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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, 2012 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.Backend.Simu

  ( loadData

  , parseData

  ) where

import Control.Monad (mplus, zipWithM)

import Text.Printf (printf)

import Ganeti.BasicTypes

import Ganeti.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 -> [String]

          -> Result (AllocPolicy, Int, Int, Int, Int, Int)

parseDesc _ [a, n, d, m, c, s] = 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

  spindles <- tryRead "spindles" s

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

parseDesc desc [a, n, d, m, c] = parseDesc desc [a, n, d, m, c, "1"]

parseDesc desc es =

  fail $ printf

         "Invalid cluster specification, expected 6 comma-separated\

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

         \ memory size, number of CPUs, spindles) 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, spindles) <- parseDesc spec $

                                              sepSplit ',' spec

  let nodes = map (\idx ->

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

                           (fromIntegral mem) 0 mem

                           (fromIntegral disk) disk

                           (fromIntegral cpu) False spindles grpIndex

                  ) [1..ncount]

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

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

  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 <- zipWithM createGroup [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 [] defIPolicy)

-- | 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