From 9ba5c28f70085d8cd2c853156857881802e69c0f Mon Sep 17 00:00:00 2001
From: Iustin Pop <iustin@google.com>
Date: Mon, 18 May 2009 10:24:24 +0200
Subject: [PATCH] Move the JSON utilities to Utils.hs
This patch moves the generic/reusable JSON functions to Utils.hs, so
that they're shared between RAPI/IAlloc.
---
Ganeti/HTools/IAlloc.hs | 83 ---------------------------
Ganeti/HTools/Rapi.hs | 120 ++++++++--------------------------------
Ganeti/HTools/Utils.hs | 98 ++++++++++++++++++++++++++++++++
3 files changed, 121 insertions(+), 180 deletions(-)
diff --git a/Ganeti/HTools/IAlloc.hs b/Ganeti/HTools/IAlloc.hs
index 483d6c994..b30b985e5 100644
--- a/Ganeti/HTools/IAlloc.hs
+++ b/Ganeti/HTools/IAlloc.hs
@@ -16,89 +16,6 @@ import Text.Printf (printf)
import Ganeti.HTools.Utils ()
--- Some constants
-
-{-- Our cheap monad-like stuff.
-
-Thi is needed since Either e a is already a monad instance somewhere
-in the standard libraries (Control.Monad.Error) and we don't need that
-entire thing.
-
--}
-combine :: (Either String a) -> (a -> Either String b) -> (Either String b)
-combine (Left s) _ = Left s
-combine (Right s) f = f s
-
-ensureList :: [Either String a] -> Either String [a]
-ensureList lst =
- foldr (\elem accu ->
- case (elem, accu) of
- (Left x, _) -> Left x
- (_, Left x) -> Left x -- should never happen
- (Right e, Right a) -> Right (e:a)
- )
- (Right []) lst
-
-listHead :: Either String [a] -> Either String a
-listHead lst =
- case lst of
- Left x -> Left x
- Right (x:_) -> Right x
- Right [] -> Left "List empty"
-
-loadJSArray :: String -> Either String [JSObject JSValue]
-loadJSArray s = resultToEither $ decodeStrict s
-
-fromObj :: JSON a => String -> JSObject JSValue -> Either String a
-fromObj k o =
- case lookup k (fromJSObject o) of
- Nothing -> Left $ printf "key '%s' not found" k
- Just val -> resultToEither $ readJSON val
-
-getStringElement :: String -> JSObject JSValue -> Either String String
-getStringElement = fromObj
-
-getIntElement :: String -> JSObject JSValue -> Either String Int
-getIntElement = fromObj
-
-getListElement :: String -> JSObject JSValue
- -> Either String [JSValue]
-getListElement = fromObj
-
-readString :: JSValue -> Either String String
-readString v =
- case v of
- JSString s -> Right $ fromJSString s
- _ -> Left "Wrong JSON type"
-
-concatElems :: Either String String
- -> Either String String
- -> Either String String
-concatElems = apply2 (\x y -> x ++ "|" ++ y)
-
-apply1 :: (a -> b) -> Either String a -> Either String b
-apply1 fn a =
- case a of
- Left x -> Left x
- Right y -> Right $ fn y
-
-apply2 :: (a -> b -> c)
- -> Either String a
- -> Either String b
- -> Either String c
-apply2 fn a b =
- case (a, b) of
- (Right x, Right y) -> Right $ fn x y
- (Left x, _) -> Left x
- (_, Left y) -> Left y
-
-parseList :: (JSObject JSValue -> Either String String)
- -> [JSObject JSValue]
- ->Either String String
-parseList fn idata =
- let ml = ensureList $ map fn idata
- in ml `combine` (Right . unlines)
-
parseInstance :: JSObject JSValue -> Either String String
parseInstance a =
let name = getStringElement "name" a
diff --git a/Ganeti/HTools/Rapi.hs b/Ganeti/HTools/Rapi.hs
index da1a9b562..c6db59340 100644
--- a/Ganeti/HTools/Rapi.hs
+++ b/Ganeti/HTools/Rapi.hs
@@ -16,7 +16,7 @@ import Data.Maybe
import Control.Monad
import Text.JSON
import Text.Printf (printf)
-import Ganeti.HTools.Utils ()
+import Ganeti.HTools.Utils
-- Some constants
@@ -24,80 +24,6 @@ import Ganeti.HTools.Utils ()
-- | The fixed drbd overhead per disk (only used with 1.2's sdx_size)
drbdOverhead = 128
-{-- Our cheap monad-like stuff.
-
-Thi is needed since Either e a is already a monad instance somewhere
-in the standard libraries (Control.Monad.Error) and we don't need that
-entire thing.
