+{-# LANGUAGE DoAndIfThenElse #-}
+{-# LANGUAGE NoMonomorphismRestriction #-}
module Main
where
-import Control.Arrow ( (&&&), arr, returnA )
+import Control.Arrow ( (&&&), (>>^), arr, returnA )
+import Control.Concurrent ( threadDelay )
+import Control.Exception ( SomeException, catch )
import Control.Monad ( when )
-import Control.Monad.IO.Class ( liftIO )
-import Database.Groundhog.Core ( PersistEntity )
+import Database.Groundhog.Generic ( runDbConn )
import Database.Groundhog.Sqlite (
- defaultMigrationLogger,
- insert,
- migrate,
- runDbConn,
- runMigration,
withSqliteConn )
-import Data.Maybe ( isNothing )
+import Database.Groundhog.Postgresql (
+ withPostgresqlConn )
import Data.Monoid ( (<>) )
+import Network.Services.TSN.Logging ( init_logging )
import System.Console.CmdArgs ( def )
+import System.Directory ( removeFile )
import System.Exit ( exitWith, ExitCode (ExitFailure) )
+import System.IO.Error ( catchIOError )
import Text.XML.HXT.Core (
ArrowXml,
IOStateArrow,
- SysConfigList,
- XmlPickler,
XmlTree,
(>>>),
(/>),
getAttrl,
getText,
hasName,
- no,
readDocument,
- runX,
- unpickleDoc,
- withPreserveComment,
- withRemoveWS,
- withSubstDTDEntities,
- withValidate,
- xpickle,
- yes )
+ runX )
+import Backend ( Backend(..) )
import CommandLine ( get_args )
import Configuration ( Configuration(..), merge_optional )
-import ExitCodes (
- exit_no_connection_string,
- exit_no_xml_files )
-import Network.Services.TSN.Logging ( init_logging )
+import ConnectionString ( ConnectionString(..) )
+import ExitCodes ( exit_no_xml_files )
import qualified OptionalConfiguration as OC (
- OptionalConfiguration ( connection_string, xml_files ),
+ OptionalConfiguration ( xml_files ),
from_rc )
import Network.Services.TSN.Report (
report_info,
report_error )
-import qualified TSN.Injuries as Injuries (
- Listing,
- Message ( listings ) )
-import qualified TSN.InjuriesDetail as InjuriesDetail (
- Listing ( player_listings ),
- Message ( listings ),
- PlayerListing )
-
-
-
--- | A list of options passed to 'readDocument' when we parse an XML
--- document. We don't validate because the DTDs from TSN are
--- wrong. As a result, we don't want to keep useless DTDs
--- areound. Thus we disable 'withSubstDTDEntities' which, when
--- combined with "withValidate no", prevents HXT from trying to read
--- the DTD at all.
+import TSN.DbImport ( DbImport(..), ImportResult(..) )
+import qualified TSN.XML.Heartbeat as Heartbeat ( verify )
+import qualified TSN.XML.Injuries as Injuries ( Listing )
+import qualified TSN.XML.InjuriesDetail as InjuriesDetail ( PlayerListing )
+import qualified TSN.XML.News as News ( Message )
+import qualified TSN.XML.Odds as Odds ( Message )
+import Xml ( DtdName(..), parse_opts )
+
+
+-- | This is where most of the work happens. This function is called
+-- on every file that we would like to import. It determines which
+-- importer to use based on the DTD, processes the file, and then
+-- returns whether or not any records were imported. If the file was
+-- processed, the number of records imported is returned (wrapped in
+-- a Just). Otherwise, if the file was not processed, 'Nothing' is
+-- returned.
+--
+-- Since we are already in arrow world with HXT, the
+-- 'import_with_dtd' function is lifted to an 'Arrow' as well with
+-- 'arr'. This prevents us from having to do a bunch of unwrapping
+-- and rewrapping with the associated error checking.
--
-parse_opts :: SysConfigList
-parse_opts =
- [ withPreserveComment no,
- withRemoveWS yes,
- withSubstDTDEntities no,
- withValidate no ]
+import_file :: Configuration -- ^ A configuration object needed for the
+ -- 'backend' and 'connection_string'.
+ -> FilePath -- ^ The path of the XML file to import.
--- | We put the 'XmlTree' argument last so that it's easy to eta
--- reduce all of the import_foo functions that call this.
