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{-| Implementation of Utility functions for storage

 -}

{-

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.Storage.Utils

  ( getClusterStorageUnits

  ) where

import Ganeti.Objects

import Ganeti.Types

import qualified Ganeti.Types as T

type StorageUnit = (StorageType, String)

-- | Get the cluster's default storage unit for a given disk template

getDefaultStorageKey :: ConfigData -> DiskTemplate -> Maybe String

getDefaultStorageKey cfg T.DTDrbd8 = clusterVolumeGroupName $ configCluster cfg

getDefaultStorageKey cfg T.DTPlain = clusterVolumeGroupName $ configCluster cfg

getDefaultStorageKey cfg T.DTFile =

    Just (clusterFileStorageDir $ configCluster cfg)

getDefaultStorageKey cfg T.DTSharedFile =

    Just (clusterSharedFileStorageDir $ configCluster cfg)

getDefaultStorageKey _ _ = Nothing

-- | Get the cluster's default spindle storage unit

getDefaultSpindleSU :: ConfigData -> (StorageType, Maybe String)

getDefaultSpindleSU cfg =

    (T.StorageLvmPv, clusterVolumeGroupName $ configCluster cfg)

-- | Get the cluster's storage units from the configuration

getClusterStorageUnits :: ConfigData -> [StorageUnit]

getClusterStorageUnits cfg = foldSUs (maybe_units ++ [spindle_unit])

  where disk_templates = clusterEnabledDiskTemplates $ configCluster cfg

        storage_types = map diskTemplateToStorageType disk_templates

        maybe_units = zip storage_types (map (getDefaultStorageKey cfg)

            disk_templates)

        spindle_unit = getDefaultSpindleSU cfg

-- | fold the storage unit list by sorting out the ones without keys

foldSUs :: [(StorageType, Maybe String)] -> [StorageUnit]

foldSUs = foldr ff []

  where ff (st, Just sk) acc = (st, sk) : acc

        ff (_, Nothing) acc = acc

-- | Mapping fo disk templates to storage type

-- FIXME: This is semantically the same as the constant

-- C.diskTemplatesStorageType

diskTemplateToStorageType :: DiskTemplate -> StorageType

diskTemplateToStorageType T.DTExt = T.StorageExt

diskTemplateToStorageType T.DTFile = T.StorageFile

diskTemplateToStorageType T.DTSharedFile = T.StorageFile

diskTemplateToStorageType T.DTDrbd8 = T.StorageLvmVg

diskTemplateToStorageType T.DTPlain = T.StorageLvmVg

diskTemplateToStorageType T.DTRbd = T.StorageRados

diskTemplateToStorageType T.DTDiskless = T.StorageDiskless

diskTemplateToStorageType T.DTBlock = T.StorageBlock