-
--}
-combine :: (Either String a) -> (a -> Either String b) -> (Either String b)
-combine (Left s) _ = Left s
-combine (Right s) f = f s
-
-ensureList :: [Either String a] -> Either String [a]
-ensureList lst =
- foldr (\elem accu ->
- case (elem, accu) of
- (Left x, _) -> Left x
- (_, Left x) -> Left x -- should never happen
- (Right e, Right a) -> Right (e:a)
- )
- (Right []) lst
-
-listHead :: Either String [a] -> Either String a
-listHead lst =
- case lst of
- Left x -> Left x
- Right (x:_) -> Right x
- Right [] -> Left "List empty"
-
-loadJSArray :: String -> Either String [JSObject JSValue]
-loadJSArray s = resultToEither $ decodeStrict s
-
-fromObj :: JSON a => String -> JSObject JSValue -> Either String a
-fromObj k o =
- case lookup k (fromJSObject o) of
- Nothing -> Left $ printf "key '%s' not found" k
- Just val -> resultToEither $ readJSON val
-
-getStringElement :: String -> JSObject JSValue -> Either String String
-getStringElement = fromObj
-
-getIntElement :: String -> JSObject JSValue -> Either String Int
-getIntElement = fromObj
-
-getListElement :: String -> JSObject JSValue
- -> Either String [JSValue]
-getListElement = fromObj
-
-readString :: JSValue -> Either String String
-readString v =
- case v of
- JSString s -> Right $ fromJSString s
- _ -> Left "Wrong JSON type"
-
-concatElems :: Either String String
- -> Either String String
- -> Either String String
-concatElems = apply2 (\x y -> x ++ "|" ++ y)
-
-apply1 :: (a -> b) -> Either String a -> Either String b
-apply1 fn a =
- case a of
- Left x -> Left x
- Right y -> Right $ fn y
-
-apply2 :: (a -> b -> c)
- -> Either String a
- -> Either String b
- -> Either String c
-apply2 fn a b =
- case (a, b) of
- (Right x, Right y) -> Right $ fn x y
- (Left x, _) -> Left x
- (_, Left y) -> Left y
-
getUrl :: String -> IO (Either String String)
getUrl url = do
(code, body) <- curlGetString url [CurlSSLVerifyPeer False,
@@ -122,7 +48,9 @@ getInstances master =
url1 = printf "http://%s:5080/instances?bulk=1" master
in do
body <- tryRapi url1 url2
- let inst = body `combine` loadJSArray `combine` (parseList parseInstance)
+ let inst = body `combineEithers`
+ loadJSArray `combineEithers`
+ (parseEitherList parseInstance)
return inst
getNodes :: String -> IO (Either String String)
@@ -132,38 +60,35 @@ getNodes master =
url1 = printf "http://%s:5080/nodes?bulk=1" master
in do
body <- tryRapi url1 url2
- let inst = body `combine` loadJSArray `combine` (parseList parseNode)
+ let inst = body `combineEithers`
+ loadJSArray `combineEithers`
+ (parseEitherList parseNode)
return inst
-parseList :: (JSObject JSValue -> Either String String)
- -> [JSObject JSValue]
- ->Either String String
-parseList fn idata =
- let ml = ensureList $ map fn idata
- in ml `combine` (Right . unlines)
-
parseInstance :: JSObject JSValue -> Either String String
parseInstance a =
let name = getStringElement "name" a
disk = case getIntElement "disk_usage" a of
- Left _ -> let log_sz = apply2 (+)
+ Left _ -> let log_sz = applyEither2 (+)
(getIntElement "sda_size" a)
(getIntElement "sdb_size" a)
- in apply2 (+) log_sz (Right $ drbdOverhead * 2)
+ in applyEither2 (+) log_sz
+ (Right $ drbdOverhead * 2)
Right x -> Right x
bep = fromObj "beparams" a
pnode = getStringElement "pnode" a
- snode = (listHead $ getListElement "snodes" a) `combine` readString
+ snode = (eitherListHead $ getListElement "snodes" a)
+ `combineEithers` readEitherString
mem = case bep of
Left _ -> getIntElement "admin_ram" a
Right o -> getIntElement "memory" o
running = getStringElement "status" a
in
- concatElems name $
- concatElems (show `apply1` mem) $
- concatElems (show `apply1` disk) $
- concatElems running $
- concatElems pnode snode
+ concatEitherElems name $
+ concatEitherElems (show `applyEither1` mem) $
+ concatEitherElems (show `applyEither1` disk) $
