-- * Creation\/destruction
hGetStringBuffer,
+ hGetStringBufferBlock,
+ appendStringBuffers,
stringToStringBuffer,
-- * Inspection
import FastString ( FastString,mkFastString,mkFastStringBytes )
import Foreign
-import System.IO ( hGetBuf, hFileSize,IOMode(ReadMode), hClose )
+import System.IO ( hGetBuf, hFileSize,IOMode(ReadMode), hClose
+ , Handle, hTell )
import GHC.Ptr ( Ptr(..) )
import GHC.Exts
-- sentinels for UTF-8 decoding
return (StringBuffer buf size 0)
+hGetStringBufferBlock :: Handle -> Int -> IO StringBuffer
+hGetStringBufferBlock handle wanted
+ = do size_i <- hFileSize handle
+ offset_i <- hTell handle
+ let size = min wanted (fromIntegral $ size_i-offset_i)
+ buf <- mallocForeignPtrArray (size+3)
+ withForeignPtr buf $ \ptr ->
+ do r <- if size == 0 then return 0 else hGetBuf handle ptr size
+ if r /= size
+ then ioError (userError $ "short read of file: "++show(r,size,fromIntegral size_i,handle))
+ else do pokeArray (ptr `plusPtr` size :: Ptr Word8) [0,0,0]
+ return (StringBuffer buf size 0)
+
+appendStringBuffers :: StringBuffer -> StringBuffer -> IO StringBuffer
+appendStringBuffers sb1 sb2
+ = do newBuf <- mallocForeignPtrArray (size+3)
+ withForeignPtr newBuf $ \ptr ->
+ withForeignPtr (buf sb1) $ \sb1Ptr ->
+ withForeignPtr (buf sb2) $ \sb2Ptr ->
+ do copyArray (sb1Ptr `advancePtr` cur sb1) ptr (calcLen sb1)
+ copyArray (sb2Ptr `advancePtr` cur sb2) (ptr `advancePtr` cur sb1) (calcLen sb2)
+ pokeArray (ptr `advancePtr` size) [0,0,0]
+ return (StringBuffer newBuf size 0)
+ where calcLen sb = len sb - cur sb
+ size = calcLen sb1 + calcLen sb2
+
stringToStringBuffer :: String -> IO StringBuffer
stringToStringBuffer str = do
let size = utf8EncodedLength str