amqp-utils-0.4.0.0: konsum.hs

-- generic amqp consumer
import Control.Concurrent
import qualified Control.Exception as X
import Control.Monad
import qualified Data.Text as T
import Data.Time
import Data.Version (showVersion)
import Network.AMQP
import Network.AMQP.Utils.Connection
import Network.AMQP.Utils.Helpers
import Network.AMQP.Utils.Options
import Paths_amqp_utils (version)
import System.Environment

main :: IO ()
main = do
  hr "starting"
  tid <- myThreadId
  args <- getArgs >>= parseargs 'k'
  let addiArgs = reverse $ additionalArgs args
  printparam' "client version" $ "amqp-utils " ++ (showVersion version)
  (conn, chan) <- connect args
  addChannelExceptionHandler chan (X.throwTo tid)
  -- set prefetch
  printparam' "prefetch" $ show $ preFetch args
  qos chan 0 (fromIntegral $ preFetch args) False
  -- attach to given queue? or build exclusive queue and bind it?
  queue <-
    maybe
      (tempQueue chan (tmpQName args) (bindings args) (currentExchange args))
      (return)
      (fmap T.pack (qName args))
  printparam' "queue name" $ T.unpack queue
  printparam "shown body chars" $ fmap show $ anRiss args
  printparam "temp dir" $ tempDir args
  printparam "callback" $ fileProcess args
  printparam "callback args" $ listToMaybeUnwords addiArgs
  -- subscribe to the queue
  ctag <-
    consumeMsgs
      chan
      queue
      (if ack args
         then Ack
         else NoAck)
      (myCallback args addiArgs tid)
  printparam' "consumer tag" $ T.unpack ctag
  printparam' "send acks" $ show (ack args)
  printparam "requeue if rejected" $
    if (ack args)
      then Just (show (requeuenack args))
      else Nothing
  hr "entering main loop"
  X.catch
    (forever $ threadDelay 5000000)
    (\exception -> printparam' "exception" $ show (exception :: X.SomeException))
  closeConnection conn
  hr "connection closed"

-- | exclusive temp queue
tempQueue :: Channel -> String -> [(String, String)] -> String -> IO T.Text
tempQueue chan tmpqname bindlist x = do
  (q, _, _) <-
    declareQueue
      chan
      newQueue {queueExclusive = True, queueName = T.pack tmpqname}
  mapM_
    (\(xchange, bkey) ->
       bindQueue chan q (T.pack xchange) (T.pack bkey) >>
       printparam' "binding" (xchange ++ ":" ++ bkey))
    (if null bindlist
       then [(x, "#")]
       else bindlist)
  return q

-- | process received message
myCallback :: Args -> [String] -> ThreadId -> (Message, Envelope) -> IO ()
myCallback a addi tid m@(_, envi) = do
  let numstring = show $ envDeliveryTag envi
  hr $ "BEGIN " ++ numstring
  now <- getZonedTime
  callbackoptions <-
    X.catch
      (printmsg Nothing m (anRiss a) now)
      (\x -> X.throwTo tid (x :: X.SomeException) >> return [])
  either
    (\e -> printparam' "ERROR" (show (e :: X.SomeException)) >> reje envi a)
    return =<<
    X.try (optionalFileStuff m callbackoptions addi numstring a tid Nothing)
  hr $ "END " ++ numstring