where
-- System imports.
+import Control.Applicative ( (<$>) )
import Control.Concurrent ( threadDelay )
import Control.Exception ( bracket, throw )
import Control.Monad ( when )
-- This can fail, but we don't purposefully throw any exceptions. If
-- something goes wrong, we would rather log it and keep going.
--
+-- And in fact the only \"error\" that can occur is from
+-- 'parse_xmlfid' if TSN sends us a non-integer XML File ID. But
+-- this is expected from time to time, and is merely unsupported. So
+-- we report any failures as info instead of as errors.
+--
save_document :: Configuration
-> String -- ^ String representation of an XML document
-> IO ()
save_document cfg doc =
case either_path of
- Left err -> report_error err
+ Left err -> report_info err -- Can only be non-integer XML File ID
Right path -> do
already_exists <- doesFileExist path
when already_exists $ do
writeFile path doc
report_info $ "Wrote file: " ++ path ++ "."
where
- -- All the fmaps are because we're working inside a Maybe.
- xmlfid = fmap show (parse_xmlfid doc)
- filename = fmap (++ ".xml") xmlfid
- either_path = fmap ((output_directory cfg) </>) filename
+ -- All the <$> are because we're working inside an Either.
+ xmlfid = show <$> (parse_xmlfid doc)
+ filename = (++ ".xml") <$> xmlfid
+ either_path = ((output_directory cfg) </>) <$> filename
-- | Loop forever, writing the @buffer@ to file whenever a
-- If we haven't received anything in fifteen minutes, return back
-- to the calling function. This should only happen in the case of
-- an error, and our caller should be prepared to handle it.
- Nothing -> do
- report_warning $ "No data received for 15 minutes."
+ Nothing -> report_warning "No data received for 15 minutes."
+
Just line -> do
-- If the recv didn't timeout, proceed normally.
let new_buffer = line : buffer
connect_and_parse :: Configuration
-> String -- ^ Hostname to connect to
-> IO ()
-connect_and_parse cfg host = do
+connect_and_parse cfg host =
bracket acquire_handle release_handle action
where
five_seconds :: Int
report_info $ "Connecting to " ++ host ++ "."
connectTo host (PortNumber 4500)
- release_handle = \h -> do
+ release_handle h = do
report_info $ "Closing connection to " ++ host ++ "."
hClose h
let cfg = (def :: Configuration) `merge_optional` opt_config
init_logging (log_level cfg) (log_file cfg) (syslog cfg)
- -- Check the optional config for missing required options. This is
- -- necessary because if the user specifies an empty list of
- -- hostnames in e.g. the config file, we want to bail rather than
- -- fall back on the default list (which was merged from a default
- -- Configuration above).
- when (null $ get_feed_hosts (OC.feed_hosts opt_config)) $ do
- report_error "No feed hosts supplied."
- exitWith (ExitFailure exit_no_feed_hosts)
-
+ -- Check the optional config for missing required options.
when (isNothing (OC.password opt_config)) $ do
report_error "No password supplied."
exitWith (ExitFailure exit_no_password)
report_error "No username supplied."
exitWith (ExitFailure exit_no_username)
+ -- This should be impossible. We had a choice to make: since the
+ -- command-line feed_hosts are usually not supplied, we don't want
+ -- to take the empty list supplied on the command-line and use
+ -- that. But that means that we need to do the same thing if the
+ -- user supplies an empty list in the config file. That "same thing"
+ -- is to use the default list. So, this should never be empty,
+ -- because if the optional config has no feed hosts, we use the
+ -- default list.
+ when (null $ get_feed_hosts (feed_hosts cfg)) $ do
+ report_error "No feed hosts supplied."
+ exitWith (ExitFailure exit_no_feed_hosts)
+
when (daemonize cfg) $ do
-- Old PID files can be left around after an unclean shutdown. We
-- only care if we're running as a daemon.