Introduce LoadParser and Types for a new Collector

Introduce the Parser and Types for a new Data Collector.
Signed-off-by: Spyros Trigazis <strigazi@gmail.com>
Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Michele Tartara <mtartara@google.com>

Makefile.am

@@ -68,6 +68,7 @@ HS_DIRS = \
 	src/Ganeti \
 	src/Ganeti/Confd \
 	src/Ganeti/Curl \
+	src/Ganeti/Cpu \
 	src/Ganeti/DataCollectors \
 	src/Ganeti/HTools \
 	src/Ganeti/HTools/Backend \
@@ -556,6 +557,8 @@ HS_LIB_SRCS = \
 	src/Ganeti/Confd/Utils.hs \
 	src/Ganeti/Config.hs \
 	src/Ganeti/ConfigReader.hs \
+	src/Ganeti/Cpu/LoadParser.hs \
+	src/Ganeti/Cpu/Types.hs \
 	src/Ganeti/Curl/Multi.hs \
 	src/Ganeti/Daemon.hs \
 	src/Ganeti/DataCollectors/CLI.hs \

src/Ganeti/Cpu/LoadParser.hs

+{-# LANGUAGE OverloadedStrings #-}
+{-| /proc/stat file parser
+
+This module holds the definition of the parser that extracts information
+about the CPU load of the system from the @/proc/stat@ file.
+
+-}
+{-
+
+Copyright (C) 2013 Google Inc.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301, USA.
+
+-}
+module Ganeti.Cpu.LoadParser (cpustatParser) where
+
+import Control.Applicative ((<*>), (<*), (*>), (<$>), (<|>))
+import qualified Data.Attoparsec.Text as A
+import qualified Data.Attoparsec.Combinator as AC
+import Data.Attoparsec.Text (Parser)
+
+import Ganeti.Parsers
+import Ganeti.Cpu.Types
+
+-- * Parser implementation
+
+-- | The parser for one line of the CPU status file.
+oneCPUstatParser :: Parser CPUstat
+oneCPUstatParser =
+  let nameP = stringP
+      userP = numberP
+      niceP = numberP
+      systemP = numberP
+      idleP = numberP
+      iowaitP = numberP
+      irqP = numberP
+      softirqP = numberP
+      stealP = numberP
+      guestP = numberP
+      guest_niceP = numberP
+  in
+    CPUstat <$> nameP <*> userP <*> niceP <*> systemP <*> idleP <*> iowaitP
+            <*> irqP <*> softirqP <*> stealP <*> guestP <*> guest_niceP
+            <* A.endOfLine
+
+-- | When this is satisfied all the lines containing information about
+-- the CPU load are parsed.
+intrFound :: Parser ()
+intrFound = (A.string "intr" *> return ())
+             <|> (A.string "page" *> return ())
+             <|> (A.string "swap" *> return ())
+
+-- | The parser for the fragment of CPU status file containing
+-- information about the CPU load.
+cpustatParser :: Parser [CPUstat]
+cpustatParser = oneCPUstatParser `AC.manyTill` intrFound

src/Ganeti/Cpu/Types.hs

+{-# LANGUAGE TemplateHaskell #-}
+{-| CPUload data types
+
+This module holds the definition of the data types describing the CPU
+load according to information collected periodically from @/proc/stat@.
+
+-}
+{-
+
+Copyright (C) 2013 Google Inc.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301, USA.
+
+-}
+module Ganeti.Cpu.Types
+  ( CPUstat(..)
+  ) where
+
+import Ganeti.THH
+
+-- | This is the format of the data parsed by the input file.
+$(buildObject "CPUstat" "cs"
+  [ simpleField "name"       [t| String |]
+  , simpleField "user"       [t| Int |]
+  , simpleField "nice"       [t| Int |]
+  , simpleField "system"     [t| Int |]
+  , simpleField "idle"       [t| Int |]
+  , simpleField "iowait"     [t| Int |]
+  , simpleField "irq"        [t| Int |]
+  , simpleField "softirq"    [t| Int |]
+  , simpleField "steal"      [t| Int |]
+  , simpleField "guest"      [t| Int |]
+  , simpleField "guest_nice" [t| Int |]
+  ])