+ concatEitherElems running $
+ concatEitherElems pnode snode
parseNode :: JSObject JSValue -> Either String String
parseNode a =
@@ -173,8 +98,9 @@ parseNode a =
mfree = getIntElement "mfree" a
dtotal = getIntElement "dtotal" a
dfree = getIntElement "dfree" a
- in concatElems name $
- concatElems (show `apply1` mtotal) $
- concatElems (show `apply1` mnode) $
- concatElems (show `apply1` mfree) $
- concatElems (show `apply1` dtotal) (show `apply1` dfree)
+ in concatEitherElems name $
+ concatEitherElems (show `applyEither1` mtotal) $
+ concatEitherElems (show `applyEither1` mnode) $
+ concatEitherElems (show `applyEither1` mfree) $
+ concatEitherElems (show `applyEither1` dtotal)
+ (show `applyEither1` dfree)
diff --git a/Ganeti/HTools/Utils.hs b/Ganeti/HTools/Utils.hs
index d1aa97557..cb29e0fef 100644
--- a/Ganeti/HTools/Utils.hs
+++ b/Ganeti/HTools/Utils.hs
@@ -11,6 +11,19 @@ module Ganeti.HTools.Utils
, varianceCoeff
, readData
, commaJoin
+ , combineEithers
+ , ensureEitherList
+ , eitherListHead
+ , readEitherString
+ , parseEitherList
+ , loadJSArray
+ , fromObj
+ , getStringElement
+ , getIntElement
+ , getListElement
+ , concatEitherElems
+ , applyEither1
+ , applyEither2
) where
import Data.Either
@@ -18,6 +31,8 @@ import Data.List
import Monad
import System
import System.IO
+import Text.JSON
+import Text.Printf (printf)
import Debug.Trace
@@ -88,3 +103,86 @@ readData fn host = do
putStrLn $ fromLeft nd
exitWith $ ExitFailure 1
return $ fromRight nd
+
+{-- Our cheap monad-like stuff.
+
+Thi is needed since Either e a is already a monad instance somewhere
+in the standard libraries (Control.Monad.Error) and we don't need that
+entire thing.
+
+-}
+combineEithers :: (Either String a)
+ -> (a -> Either String b)
+ -> (Either String b)
+combineEithers (Left s) _ = Left s
+combineEithers (Right s) f = f s
+
+ensureEitherList :: [Either String a] -> Either String [a]
+ensureEitherList lst =
+ foldr (\elem accu ->
+ case (elem, accu) of
+ (Left x, _) -> Left x
+ (_, Left x) -> Left x -- should never happen
+ (Right e, Right a) -> Right (e:a)
+ )
+ (Right []) lst
+
+eitherListHead :: Either String [a] -> Either String a
+eitherListHead lst =
+ case lst of
+ Left x -> Left x
+ Right (x:_) -> Right x
+ Right [] -> Left "List empty"
+
+readEitherString :: JSValue -> Either String String
+readEitherString v =
+ case v of
+ JSString s -> Right $ fromJSString s
+ _ -> Left "Wrong JSON type"
+
+parseEitherList :: (JSObject JSValue -> Either String String)
+ -> [JSObject JSValue]
+ -> Either String String
+parseEitherList fn idata =
+ let ml = ensureEitherList $ map fn idata
+ in ml `combineEithers` (Right . unlines)
+
+loadJSArray :: String -> Either String [JSObject JSValue]
+loadJSArray s = resultToEither $ decodeStrict s
+
+fromObj :: JSON a => String -> JSObject JSValue -> Either String a
+fromObj k o =
+ case lookup k (fromJSObject o) of
+ Nothing -> Left $ printf "key '%s' not found" k
+ Just val -> resultToEither $ readJSON val
+
+getStringElement :: String -> JSObject JSValue -> Either String String
+getStringElement = fromObj
+
+getIntElement :: String -> JSObject JSValue -> Either String Int
+getIntElement = fromObj
+
+getListElement :: String -> JSObject JSValue
+ -> Either String [JSValue]
+getListElement = fromObj
+
+concatEitherElems :: Either String String
+ -> Either String String
+ -> Either String String
+concatEitherElems = applyEither2 (\x y -> x ++ "|" ++ y)
+
+applyEither1 :: (a -> b) -> Either String a -> Either String b
+applyEither1 fn a =
+ case a of
+ Left x -> Left x
+ Right y -> Right $ fn y
+
+applyEither2 :: (a -> b -> c)
+ -> Either String a
+ -> Either String b
+ -> Either String c
+applyEither2 fn a b =
+ case (a, b) of
+ (Right x, Right y) -> Right $ fn x y
+ (Left x, _) -> Left x
+ (_, Left y) -> Left y
--
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