1 files changed, 124 insertions, 0 deletions
diff --git a/compiler/utils/BufWrite.hs b/compiler/utils/BufWrite.hs
new file mode 100644
index 0000000000..a03db3d084
--- /dev/null
+++ b/compiler/utils/BufWrite.hs
@@ -0,0 +1,124 @@
+-----------------------------------------------------------------------------
+--
+-- Fast write-buffered Handles
+--
+-- (c) The University of Glasgow 2005
+--
+-- This is a simple abstraction over Handles that offers very fast write
+-- buffering, but without the thread safety that Handles provide.  It's used
+-- to save time in Pretty.printDoc.
+--
+-----------------------------------------------------------------------------
+
+module BufWrite (
+	BufHandle(..),
+	newBufHandle,
+	bPutChar,
+	bPutStr,
+	bPutFS,
+	bPutLitString,
+	bFlush,
+  ) where
+
+#include "HsVersions.h"
+
+import FastString
+import FastMutInt
+import Panic		( panic )
+
+import Monad		( when )
+import Char		( ord )
+import Foreign
+import IO
+
+import GHC.IOBase	( IO(..) )
+import System.IO	( hPutBuf )
+import GHC.Ptr		( Ptr(..) )
+
+import GLAEXTS		( Int(..), Int#, Addr# )
+
+-- -----------------------------------------------------------------------------
+
+data BufHandle = BufHandle {-#UNPACK#-}!(Ptr Word8)
+			   {-#UNPACK#-}!FastMutInt
+			   Handle
+
+newBufHandle :: Handle -> IO BufHandle
+newBufHandle hdl = do
+  ptr <- mallocBytes buf_size
+  r <- newFastMutInt
+  writeFastMutInt r 0
+  return (BufHandle ptr r hdl)
+
+buf_size = 8192 :: Int
+
+#define STRICT2(f) f a b | a `seq` b `seq` False = undefined
+#define STRICT3(f) f a b c | a `seq` b `seq` c `seq` False = undefined
+
+bPutChar :: BufHandle -> Char -> IO ()
+STRICT2(bPutChar)
+bPutChar b@(BufHandle buf r hdl) c = do
+  i <- readFastMutInt r
+  if (i >= buf_size)
+	then do hPutBuf hdl buf buf_size
+		writeFastMutInt r 0
+		bPutChar b c
+	else do pokeElemOff buf i (fromIntegral (ord c) :: Word8)
+		writeFastMutInt r (i+1)
+
+bPutStr :: BufHandle -> String -> IO ()
+STRICT2(bPutStr)
+bPutStr b@(BufHandle buf r hdl) str = do
+  i <- readFastMutInt r
+  loop str i
+  where loop _ i | i `seq` False = undefined
+	loop "" i = do writeFastMutInt r i; return ()
+	loop (c:cs) i
+	   | i >= buf_size = do
+		hPutBuf hdl buf buf_size
+		loop (c:cs) 0
+	   | otherwise = do
+		pokeElemOff buf i (fromIntegral (ord c))
+		loop cs (i+1)
+  
+bPutFS :: BufHandle -> FastString -> IO ()
+bPutFS b@(BufHandle buf r hdl) fs@(FastString _ len _ fp _) =
+ withForeignPtr fp $ \ptr -> do
+  i <- readFastMutInt r
+  if (i + len) >= buf_size
+	then do hPutBuf hdl buf i
+		writeFastMutInt r 0
+		if (len >= buf_size) 
+		    then hPutBuf hdl ptr len
+		    else bPutFS b fs
+	else do
+		copyBytes (buf `plusPtr` i) ptr len
+		writeFastMutInt r (i+len)
+
+bPutLitString :: BufHandle -> Addr# -> Int# -> IO ()
+bPutLitString b@(BufHandle buf r hdl) a# len# = do
+  let len = I# len#
+  i <- readFastMutInt r
+  if (i+len) >= buf_size
+	then do hPutBuf hdl buf i
+		writeFastMutInt r 0
+		if (len >= buf_size) 
+		    then hPutBuf hdl (Ptr a#) len
+		    else bPutLitString b a# len#
+	else do
+		copyBytes (buf `plusPtr` i) (Ptr a#) len
+		writeFastMutInt r (i+len)
+
+bFlush :: BufHandle -> IO ()
+bFlush b@(BufHandle buf r hdl) = do
+  i <- readFastMutInt r
+  when (i > 0) $ hPutBuf hdl buf i
+  free buf
+  return ()
+
+#if 0
+myPutBuf s hdl buf i = 
+  modifyIOError (\e -> ioeSetErrorString e (ioeGetErrorString e ++ ':':s ++ " (" ++ show buf ++ "," ++ show i ++ ")")) $
+
+  hPutBuf hdl buf i
+#endif