4 files changed, 134 insertions, 15 deletions
diff --git a/src/Xmobar/Plugins/Monitors/Load.hs b/src/Xmobar/Plugins/Monitors/Load.hs
index bc0af09..270c049 100644
--- a/src/Xmobar/Plugins/Monitors/Load.hs
+++ b/src/Xmobar/Plugins/Monitors/Load.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE CPP #-}
+
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Plugins.Monitors.Load
@@ -17,28 +19,28 @@
 module Xmobar.Plugins.Monitors.Load (loadConfig, runLoad) where
 
 import Xmobar.Plugins.Monitors.Common
-import qualified Data.ByteString.Lazy.Char8 as B
-import System.Posix.Files (fileExist)
+import Xmobar.Plugins.Monitors.Load.Common (Result(..))
+
+#if defined(freebsd_HOST_OS)
+import qualified Xmobar.Plugins.Monitors.Load.FreeBSD as ML
+#else
+import qualified Xmobar.Plugins.Monitors.Load.Linux as ML
+#endif
+
 
 -- | Default configuration.
 loadConfig :: IO MConfig
 loadConfig = mkMConfig "Load: <load1>" ["load1", "load5", "load15"]
 
--- | Parses the contents of a loadavg proc file, returning
--- the list of load averages
-parseLoadAvgs :: B.ByteString -> [Float]
-parseLoadAvgs =
-  map (read . B.unpack) . take 3 . B.words . head . B.lines
 
 -- | Retrieves load information.  Returns the monitor string parsed
 -- according to template (either default or user specified).
 runLoad :: [String] -> Monitor String
 runLoad _ = do
-  let file = "/proc/loadavg"
-  exists <- io $ fileExist file
-  if exists then
-      (do l <- io $ B.readFile file >>= return . parseLoadAvgs
-          d <- getConfigValue decDigits
-          parseTemplate =<< mapM (showWithColors (showDigits d)) l)
-    else
-      getConfigValue naString
+  result <- io ML.fetchLoads
+  case result of
+    Result loads ->
+      do
+        d <- getConfigValue decDigits
+        parseTemplate =<< mapM (showWithColors (showDigits d)) loads
+    NA -> getConfigValue naString
diff --git a/src/Xmobar/Plugins/Monitors/Load/Common.hs b/src/Xmobar/Plugins/Monitors/Load/Common.hs
new file mode 100644
index 0000000..578944c
--- /dev/null
+++ b/src/Xmobar/Plugins/Monitors/Load/Common.hs
@@ -0,0 +1,21 @@
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  Plugins.Monitors.Load.Common
+-- Copyright   :  Finn Lawler
+-- License     :  BSD-style (see LICENSE)
+--
+-- Author      :  Finn Lawler <flawler@cs.tcd.ie>
+-- Maintainer  :  jao <mail@jao.io>
+-- Stability   :  unstable
+-- Portability :  unportable
+--
+-- A load average monitor for Xmobar.  Adapted from
+-- Xmobar.Plugins.Monitors.Thermal by Juraj Hercek.
+--
+-----------------------------------------------------------------------------
+
+module Xmobar.Plugins.Monitors.Load.Common (
+  Result(..)
+  ) where
+
+data Result = Result [Float] | NA
diff --git a/src/Xmobar/Plugins/Monitors/Load/FreeBSD.hsc b/src/Xmobar/Plugins/Monitors/Load/FreeBSD.hsc
new file mode 100644
index 0000000..bde7e91
--- /dev/null
+++ b/src/Xmobar/Plugins/Monitors/Load/FreeBSD.hsc
@@ -0,0 +1,58 @@
+{-# LANGUAGE ForeignFunctionInterface #-}
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE CApiFFI #-}
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  Plugins.Monitors.Load.FreeBSD
+-- Copyright   :  Finn Lawler
+-- License     :  BSD-style (see LICENSE)
+--
+-- Author      :  Finn Lawler <flawler@cs.tcd.ie>
+-- Maintainer  :  jao <mail@jao.io>
+-- Stability   :  unstable
+-- Portability :  unportable
+--
+-- A load average monitor for Xmobar.  Adapted from
+-- Xmobar.Plugins.Monitors.Thermal by Juraj Hercek.
+--
+-----------------------------------------------------------------------------
+
+module Xmobar.Plugins.Monitors.Load.FreeBSD (fetchLoads) where
+
+import Xmobar.Plugins.Monitors.Load.Common (Result(..))
+import Foreign.C.Types (CUInt, CUIntMax)
+import Foreign.Marshal.Array (peekArray)
+import Foreign.Ptr (plusPtr)
+import Foreign.Storable (Storable, alignment, peek, peekByteOff, poke, sizeOf)
+import System.BSD.Sysctl (sysctlPeek)
+
+#include <sys/resource.h>
+
+
+data LoadAvg = LoadAvg {loads :: [Float]}
+
+
+calcLoad :: CUInt -> CUIntMax -> Float
+calcLoad l s = ((fromIntegral . toInteger) l) / ((fromIntegral . toInteger) s)
+
+
+instance Storable LoadAvg where
+  alignment _ = #{alignment struct loadavg}
+  sizeOf _    = #{size struct loadavg}
+  peek ptr    = do
+    load_values <- peekArray 3 $ #{ptr struct loadavg, ldavg} ptr  :: IO [CUInt]
+    scale <- #{peek struct loadavg, fscale} ptr :: IO CUIntMax
+    let
+      l1 = calcLoad (load_values !! 0) scale
+      l5 = calcLoad (load_values !! 1) scale
+      l15 = calcLoad (load_values !! 2) scale
+
+    return $ LoadAvg{loads = [l1, l5, l15]}
+
+  poke _ _    = pure ()
+
+
+fetchLoads :: IO Result
+fetchLoads = do
+  res <- sysctlPeek "vm.loadavg" :: IO LoadAvg
+  return $ Result (loads res)
diff --git a/src/Xmobar/Plugins/Monitors/Load/Linux.hs b/src/Xmobar/Plugins/Monitors/Load/Linux.hs
new file mode 100644
index 0000000..9ba5a5c
--- /dev/null
+++ b/src/Xmobar/Plugins/Monitors/Load/Linux.hs
@@ -0,0 +1,38 @@
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  Plugins.Monitors.Load.Linux
+-- Copyright   :  Finn Lawler
+-- License     :  BSD-style (see LICENSE)
+--
+-- Author      :  Finn Lawler <flawler@cs.tcd.ie>
+-- Maintainer  :  jao <mail@jao.io>
+-- Stability   :  unstable
+-- Portability :  unportable
+--
+-- A load average monitor for Xmobar.  Adapted from
+-- Xmobar.Plugins.Monitors.Thermal by Juraj Hercek.
+--
+-----------------------------------------------------------------------------
+
+module Xmobar.Plugins.Monitors.Load.Linux (fetchLoads) where
+
+import Xmobar.Plugins.Monitors.Load.Common (Result(..))
+import qualified Data.ByteString.Lazy.Char8 as B
+import System.Posix.Files (fileExist)
+
+-- | Parses the contents of a loadavg proc file, returning
+-- the list of load averages
+parseLoadAvgs :: B.ByteString -> [Float]
+parseLoadAvgs =
+  map (read . B.unpack) . take 3 . B.words . head . B.lines
+
+fetchLoads :: IO Result
+fetchLoads = do
+  let file = "/proc/loadavg"
+
+  exists <- fileExist file
+  if exists then
+    (do contents <- B.readFile file
+        return $ Result (parseLoadAvgs contents))
+    else
+      return NA