Instance NFData CollectorData

...so that we can force the states of stateful collectors.
This is necessary to avoid thunks accumulating in unobserved
collectors.
Signed-off-by: Klaus Aehlig <aehlig@google.com>
Reviewed-by: Petr Pudlak <pudlak@google.com>

src/Ganeti/DataCollectors/Types.hs

@@ -49,6 +49,7 @@ module Ganeti.DataCollectors.Types
   , getCategoryName
   ) where
 
+import Control.DeepSeq (NFData, rnf, force)
 import Data.Char
 import Data.Ratio
 import qualified Data.Map as Map
@@ -138,6 +139,9 @@ instance JSON DCVersion where
 -- | Type for the value field of the `CollectorMap` below.
 data CollectorData = CPULoadData (Seq.Seq (Integer, [Int]))
 
+instance NFData CollectorData where
+  rnf (CPULoadData x) = rnf x
+
 -- | Type for the map storing the data of the statefull DataCollectors.
 type CollectorMap = Map.Map String CollectorData