clean code

src/Kafka/Client.hs

@@ -50,18 +50,18 @@ import Kafka.Protocol
 import Network.Socket
 import qualified Network.Socket.ByteString.Lazy as SBL
 
--------------------
---Send Functions
-------------------
+----------------
+-- Types
+----------------
+
+-- | Pack and encode given Request of Type Req and send via given socket
 sendRequest :: Socket -> Req -> IO ()
 sendRequest socket req = do
     print $ show $ BL.length msg
     SBL.sendAll socket msg
     where msg = runPut $ buildRqMessage $ pack req
 
---------------------
---Types
--------------------
+-- | Request Type
 data Req = Produce Head [ToTopic] | Fetch Head [FromTopic] | Metadata Head [OfTopic]
 
 class Packable a where
@@ -72,42 +72,55 @@ instance Packable Req where
   pack (Fetch head ts) = packFtRqMessage head ts
   pack (Metadata head ts) = packMdRqMessage head ts
 
+-- | Header information each request includes
 data Head = Head
   { apiV      :: Int
   , corr      :: Int
   , client    :: BS.ByteString
   }
 
+-- | Topic for Produce Request
 data ToTopic = ToTopic BS.ByteString [ToPart]
+-- | Partition for Produce Request
 data ToPart = ToPart Int [Data]
 type Data = BS.ByteString
 
+-- | Topic for Fetch Request
 data FromTopic = FromTopic BS.ByteString [FromPart]
+-- | Partition for Fetch Request
 data FromPart = FromPart
   { partId    :: Int
   , offset    :: Int
   }
 
+-- | Topic for Metadata Request
 data OfTopic = OfTopic BS.ByteString
 
 ----------------
 -- Converting API
 ----------------
+
+-- | Convert string to topicsName (ByteString)
 stringToTopic :: String -> BS.ByteString
 stringToTopic s = BC.pack s
 
+-- | Convert Data.Text to topicsName (ByteString)
 textToTopic :: T.Text -> BS.ByteString
 textToTopic t = encodeUtf8 t
 
+-- | Convert string to clientId (ByteString)
 stringToClientId :: String -> BS.ByteString
 stringToClientId s = BC.pack s
 
+-- | Convert Data.Text to clientId (ByteString)
 textToClientId :: T.Text -> BS.ByteString
 textToClientId t = encodeUtf8 t
 
+-- | Convert string to message data (ByteString)
 stringToData :: String -> BS.ByteString
 stringToData s = BC.pack s
 
+-- | Convert Data.Text to message data (ByteString)
 textToData :: T.Text -> BS.ByteString
 textToData t = encodeUtf8 t
 
@@ -126,6 +139,7 @@ arrayLength xs = fromIntegral $ length xs
 --------------------
 --Pack Functions
 --------------------
+
 -- | Pack a protocol conform RequestMessage for Produce API
 packPrRqMessage :: Head -> [ToTopic] -> RequestMessage
 packPrRqMessage head ts = RequestMessage

src/Kafka/Protocol/Decode.hs

@@ -6,6 +6,10 @@ License     :
 Maintainer  :  mail@marcjuch.li, lorenz.wolf@bluewin.ch
 Stability   :  experimental
 Portability :  portable
+
+This module exposes functions for decoding requests and responses of kafka
+prototol implemention.
+
 -}
 module Kafka.Protocol.Decode
     ( messageSetParser

src/Kafka/Protocol/Encode.hs

@@ -6,6 +6,8 @@ License     :
 Maintainer  :  mail@marcjuch.li, lorenz.wolf@bluewin.ch
 Stability   :  experimental
 Portability :  portable
+
+This module exposes Encode functionalities for kafka protocol implementation.
 -}
 module Kafka.Protocol.Encode
     ( buildMessageSet
@@ -92,7 +94,7 @@ buildRqMessage e = do
     0 -> buildProduceRequest  $ rqRequest e
     1 -> buildFetchRequest    $ rqRequest e
     3 -> buildMetadataRequest $ rqRequest e
-    -- further API Codes not implemented yet
+    -- TODO: further API Codes
 
 buildTopic :: (Partition -> Put) -> RqTopic -> Put
 buildTopic pb t = do
@@ -170,7 +172,7 @@ buildRsTopic b t = do
   putWord16be $      rsTopicNameLen t
   putByteString $    rsTopicName t
   putWord32be $      rsNumPayloads t
-  buildList buildRsPrPayload $ rsPayloads t
+  buildList b $ rsPayloads t
 
 -- | Produce Response (Pr)
 buildRsPrPayload :: RsPayload -> Put

src/Kafka/Protocol/Types.hs

@@ -79,10 +79,11 @@ type Attributes = Word8
 data Payload = Payload
   { plMagic           :: !Magic
   , plAttr            :: !Attributes
-  --, plKeylen          :: !BytesLength wolflo: According to Kafka documentation
-  --the key is type bytes, therefore it should have a len field before. In
-  --actual produced message from Kafka, there is no field len for key, key is
-  --fix 32 Bit 
+  --, plKeylen          :: !BytesLength 
+  -- TODO: According to Kafka documentation
+  -- the key is type bytes, therefore it should have a len field before. In
+  -- actual produced message from Kafka, there is no field len for key. To
+  -- provide compatibility with tested version keylen is commented out. 
   , plKey             :: !MessageKey
   , plValueLen        :: !BytesLength
   , plValue           :: !MessageValue
@@ -136,10 +137,6 @@ data RequestMessage = RequestMessage
   , rqRequest            :: Request
   } deriving (Show, Eq)
 
--- NOTE (meiersi): the field accessors generated from your declaration are all
--- partial functions. You can avoid that by introducing proper records for all
--- the constructors and the create 'Request' such that it just tags these
--- individual types.
 data Request = ProduceRequest
   { rqPrRequiredAcks     :: !RequiredAcks
   , rqPrTimeout          :: !Timeout