-{-# OPTIONS_GHC -XNoImplicitPrelude -#include "HsBase.h" #-}
+{-# LANGUAGE NoImplicitPrelude
+ , RecordWildCards
+ , BangPatterns
+ , PatternGuards
+ , NondecreasingIndentation
+ , Rank2Types
+ #-}
{-# OPTIONS_GHC -fno-warn-unused-matches #-}
{-# OPTIONS_GHC -fno-warn-name-shadowing #-}
-{-# OPTIONS_GHC -XRecordWildCards #-}
{-# OPTIONS_HADDOCK hide #-}
-----------------------------------------------------------------------------
wantSeekableHandle,
mkHandle, mkFileHandle, mkDuplexHandle,
- openTextEncoding, initBufferState,
+ openTextEncoding, closeTextCodecs, initBufferState,
dEFAULT_CHAR_BUFFER_SIZE,
- flushBuffer, flushWriteBuffer, flushWriteBuffer_, flushCharReadBuffer,
- flushCharBuffer, flushByteReadBuffer,
+ flushBuffer, flushWriteBuffer, flushCharReadBuffer,
+ flushCharBuffer, flushByteReadBuffer, flushByteWriteBuffer,
- readTextDevice, writeTextDevice, readTextDeviceNonBlocking,
+ readTextDevice, writeCharBuffer, readTextDeviceNonBlocking,
decodeByteBuf,
augmentIOError,
import GHC.IO
import GHC.IO.IOMode
-import GHC.IO.Encoding
+import GHC.IO.Encoding as Encoding
import GHC.IO.Handle.Types
import GHC.IO.Buffer
import GHC.IO.BufferedIO (BufferedIO)
import qualified GHC.IO.Device as IODevice
import qualified GHC.IO.BufferedIO as Buffered
-import GHC.Conc
+import GHC.Conc.Sync
import GHC.Real
import GHC.Base
import GHC.Exception
import Data.Typeable
import Control.Monad
import Data.Maybe
-import Foreign
+import Foreign hiding (unsafePerformIO)
-- import System.IO.Error
import System.Posix.Internals hiding (FD)
withHandle' :: String -> Handle -> MVar Handle__
-> (Handle__ -> IO (Handle__,a)) -> IO a
withHandle' fun h m act =
- block $ do
+ mask_ $ do
(h',v) <- do_operation fun h act m
checkHandleInvariants h'
putMVar m h'
withHandle__' :: String -> Handle -> MVar Handle__ -> (Handle__ -> IO Handle__)
-> IO ()
withHandle__' fun h m act =
- block $ do
+ mask_ $ do
h' <- do_operation fun h act m
checkHandleInvariants h'
putMVar m h'
wantWritableHandle fun h@(FileHandle _ m) act
= wantWritableHandle' fun h m act
wantWritableHandle fun h@(DuplexHandle _ _ m) act
- = withHandle_' fun h m act
+ = wantWritableHandle' fun h m act
+ -- we know it's not a ReadHandle or ReadWriteHandle, but we have to
+ -- check for ClosedHandle/SemiClosedHandle. (#4808)
wantWritableHandle'
:: String -> Handle -> MVar Handle__
wantReadableHandle_ fun h@(FileHandle _ m) act
= wantReadableHandle' fun h m act
wantReadableHandle_ fun h@(DuplexHandle _ m _) act
- = withHandle_' fun h m act
+ = wantReadableHandle' fun h m act
+ -- we know it's not a WriteHandle or ReadWriteHandle, but we have to
+ -- check for ClosedHandle/SemiClosedHandle. (#4808)
wantReadableHandle'
:: String -> Handle -> MVar Handle__
ReadWriteHandle -> do
-- a read/write handle and we want to read from it. We must
-- flush all buffered write data first.
- cbuf <- readIORef haCharBuffer
- when (isWriteBuffer cbuf) $ do
- cbuf' <- flushWriteBuffer_ h_ cbuf
+ bbuf <- readIORef haByteBuffer
+ when (isWriteBuffer bbuf) $ do
+ when (not (isEmptyBuffer bbuf)) $ flushByteWriteBuffer h_
+ cbuf' <- readIORef haCharBuffer
writeIORef haCharBuffer cbuf'{ bufState = ReadBuffer }
bbuf <- readIORef haByteBuffer
writeIORef haByteBuffer bbuf{ bufState = ReadBuffer }
("illegal buffer size " ++ showsPrec 9 n []) Nothing Nothing)
-- 9 => should be parens'ified.
