module Sound.OpenSoundControl.Coding.Decode.Binary
(getPacket
,decodePacket
,decodePacket_strict) where
import Control.Applicative
import Data.Binary.Get
import qualified Data.Binary.IEEE754 as I
import qualified Data.ByteString as S
import qualified Data.ByteString.Lazy as L
import qualified Data.ByteString.Lazy.Char8 as C
import Data.Int (Int32)
import Data.Word (Word32)
import Sound.OpenSoundControl.Coding.Byte
import Sound.OpenSoundControl.Time
import Sound.OpenSoundControl.Type
isolate :: Word32 -> Get a -> Get a
isolate n m = do
s <- get_bytes n
let (a, s', _) = runGetState m s 0
if L.null s'
then return a
else fail "isolate: not all bytes consumed"
getInt32be :: Get Int32
getInt32be = fromIntegral <$> getWord32be
get_string :: Get String
get_string = do
s <- getLazyByteStringNul
skip (fromIntegral (align (L.length s + 1)))
return $ C.unpack s
get_bytes :: Word32 -> Get L.ByteString
get_bytes n = do
b <- getLazyByteString (fromIntegral n)
if n /= fromIntegral (L.length b)
then fail "get_bytes: end of stream"
else skip (fromIntegral (align n))
return b
get_datum :: Datum_Type -> Get Datum
get_datum ty =
case ty of
'i' -> Int <$> fromIntegral <$> getInt32be
'f' -> Float <$> realToFrac <$> I.getFloat32be
'd' -> Double <$> I.getFloat64be
's' -> String <$> get_string
'b' -> Blob <$> (get_bytes =<< getWord32be)
't' -> TimeStamp <$> ntpi_to_ntpr <$> getWord64be
'm' -> do b0 <- getWord8
b1 <- getWord8
b2 <- getWord8
b3 <- getWord8
return $ Midi (b0,b1,b2,b3)
_ -> fail ("get_datum: illegal type " ++ show ty)
get_message :: Get Message
get_message = do
cmd <- get_string
dsc <- get_string
case dsc of
(',':tags) -> do
arg <- mapM get_datum tags
return $ Message cmd arg
_ -> fail "get_message: invalid type descriptor string"
get_message_seq :: Get [Message]
get_message_seq = do
b <- isEmpty
if b
then return []
else do
p <- flip isolate get_message =<< getWord32be
ps <- get_message_seq
return (p:ps)
get_bundle :: Get Bundle
get_bundle = do
skip (fromIntegral (L.length bundleHeader))
t <- ntpi_to_ntpr <$> getWord64be
ps <- get_message_seq
return $ Bundle t ps
getPacket :: Get Packet
getPacket = do
h <- uncheckedLookAhead (L.length bundleHeader)
if h == bundleHeader
then fmap Packet_Bundle get_bundle
else fmap Packet_Message get_message
decodePacket :: L.ByteString -> Packet
decodePacket = runGet getPacket
decodePacket_strict :: S.ByteString -> Packet
decodePacket_strict = runGet getPacket . L.fromChunks . (:[])