root / src / Ganeti / Cpu / LoadParser.hs @ e817723c
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{-# LANGUAGE OverloadedStrings #-} |
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{-| /proc/stat file parser |
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This module holds the definition of the parser that extracts information |
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about the CPU load of the system from the @/proc/stat@ file. |
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-} |
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{- |
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Copyright (C) 2013 Google Inc. |
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This program is free software; you can redistribute it and/or modify |
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it under the terms of the GNU General Public License as published by |
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the Free Software Foundation; either version 2 of the License, or |
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(at your option) any later version. |
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|
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This program is distributed in the hope that it will be useful, but |
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WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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General Public License for more details. |
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|
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You should have received a copy of the GNU General Public License |
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along with this program; if not, write to the Free Software |
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
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02110-1301, USA. |
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|
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-} |
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module Ganeti.Cpu.LoadParser (cpustatParser) where |
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import Control.Applicative ((<*>), (<*), (*>), (<$>), (<|>)) |
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import qualified Data.Attoparsec.Text as A |
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import qualified Data.Attoparsec.Combinator as AC |
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import Data.Attoparsec.Text (Parser) |
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import Ganeti.Parsers |
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import Ganeti.Cpu.Types |
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-- * Parser implementation |
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-- | The parser for one line of the CPU status file. |
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oneCPUstatParser :: Parser CPUstat |
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oneCPUstatParser = |
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let nameP = stringP |
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userP = numberP |
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niceP = numberP |
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systemP = numberP |
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idleP = numberP |
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iowaitP = numberP |
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irqP = numberP |
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softirqP = numberP |
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stealP = numberP |
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guestP = numberP |
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guest_niceP = numberP |
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in |
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CPUstat <$> nameP <*> userP <*> niceP <*> systemP <*> idleP <*> iowaitP |
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<*> irqP <*> softirqP <*> stealP <*> guestP <*> guest_niceP |
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<* A.endOfLine |
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-- | When this is satisfied all the lines containing information about |
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-- the CPU load are parsed. |
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intrFound :: Parser () |
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intrFound = (A.string "intr" *> return ()) |
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<|> (A.string "page" *> return ()) |
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<|> (A.string "swap" *> return ()) |
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-- | The parser for the fragment of CPU status file containing |
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-- information about the CPU load. |
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cpustatParser :: Parser [CPUstat] |
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cpustatParser = oneCPUstatParser `AC.manyTill` intrFound |