+-- ---------------------------------------------------------------------------
+-- Wrapper for Handle encoding/decoding.
+
+-- The interface for TextEncoding changed so that a TextEncoding doesn't raise
+-- an exception if it encounters an invalid sequnce. Furthermore, encoding
+-- returns a reason as to why encoding stopped, letting us know if it was due
+-- to input/output underflow or an invalid sequence.
+--
+-- This code adapts this elaborated interface back to the original TextEncoding
+-- interface.
+--
+-- FIXME: it is possible that Handle code using the haDecoder/haEncoder fields
+-- could be made clearer by using the 'encode' interface directly. I have not
+-- looked into this.
+--
+-- FIXME: we should use recover to deal with EOF, rather than always throwing an
+-- IOException (ioe_invalidCharacter).
+
+streamEncode :: BufferCodec from to state
+ -> Buffer from -> Buffer to
+ -> IO (Buffer from, Buffer to)
+streamEncode codec from to = go (from, to)
+ where
+ go (from, to) = do
+ (why, from', to') <- encode codec from to
+ -- When we are dealing with Handles, we don't care about input/output
+ -- underflow particularly, and we want to delay errors about invalid
+ -- sequences as far as possible.
+ case why of
+ Encoding.InvalidSequence | bufL from == bufL from' -> recover codec from' to' >>= go
+ _ -> return (from', to')
+
-- -----------------------------------------------------------------------------
-- Handle Finalizers
-- has become unreferenced and then resurrected (arguably in the
-- latter case we shouldn't finalize the Handle...). Anyway,
-- we try to emit a helpful message which is better than nothing.
+--
+-- [later; 8/2010] However, a program like this can yield a strange
+-- error message:
+--
+-- main = writeFile "out" loop
+-- loop = let x = x in x
+--
+-- because the main thread and the Handle are both unreachable at the
+-- same time, the Handle may get finalized before the main thread
+-- receives the NonTermination exception, and the exception handler
+-- will then report an error. We'd rather this was not an error and
+-- the program just prints "<<loop>>".
handleFinalizer :: FilePath -> MVar Handle__ -> IO ()
handleFinalizer fp m = do
handle_ <- takeMVar m
- case haType handle_ of
- ClosedHandle -> return ()
- _ -> do flushWriteBuffer handle_ `catchAny` \_ -> return ()
- -- ignore errors and async exceptions, and close the
- -- descriptor anyway...
- _ <- hClose_handle_ handle_
- return ()
- putMVar m (ioe_finalizedHandle fp)
+ (handle_', _) <- hClose_help handle_
+ putMVar m handle_'
+ return ()
-- ---------------------------------------------------------------------------
-- Allocating buffers
-- using an 8k char buffer instead of 32k improved performance for a
-- basic "cat" program by ~30% for me. --SDM
dEFAULT_CHAR_BUFFER_SIZE :: Int
-dEFAULT_CHAR_BUFFER_SIZE = dEFAULT_BUFFER_SIZE `div` 4
+dEFAULT_CHAR_BUFFER_SIZE = 2048 -- 8k/sizeof(HsChar)
getCharBuffer :: IODevice dev => dev -> BufferState
-> IO (IORef CharBuffer, BufferMode)
mkUnBuffer :: BufferState -> IO (IORef CharBuffer, BufferMode)
mkUnBuffer state = do
- buffer <- case state of -- See [note Buffer Sizing], GHC.IO.Handle.Types
- ReadBuffer -> newCharBuffer dEFAULT_CHAR_BUFFER_SIZE state
- WriteBuffer -> newCharBuffer 1 state
+ buffer <- newCharBuffer dEFAULT_CHAR_BUFFER_SIZE state
+ -- See [note Buffer Sizing], GHC.IO.Handle.Types
ref <- newIORef buffer
return (ref, NoBuffering)
flushCharReadBuffer h_
flushByteReadBuffer h_
WriteBuffer -> do
- buf' <- flushWriteBuffer_ h_ buf
- writeIORef haCharBuffer buf'
+ flushByteWriteBuffer h_
--- | flushes at least the Char buffer, and the byte buffer for a write
--- Handle. Works on all Handles.
