src/Main.hs: add an explicit export list to silence a GHC warning.

[haeredes.git] / src / Main.hs

diff --git a/src/Main.hs b/src/Main.hs
index a5dc79466067f0dc70fc529169f55d111ae13b96..89d2cd56d1a2aeaca07420d403e2e29da1e7abfe 100644 (file)
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -1,69 +1,81 @@
-module Main
+module Main (main)
 where
 
 import Control.Concurrent.ParallelIO.Global (
-  parallel,
+  parallelInterleaved,
   stopGlobalPool )
 import Control.Monad (unless)
 import qualified Data.ByteString.Char8 as BS (
   getContents,
   pack,
   words )
-import Data.List ((\\))
-import Data.String.Utils (join)
+import Data.List ( (\\), intersperse )
 import Network.DNS (
   Domain,
   FileOrNumericHost(RCHostName),
   ResolvConf(resolvInfo, resolvTimeout),
   defaultResolvConf,
   makeResolvSeed,
+  normalize,
+  normalizeCase,
   withResolver )
-import System.Exit (ExitCode(..), exitWith)
+import System.Exit (ExitCode(ExitFailure), exitWith)
 import System.IO (hPutStrLn, stderr)
 
-
-import CommandLine (Args(..), get_args)
+import CommandLine (
+   Args(NS,MX,delegates,no_append_root,server,timeout),
+   get_args)
 import DNS (
   LookupResult,
   lookupMX',
   lookupNS',
-  normalize,
-  normalize_case,
   resolve_address )
 import ExitCodes (exit_bad_server)
-import Timeout (Timeout(..))
+import Timeout (Timeout(seconds))
 
 
 -- | Given a list of delegates, report results for this
---   LookupResult.
+--   'LookupResult'.
 --
 --   If there's an empty list in the second component, there were no
 --   query results, so we report that the domain was not delegated. If
 --   there were some results and there are leftovers (after removing
 --   the delegates), we report those as well.
 --
+--   Before processing, all names are normalized using the supplied
+--   function @normalize_function@. Ideally this should be the same
+--   function applied to the user-input names.
+--
 report :: [Domain] -- ^ The list of @delgts@
+       -> (Domain -> Domain) -- ^ Domain name normalization function,
+                             --   @normalize_function@.
        -> LookupResult
        -> IO ()
 
 -- If the lookup resulted in a DNS error, we just ignore the whole
 -- thing.
-report _ (_, Left _) = return ()
+report _ _ (_, Left _) = return ()
 
 -- If the lookup succeeded but there were no results, report that the
 -- domain is not delegated.
-report _ (d, Right []) =
+report _ _ (d, Right []) =
   putStrLn $ "Domain " ++ (show d) ++ " not delegated."
 
 -- Otherwise, subtract our delegates from the list of results and
 -- report the leftovers.
-report delgts (d, Right hosts) = do
-  let leftovers = hosts \\ delgts
+report delgts normalize_function (d, Right raw_hosts) = do
+  let nrml_hosts = map normalize_function raw_hosts
+  let leftovers = nrml_hosts \\ delgts
   unless (null leftovers) $
     putStrLn $ "Domain " ++
                (show d) ++
                " delegates somewhere else: " ++
                (join " " (map show leftovers))
+  where
+    -- Create one big string by joining together a list of smaller
+    -- strings and placing a delimiter between them.
+    join :: String -> [String] -> String
+    join delimiter strings = concat (intersperse delimiter strings)
 
 
 main :: IO ()
@@ -81,7 +93,7 @@ main = do
 
   let normalize_function =
         if (no_append_root cfg)
-        then normalize_case
+        then normalizeCase
         else normalize
 
   -- Normalize the given names and delegates
@@ -106,17 +118,25 @@ main = do
 
   -- Set the timeout from the command line. The resolvTimeout field is
   -- in microseconds, so we multiply by one million.
-  let rc = rc' { resolvTimeout = 1000 * 1000 * seconds (timeout cfg) }
+  let a_million = 1000 * 1000 :: Int
+  let rc = rc' { resolvTimeout = a_million * seconds (timeout cfg) }
   rs <- makeResolvSeed rc
 
   let lookup_function = case cfg of
                           NS{} -> lookupNS'
                           MX{} -> lookupMX'
 
-  _ <- withResolver rs $ \resolver -> do
-         -- Bad stuff happens if we try to run these lookups in parallel
-         -- instead of the reports.
-         records <- mapM (lookup_function resolver) nrml_domains
-         parallel (map (report nrml_delegates) records)
+  let lookup' d = withResolver rs $ \resolver ->
+                    lookup_function resolver d
+
+  -- Construct a list of [IO whatever]. The withResolver calls
+  -- are the ones that should be run in parallel.
+  let actions = map lookup' nrml_domains
+
+  -- Run the lookup actions in parallel.
+  results <- parallelInterleaved actions
+
+  -- Output the results.
+  _ <- mapM (report nrml_delegates normalize_function) results
 
   stopGlobalPool