## root / Ganeti / HTools / Loader.hs @ 497e30a1

History | View | Annotate | Download (3.5 kB)

1 |
{-| Loading data from external sources |
---|---|

2 | |

3 |
This module holds the common code for loading the cluster state from external sources. |

4 | |

5 |
-} |

6 | |

7 |
module Ganeti.HTools.Loader |

8 |
where |

9 | |

10 |
import Data.List |

11 |
import Data.Maybe (isNothing, fromJust) |

12 | |

13 |
import qualified Ganeti.HTools.Container as Container |

14 |
import qualified Ganeti.HTools.Instance as Instance |

15 |
import qualified Ganeti.HTools.Node as Node |

16 | |

17 |
import Ganeti.HTools.Types |

18 | |

19 | |

20 |
-- | Swap a list of @(a, b)@ into @(b, a)@ |

21 |
swapPairs :: [(a, b)] -> [(b, a)] |

22 |
swapPairs = map (\ (a, b) -> (b, a)) |

23 | |

24 |
-- | Lookups a node into an assoc list |

25 |
lookupNode :: (Monad m) => NameAssoc -> String -> String -> m Int |

26 |
lookupNode ktn inst node = |

27 |
case lookup node ktn of |

28 |
Nothing -> fail $ "Unknown node '" ++ node ++ "' for instance " ++ inst |

29 |
Just idx -> return idx |

30 | |

31 |
assignIndices :: (Element a) => |

32 |
[(String, a)] |

33 |
-> (NameAssoc, [(Int, a)]) |

34 |
assignIndices = |

35 |
unzip . map (\ (idx, (k, v)) -> ((k, idx), (idx, setIdx v idx))) |

36 |
. zip [0..] |

37 | |

38 |
-- | For each instance, add its index to its primary and secondary nodes |

39 |
fixNodes :: [(Int, Node.Node)] |

40 |
-> [(Int, Instance.Instance)] |

41 |
-> [(Int, Node.Node)] |

42 |
fixNodes nl il = |

43 |
foldl' (\accu (idx, inst) -> |

44 |
let |

45 |
assocEqual = (\ (i, _) (j, _) -> i == j) |

46 |
pdx = Instance.pnode inst |

47 |
sdx = Instance.snode inst |

48 |
pold = fromJust $ lookup pdx accu |

49 |
pnew = Node.setPri pold idx |

50 |
ac1 = deleteBy assocEqual (pdx, pold) accu |

51 |
ac2 = (pdx, pnew):ac1 |

52 |
in |

53 |
if sdx /= Node.noSecondary then |

54 |
let |

55 |
sold = fromJust $ lookup sdx accu |

56 |
snew = Node.setSec sold idx |

57 |
ac3 = deleteBy assocEqual (sdx, sold) ac2 |

58 |
ac4 = (sdx, snew):ac3 |

59 |
in ac4 |

60 |
else |

61 |
ac2 |

62 |
) nl il |

63 | |

64 |
-- | Compute the longest common suffix of a NameList list that |

65 |
-- | starts with a dot |

66 |
longestDomain :: NameList -> String |

67 |
longestDomain [] = "" |

68 |
longestDomain ((_,x):xs) = |

69 |
let |

70 |
onlyStrings = snd $ unzip xs |

71 |
in |

72 |
foldr (\ suffix accu -> if all (isSuffixOf suffix) onlyStrings |

73 |
then suffix |

74 |
else accu) |

75 |
"" $ filter (isPrefixOf ".") (tails x) |

76 | |

77 |
-- | Remove tails from the (Int, String) lists |

78 |
stripSuffix :: String -> NameList -> NameList |

79 |
stripSuffix suffix lst = |

80 |
let sflen = length suffix in |

81 |
map (\ (key, name) -> (key, take ((length name) - sflen) name)) lst |

82 | |

83 |
{-| Initializer function that loads the data from a node and list file |

84 |
and massages it into the correct format. -} |

85 |
mergeData :: ([(String, Int)], Node.AssocList, |

86 |
[(String, Int)], Instance.AssocList) -- ^ Data from either |

87 |
-- Text.loadData |

88 |
-- or Rapi.loadData |

89 |
-> Result (NodeList, InstanceList, String, NameList, NameList) |

90 |
mergeData (ktn, nl, kti, il) = do |

91 |
let |

92 |
nl2 = fixNodes nl il |

93 |
il3 = Container.fromAssocList il |

94 |
nl3 = Container.fromAssocList |

95 |
(map (\ (k, v) -> (k, Node.buildPeers v il3 (length nl2))) nl2) |

96 |
xtn = swapPairs ktn |

97 |
xti = swapPairs kti |

98 |
common_suffix = longestDomain (xti ++ xtn) |

99 |
stn = stripSuffix common_suffix xtn |

100 |
sti = stripSuffix common_suffix xti |

101 |
return (nl3, il3, common_suffix, stn, sti) |