+-- | flushes the Char buffer only. Works on all Handles.
flushCharBuffer :: Handle__ -> IO ()
flushCharBuffer h_@Handle__{..} = do
- buf <- readIORef haCharBuffer
- case bufState buf of
+ cbuf <- readIORef haCharBuffer
+ case bufState cbuf of
ReadBuffer -> do
flushCharReadBuffer h_
- WriteBuffer -> do
- buf' <- flushWriteBuffer_ h_ buf
- writeIORef haCharBuffer buf'
+ WriteBuffer ->
+ when (not (isEmptyBuffer cbuf)) $
+ error "internal IO library error: Char buffer non-empty"
-- -----------------------------------------------------------------------------
-- Writing data (flushing write buffers)
-- empty.
flushWriteBuffer :: Handle__ -> IO ()
flushWriteBuffer h_@Handle__{..} = do
- buf <- readIORef haCharBuffer
- if isWriteBuffer buf
- then do buf' <- flushWriteBuffer_ h_ buf
- writeIORef haCharBuffer buf'
- else return ()
+ buf <- readIORef haByteBuffer
+ when (isWriteBuffer buf) $ flushByteWriteBuffer h_
-flushWriteBuffer_ :: Handle__ -> CharBuffer -> IO CharBuffer
-flushWriteBuffer_ h_@Handle__{..} cbuf = do
+flushByteWriteBuffer :: Handle__ -> IO ()
+flushByteWriteBuffer h_@Handle__{..} = do
bbuf <- readIORef haByteBuffer
- if not (isEmptyBuffer cbuf) || not (isEmptyBuffer bbuf)
- then do writeTextDevice h_ cbuf
- return cbuf{ bufL=0, bufR=0 }
- else return cbuf
+ when (not (isEmptyBuffer bbuf)) $ do
+ bbuf' <- Buffered.flushWriteBuffer haDevice bbuf
+ writeIORef haByteBuffer bbuf'
+
+-- write the contents of the CharBuffer to the Handle__.
+-- The data will be encoded and pushed to the byte buffer,
+-- flushing if the buffer becomes full.
+writeCharBuffer :: Handle__ -> CharBuffer -> IO ()
+writeCharBuffer h_@Handle__{..} !cbuf = do
+ --
+ bbuf <- readIORef haByteBuffer
+
+ debugIO ("writeCharBuffer: cbuf=" ++ summaryBuffer cbuf ++
+ " bbuf=" ++ summaryBuffer bbuf)
+
+ (cbuf',bbuf') <- case haEncoder of
+ Nothing -> latin1_encode cbuf bbuf
+ Just encoder -> (streamEncode encoder) cbuf bbuf
+
+ debugIO ("writeCharBuffer after encoding: cbuf=" ++ summaryBuffer cbuf' ++
+ " bbuf=" ++ summaryBuffer bbuf')
+
+ -- flush if the write buffer is full
+ if isFullBuffer bbuf'
+ -- or we made no progress
+ || not (isEmptyBuffer cbuf') && bufL cbuf' == bufL cbuf
+ -- or the byte buffer has more elements than the user wanted buffered
+ || (case haBufferMode of
+ BlockBuffering (Just s) -> bufferElems bbuf' >= s
+ NoBuffering -> True
+ _other -> False)
+ then do
+ bbuf'' <- Buffered.flushWriteBuffer haDevice bbuf'
+ writeIORef haByteBuffer bbuf''
+ else
+ writeIORef haByteBuffer bbuf'
+
+ if not (isEmptyBuffer cbuf')
+ then writeCharBuffer h_ cbuf'
+ else return ()
-- -----------------------------------------------------------------------------
-- Flushing read buffers
-- restore the codec state
setState decoder codec_state
- (bbuf1,cbuf1) <- (encode decoder) bbuf0
+ (bbuf1,cbuf1) <- (streamEncode decoder) bbuf0
cbuf0{ bufL=0, bufR=0, bufSize = bufL cbuf0 }
debugIO ("finished, bbuf=" ++ summaryBuffer bbuf1 ++
-- | like 'mkFileHandle', except that a 'Handle' is created with two
-- independent buffers, one for reading and one for writing. Used for
--- full-dupliex streams, such as network sockets.
