Move allocation primitives to a separate module

In this way we avoid a circular dependency: tryAlloc depends on
the notion of global N+1 redundancy and global N+1 redundancy for
plain instances depends on knowing how to allocate an instance on
a single node.
Signed-off-by: Klaus Aehlig <aehlig@google.com>
Reviewed-by: Petr Pudlak <pudlak@google.com>

Makefile.am

@@ -910,6 +910,7 @@ HS_LIB_SRCS = \
 	src/Ganeti/HTools/Backend/Text.hs \
 	src/Ganeti/HTools/CLI.hs \
 	src/Ganeti/HTools/Cluster.hs \
+	src/Ganeti/HTools/Cluster/AllocatePrimitives.hs \
 	src/Ganeti/HTools/Cluster/AllocateSecondary.hs \
 	src/Ganeti/HTools/Cluster/AllocationSolution.hs \
 	src/Ganeti/HTools/Cluster/Evacuate.hs \

src/Ganeti/HTools/Cluster.hs

@@ -94,18 +94,18 @@ import Text.Printf (printf)
 import Ganeti.BasicTypes
 import Ganeti.HTools.AlgorithmParams (AlgorithmOptions(..), defaultOptions)
 import qualified Ganeti.HTools.Container as Container
+import Ganeti.HTools.Cluster.AllocatePrimitives ( allocateOnSingle
+                                                , allocateOnPair)
 import Ganeti.HTools.Cluster.AllocationSolution
-    ( AllocElement, GenericAllocSolution(..) , AllocSolution, emptyAllocSolution
+    ( GenericAllocSolution(..) , AllocSolution, emptyAllocSolution
     , sumAllocs, extractNl, updateIl
     , annotateSolution, solutionDescription, collapseFailures
     , emptyAllocCollection, concatAllocCollections, collectionToSolution )
 import Ganeti.HTools.Cluster.Evacuate ( EvacSolution(..), emptyEvacSolution
                                       , updateEvacSolution, reverseEvacSolution
                                       , nodeEvacInstance)
-import Ganeti.HTools.Cluster.Metrics ( compCV, compCVfromStats
-                                     , compClusterStatistics
-                                     , updateClusterStatisticsTwice)
-import Ganeti.HTools.Cluster.Moves (setInstanceLocationScore, applyMoveEx)
+import Ganeti.HTools.Cluster.Metrics (compCV, compClusterStatistics)
+import Ganeti.HTools.Cluster.Moves (applyMoveEx)
 import Ganeti.HTools.Cluster.Utils (splitCluster, instancePriGroup
                                    , availableGroupNodes, iMoveToJob)
 import Ganeti.HTools.GlobalN1 (allocGlobalN1, redundant)
@@ -116,7 +116,6 @@ import qualified Ganeti.HTools.Group as Group
 import Ganeti.HTools.Types
 import Ganeti.Compat
 import Ganeti.Utils
-import Ganeti.Utils.Statistics
 import Ganeti.Types (EvacMode(..))
 
 -- * Types
@@ -314,42 +313,6 @@ compareTables :: Table -> Table -> Table
 compareTables a@(Table _ _ a_cv _) b@(Table _ _ b_cv _ ) =
   if a_cv > b_cv then b else a
 
