module Main
where
-import Control.Concurrent (threadDelay)
-import Control.Exception.Base (bracket)
-import Control.Monad (when)
-import Data.List (isPrefixOf)
-import Data.Maybe (isNothing)
-import Data.Monoid ((<>))
+import Control.Concurrent ( threadDelay )
+import Control.Exception.Base ( bracket )
+import Control.Monad ( when )
+import Data.List ( isPrefixOf )
+import Data.Maybe ( isNothing )
+import Data.Monoid ( (<>) )
import Network (
connectTo,
PortID (PortNumber) )
-import System.Console.CmdArgs (def)
-import System.Directory (doesFileExist)
-import System.Exit (ExitCode(..), exitWith)
-import System.FilePath ((</>))
+import System.Console.CmdArgs ( def )
+import System.Directory ( doesFileExist )
+import System.Exit ( ExitCode(..), exitWith )
+import System.FilePath ( (</>) )
import System.IO (
BufferMode (NoBuffering),
Handle,
hSetBuffering,
stderr,
stdout )
-import System.IO.Error (catchIOError)
-import System.Timeout (timeout)
+import System.IO.Error ( catchIOError )
+import System.Timeout ( timeout )
-import CommandLine (get_args)
-import Configuration (Configuration(..), merge_optional)
+import CommandLine ( get_args )
+import Configuration ( Configuration(..), merge_optional )
import ExitCodes (
exit_no_feed_hosts,
exit_no_password,
- exit_no_username )
+ exit_no_username,
+ exit_pidfile_exists )
import Logging (
init_logging,
log_debug,
display_info,
display_sent,
display_warning )
-import TSN.FeedHosts (FeedHosts(..))
-import TSN.Xml (parse_xmlfid, xml_prologue)
+import TSN.FeedHosts ( FeedHosts(..) )
+import TSN.Xml ( parse_xmlfid )
+import Unix ( full_daemonize )
-
--- | Warning! This does not automatically append a newline. The output
--- is displayed/logged as-is, for, you know, debug purposes.
+-- | Display and log debug information. WARNING! This does not
+-- automatically append a newline. The output is displayed/logged
+-- as-is, for, you know, debug purposes.
report_debug :: String -> IO ()
report_debug s = do
display_debug s
log_debug s
+
+-- | Display and log an error condition. This will prefix the error
+-- with "ERROR: " when displaying (but not logging) it so that it
+-- stands out.
+--
report_error :: String -> IO ()
report_error s = do
display_error $ "ERROR: " ++ s
log_error s
+
+-- | Display and log an informational (status) message.
report_info :: String -> IO ()
report_info s = do
display_info s
log_info s
--- | Warning! This does not automatically append a newline.
-report_sent :: String -> IO ()
-report_sent s = do
- display_sent s
- log_debug s
+-- | Display and log a warning. This will prefix the warning with
+-- "WARNING: " when displaying (but not logging) it so that it
+-- stands out.
+--
report_warning :: String -> IO ()
report_warning s = do
display_warning $ "WARNING: " ++ s
--
save_document :: Configuration -> String -> IO ()
save_document cfg doc =
- case maybe_path of
- Nothing ->
- report_error "Document missing XML_File_ID element."
- Just path -> do
+ case either_path of
+ Left err -> report_error err
+ Right path -> do
already_exists <- doesFileExist path
when already_exists $ do
let msg = "File " ++ path ++ " already exists, overwriting."
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
- maybe_path = fmap ((output_directory cfg) </>) filename
+ either_path = fmap ((output_directory cfg) </>) filename
--- | Loop forever, writing the buffer to file whenever a new XML
--- prologue is seen. This is the low-level "loop forever" function
--- that we stay in as long as we are connected to one feed.
+-- | Loop forever, writing the buffer to file whenever a </message>
+-- tag is seen. This is the low-level "loop forever" function that
+-- we stay in as long as we are connected to one feed.
+--
+-- The documentation at
+-- <http://www.sportsnetworkdata.com/feeds/xml-levels.asp> states
+-- that \<message\> will always be the root element of the XML
+-- documents, and \</message\> will be the final line transmitted
+-- for a given document. We therefore rely on this to simplify
+-- processing.
