+ -> Bool -- allow blocking?
+ -> IO Int
+hPutBuf' handle ptr count can_block
+ | count == 0 = return 0
| count < 0 = illegalBufferSize handle "hPutBuf" count
| otherwise =
wantWritableHandle "hPutBuf" handle $
- \ handle_@Handle__{ haFD=fd, haBuffer=ref, haIsStream=is_stream } -> do
-
- old_buf@Buffer{ bufBuf=old_raw, bufRPtr=r, bufWPtr=w, bufSize=size }
- <- readIORef ref
-
- -- enough room in handle buffer?
- if (size - w > count)
- -- There's enough room in the buffer:
- -- just copy the data in and update bufWPtr.
- then do memcpy_baoff_ptr old_raw w ptr (fromIntegral count)
- writeIORef ref old_buf{ bufWPtr = w + count }
- return ()
-
- -- else, we have to flush
- else do flushed_buf <- flushWriteBuffer fd is_stream old_buf
- writeIORef ref flushed_buf
- -- ToDo: should just memcpy instead of writing if possible
- writeChunk fd is_stream (castPtr ptr) count
+ \ handle_@Handle__{ haFD=fd, haBuffer=ref, haIsStream=is_stream } ->
+ bufWrite fd ref is_stream ptr count can_block
+
+bufWrite fd ref is_stream ptr count can_block =
+ seq count $ seq fd $ do -- strictness hack
+ old_buf@Buffer{ bufBuf=old_raw, bufRPtr=r, bufWPtr=w, bufSize=size }
+ <- readIORef ref
+
+ -- enough room in handle buffer?
+ if (size - w > count)
+ -- There's enough room in the buffer:
+ -- just copy the data in and update bufWPtr.
+ then do memcpy_baoff_ptr old_raw w ptr (fromIntegral count)
+ writeIORef ref old_buf{ bufWPtr = w + count }
+ return count
+
+ -- else, we have to flush
+ else do flushed_buf <- flushWriteBuffer fd is_stream old_buf
+ -- TODO: we should do a non-blocking flush here
+ writeIORef ref flushed_buf
+ -- if we can fit in the buffer, then just loop
+ if count < size
+ then bufWrite fd ref is_stream ptr count can_block
+ else if can_block
+ then do writeChunk fd is_stream (castPtr ptr) count
+ return count
+ else writeChunkNonBlocking fd is_stream ptr count
writeChunk :: FD -> Bool -> Ptr CChar -> Int -> IO ()
writeChunk fd is_stream ptr bytes = loop 0 bytes
-- write can't return 0
loop (off + r) (bytes - r)
+writeChunkNonBlocking :: FD -> Bool -> Ptr a -> Int -> IO Int
+writeChunkNonBlocking fd is_stream ptr bytes = loop 0 bytes
+ where
+ loop :: Int -> Int -> IO Int
+ loop off bytes | bytes <= 0 = return off
+ loop off bytes = do
+#ifndef mingw32_HOST_OS
+ ssize <- c_write (fromIntegral fd) (ptr `plusPtr` off) (fromIntegral bytes)
+ let r = fromIntegral ssize :: Int
+ if (r == -1)
+ then do errno <- getErrno
+ if (errno == eAGAIN || errno == eWOULDBLOCK)
+ then return off
+ else throwErrno "writeChunk"
+ else loop (off + r) (bytes - r)
+#else
+ (ssize, rc) <- asyncWrite fd (fromIntegral $ fromEnum is_stream)
+ (fromIntegral bytes)
+ (ptr `plusPtr` off)
+ let r = fromIntegral ssize :: Int
+ if r == (-1)
+ then ioError (errnoToIOError "hPutBufNonBlocking" (Errno (fromIntegral rc)) Nothing Nothing)
+ else loop (off + r) (bytes - r)
+#endif
+
-- ---------------------------------------------------------------------------
-- hGetBuf
-- is closed, 'hGetBuf' will behave as if EOF was reached.