--- | Tries to allocate an instance on one given node.
-allocateOnSingle :: AlgorithmOptions
-                 -> Node.List -> Instance.Instance -> Ndx
-                 -> OpResult AllocElement
-allocateOnSingle opts nl inst new_pdx =
-  let p = Container.find new_pdx nl
-      new_inst = Instance.setBoth inst new_pdx Node.noSecondary
-      force = algIgnoreSoftErrors opts
-  in do
-    Instance.instMatchesPolicy inst (Node.iPolicy p) (Node.exclStorage p)
-    new_p <- Node.addPriEx force p inst
-    let new_nl = Container.add new_pdx new_p nl
-        new_score = compCV new_nl
-    return (new_nl, new_inst, [new_p], new_score)
-
--- | Tries to allocate an instance on a given pair of nodes.
-allocateOnPair :: AlgorithmOptions
-               -> [Statistics]
-               -> Node.List -> Instance.Instance -> Ndx -> Ndx
-               -> OpResult AllocElement
-allocateOnPair opts stats nl inst new_pdx new_sdx =
-  let tgt_p = Container.find new_pdx nl
-      tgt_s = Container.find new_sdx nl
-      force = algIgnoreSoftErrors opts
-  in do
-    Instance.instMatchesPolicy inst (Node.iPolicy tgt_p)
-      (Node.exclStorage tgt_p)
-    let new_inst = Instance.setBoth (setInstanceLocationScore inst tgt_p tgt_s)
-                   new_pdx new_sdx
-    new_p <- Node.addPriEx force tgt_p new_inst
-    new_s <- Node.addSec tgt_s new_inst new_pdx
-    let new_nl = Container.addTwo new_pdx new_p new_sdx new_s nl
-        new_stats = updateClusterStatisticsTwice stats
-                      (tgt_p, new_p) (tgt_s, new_s)
-    return (new_nl, new_inst, [new_p, new_s], compCVfromStats new_stats)
-
 -- | Tries to perform an instance move and returns the best table
 -- between the original one and the new one.
 checkSingleStep :: Bool -- ^ Whether to unconditionally ignore soft errors

src/Ganeti/HTools/Cluster/AllocatePrimitives.hs

+{-| Implementation of the primitives of instance allocation
+
+-}
+
+{-
+
+Copyright (C) 2009, 2010, 2011, 2012, 2013, 2015 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.Cluster.AllocatePrimitives
+  ( allocateOnSingle
+  , allocateOnPair
+  ) where
+
+import Ganeti.HTools.AlgorithmParams (AlgorithmOptions(..))
+import Ganeti.HTools.Cluster.AllocationSolution (AllocElement)
+import Ganeti.HTools.Cluster.Metrics ( compCV, compCVfromStats
+                                     , updateClusterStatisticsTwice)
+import Ganeti.HTools.Cluster.Moves (setInstanceLocationScore)
+import qualified Ganeti.HTools.Container as Container
+import qualified Ganeti.HTools.Instance as Instance
+import qualified Ganeti.HTools.Node as Node
+import Ganeti.HTools.Types
+import Ganeti.Utils.Statistics
+
+-- | Tries to allocate an instance on one given node.
+allocateOnSingle :: AlgorithmOptions
+                 -> Node.List -> Instance.Instance -> Ndx
+                 -> OpResult AllocElement
+allocateOnSingle opts nl inst new_pdx =
+  let p = Container.find new_pdx nl
+      new_inst = Instance.setBoth inst new_pdx Node.noSecondary
+      force = algIgnoreSoftErrors opts
+  in do
+    Instance.instMatchesPolicy inst (Node.iPolicy p) (Node.exclStorage p)
+    new_p <- Node.addPriEx force p inst
+    let new_nl = Container.add new_pdx new_p nl
+        new_score = compCV new_nl
+    return (new_nl, new_inst, [new_p], new_score)
+
+-- | Tries to allocate an instance on a given pair of nodes.
+allocateOnPair :: AlgorithmOptions
+               -> [Statistics]
+               -> Node.List -> Instance.Instance -> Ndx -> Ndx
+               -> OpResult AllocElement
+allocateOnPair opts stats nl inst new_pdx new_sdx =
+  let tgt_p = Container.find new_pdx nl
+      tgt_s = Container.find new_sdx nl
+      force = algIgnoreSoftErrors opts
+  in do
+    Instance.instMatchesPolicy inst (Node.iPolicy tgt_p)
+      (Node.exclStorage tgt_p)
+    let new_inst = Instance.setBoth (setInstanceLocationScore inst tgt_p tgt_s)
+                   new_pdx new_sdx
+    new_p <- Node.addPriEx force tgt_p new_inst
+    new_s <- Node.addSec tgt_s new_inst new_pdx
+    let new_nl = Container.addTwo new_pdx new_p new_sdx new_s nl
+        new_stats = updateClusterStatisticsTwice stats
+                      (tgt_p, new_p) (tgt_s, new_s)
+    return (new_nl, new_inst, [new_p, new_s], compCVfromStats new_stats)