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authorTomas Janousek <tomi@nomi.cz>2019-10-28 22:59:31 +0100
committerTomas Janousek <tomi@nomi.cz>2019-10-28 23:22:04 +0100
commit74df93eaa2da360af6593fe473698d211370de15 (patch)
tree0d7767126520849c66fa3e4a9872614458e91ead /src/Xmobar/Plugins/Monitors
parent8c296301d4b9483a0501939def0449185842699a (diff)
downloadxmobar-74df93eaa2da360af6593fe473698d211370de15.tar.gz
xmobar-74df93eaa2da360af6593fe473698d211370de15.tar.bz2
Optimize Net a bit (noticeably less CPU/power usage)
- use strict ByteString as the Lazy version of readFile allocates a 32k buffer even though we usually need much less (isUp needs a few bytes) - refactor NetDev datatype and use unsafeInterleaveIO in isUp to avoid reading the operstate file entirely if we're not interested in that device - postpone ByteString unpacking in netParser to shave off some cycles, and avoid ByteString unpacking in isUp entirely On my system with 8 network devices (and more if docker is up), this seems to reduce xmobar's CPU usage noticeably. I have two "Run Network" in xmobar configuration, for eth and wlan, so without these changes, xmobar would evaluate isUp 16 times a second, and each evaluation would allocate a buffer for the IO Handle and then another buffer for the lazy ByteString readFile. Now it only does isUp once for every device I'm interested in, and the only large buffers allocated are the IO Handle ones (getting rid of these isn't worth the code complexity).
Diffstat (limited to 'src/Xmobar/Plugins/Monitors')
-rw-r--r--src/Xmobar/Plugins/Monitors/Net.hs63
1 files changed, 29 insertions, 34 deletions
diff --git a/src/Xmobar/Plugins/Monitors/Net.hs b/src/Xmobar/Plugins/Monitors/Net.hs
index 1e8fb72..6acec62 100644
--- a/src/Xmobar/Plugins/Monitors/Net.hs
+++ b/src/Xmobar/Plugins/Monitors/Net.hs
@@ -13,6 +13,8 @@
--
-----------------------------------------------------------------------------
+{-# LANGUAGE OverloadedStrings #-}
+
module Xmobar.Plugins.Monitors.Net (
startNet
, startDynNet
@@ -20,16 +22,18 @@ module Xmobar.Plugins.Monitors.Net (
import Xmobar.Plugins.Monitors.Common
-import Data.Word (Word64)
import Data.IORef (IORef, newIORef, readIORef, writeIORef)
+import Data.Monoid ((<>))
import Data.Time.Clock (UTCTime, getCurrentTime, diffUTCTime)
+import Data.Word (Word64)
import Control.Monad (forM, filterM)
import System.Directory (getDirectoryContents, doesFileExist)
import System.FilePath ((</>))
import System.Console.GetOpt
import System.IO.Error (catchIOError)
+import System.IO.Unsafe (unsafeInterleaveIO)
-import qualified Data.ByteString.Lazy.Char8 as B
+import qualified Data.ByteString.Char8 as B
type DevList = [String]
@@ -79,10 +83,8 @@ instance Show UnitPerSec where
show MBs = "MB/s"
show GBs = "GB/s"
-data NetDev num
- = NA
- | NI String
- | ND String num num deriving (Eq,Show,Read)
+data NetDev num = N String (NetDevInfo num) | NA deriving (Eq,Show,Read)
+data NetDevInfo num = NI | ND num num deriving (Eq,Show,Read)
type NetDevRawTotal = NetDev Word64
type NetDevRate = NetDev Float
@@ -93,17 +95,16 @@ type NetDevRef = IORef (NetDevRawTotal, UTCTime)
-- Note that names don't matter. Therefore, if only the names differ,
-- a compare evaluates to EQ while (==) evaluates to False.
