X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2FMain.hs;h=de0e28e53ea9dfa48fa4d8cb202216b1e9b67788;hb=HEAD;hp=0a2f7d7473482d624935cccc931600c39494aa4c;hpb=ac97e3119df309c4eaaff0c72e5b5879f156616f;p=dead%2Fhtsn.git

diff --git a/src/Main.hs b/src/Main.hs
index 0a2f7d7..de0e28e 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -5,6 +5,7 @@ module Main
 where
 
 -- System imports.
+import Control.Applicative ( (<$>) )
 import Control.Concurrent ( threadDelay )
 import Control.Exception ( bracket, throw )
 import Control.Monad ( when )
@@ -71,12 +72,17 @@ recv_line h = do
 --   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
@@ -85,10 +91,10 @@ save_document cfg doc =
       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
@@ -122,8 +128,8 @@ loop !cfg !h !buffer = do
     -- 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
@@ -225,7 +231,7 @@ log_in cfg h = do
 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
@@ -235,7 +241,7 @@ connect_and_parse cfg host = do
       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
 
@@ -297,15 +303,7 @@ main = do
   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)
@@ -314,6 +312,18 @@ main = do
     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.