---
-import_generic :: (XmlPickler a, PersistEntity b)
- => b -- ^ Dummy Listing instance needed for 'migrate'
- -> (a -> [b]) -- ^ listings getter
- -> XmlTree
- -> IO ()
-import_generic dummy g xml =
- withSqliteConn "foo.sqlite3" $ runDbConn $ do
- runMigration defaultMigrationLogger $ do
- migrate dummy
- let root_element = unpickleDoc xpickle xml
- case root_element of
- Nothing -> let msg = "Could not unpickle document in import_generic."
- in liftIO $ report_error msg
- Just elt -> mapM_ (\l -> insert l) (g elt)
-
--- | Import TSN.Injuries from an 'XmlTree'.
-import_injuries :: XmlTree -> IO ()
-import_injuries =
- import_generic
- (undefined :: Injuries.Listing)
- Injuries.listings
-
--- | Import TSN.InjuriesDetail from an 'XmlTree'.
-import_injuries_detail :: XmlTree -> IO ()
-import_injuries_detail =
- import_generic
- (undefined :: InjuriesDetail.PlayerListing)
- ( (concatMap InjuriesDetail.player_listings) . InjuriesDetail.listings)
-
-import_file :: FilePath -> IO ()
-import_file path = do
- report_info $ "Attempting to import " ++ path ++ "."
- results <- runX $ readA >>> (doctypeA &&& returnA) >>> (arr import_with_dtd)
+ -> IO (Maybe Int) -- ^ If we processed the file, Just the number
+ -- of records imported. Otherwise, Nothing.
+import_file cfg path = do
+ results <- parse_and_import `catch` exception_handler
case results of
- [] -> report_error $ "Unable to determine DTD for file " ++ path ++ "."
- (r:_) -> r -- Need to do something with the result or it gets GCed?
- -- We do only expect one result fortunately.
+ [] -> do
+ -- One of the arrows returned "nothing."
+ report_error $ "Unable to determine DTD for file " ++ path ++ "."
+ return Nothing
+ (ImportFailed errmsg:_) -> do
+ report_error errmsg
+ return Nothing
+ (ImportSkipped infomsg:_) -> do
+ -- We processed the message but didn't import anything. Return
+ -- "success" so that the XML file is deleted.
+ report_info infomsg
+ return $ Just 0
+ (ImportSucceeded count:_) -> do
+ report_info $ "Successfully imported " ++ (show count) ++
+ " records from " ++ path ++ "."
+ return $ Just count
+ (ImportUnsupported infomsg:_) -> do
+ -- For now we return "success" for these too, since we know we don't
+ -- support a bunch of DTDs and we want them to get deleted.
+ report_info infomsg
+ return $ Just 0
where
+ -- | This will catch *any* exception, even the ones thrown by
+ -- Haskell's 'error' (which should never occur under normal
+ -- circumstances).
+ exception_handler :: SomeException -> IO [ImportResult]
+ exception_handler e = do
+ report_error (show e)
+ let errdesc = "Failed to import file " ++ path ++ "."
+ -- Return a nonempty list so we don't claim incorrectly that
+ -- we couldn't parse the DTD.
+ return [ImportFailed errdesc]
+
-- | An arrow that reads a document into an 'XmlTree'.
readA :: IOStateArrow s a XmlTree
readA = readDocument parse_opts path
-- | An arrow which parses the doctype "SYSTEM" of an 'XmlTree'.
-- We use these to determine the parser to use.
- doctypeA :: ArrowXml a => a XmlTree String
- doctypeA = getAttrl >>> hasName "doctype-SYSTEM" /> getText
-
- -- | Takes a 'Doctype', 'XmlTree' pair and uses the 'Doctype' to
- -- determine which function to call on the 'XmlTree'.
- import_with_dtd :: (String, XmlTree) -> IO ()
- import_with_dtd (dtd,xml)
- | dtd == "injuriesxml.dtd" = import_injuries xml
- | dtd == "Injuries_Detail_XML.dtd" = import_injuries_detail xml
- | otherwise = report_info $
- "Unrecognized DTD in " ++ path ++ ": " ++ dtd ++ "."
