THRIFT-407. hs: Refactor and improve Haskell-related code
git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@763031 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/hs/src/Thrift/Protocol/Binary.hs b/lib/hs/src/Thrift/Protocol/Binary.hs
new file mode 100644
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+++ b/lib/hs/src/Thrift/Protocol/Binary.hs
@@ -0,0 +1,147 @@
+--
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements. See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership. The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License. You may obtain a copy of the License at
+--
+-- http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied. See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+--
+
+module Thrift.Protocol.Binary
+ ( module Thrift.Protocol
+ , BinaryProtocol(..)
+ ) where
+
+import Control.Exception ( throw )
+
+import Data.Bits
+import Data.Int
+import Data.List ( foldl' )
+
+import GHC.Exts
+import GHC.Word
+
+import Thrift.Protocol
+import Thrift.Transport
+
+
+version_mask = 0xffff0000
+version_1 = 0x80010000
+
+data BinaryProtocol a = Transport a => BinaryProtocol a
+
+
+instance Protocol BinaryProtocol where
+ getTransport (BinaryProtocol t) = t
+
+ writeMessageBegin p (n, t, s) = do
+ writeI32 p (version_1 .|. (fromEnum t))
+ writeString p n
+ writeI32 p s
+ writeMessageEnd _ = return ()
+
+ writeStructBegin _ _ = return ()
+ writeStructEnd _ = return ()
+ writeFieldBegin p (_, t, i) = writeType p t >> writeI16 p i
+ writeFieldEnd _ = return ()
+ writeFieldStop p = writeType p T_STOP
+ writeMapBegin p (k, v, n) = writeType p k >> writeType p v >> writeI32 p n
+ writeMapEnd p = return ()
+ writeListBegin p (t, n) = writeType p t >> writeI32 p n
+ writeListEnd _ = return ()
+ writeSetBegin p (t, n) = writeType p t >> writeI32 p n
+ writeSetEnd _ = return ()
+
+ writeBool p b = tWrite (getTransport p) [toEnum $ if b then 1 else 0]
+ writeByte p b = tWrite (getTransport p) (getBytes b 1)
+ writeI16 p b = tWrite (getTransport p) (getBytes b 2)
+ writeI32 p b = tWrite (getTransport p) (getBytes b 4)
+ writeI64 p b = tWrite (getTransport p) (getBytes b 8)
+ writeDouble p d = writeI64 p (fromIntegral $ floatBits d)
+ writeString p s = writeI32 p (length s) >> tWrite (getTransport p) s
+ writeBinary = writeString
+
+ readMessageBegin p = do
+ ver <- readI32 p
+ if (ver .&. version_mask /= version_1)
+ then throw $ ProtocolExn PE_BAD_VERSION "Missing version identifier"
+ else do
+ s <- readString p
+ sz <- readI32 p
+ return (s, toEnum $ ver .&. 0xFF, sz)
+ readMessageEnd _ = return ()
+ readStructBegin _ = return ""
+ readStructEnd _ = return ()
+ readFieldBegin p = do
+ t <- readType p
+ n <- if t /= T_STOP then readI16 p else return 0
+ return ("", t, n)
+ readFieldEnd _ = return ()
+ readMapBegin p = do
+ kt <- readType p
+ vt <- readType p
+ n <- readI32 p
+ return (kt, vt, n)
+ readMapEnd _ = return ()
+ readListBegin p = do
+ t <- readType p
+ n <- readI32 p
+ return (t, n)
+ readListEnd _ = return ()
+ readSetBegin p = do
+ t <- readType p
+ n <- readI32 p
+ return (t, n)
+ readSetEnd _ = return ()
+
+ readBool p = (== 1) `fmap` readByte p
+ readByte p = do
+ bs <- tReadAll (getTransport p) 1
+ return $ fromIntegral (composeBytes bs :: Int8)
+ readI16 p = do
+ bs <- tReadAll (getTransport p) 2
+ return $ fromIntegral (composeBytes bs :: Int16)
+ readI32 p = composeBytes `fmap` tReadAll (getTransport p) 4
+ readI64 p = composeBytes `fmap` tReadAll (getTransport p) 8
+ readDouble p = do
+ bs <- readI64 p
+ return $ floatOfBits $ fromIntegral bs
+ readString p = readI32 p >>= tReadAll (getTransport p)
+ readBinary = readString
+
+
+-- | Write a type as a byte
+writeType :: (Protocol p, Transport t) => p t -> ThriftType -> IO ()
+writeType p t = writeByte p (fromEnum t)
+
+-- | Read a byte as though it were a ThriftType
+readType :: (Protocol p, Transport t) => p t -> IO ThriftType
+readType p = toEnum `fmap` readByte p
+
+composeBytes :: (Bits b, Enum t) => [t] -> b
+composeBytes = (foldl' fn 0) . (map $ fromIntegral . fromEnum)
+ where fn acc b = (acc `shiftL` 8) .|. b
+
+getByte :: Bits a => a -> Int -> a
+getByte i n = 255 .&. (i `shiftR` (8 * n))
+
+getBytes :: (Bits a, Integral a) => a -> Int -> String
+getBytes i 0 = []
+getBytes i n = (toEnum $ fromIntegral $ getByte i (n-1)):(getBytes i (n-1))
+
+floatBits :: Double -> Word64
+floatBits (D# d#) = W64# (unsafeCoerce# d#)
+
+floatOfBits :: Word64 -> Double
+floatOfBits (W64# b#) = D# (unsafeCoerce# b#)
+