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{-| Implementation of the Ganeti Query2 basic types.
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These are types internal to the library, and for example clients that
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use the library should not need to import it.
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 -}
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{-
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Copyright (C) 2012 Google Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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02110-1301, USA.
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-}
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module Ganeti.Query.Types
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  ( FieldGetter(..)
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  , FieldData
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  , FieldList
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  , FieldMap
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  , isRuntimeField
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  ) where
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import qualified Data.Map as Map
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import Ganeti.Query.Language
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import Ganeti.Objects
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-- | The type of field getters. The \"a\" type represents the type
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-- we're querying, whereas the \"b\" type represents the \'runtime\'
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-- data for that type (if any). Note that we don't support multiple
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-- runtime sources, and we always consider the entire configuration as
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-- a given (so no equivalent for Python's /*_CONFIG/ and /*_GROUP/;
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-- configuration accesses are cheap for us).
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data FieldGetter a b = FieldSimple  (a -> ResultEntry)
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                     | FieldRuntime (b -> a -> ResultEntry)
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                     | FieldConfig  (ConfigData -> a -> ResultEntry)
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                     | FieldUnknown
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-- | Alias for a field data (definition and getter).
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type FieldData a b = (FieldDefinition, FieldGetter a b)
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-- | Alias for a field data list.
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type FieldList a b = [FieldData a b]
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-- | Alias for field maps.
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type FieldMap a b = Map.Map String (FieldData a b)
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-- | Helper function to check if a getter is a runtime one.
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isRuntimeField :: FieldGetter a b -> Bool
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isRuntimeField (FieldRuntime _) = True
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isRuntimeField _                = False