X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2FMain.hs;h=12cd00268bf60444faf2d7449dd2cd5ed4866a3f;hb=49c23c133221c9686dde0d52d06904db8d048724;hp=374981248fd9bf2b17905175949914d89cea70e4;hpb=95e23e65db31cf51c9f207a6b447da19920ee1a1;p=dead%2Fhtsn.git diff --git a/src/Main.hs b/src/Main.hs index 3749812..12cd002 100644 --- a/src/Main.hs +++ b/src/Main.hs @@ -28,6 +28,7 @@ import System.IO ( stderr, stdout ) import System.IO.Error (catchIOError) +import System.Log.Logger ( getLogger, rootLoggerName, saveGlobalLogger ) import System.Timeout (timeout) import CommandLine (get_args) @@ -36,39 +37,59 @@ import ExitCodes ( exit_no_feed_hosts, exit_no_password, exit_no_username ) +import Logging ( + init_logging, + log_debug, + log_error, + log_info, + log_warning ) import qualified OptionalConfiguration as OC ( OptionalConfiguration(..), from_rc ) -import Terminal (putGreenLn, report_error) +import Terminal (putGreenLn) import TSN.FeedHosts (FeedHosts(..)) import TSN.Xml (parse_xmlfid, xml_prologue) +-- | 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 = 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 @@ -83,7 +104,8 @@ loop !cfg !h !buffer = do 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 () @@ -91,13 +113,13 @@ log_in cfg h = do 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" @@ -122,7 +144,7 @@ log_in cfg h = do 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 @@ -146,20 +168,26 @@ connect_and_loop cfg host = do -- 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 @@ -172,31 +200,40 @@ main = do -- 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)