root / Ganeti / HTools / Utils.hs @ 8bcdde0c
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1 | e4f08c46 | Iustin Pop | {-| Utility functions -} |
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2 | e4f08c46 | Iustin Pop | |
3 | e2fa2baf | Iustin Pop | {- |
4 | e2fa2baf | Iustin Pop | |
5 | e2fa2baf | Iustin Pop | Copyright (C) 2009 Google Inc. |
6 | e2fa2baf | Iustin Pop | |
7 | e2fa2baf | Iustin Pop | This program is free software; you can redistribute it and/or modify |
8 | e2fa2baf | Iustin Pop | it under the terms of the GNU General Public License as published by |
9 | e2fa2baf | Iustin Pop | the Free Software Foundation; either version 2 of the License, or |
10 | e2fa2baf | Iustin Pop | (at your option) any later version. |
11 | e2fa2baf | Iustin Pop | |
12 | e2fa2baf | Iustin Pop | This program is distributed in the hope that it will be useful, but |
13 | e2fa2baf | Iustin Pop | WITHOUT ANY WARRANTY; without even the implied warranty of |
14 | e2fa2baf | Iustin Pop | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
15 | e2fa2baf | Iustin Pop | General Public License for more details. |
16 | e2fa2baf | Iustin Pop | |
17 | e2fa2baf | Iustin Pop | You should have received a copy of the GNU General Public License |
18 | e2fa2baf | Iustin Pop | along with this program; if not, write to the Free Software |
19 | e2fa2baf | Iustin Pop | Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
20 | e2fa2baf | Iustin Pop | 02110-1301, USA. |
21 | e2fa2baf | Iustin Pop | |
22 | e2fa2baf | Iustin Pop | -} |
23 | e2fa2baf | Iustin Pop | |
24 | 209b3711 | Iustin Pop | module Ganeti.HTools.Utils |
25 | 209b3711 | Iustin Pop | ( |
26 | 209b3711 | Iustin Pop | debug |
27 | 209b3711 | Iustin Pop | , sepSplit |
28 | a80bf544 | Iustin Pop | , fst3 |
29 | 209b3711 | Iustin Pop | , varianceCoeff |
30 | 3d7cd10b | Iustin Pop | , commaJoin |
31 | 9ba5c28f | Iustin Pop | , readEitherString |
32 | 9ba5c28f | Iustin Pop | , loadJSArray |
33 | 9ba5c28f | Iustin Pop | , fromObj |
34 | 117dc2d8 | Iustin Pop | , tryFromObj |
35 | 117dc2d8 | Iustin Pop | , fromJVal |
36 | 3f6af65c | Iustin Pop | , asJSObject |
37 | 3f6af65c | Iustin Pop | , asObjectList |
38 | 942403e6 | Iustin Pop | , fromJResult |
39 | 5b763470 | Iustin Pop | , tryRead |
40 | c5f7412e | Iustin Pop | , formatTable |
41 | 117dc2d8 | Iustin Pop | , annotateResult |
42 | 209b3711 | Iustin Pop | ) where |
43 | e4f08c46 | Iustin Pop | |
44 | 29ac5975 | Iustin Pop | import Data.List |
45 | 942403e6 | Iustin Pop | import qualified Text.JSON as J |
46 | 9ba5c28f | Iustin Pop | import Text.Printf (printf) |
47 | e4f08c46 | Iustin Pop | |
48 | e4f08c46 | Iustin Pop | import Debug.Trace |
49 | e4f08c46 | Iustin Pop | |
50 | 117dc2d8 | Iustin Pop | import Ganeti.HTools.Types |
51 | 117dc2d8 | Iustin Pop | |
52 | 9188aeef | Iustin Pop | -- * Debug functions |
53 | 9188aeef | Iustin Pop | |
54 | e4f08c46 | Iustin Pop | -- | To be used only for debugging, breaks referential integrity. |
55 | e4f08c46 | Iustin Pop | debug :: Show a => a -> a |
56 | e4f08c46 | Iustin Pop | debug x = trace (show x) x |
57 | e4f08c46 | Iustin Pop | |
58 | 9188aeef | Iustin Pop | -- * Miscelaneous |
59 | 1b7cf8ca | Iustin Pop | |
60 | e4f08c46 | Iustin Pop | -- | Comma-join a string list. |
61 | e4f08c46 | Iustin Pop | commaJoin :: [String] -> String |
62 | e4f08c46 | Iustin Pop | commaJoin = intercalate "," |
63 | e4f08c46 | Iustin Pop | |
64 | e4f08c46 | Iustin Pop | -- | Split a string on a separator and return an array. |
65 | e4f08c46 | Iustin Pop | sepSplit :: Char -> String -> [String] |
66 | e4f08c46 | Iustin Pop | sepSplit sep s |
