content: {-| Module abstracting the node and instance container implementation.
  
  This is currently implemented on top of an 'IntMap', which seems to
  give the best performance for our workload.
  
  -}
  
  {-
  
  Copyright (C) 2009, 2010, 2011 Google Inc.
  All rights reserved.
  
  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions are
  met:
  
  1. Redistributions of source code must retain the above copyright notice,
  this list of conditions and the following disclaimer.
  
  2. Redistributions in binary form must reproduce the above copyright
  notice, this list of conditions and the following disclaimer in the
  documentation and/or other materials provided with the distribution.
  
  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  -}
  
  module Ganeti.HTools.Container
    ( -- * Types
      Container
    , Key
    -- * Creation
    , IntMap.empty
    , IntMap.singleton
    , IntMap.fromList
    -- * Query
    , IntMap.size
    , IntMap.null
    , find
    , IntMap.findMax
    , IntMap.member
    , IntMap.lookup
    -- * Update
    , add
    , addTwo
    , IntMap.map
    , IntMap.mapAccum
    , IntMap.filter
    -- * Conversion
    , IntMap.elems
    , IntMap.keys
    -- * Element functions
    , nameOf
    , findByName
    ) where
  
  import Control.Monad.Fail (MonadFail)
  import qualified Data.IntMap as IntMap
  
  import qualified Ganeti.HTools.Types as T
  
  -- | Our key type.
  
  type Key = IntMap.Key
  
  -- | Our container type.
  type Container = IntMap.IntMap
  
  -- | Locate a key in the map (must exist).
  find :: Key -> Container a -> a
  find k = (IntMap.! k)
  
  -- | Add or update one element to the map.
  add :: Key -> a -> Container a -> Container a
  add = IntMap.insert
  
  -- | Add or update two elements of the map.
  addTwo :: Key -> a -> Key -> a -> Container a -> Container a
  addTwo k1 v1 k2 v2 = add k1 v1 . add k2 v2
  
  -- | Compute the name of an element in a container.
  nameOf :: (T.Element a) => Container a -> Key -> String
  nameOf c k = T.nameOf $ find k c
  
  -- | Find an element by name in a Container; this is a very slow function.
  findByName :: (T.Element a, MonadFail m) =>
                Container a -> String -> m a
  findByName c n =
    let all_elems = IntMap.elems c
        result = filter ((n `elem`) . T.allNames) all_elems
    in case result of
         [item] -> return item
         _ -> fail $ "Wrong number of elems found with name " ++ n
  