hGetBuf :: Handle -> Ptr a -> Int -> IO Int
-hGetBuf handle ptr count
+hGetBuf h ptr count
| count == 0 = return 0
- | count < 0 = illegalBufferSize handle "hGetBuf" count
+ | count < 0 = illegalBufferSize h "hGetBuf" count
| otherwise =
- wantReadableHandle "hGetBuf" handle $
+ wantReadableHandle "hGetBuf" h $
\ handle_@Handle__{ haFD=fd, haBuffer=ref, haIsStream=is_stream } -> do
- buf@Buffer{ bufBuf=raw, bufWPtr=w, bufRPtr=r } <- readIORef ref
- if bufferEmpty buf
- then readChunk fd is_stream ptr count
+ bufRead fd ref is_stream ptr 0 count
+
+-- small reads go through the buffer, large reads are satisfied by
+-- taking data first from the buffer and then direct from the file
+-- descriptor.
+bufRead fd ref is_stream ptr so_far count =
+ seq fd $ seq so_far $ seq count $ do -- strictness hack
+ buf@Buffer{ bufBuf=raw, bufWPtr=w, bufRPtr=r, bufSize=sz } <- readIORef ref
+ if bufferEmpty buf
+ then if count > sz -- small read?
+ then do rest <- readChunk fd is_stream ptr count
+ return (so_far + rest)
+ else do mb_buf <- maybeFillReadBuffer fd True is_stream buf
+ case mb_buf of
+ Nothing -> return so_far -- got nothing, we're done
+ Just buf' -> do
+ writeIORef ref buf'
+ bufRead fd ref is_stream ptr so_far count
+ else do
+ let avail = w - r
+ if (count == avail)
+ then do
+ memcpy_ptr_baoff ptr raw r (fromIntegral count)
+ writeIORef ref buf{ bufWPtr=0, bufRPtr=0 }
+ return (so_far + count)
+ else do
+ if (count < avail)
+ then do
+ memcpy_ptr_baoff ptr raw r (fromIntegral count)
+ writeIORef ref buf{ bufRPtr = r + count }
+ return (so_far + count)
+ else do
+
+ memcpy_ptr_baoff ptr raw r (fromIntegral avail)
+ writeIORef ref buf{ bufWPtr=0, bufRPtr=0 }
+ let remaining = count - avail
+ so_far' = so_far + avail
+ ptr' = ptr `plusPtr` avail
+
+ if remaining < sz
+ then bufRead fd ref is_stream ptr' so_far' remaining
else do
- let avail = w - r
- copied <- if (count >= avail)
- then do
- memcpy_ptr_baoff ptr raw r (fromIntegral avail)
- writeIORef ref buf{ bufWPtr=0, bufRPtr=0 }
- return avail
- else do
- memcpy_ptr_baoff ptr raw r (fromIntegral count)
- writeIORef ref buf{ bufRPtr = r + count }
- return count
-
- let remaining = count - copied
- if remaining > 0
- then do rest <- readChunk fd is_stream (ptr `plusPtr` copied) remaining
- return (rest + copied)
- else return count
-
+
+ rest <- readChunk fd is_stream ptr' remaining
+ return (so_far' + rest)
+
readChunk :: FD -> Bool -> Ptr a -> Int -> IO Int
readChunk fd is_stream ptr bytes = loop 0 bytes
where
then return off
else loop (off + r) (bytes - r)
+
+-- | 'hGetBufNonBlocking' @hdl buf count@ reads data from the handle @hdl@
+-- into the buffer @buf@ until either EOF is reached, or
+-- @count@ 8-bit bytes have been read, or there is no more data available
+-- to read immediately.
+--
+-- 'hGetBufNonBlocking' is identical to 'hGetBuf', except that it will
+-- never block waiting for data to become available, instead it returns
+-- only whatever data is available. To wait for data to arrive before
+-- calling 'hGetBufNonBlocking', use 'hWaitForInput'.