67 | e4f08c46 | Iustin Pop | | x == "" && xs == [] = [] |
68 | e4f08c46 | Iustin Pop | | xs == [] = [x] |
69 | 9f6dcdea | Iustin Pop | | ys == [] = [x,""] |
70 | 9f6dcdea | Iustin Pop | | otherwise = x:sepSplit sep ys |
71 | e4f08c46 | Iustin Pop | where (x, xs) = break (== sep) s |
72 | e4f08c46 | Iustin Pop | ys = drop 1 xs |
73 | e4f08c46 | Iustin Pop | |
74 | a80bf544 | Iustin Pop | -- | Simple version of 'fst' for a triple |
75 | a80bf544 | Iustin Pop | fst3 :: (a, b, c) -> a |
76 | a80bf544 | Iustin Pop | fst3 (a, _, _) = a |
77 | a80bf544 | Iustin Pop | |
78 | 9188aeef | Iustin Pop | -- * Mathematical functions |
79 | 9188aeef | Iustin Pop | |
80 | 185297fa | Iustin Pop | -- Simple and slow statistical functions, please replace with better |
81 | 185297fa | Iustin Pop | -- versions |
82 | e4f08c46 | Iustin Pop | |
83 | 185297fa | Iustin Pop | -- | The covariance of the list |
84 | e27eb8ab | Iustin Pop | varianceCoeff :: [Double] -> Double |
85 | 185297fa | Iustin Pop | varianceCoeff lst = |
86 | 185297fa | Iustin Pop | let ll = fromIntegral (length lst)::Double -- length of list |
87 | 185297fa | Iustin Pop | mv = sum lst / ll -- mean value |
88 | 185297fa | Iustin Pop | av = foldl' (\accu em -> let d = em - mv in accu + d * d) 0.0 lst |
89 | 185297fa | Iustin Pop | bv = sqrt (av / ll) -- stddev |
90 | 185297fa | Iustin Pop | cv = bv / ll -- covariance |
91 | 185297fa | Iustin Pop | in cv |
92 | dd4c56ed | Iustin Pop | |
93 | 9188aeef | Iustin Pop | -- * JSON-related functions |
94 | 9188aeef | Iustin Pop | |
95 | 9188aeef | Iustin Pop | -- | Converts a JSON Result into a monadic value. |
96 | 9188aeef | Iustin Pop | fromJResult :: Monad m => J.Result a -> m a |
97 | 9188aeef | Iustin Pop | fromJResult (J.Error x) = fail x |
98 | 9188aeef | Iustin Pop | fromJResult (J.Ok x) = return x |
99 | 9188aeef | Iustin Pop | |
100 | 9188aeef | Iustin Pop | -- | Tries to read a string from a JSON value. |
101 | 9188aeef | Iustin Pop | -- |
102 | 9188aeef | Iustin Pop | -- In case the value was not a string, we fail the read (in the |
103 | 9188aeef | Iustin Pop | -- context of the current monad. |
104 | 5aa48dbe | Iustin Pop | readEitherString :: (Monad m) => J.JSValue -> m String |
105 | 9ba5c28f | Iustin Pop | readEitherString v = |
106 | 9ba5c28f | Iustin Pop | case v of |
107 | 5aa48dbe | Iustin Pop | J.JSString s -> return $ J.fromJSString s |
108 | 5aa48dbe | Iustin Pop | _ -> fail "Wrong JSON type" |
109 | 9ba5c28f | Iustin Pop | |
110 | 9188aeef | Iustin Pop | -- | Converts a JSON message into an array of JSON objects. |
111 | 5aa48dbe | Iustin Pop | loadJSArray :: (Monad m) => String -> m [J.JSObject J.JSValue] |
112 | 9f6dcdea | Iustin Pop | loadJSArray = fromJResult . J.decodeStrict |
113 | 9ba5c28f | Iustin Pop | |
114 | 9188aeef | Iustin Pop | -- | Reads a the value of a key in a JSON object. |
115 | 262f3e6c | Iustin Pop | fromObj :: (J.JSON a, Monad m) => String -> [(String, J.JSValue)] -> m a |
116 | 9ba5c28f | Iustin Pop | fromObj k o = |
117 | 262f3e6c | Iustin Pop | case lookup k o of |
118 | 585d4420 | Iustin Pop | Nothing -> fail $ printf "key '%s' not found in %s" k (show o) |
119 | 942403e6 | Iustin Pop | Just val -> fromJResult $ J.readJSON val |
120 | 9ba5c28f | Iustin Pop | |
121 | 117dc2d8 | Iustin Pop | -- | Annotate a Result with an ownership information |
122 | 117dc2d8 | Iustin Pop | annotateResult :: String -> Result a -> Result a |
123 | 117dc2d8 | Iustin Pop | annotateResult owner (Bad s) = Bad $ owner ++ ": " ++ s |
124 | 117dc2d8 | Iustin Pop | annotateResult _ v = v |