-
-
+ dtdnameA :: ArrowXml a => a XmlTree DtdName
+ dtdnameA = getAttrl >>> hasName "doctype-SYSTEM" /> getText >>^ DtdName
+
+ -- | Combine the arrows above as well as the function below
+ -- (arrowized with 'arr') into an IO action that does everything
+ -- (parses and then runs the import on what was parsed).
+ --
+ -- The result of runX has type IO [IO ImportResult]. We thus use
+ -- bind (>>=) and sequence to combine all of the IOs into one
+ -- big one outside of the list.
+ parse_and_import :: IO [ImportResult]
+ parse_and_import =
+ runX (readA >>> (dtdnameA &&& returnA) >>> (arr import_with_dtd))
+ >>=
+ sequence
+
+ -- | Takes a ('DtdName', 'XmlTree') pair and uses the 'DtdName'
+ -- to determine which function to call on the 'XmlTree'.
+ import_with_dtd :: (DtdName, XmlTree) -> IO ImportResult
+ import_with_dtd (DtdName dtd,xml)
+ -- We special-case the heartbeat so it doesn't have to run in
+ -- the database monad.
+ | dtd == "Heartbeat.dtd" = Heartbeat.verify xml
+ | otherwise =
+ -- We need NoMonomorphismRestriction here.
+ if backend cfg == Postgres
+ then withPostgresqlConn cs $ runDbConn $ importer xml
+ else withSqliteConn cs $ runDbConn $ importer xml
+ where
+ -- | Pull the real connection String out of the configuration.
+ cs :: String
+ cs = get_connection_string $ connection_string cfg
+
+ importer
+ | dtd == "injuriesxml.dtd" =
+ dbimport (undefined :: Injuries.Listing)
+
+ | dtd == "Injuries_Detail_XML.dtd" =
+ dbimport (undefined :: InjuriesDetail.PlayerListing)
+
+ | dtd == "newsxml.dtd" =
+ dbimport (undefined :: News.Message)
+
+ | dtd == "Odds_XML.dtd" = undefined
+
+ | otherwise = \_ -> do -- Dummy arg simplifies the other cases.
+ let infomsg =
+ "Unrecognized DTD in " ++ path ++ ": " ++ dtd ++ "."
+ return $ ImportUnsupported infomsg
+
+
+-- | Entry point of the program. It twiddles some knobs for
+-- configuration options and then calls 'import_file' on each XML file
+-- given on the command-line.
+--
+-- Any file successfully processed is then removed, and we're done.
+--
main :: IO ()
main = do
rc_cfg <- OC.from_rc
report_error "No XML files given."
exitWith (ExitFailure exit_no_xml_files)
- -- There's a default connection string, namely the empty string, but
- -- it's not much use to us. So we make sure that we were given
- -- something explicitly.
- when (isNothing (OC.connection_string opt_config)) $ do
- report_error "No connection string supplied."
- exitWith (ExitFailure exit_no_connection_string)
+ -- We don't do this in parallel (for now?) to keep the error
+ -- messages nice and linear.
+ results <- mapM (import_file cfg) (OC.xml_files opt_config)
+ -- Zip the results with the files list to find out which ones can be
+ -- deleted.
+ let result_pairs = zip (OC.xml_files opt_config) results
+ let victims = [ (p,c) | (p, Just c) <- result_pairs ]
+ let imported_count = sum $ map snd victims
+ report_info $ "Imported " ++ (show imported_count) ++ " records total."
+ mapM_ ((kill True) . fst) victims
- return ()
+ where
+ -- | Wrap these two actions into one function so that we don't
+ -- report that the file was removed if the exception handler is
+ -- run.
+ remove_and_report path = do
+ removeFile path
+ report_info $ "Removed processed file " ++ path ++ "."
+
+ -- | Try to remove @path@ and potentially try again.
+ kill try_again path = do
+ (remove_and_report path) `catchIOError` exception_handler
+ where
+ -- | 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
+
+ -- | If we can't remove the file, report that, and try once
+ -- more after waiting a few seconds.
+ exception_handler :: IOError -> IO ()
+ exception_handler e = do
+ report_error (show e)
+ report_error $ "Failed to remove imported file " ++ path ++ "."
+ if try_again then do
+ report_info $ "Waiting 5 seconds to attempt removal again..."
+ thread_sleep 5
+ kill False path
+ else
+ report_info $ "Giving up on " ++ path ++ "."