Invoke write directly instead of via hPutBuf

Ignore-this: 172072f7a4876e5864c8e54f896bf0b0

darcs-hash:20100114091229-f0a0d-915e8160f8cf596abbae4df8c9d883febeedf509.gz

cbits/output_buffer.c

@@ -0,0 +1,18 @@
+#define _XOPEN_SOURCE 500
+#include <unistd.h>
+
+#include "output_buffer.h"
+
+void stdout_output_buffer ( uint8_t* buffer, size_t buffer_size )
+{
+    while ( buffer_size )
+    {
+        const ssize_t r = write( STDOUT_FILENO, (void*) buffer, buffer_size );
+
+        buffer_size -= (size_t) r;
+        buffer += (size_t) r;
+    }
+
+    fdatasync( STDOUT_FILENO );
+}
+

cbits/output_buffer.h

@@ -0,0 +1,5 @@
+#define _XOPEN_SOURCE 500
+#include <unistd.h>
+#include <stdint.h>
+
+void stdout_output_buffer ( uint8_t* buffer, size_t buffer_size );

src/Graphics/Vty/Terminal/TerminfoBased.hs

@@ -2,6 +2,7 @@
 {-# LANGUAGE ForeignFunctionInterface #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE FlexibleInstances #-}
+{-# OPTIONS_GHC -D_XOPEN_SOURCE=500 #-}
 module Graphics.Vty.Terminal.TerminfoBased ( terminal_instance
                                            )
     where
@@ -22,7 +23,8 @@ import Data.Bits ( (.&.) )
 import Data.Maybe ( isJust, isNothing, fromJust )
 import Data.Word
 
-import Foreign.C.Types ( CLong )
+import Foreign.Ptr
+import Foreign.C.Types ( CLong, CSize )
 
 import qualified System.Console.Terminfo as Terminfo
 import System.IO
@@ -164,12 +166,17 @@ instance Terminal Term where
 
     -- Output the byte buffer of the specified size to the terminal device.
     output_byte_buffer _t out_ptr out_byte_count = do
-        if out_byte_count == 0
-            then return ()
-            else hPutBuf stdout out_ptr (fromEnum out_byte_count) 
+        -- flush is required *before* the c_output_byte_buffer call
+        -- otherwise there may still be data in GHC's internal stdout buffer.
         hFlush stdout
+        if out_byte_count /= 0 
+            then c_output_byte_buffer out_ptr ( toEnum $! fromEnum out_byte_count )
+            else return ()
 
-foreign import ccall "gwinsz.h c_get_window_size" c_get_window_size :: IO CLong
+foreign import ccall unsafe "output_buffer.h stdout_output_buffer" c_output_byte_buffer 
+    :: Ptr Word8 -> CSize -> IO ()
+foreign import ccall "gwinsz.h c_get_window_size" c_get_window_size 
+    :: IO CLong
 
 get_window_size :: IO (Int,Int)
 get_window_size = do 

test/Makefile

@@ -26,7 +26,7 @@ $(VERIF_TESTS)
 $(shell mkdir -p objects )
 
 # TODO: Tests should also be buildable referencing the currently installed vty
-GHC_ARGS=--make -i../src -package parallel -package deepseq-1.1.0.0 -hide-package transformers -hide-package monads-fd -hide-package monads-tf -package QuickCheck-2.1.0.2 -ignore-package vty ../cbits/gwinsz.c ../cbits/set_term_timing.c  ../cbits/mk_wcwidth.c -O -funbox-strict-fields -Wall -threaded -fno-full-laziness -fspec-constr -odir objects -hidir objects
+GHC_ARGS=--make -i../src -package parallel -package deepseq-1.1.0.0 -hide-package transformers -hide-package monads-fd -hide-package monads-tf -package QuickCheck-2.1.0.2 -ignore-package vty ../cbits/gwinsz.c ../cbits/output_buffer.c ../cbits/set_term_timing.c  ../cbits/mk_wcwidth.c -O -funbox-strict-fields -Wall -threaded -fno-full-laziness -fspec-constr -odir objects -hidir objects
 
 GHC_PROF_ARGS=-prof -auto-all $(GHC_ARGS)
 

vty.cabal

@@ -59,6 +59,8 @@ other-modules:       Codec.Binary.UTF8.Width
 C-Sources:           cbits/gwinsz.c
                      cbits/set_term_timing.c
                      cbits/mk_wcwidth.c
+                     cbits/output_buffer.c
+
 Include-Dirs:        cbits
 hs-source-dirs:      src
 Extra-Source-Files: test/Makefile