utilize all processors

2 files changed, 11 insertions, 1 deletions

diff --git a/app/History.hs b/app/History.hs
index 1604760..b1ccd10 100644
--- a/app/History.hs
+++ b/app/History.hs
@@ -15,6 +15,7 @@ import Data.Text (Text, lines, unpack)
 import Data.Text.Encoding (decodeUtf8)
 import Issue (Issue (..), fromMatch, id)
 import Issue.Filter (Filter, applyFilter)
+import Parallel (parMapM)
 import Process (quote, sh, sh_)
 import System.Directory (createDirectoryIfMissing, doesFileExist, getCurrentDirectory)
 import System.Exit (ExitCode (ExitFailure), exitWith)
@@ -44,7 +45,7 @@ instance Exception InvalidTreeGrepperResult
 listIssues :: [Filter] -> [FilePath] -> IO [Issue]
 listIssues filters files = do
   commits <- fmap (lines . decodeUtf8 . L8.toStrict) $ sh ("git log --format=%H")
-  issueses <- mapM (\commit -> cached commit (\_ -> listIssuesOf commit filters files)) commits
+  issueses <- parMapM (\commit -> cached commit (\_ -> listIssuesOf commit filters files)) commits
   (currentIssues, historicalIssues) <-
     case issueses of
       currentIssues : historicalIssueses ->
diff --git a/app/Parallel.hs b/app/Parallel.hs
new file mode 100644
index 0000000..0b57545
--- /dev/null
+++ b/app/Parallel.hs
@@ -0,0 +1,9 @@
+module Parallel (parMapM) where
+
+import Control.Concurrent.ParallelIO.Local (parallel, withPool)
+import GHC.Conc (getNumProcessors)
+
+parMapM :: (a -> IO b) -> [a] -> IO [b]
+parMapM f xs = do
+  n <- getNumProcessors
+  withPool n $ \pool -> parallel pool (map f xs)