Move some tiered spec functionality to Cluster.hs

This splits out a bit of code from hspace.hs and moves it into its own
function in Cluster.hs.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

Ganeti/HTools/Cluster.hs

@@ -62,11 +62,14 @@ module Ganeti.HTools.Cluster
     -- * Allocation functions
     , iterateAlloc
     , tieredAlloc
+    , tieredSpecMap
+     -- * Node group functions
     , instanceGroup
     , findSplitInstances
     , splitCluster
     ) where
 
+import Data.Function (on)
 import Data.List
 import Data.Ord (comparing)
 import Text.Printf (printf)
@@ -762,6 +765,7 @@ iterateAlloc nl il newinst nreq ixes =
                  _ -> Bad "Internal error: multiple solutions for single\
                           \ allocation"
 
+-- | The core of the tiered allocation mode
 tieredAlloc :: Node.List
             -> Instance.List
             -> Instance.Instance
@@ -779,6 +783,18 @@ tieredAlloc nl il newinst nreq ixes =
             Ok newinst' ->
                 tieredAlloc nl' il' newinst' nreq ixes'
 
+-- | Compute the tiered spec string description from a list of
+-- allocated instances.
+tieredSpecMap :: [Instance.Instance]
+              -> [String]
+tieredSpecMap trl_ixes =
+    let fin_trl_ixes = reverse trl_ixes
+        ix_byspec = groupBy ((==) `on` Instance.specOf) fin_trl_ixes
+        spec_map = map (\ixs -> (Instance.specOf $ head ixs, length ixs))
+                   ix_byspec
+    in  map (\(spec, cnt) -> printf "%d,%d,%d=%d" (rspecMem spec)
+                             (rspecDsk spec) (rspecCpu spec) cnt) spec_map
+
 -- * Formatting functions
 
 -- | Given the original and final nodes, computes the relocation description.
@@ -941,6 +957,8 @@ iMoveToJob nl il idx move =
          ReplaceAndFailover np -> [ opR np, opF ]
          FailoverAndReplace ns -> [ opF, opR ns ]
 
+-- * Node group functions
+
 -- | Computes the group of an instance
 instanceGroup :: Node.List -> Instance.Instance -> Result Gdx
 instanceGroup nl i =

hspace.hs

@@ -27,7 +27,6 @@ module Main (main) where
 
 import Data.Char (toUpper, isAlphaNum)
 import Data.List
-import Data.Function
 import Data.Maybe (isJust, fromJust)
 import Data.Ord (comparing)
 import Monad
@@ -289,19 +288,12 @@ main = do
            then return result_noalloc
            else exitifbad (Cluster.tieredAlloc nl il (iofspec tspec)
                                   req_nodes [])
-       let fin_trl_ixes = reverse trl_ixes
-           ix_byspec = groupBy ((==) `on` Instance.specOf) fin_trl_ixes
-           spec_map = map (\ixs -> (Instance.specOf $ head ixs, length ixs))
-                      ix_byspec::[(RSpec, Int)]
-           spec_map' = map (\(spec, cnt) ->
-                                printf "%d,%d,%d=%d" (rspecMem spec)
-                                       (rspecDsk spec) (rspecCpu spec) cnt)
-                       spec_map::[String]
+       let spec_map' = Cluster.tieredSpecMap trl_ixes
 
        when (verbose > 1) $ do
          hPutStrLn stderr "Tiered allocation map"
          hPutStr stderr . unlines . map ((:) ' ' .  intercalate " ") $
-                 formatTable (map (printInstance trl_nl) fin_trl_ixes)
+                 formatTable (map (printInstance trl_nl) (reverse trl_ixes))
                                  [False, False, False, True, True, True]
 
        when (isJust shownodes) $ do