+--
+-- If the handle is a pipe or socket, and the writing end
+-- is closed, 'hGetBufNonBlocking' will behave as if EOF was reached.
+--
+hGetBufNonBlocking :: Handle -> Ptr a -> Int -> IO Int
+hGetBufNonBlocking h ptr count
+ | count == 0 = return 0
+ | count < 0 = illegalBufferSize h "hGetBufNonBlocking" count
+ | otherwise =
+ wantReadableHandle "hGetBufNonBlocking" h $
+ \ handle_@Handle__{ haFD=fd, haBuffer=ref, haIsStream=is_stream } -> do
+ bufReadNonBlocking fd ref is_stream ptr 0 count
+
+bufReadNonBlocking fd ref is_stream ptr so_far count =
+ seq fd $ seq so_far $ seq count $ do -- strictness hack
+ buf@Buffer{ bufBuf=raw, bufWPtr=w, bufRPtr=r, bufSize=sz } <- readIORef ref
+ if bufferEmpty buf
+ then if count > sz -- large read?
+ then do rest <- readChunkNonBlocking fd is_stream ptr count
+ return (so_far + rest)
+ else do buf' <- fillReadBufferWithoutBlocking fd is_stream buf
+ case buf' of { Buffer{ bufWPtr=w } ->
+ if (w == 0)
+ then return so_far
+ else do writeIORef ref buf'
+ bufReadNonBlocking fd ref is_stream ptr
+ so_far (min count w)
+ -- NOTE: new count is 'min count w'
+ -- so we will just copy the contents of the
+ -- buffer in the recursive call, and not
+ -- loop again.
+ }
+ else do
+ let avail = w - r
+ if (count == avail)
+ then do
+ memcpy_ptr_baoff ptr raw r (fromIntegral count)
+ writeIORef ref buf{ bufWPtr=0, bufRPtr=0 }
+ return (so_far + count)
+ else do
+ if (count < avail)
+ then do
+ memcpy_ptr_baoff ptr raw r (fromIntegral count)
+ writeIORef ref buf{ bufRPtr = r + count }
+ return (so_far + count)
+ else do
+
+ memcpy_ptr_baoff ptr raw r (fromIntegral avail)
+ writeIORef ref buf{ bufWPtr=0, bufRPtr=0 }
+ let remaining = count - avail
+ so_far' = so_far + avail
+ ptr' = ptr `plusPtr` avail
+
+ -- we haven't attempted to read anything yet if we get to here.
+ if remaining < sz
+ then bufReadNonBlocking fd ref is_stream ptr' so_far' remaining
+ else do
+
+ rest <- readChunkNonBlocking fd is_stream ptr' remaining
+ return (so_far' + rest)
+
+
+readChunkNonBlocking :: FD -> Bool -> Ptr a -> Int -> IO Int
+readChunkNonBlocking fd is_stream ptr bytes = do
+#ifndef mingw32_HOST_OS
+ ssize <- c_read (fromIntegral fd) (castPtr ptr) (fromIntegral bytes)
+ let r = fromIntegral ssize :: Int
+ if (r == -1)
+ then do errno <- getErrno
+ if (errno == eAGAIN || errno == eWOULDBLOCK)
+ then return 0
+ else throwErrno "readChunk"
+ else return r
+#else
+ fromIntegral `liftM`
+ readRawBufferPtr "readChunkNonBlocking" (fromIntegral fd) is_stream
+ (castPtr ptr) 0 (fromIntegral bytes)
+
+ -- we don't have non-blocking read support on Windows, so just invoke
+ -- the ordinary low-level read which will block until data is available,
+ -- but won't wait for the whole buffer to fill.
+#endif
+
slurpFile :: FilePath -> IO (Ptr (), Int)
slurpFile fname = do
handle <- openFile fname ReadMode
projects / haskell-directory.git / blobdiff