+-- full-duplex streams, such as network sockets.
mkDuplexHandle :: (IODevice dev, BufferedIO dev, Typeable dev) => dev
-> FilePath -> Maybe TextEncoding -> NewlineMode -> IO Handle
mkDuplexHandle dev filepath mb_codec tr_newlines = do
return Nothing
cont mb_encoder mb_decoder
+closeTextCodecs :: Handle__ -> IO ()
+closeTextCodecs Handle__{..} = do
+ case haDecoder of Nothing -> return (); Just d -> Encoding.close d
+ case haEncoder of Nothing -> return (); Just d -> Encoding.close d
+
-- ---------------------------------------------------------------------------
-- closing Handles
trymaybe io = (do io; return Nothing) `catchException` \e -> return (Just e)
hClose_handle_ :: Handle__ -> IO (Handle__, Maybe SomeException)
-hClose_handle_ Handle__{..} = do
+hClose_handle_ h_@Handle__{..} = do
-- close the file descriptor, but not when this is the read
-- side of a duplex handle.
writeIORef haByteBuffer noByteBuffer
-- release our encoder/decoder
- case haDecoder of Nothing -> return (); Just d -> close d
- case haEncoder of Nothing -> return (); Just d -> close d
+ closeTextCodecs h_
-- we must set the fd to -1, because the finalizer is going
-- to run eventually and try to close/unlock it.
-- ----------------------------------------------------------------------------
-- Text input/output
--- Write the contents of the supplied Char buffer to the device, return
--- only when all the data has been written.
-writeTextDevice :: Handle__ -> CharBuffer -> IO ()
-writeTextDevice h_@Handle__{..} cbuf = do
- --
- bbuf <- readIORef haByteBuffer
-
- debugIO ("writeTextDevice: cbuf=" ++ summaryBuffer cbuf ++
- " bbuf=" ++ summaryBuffer bbuf)
-
- (cbuf',bbuf') <- case haEncoder of
- Nothing -> latin1_encode cbuf bbuf
- Just encoder -> (encode encoder) cbuf bbuf
-
- debugIO ("writeTextDevice after encoding: cbuf=" ++ summaryBuffer cbuf' ++
- " bbuf=" ++ summaryBuffer bbuf')
-
- bbuf' <- Buffered.flushWriteBuffer haDevice bbuf'
- writeIORef haByteBuffer bbuf'
- if not (isEmptyBuffer cbuf')
- then writeTextDevice h_ cbuf'
- else return ()
-
-- Read characters into the provided buffer. Return when any
-- characters are available; raise an exception if the end of
-- file is reached.
Just decoder -> do
state <- getState decoder
writeIORef haLastDecode (state, bbuf1)
- (encode decoder) bbuf1 cbuf
+ (streamEncode decoder) bbuf1 cbuf
debugIO ("readTextDevice after decoding: cbuf=" ++ summaryBuffer cbuf' ++
" bbuf=" ++ summaryBuffer bbuf2)
then ioe_invalidCharacter
else return bbuf2
- debugIO ("readTextDevice after reading: bbuf=" ++ summaryBuffer bbuf2)
+ debugIO ("readTextDevice' after reading: bbuf=" ++ summaryBuffer bbuf2)
(bbuf3,cbuf') <-
case haDecoder of
Just decoder -> do
state <- getState decoder
writeIORef haLastDecode (state, bbuf2)
- (encode decoder) bbuf2 cbuf
+ (streamEncode decoder) bbuf2 cbuf
- debugIO ("readTextDevice after decoding: cbuf=" ++ summaryBuffer cbuf' ++
+ debugIO ("readTextDevice' after decoding: cbuf=" ++ summaryBuffer cbuf' ++
" bbuf=" ++ summaryBuffer bbuf3)
writeIORef haByteBuffer bbuf3
Just decoder -> do
state <- getState decoder
writeIORef haLastDecode (state, bbuf0)
- (encode decoder) bbuf0 cbuf
+ (streamEncode decoder) bbuf0 cbuf
writeIORef haByteBuffer bbuf2
return cbuf'
projects / ghc-base.git / blobdiff