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{-| Parsing data from a simulated description of the cluster.

This module holds the code for parsing a cluster description.

-}

{-

Copyright (C) 2009, 2010, 2011 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.HTools.Simu

  ( loadData

  , parseData

  ) where

import Control.Monad (mplus)

import Text.Printf (printf)

import Ganeti.HTools.Utils

import Ganeti.HTools.Types

import Ganeti.HTools.Loader

import qualified Ganeti.HTools.Container as Container

import qualified Ganeti.HTools.Group as Group

import qualified Ganeti.HTools.Node as Node

-- | Parse a shortened policy string (for command line usage).

apolAbbrev :: String -> Result AllocPolicy

apolAbbrev c | c == "p"  = return AllocPreferred

             | c == "a"  = return AllocLastResort

             | c == "u"  = return AllocUnallocable

             | otherwise = fail $ "Cannot parse AllocPolicy abbreviation '"

                           ++ c ++ "'"

-- | Parse the string description into nodes.

parseDesc :: String -> Result (AllocPolicy, Int, Int, Int, Int)

parseDesc desc =

  case sepSplit ',' desc of

    [a, n, d, m, c] -> do

      apol <- allocPolicyFromRaw a `mplus` apolAbbrev a

      ncount <- tryRead "node count" n

      disk <- annotateResult "disk size" (parseUnit d)

      mem <- annotateResult "memory size" (parseUnit m)

      cpu <- tryRead "cpu count" c

      return (apol, ncount, disk, mem, cpu)

    es -> fail $ printf

          "Invalid cluster specification, expected 5 comma-separated\

          \ sections (allocation policy, node count, disk size,\

          \ memory size, number of CPUs) but got %d: '%s'" (length es) desc

-- | Creates a node group with the given specifications.

createGroup :: Int    -- ^ The group index

            -> String -- ^ The group specification

            -> Result (Group.Group, [Node.Node])

createGroup grpIndex spec = do

  (apol, ncount, disk, mem, cpu) <- parseDesc spec

  let nodes = map (\idx ->

                     Node.create (printf "node-%02d-%03d" grpIndex idx)

                           (fromIntegral mem) 0 mem

                           (fromIntegral disk) disk

                           (fromIntegral cpu) False grpIndex

                  ) [1..ncount]

      grp = Group.create (printf "group-%02d" grpIndex)

            (printf "fake-uuid-%02d" grpIndex) apol

  return (Group.setIdx grp grpIndex, nodes)

-- | Builds the cluster data from node\/instance files.

parseData :: [String] -- ^ Cluster description in text format

          -> Result ClusterData

parseData ndata = do

  grpNodeData <- mapM (uncurry createGroup) $ zip [1..] ndata

  let (groups, nodes) = unzip grpNodeData

      nodes' = concat nodes

  let ktn = map (\(idx, n) -> (idx, Node.setIdx n idx))

            $ zip [1..] nodes'

      ktg = map (\g -> (Group.idx g, g)) groups

  return (ClusterData (Container.fromList ktg)

                      (Container.fromList ktn) Container.empty [])

-- | Builds the cluster data from node\/instance files.

loadData :: [String] -- ^ Cluster description in text format

         -> IO (Result ClusterData)

loadData = -- IO monad, just for consistency with the other loaders

  return . parseData