--
loop :: Configuration -> Handle -> [String] -> IO ()
loop !cfg !h !buffer = do
line <- recv_line h
+ let new_buffer = line : buffer
- if (xml_prologue `isPrefixOf` line && not (null buffer))
+ -- Use isPrefixOf to avoid line-ending issues. Hopefully they won't
+ -- send invalid junk (on the same line) after closing the root
+ -- element.
+ if "</message>" `isPrefixOf` line
then do
- -- This is the beginning of a new document, and we have an "old"
- -- one to save. The buffer is in reverse (newest first) order,
- -- though, so we have to reverse it first. We then concatenate all
- -- of its lines into one big string.
- let document = concat $ reverse buffer
+ -- The buffer is in reverse (newest first) order, though, so we
+ -- have to reverse it first. We then concatenate all of its lines
+ -- into one big string.
+ let document = concat $ reverse new_buffer
save_document cfg document
- loop cfg h [line] -- Empty the buffer before looping again.
+ loop cfg h [] -- Empty the buffer before looping again.
else
-- Append line to the head of the buffer and loop.
- loop cfg h (line : buffer)
+ loop cfg h new_buffer
log_in :: Configuration -> Handle -> IO ()
send_line h' s = do
let line = s ++ "\r\n"
hPutStr h' line
+ -- Don't log the username/password!
display_sent line
recv_chars :: Int -> Handle -> IO String
connect_and_loop :: Configuration -> String -> IO ()
connect_and_loop cfg host = do
- report_info $ "Connecting to " ++ host ++ "..."
+ report_info $ "Connecting to " ++ host ++ "."
bracket acquire_handle release_handle action
return ()
where
--
-- If we dump the packets with tcpdump, it looks like their
-- software is getting confused: they send us some XML in
- -- the middle of the log-in procedure. In any case, the easiest
- -- fix is to disconnect and try again.
+ -- the middle of the log-in procedure.
+ --
+ -- On the other hand, the documentation at
+ -- <http://www.sportsnetworkdata.com/feeds/xml-levels.asp>
+ -- states that you can only make one connection per username to
+ -- a given host. So maybe they're simply rejecting the username
+ -- in an unfriendly fashion. In any case, the easiest fix is to
+ -- disconnect and try again.
--
login_worked <- timeout five_seconds $ log_in cfg h
case login_worked of
-- logging before the missing parameter checks below so that we can
-- log the errors.
let cfg = (def :: Configuration) `merge_optional` opt_config
- init_logging (syslog cfg)
+ init_logging (log_file cfg) (log_level cfg) (syslog cfg)
-- Check the optional config for missing required options. This is
-- necessary because if the user specifies an empty list of
report_error "No username supplied."
exitWith (ExitFailure exit_no_username)
+ when (daemonize cfg) $ do
+ pidfile_exists <- doesFileExist (pidfile cfg)
+ when pidfile_exists $ do
+ report_error $ "PID file " ++ (pidfile cfg) ++ " already exists. "
+ ++ "Refusing to start."
+ exitWith (ExitFailure exit_pidfile_exists)
+
-- This may be superstition (and I believe stderr is unbuffered),
-- but it can't hurt.
hSetBuffering stderr NoBuffering
hSetBuffering stdout NoBuffering
- -- Begin connecting to our feed hosts, starting with the first one.
- round_robin cfg 0
+ -- The rest of the program is kicked off by the following line which
+ -- begins connecting to our feed hosts, starting with the first one,
+ -- and proceeds in a round-robin fashion.
+ let run_program = round_robin cfg 0
+
+ -- If we were asked to daemonize, do that; otherwise just run the thing.
+ if (daemonize cfg)
+ then full_daemonize cfg run_program
+ else run_program
where
-- | This is the top-level "loop forever" function. If an
let hosts = get_feed_hosts $ feed_hosts cfg
let host = hosts !! feed_host_idx
catchIOError (connect_and_loop cfg host) (report_error . show)
- thread_sleep 10 -- Wait 10s before attempting to reconnect.
+ thread_sleep 5 -- Wait 5s before attempting to reconnect.
round_robin cfg $ (feed_host_idx + 1) `mod` (length hosts)
projects / dead / htsn.git / blobdiff