Revision 1e0d1a19
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import Control.Monad.Base |
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import Control.Monad.Error |
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import qualified Control.Monad.State.Strict as S |
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import Control.Monad.Trans.Control |
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import Ganeti.BasicTypes |
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import Ganeti.Errors |
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setOwnerWGroupR fname |
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saveConfig fh cfg |
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-- Reads the current configuration state in the 'WConfdMonad'. |
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readConfig :: WConfdMonad ConfigData |
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readConfig = csConfigData <$> readConfigState |
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-- Replaces the current configuration state within the 'WConfdMonad'. |
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writeConfig :: ConfigData -> WConfdMonad () |
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writeConfig cd = modifyConfigState $ const (mkConfigState cd, ()) |
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-- * Asynchronous tasks |
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-- | Creates an asynchronous task that handles errors in its actions. |
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-- If an error occurs, it's logged and the internal state remains unchanged. |
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mkStatefulAsyncTask :: (MonadBaseControl IO m, Show e) |
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=> Priority |
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-> String |
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-> (s -> ResultT e m s) |
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-> s |
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-> m (AsyncWorker ()) |
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mkStatefulAsyncTask logPrio logPrefix action start = |
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flip S.evalStateT start . mkAsyncWorker $ |
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S.get >>= lift . runResultT . action |
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>>= genericResult |
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(logAt logPrio . (++) (logPrefix ++ ": ") . show) |
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S.put -- on success save the state |
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-- | Construct an asynchronous worker whose action is to save the |
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-- configuration to the master file. |
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-- The worker's action reads the configuration using the given @IO@ action |
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-> IO ConfigState -- ^ An action to read the current config |
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-> ResultG (AsyncWorker ()) |
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saveConfigAsyncTask fpath fstat cdRef = |
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flip S.evalStateT fstat . mkAsyncWorker $ |
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catchError (do |
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oldstat <- S.get |
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cd <- liftBase (csConfigData `liftM` cdRef) |
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newstat <- writeConfigToFile cd fpath oldstat |
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S.put newstat |
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) (logEmergency . (++) "Can't write the master configuration file: " |
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. show) |
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-- Reads the current configuration state in the 'WConfdMonad'. |
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readConfig :: WConfdMonad ConfigData |
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readConfig = csConfigData <$> readConfigState |
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-- Replaces the current configuration state within the 'WConfdMonad'. |
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writeConfig :: ConfigData -> WConfdMonad () |
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writeConfig cd = modifyConfigState $ const (mkConfigState cd, ()) |
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let action oldstat = do |
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cd <- liftBase (csConfigData `liftM` cdRef) |
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writeConfigToFile cd fpath oldstat |
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in lift $ mkStatefulAsyncTask |
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EMERGENCY "Can't write the master configuration file" |
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action fstat |
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