X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2FOptionalConfiguration.hs;h=69ea04176583956f4bac6cf9ce89637bdc7806b7;hb=f6cb0ba712e06e52d080b86e9eba6c3585a7514b;hp=f636a17e2d623104dc2b06ea4983a9ff09c81d74;hpb=95e23e65db31cf51c9f207a6b447da19920ee1a1;p=dead%2Fhtsn.git diff --git a/src/OptionalConfiguration.hs b/src/OptionalConfiguration.hs index f636a17..69ea041 100644 --- a/src/OptionalConfiguration.hs +++ b/src/OptionalConfiguration.hs @@ -1,6 +1,7 @@ {-# LANGUAGE DeriveDataTypeable #-} {-# LANGUAGE FlexibleInstances #-} {-# LANGUAGE OverloadedStrings #-} +{-# LANGUAGE StandaloneDeriving #-} -- | An OptionalConfiguration is just like a 'Configuration', except -- all of its fields are optional. The user can set options in two @@ -11,25 +12,37 @@ module OptionalConfiguration ( OptionalConfiguration(..), - from_rc ) + from_rc, + merge_maybes ) where import qualified Data.Configurator as DC ( Worth(Optional), load, lookup ) -import Data.Data (Data) -import Data.Maybe (fromMaybe) -import Data.Monoid (Monoid(..)) -import Data.Typeable (Typeable) -import System.Directory (getHomeDirectory) +import qualified Data.Configurator.Types as DCT ( + Configured, + Value( String ), + convert ) +import Data.Data ( Data ) +import Data.Maybe ( fromMaybe ) +import Data.Monoid ( Monoid(..) ) +import Data.Typeable ( Typeable ) +import System.Directory ( getHomeDirectory ) import System.FilePath ( () ) -import System.IO.Error (catchIOError) +import System.IO.Error ( catchIOError ) +import System.Log ( Priority(..) ) -import Terminal (report_error) -import TSN.FeedHosts (FeedHosts(..)) +import Logging ( log_error ) +import TSN.FeedHosts ( FeedHosts(..) ) +-- Derive standalone instances of Data and Typeable for Priority. This +-- is necessary for OptionalConfiguration (which contains a Maybe +-- Priority) to derive Data and Typeable. +deriving instance Data Priority +deriving instance Typeable Priority + -- | The same as Configuration, except everything is optional. It's easy to -- merge two of these by simply dropping the Nothings in favor of -- the Justs. The 'feed_hosts' are left un-maybed so that cmdargs @@ -37,47 +50,69 @@ import TSN.FeedHosts (FeedHosts(..)) -- data OptionalConfiguration = OptionalConfiguration { - feed_hosts :: FeedHosts, - password :: Maybe String, + daemonize :: Maybe Bool, + feed_hosts :: FeedHosts, + log_file :: Maybe FilePath, + log_level :: Maybe Priority, output_directory :: Maybe FilePath, - username :: Maybe String } + password :: Maybe String, + pidfile :: Maybe FilePath, + run_as_group :: Maybe String, + run_as_user :: Maybe String, + syslog :: Maybe Bool, + username :: Maybe String } deriving (Show, Data, Typeable) +-- | Combine two Maybes into one, essentially mashing them +-- together. We give precedence to the second argument when both are +-- Justs. +merge_maybes :: (Maybe a) -> (Maybe a) -> (Maybe a) +merge_maybes Nothing Nothing = Nothing +merge_maybes (Just x) Nothing = Just x +merge_maybes Nothing (Just x) = Just x +merge_maybes (Just _) (Just y) = Just y + + -- | The Monoid instance for these lets us "combine" two -- OptionalConfigurations. The "combine" operation that we'd like to -- perform is, essentially, to mash them together. So if we have two -- OptionalConfigurations, each half full, we could combine them -- into one big one. -- --- One of the two must take precedence during this mashing, and we --- choose the second one for no reason. --- -- This is used to merge command-line and config-file settings. -- instance Monoid OptionalConfiguration where -- | An empty OptionalConfiguration. mempty = OptionalConfiguration + Nothing (FeedHosts []) Nothing Nothing Nothing + Nothing + Nothing + Nothing + Nothing + Nothing + Nothing -- | Combine @cfg1@ and @cfg2@, giving precedence to @cfg2@. cfg1 `mappend` cfg2 = OptionalConfiguration + (merge_maybes (daemonize cfg1) (daemonize cfg2)) all_feed_hosts - (merge (password cfg1) (password cfg2)) - (merge (output_directory cfg1) (output_directory cfg2)) - (merge (username cfg1) (username cfg2)) + (merge_maybes (log_file cfg1) (log_file cfg2)) + (merge_maybes (log_level cfg1) (log_level cfg2)) + (merge_maybes (output_directory cfg1) (output_directory cfg2)) + (merge_maybes (password cfg1) (password cfg2)) + (merge_maybes (pidfile cfg1) (pidfile cfg2)) + (merge_maybes (run_as_group cfg1) (run_as_group cfg2)) + (merge_maybes (run_as_user cfg1) (run_as_user cfg2)) + (merge_maybes (syslog cfg1) (syslog cfg2)) + (merge_maybes (username cfg1) (username cfg2)) where - merge :: (Maybe a) -> (Maybe a) -> (Maybe a) - merge Nothing Nothing = Nothing - merge (Just x) Nothing = Just x - merge Nothing (Just x) = Just x - merge (Just _) (Just y) = Just y - -- Use only the latter feed_hosts if there are any. all_feed_hosts = feed_hosts $ if (null (get_feed_hosts (feed_hosts cfg2))) @@ -85,6 +120,17 @@ instance Monoid OptionalConfiguration where else cfg2 +instance DCT.Configured Priority where + -- | This allows us to read a Priority level out of a Configurator + -- config file. By default Configurator wouldn't know what to do, + -- so we have to tell it that we expect one of the valid Priority + -- constructors. + convert (DCT.String "INFO") = Just INFO + convert (DCT.String "WARNING") = Just WARNING + convert (DCT.String "ERROR") = Just ERROR + convert _ = Nothing + + -- | Obtain an OptionalConfiguration from the file ".htsnrc" in the -- user's home directory. -- @@ -101,18 +147,31 @@ from_rc = do -- not serve much purpose. It could also be a security risk (visible -- password) if the admin screws up. home <- catchIOError getHomeDirectory (\e -> do - report_error (show e) + log_error (show e) return "$(HOME)") let user_config_path = home ".htsnrc" cfg <- DC.load [ DC.Optional user_config_path ] - cfg_password <- DC.lookup cfg "password" + cfg_daemonize <- DC.lookup cfg "daemonize" + cfg_feed_hosts <- DC.lookup cfg "feed_hosts" + cfg_log_file <- DC.lookup cfg "log_file" + cfg_log_level <- DC.lookup cfg "log_level" cfg_output_directory <- DC.lookup cfg "output_directory" + cfg_password <- DC.lookup cfg "password" + cfg_pidfile <- DC.lookup cfg "pidfile" + cfg_run_as_group <- DC.lookup cfg "run_as_group" + cfg_run_as_user <- DC.lookup cfg "run_as_user" + cfg_syslog <- DC.lookup cfg "syslog" cfg_username <- DC.lookup cfg "username" - cfg_feed_hosts <- DC.lookup cfg "feed_hosts" return $ OptionalConfiguration + cfg_daemonize (fromMaybe (FeedHosts []) cfg_feed_hosts) - cfg_password + cfg_log_file + cfg_log_level cfg_output_directory + cfg_password + cfg_pidfile + cfg_run_as_group + cfg_run_as_user + cfg_syslog cfg_username -