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{-| Implementation of the Ganeti Query2 export queries.

 -}

{-

Copyright (C) 2013 Google Inc.

This program is free software; you can redistribute it and/or modify

it under the terms of the GNU General Public License as published by

the Free Software Foundation; either version 2 of the License, or

(at your option) any later version.

This program is distributed in the hope that it will be useful, but

WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

General Public License for more details.

You should have received a copy of the GNU General Public License

along with this program; if not, write to the Free Software

Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

02110-1301, USA.

-}

module Ganeti.Query.Export

  ( Runtime

  , fieldsMap

  , collectLiveData

  ) where

import Control.Monad (liftM)

import Ganeti.Objects

import Ganeti.Rpc

import Ganeti.Query.Language

import Ganeti.Query.Common

import Ganeti.Query.Types

-- | The parsed result of the ExportList. This is a bit tricky, in

-- that we already do parsing of the results in the RPC calls, so the

-- runtime type is a plain 'ResultEntry', as we have just one type.

type Runtime = ResultEntry

-- | Small helper for rpc to rs.

rpcErrToRs :: RpcError -> ResultEntry

rpcErrToRs err = ResultEntry (rpcErrorToStatus err) Nothing

-- | Helper for extracting fields from RPC result.

rpcExtractor :: Node -> Either RpcError RpcResultExportList

             -> [(Node, ResultEntry)]

rpcExtractor node (Right res) =

  [(node, rsNormal path) | path <- rpcResExportListExports res]

rpcExtractor node (Left err)  = [(node, rpcErrToRs err)]

-- | List of all node fields.

exportFields :: FieldList Node Runtime

exportFields =

  [ (FieldDefinition "node" "Node" QFTText "Node name",

     FieldRuntime (\_ n -> rsNormal $ nodeName n), QffHostname)

  , (FieldDefinition "export" "Export" QFTText "Export name",

     FieldRuntime (curry fst), QffNormal)

  ]

-- | The node fields map.

fieldsMap :: FieldMap Node Runtime

fieldsMap = fieldListToFieldMap exportFields

-- | Collect live data from RPC query if enabled.

--

-- Note that this function is \"funny\": the returned rows will not be

-- 1:1 with the input, as nodes without exports will be pruned,

-- whereas nodes with multiple exports will be listed multiple times.

collectLiveData:: Bool -> ConfigData -> [Node] -> IO [(Node, Runtime)]

collectLiveData False _ nodes =

  return [(n, rpcErrToRs $ RpcResultError "Live data disabled") | n <- nodes]

collectLiveData True _ nodes =

  concatMap (uncurry rpcExtractor) `liftM`

    executeRpcCall nodes RpcCallExportList