stderr,
stdout )
import System.IO.Error (catchIOError)
+import System.Log.Logger ( getLogger, rootLoggerName, saveGlobalLogger )
import System.Timeout (timeout)
import CommandLine (get_args)
exit_no_feed_hosts,
exit_no_password,
exit_no_username )
-import FeedHosts (FeedHosts(..))
+import Logging (
+ init_logging,
+ log_debug,
+ log_error,
+ log_info,
+ log_warning )
import qualified OptionalConfiguration as OC (
OptionalConfiguration(..),
from_rc )
-import Terminal (hPutRedLn, putGreenLn)
+import Terminal (putGreenLn)
+import TSN.FeedHosts (FeedHosts(..))
import TSN.Xml (parse_xmlfid, xml_prologue)
-report_error :: String -> IO ()
-report_error = hPutRedLn stderr
-
-
+-- | Receive a single line of text from a Handle, and send it to the
+-- debug log.
+--
recv_line :: Handle -> IO String
recv_line h = do
line <- hGetLine h
- putStrLn line
+ log_debug line
return line
+-- | Takes a Configuration, and an XML document (as a String). The XML
+-- document is written to the output directory, as specified by the
+-- Configuration.
+--
+-- This can fail, but we don't purposefully throw any exceptions. If
+-- something goes wrong, we would rather log it and keep going.
+--
save_document :: Configuration -> String -> IO ()
-save_document cfg doc = do
+save_document cfg doc =
case maybe_path of
Nothing ->
- report_error "ERROR: document missing XML_File_ID element."
+ log_error "Document missing XML_File_ID element."
Just path -> do
already_exists <- doesFileExist path
when already_exists $ do
- let msg = "WARNING: file " ++ path ++ " already exists. Overwriting."
- report_error msg
+ let msg = "File " ++ path ++ " already exists, overwriting."
+ log_warning msg
writeFile path doc
+ log_info $ "Wrote file: " ++ path ++ "."
where
xmlfid = fmap show (parse_xmlfid doc)
filename = fmap (++ ".xml") xmlfid
maybe_path = fmap ((output_directory cfg) </>) filename
+
-- | Loop forever, writing the buffer to file whenever a new XML
--- prologue is seen.
+-- 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 :: Configuration -> Handle -> [String] -> IO ()
loop !cfg !h !buffer = do
line <- recv_line h
save_document cfg document
loop cfg h [line] -- empty the buffer before looping again
else
- loop cfg h (line : buffer) -- append line to the head of the buffer and loop
+ -- append line to the head of the buffer and loop
+ loop cfg h (line : buffer)
log_in :: Configuration -> Handle -> IO ()
prompt1 <- recv_prompt h
if prompt1 /= username_prompt then
- report_error "ERROR: didn't receive username prompt."
+ log_error "Didn't receive username prompt."
else do
send_line h (username cfg)
prompt2 <- recv_prompt h
if prompt2 /= password_prompt then
- report_error "ERROR: didn't receive password prompt."
+ log_error "Didn't receive password prompt."
else do
send_line h (password cfg)
_ <- recv_line h -- "The Sports Network"
connect_and_loop :: Configuration -> String -> IO ()
connect_and_loop cfg host = do
- putStrLn $ "Connecting to " ++ host ++ "..."
+ log_info $ "Connecting to " ++ host ++ "..."
bracket acquire_handle release_handle action
return ()
where
--
login_worked <- timeout five_seconds $ log_in cfg h
case login_worked of
- Nothing -> putStrLn "Login timed out (5s)."
+ Nothing -> log_info "Login timed out (5s)."
Just _ -> loop cfg h []
-- | A wrapper around threadDelay which takes seconds instead of
-- microseconds as its argument.
+--
thread_sleep :: Int -> IO ()
thread_sleep seconds = do
let microseconds = seconds * (10 ^ (6 :: Int))
threadDelay microseconds
+-- | The entry point of the program.
main :: IO ()
main = do
+ init_logging
+ root_logger <- getLogger rootLoggerName
+ saveGlobalLogger root_logger
+
rc_cfg <- OC.from_rc
cmd_cfg <- get_args
-- fall back on the default list (which gets merged from a
-- Configuration below).
when (null $ get_feed_hosts (OC.feed_hosts opt_config)) $ do
- report_error "ERROR: no feed hosts supplied."
+ log_error "No feed hosts supplied."
exitWith (ExitFailure exit_no_feed_hosts)
when (isNothing (OC.password opt_config)) $ do
- report_error "ERROR: no password supplied."
+ log_error "No password supplied."
exitWith (ExitFailure exit_no_password)
when (isNothing (OC.username opt_config)) $ do
- report_error "ERROR: no username supplied."
+ log_error "No username supplied."
exitWith (ExitFailure exit_no_username)
-- Finally, update a default config with any options that have been
-- set in either the config file or on the command-line.
let cfg = (def :: Configuration) `merge_optional` opt_config
+ -- 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
where
+ -- | This is the top-level "loop forever" function. If an
+ -- exception is thrown, it will propagate up to this point, where
+ -- it will be logged and ignored in style.
+ --
+ -- Afterwards, we recurse (call ourself) again to loop more forevers.
+ --
round_robin :: Configuration -> Int -> IO ()
round_robin cfg feed_host_idx = do
let hosts = get_feed_hosts $ feed_hosts cfg
let host = hosts !! feed_host_idx
- catchIOError (connect_and_loop cfg host) (report_error . show)
+ catchIOError (connect_and_loop cfg host) (log_error . show)
thread_sleep 10 -- Wait 10s before attempting to reconnect.
round_robin cfg $ (feed_host_idx + 1) `mod` (length hosts)
projects / dead / htsn.git / blobdiff