125 | 117dc2d8 | Iustin Pop | |
126 | 117dc2d8 | Iustin Pop | -- | Try to extract a key from a object with better error reporting |
127 | 117dc2d8 | Iustin Pop | -- than fromObj |
128 | 117dc2d8 | Iustin Pop | tryFromObj :: (J.JSON a) => |
129 | 117dc2d8 | Iustin Pop | String -> [(String, J.JSValue)] -> String -> Result a |
130 | 117dc2d8 | Iustin Pop | tryFromObj t o k = annotateResult (t ++ " key '" ++ k ++ "'") (fromObj k o) |
131 | 117dc2d8 | Iustin Pop | |
132 | 117dc2d8 | Iustin Pop | -- | Small wrapper over readJSON. |
133 | 117dc2d8 | Iustin Pop | fromJVal :: (Monad m, J.JSON a) => J.JSValue -> m a |
134 | 117dc2d8 | Iustin Pop | fromJVal v = |
135 | 117dc2d8 | Iustin Pop | case J.readJSON v of |
136 | 117dc2d8 | Iustin Pop | J.Error s -> fail ("Cannot convert value " ++ show v ++ ", error: " ++ s) |
137 | 117dc2d8 | Iustin Pop | J.Ok x -> return x |
138 | 117dc2d8 | Iustin Pop | |
139 | 9188aeef | Iustin Pop | -- | Converts a JSON value into a JSON object. |
140 | 5aa48dbe | Iustin Pop | asJSObject :: (Monad m) => J.JSValue -> m (J.JSObject J.JSValue) |
141 | 5aa48dbe | Iustin Pop | asJSObject (J.JSObject a) = return a |
142 | 5aa48dbe | Iustin Pop | asJSObject _ = fail "not an object" |
143 | 942403e6 | Iustin Pop | |
144 | 9188aeef | Iustin Pop | -- | Coneverts a list of JSON values into a list of JSON objects. |
145 | 5aa48dbe | Iustin Pop | asObjectList :: (Monad m) => [J.JSValue] -> m [J.JSObject J.JSValue] |
146 | 9f6dcdea | Iustin Pop | asObjectList = mapM asJSObject |
147 | 5b763470 | Iustin Pop | |
148 | 5b763470 | Iustin Pop | -- * Parsing utility functions |
149 | 5b763470 | Iustin Pop | |
150 | 5b763470 | Iustin Pop | -- | Parse results from readsPrec |
151 | 5b763470 | Iustin Pop | parseChoices :: (Monad m, Read a) => String -> String -> [(a, String)] -> m a |
152 | 5b763470 | Iustin Pop | parseChoices _ _ ((v, ""):[]) = return v |
153 | 5b763470 | Iustin Pop | parseChoices name s ((_, e):[]) = |
154 | 5b763470 | Iustin Pop | fail $ name ++ ": leftover characters when parsing '" |
155 | 5b763470 | Iustin Pop | ++ s ++ "': '" ++ e ++ "'" |
156 | 5b763470 | Iustin Pop | parseChoices name s _ = fail $ name ++ ": cannot parse string '" ++ s ++ "'" |
157 | 5b763470 | Iustin Pop | |
158 | 5b763470 | Iustin Pop | -- | Safe 'read' function returning data encapsulated in a Result. |
159 | 5b763470 | Iustin Pop | tryRead :: (Monad m, Read a) => String -> String -> m a |
160 | 5b763470 | Iustin Pop | tryRead name s = parseChoices name s $ reads s |
161 | c5f7412e | Iustin Pop | |
162 | c5f7412e | Iustin Pop | -- | Format a table of strings to maintain consistent length |
163 | c5f7412e | Iustin Pop | formatTable :: [[String]] -> [Bool] -> [[String]] |
164 | c5f7412e | Iustin Pop | formatTable vals numpos = |
165 | c5f7412e | Iustin Pop | let vtrans = transpose vals -- transpose, so that we work on rows |
166 | c5f7412e | Iustin Pop | -- rather than columns |
167 | c5f7412e | Iustin Pop | mlens = map (maximum . map length) vtrans |
168 | c5f7412e | Iustin Pop | expnd = map (\(flds, isnum, ml) -> |
169 | c5f7412e | Iustin Pop | map (\val -> |
170 | c5f7412e | Iustin Pop | let delta = ml - length val |
171 | c5f7412e | Iustin Pop | filler = replicate delta ' ' |
172 | c5f7412e | Iustin Pop | in if delta > 0 |
173 | c5f7412e | Iustin Pop | then if isnum |
174 | c5f7412e | Iustin Pop | then filler ++ val |
175 | c5f7412e | Iustin Pop | else val ++ filler |
176 | c5f7412e | Iustin Pop | else val |
177 | c5f7412e | Iustin Pop | ) flds |
178 | c5f7412e | Iustin Pop | ) (zip3 vtrans numpos mlens) |
179 | c5f7412e | Iustin Pop | in transpose expnd |