instance Ord num => Ord (NetDev num) where
- compare NA NA = EQ
- compare NA _ = LT
- compare _ NA = GT
- compare (NI _) (NI _) = EQ
- compare (NI _) ND {} = LT
- compare ND {} (NI _) = GT
- compare (ND _ x1 y1) (ND _ x2 y2) =
- if downcmp /= EQ
- then downcmp
- else y1 `compare` y2
- where downcmp = x1 `compare` x2
+ compare NA NA = EQ
+ compare NA _ = LT
+ compare _ NA = GT
+ compare (N _ i1) (N _ i2) = i1 `compare` i2
+
+instance Ord num => Ord (NetDevInfo num) where
+ compare NI NI = EQ
+ compare NI ND {} = LT
+ compare ND {} NI = GT
+ compare (ND x1 y1) (ND x2 y2) = x1 `compare` x2 <> y1 `compare` y2
netConfig :: IO MConfig
netConfig = mkMConfig
@@ -122,25 +123,20 @@ existingDevs = getDirectoryContents "/sys/class/net" >>= filterM isDev
isUp :: String -> IO Bool
isUp d = flip catchIOError (const $ return False) $ do
operstate <- B.readFile (operstateDir d)
- return $! (B.unpack . head . B.lines) operstate `elem` ["up", "unknown"]
+ return $! (head . B.lines) operstate `elem` ["up", "unknown"]
readNetDev :: [String] -> IO NetDevRawTotal
-readNetDev (d:x:y:_) = do
- up <- isUp d
- return (if up then ND d (r x) (r y) else NI d)
+readNetDev ~[d, x, y] = do
+ up <- unsafeInterleaveIO $ isUp d
+ return $ N d (if up then ND (r x) (r y) else NI)
where r s | s == "" = 0
| otherwise = read s
-readNetDev _ = return NA
-
netParser :: B.ByteString -> IO [NetDevRawTotal]
netParser = mapM (readNetDev . splitDevLine) . readDevLines
where readDevLines = drop 2 . B.lines
- splitDevLine = selectCols . wordsBy (`elem` " :") . B.unpack
+ splitDevLine = map B.unpack . selectCols . filter (not . B.null) . B.splitWith (`elem` [' ',':'])
selectCols cols = map (cols!!) [0,1,9]
- wordsBy f s = case dropWhile f s of
- [] -> []
- s' -> w : wordsBy f s'' where (w, s'') = break f s'
findNetDev :: String -> IO NetDevRawTotal
findNetDev dev = do
@@ -148,8 +144,7 @@ findNetDev dev = do
case filter isDev nds of
x:_ -> return x
_ -> return NA
- where isDev (ND d _ _) = d == dev
- isDev (NI d) = d == dev
+ where isDev (N d _) = d == dev
isDev NA = False
formatNet :: Maybe IconPattern -> Float -> Monitor (String, String, String, String)
@@ -168,11 +163,11 @@ formatNet mipat d = do
printNet :: NetOpts -> NetDevRate -> Monitor String
printNet opts nd =
case nd of
- ND d r t -> do
+ N d (ND r t) -> do
(rx, rb, rvb, ripat) <- formatNet (rxIconPattern opts) r
(tx, tb, tvb, tipat) <- formatNet (txIconPattern opts) t
parseTemplate [d,rx,tx,rb,rvb,ripat,tb,tvb,tipat]
- NI _ -> return ""
+ N _ NI -> return ""
NA -> getConfigValue naString
parseNet :: NetDevRef -> String -> IO NetDevRate
@@ -184,9 +179,9 @@ parseNet nref nd = do
let scx = realToFrac (diffUTCTime t1 t0)
scx' = if scx > 0 then scx else 1
rate da db = takeDigits 2 $ fromIntegral (db - da) / scx'
- diffRate (ND d ra ta) (ND _ rb tb) = ND d (rate ra rb) (rate ta tb)
- diffRate (NI d) _ = NI d
- diffRate _ (NI d) = NI d
+ diffRate (N d (ND ra ta)) (N _ (ND rb tb)) = N d (ND (rate ra rb) (rate ta tb))
+ diffRate (N d NI) _ = N d NI
+ diffRate _ (N d NI) = N d NI
diffRate _ _ = NA
return $ diffRate n0 n1