Write hoogle DB generation errors to a file #47

Handler/Haddock.hs

@@ -19,7 +19,7 @@ import System.Process (createProcess, proc, cwd, waitForProcess)
 import System.Exit (ExitCode (ExitSuccess))
 import Network.Mime (defaultMimeLookup)
 import Crypto.Hash.Conduit (sinkHash)
-import System.IO (IOMode (ReadMode), withBinaryFile, openBinaryFile)
+import System.IO (IOMode (ReadMode, WriteMode), withBinaryFile, openBinaryFile)
 import Data.Conduit.Zlib (gzip)
 import System.Posix.Files (createLink)
 import qualified Data.ByteString.Base16 as B16
@@ -307,17 +307,19 @@ createHaddockUnpacker root store runDB' urlRenderRef = do
                 ec <- waitForProcess ph
                 if ec == ExitSuccess then return () else throwM ec
 
-                -- TODO: run hoogle and the database update in
-                -- concurrent threads.
-
                 urlRender <- readIORef urlRenderRef
                 runResourceT $ do
+                    liftIO $ createTree $ dirHoogleIdent dirs ident
                     tmp <- liftIO getTemporaryDirectory
                     (_releasekey, hoogletemp) <- allocate
                         (fpFromString <$> createTempDirectory tmp "hoogle-database-gen")
                         removeTree
-                    copyHoogleTextFiles destdir hoogletemp
+                    let logFp = fpToString (dirHoogleFp dirs ident ["error-log"])
-                    void $ resourceForkIO $ createHoogleDb dirs stackageEnt hoogletemp urlRender
+                    (_, errorLog) <- allocate (openBinaryFile logFp WriteMode) hClose
+                    copyHoogleTextFiles errorLog destdir hoogletemp
+                    -- TODO: Have hoogle requests block on this finishing.
+                    -- (Or display a "compiling DB" message to the user)
+                    void $ resourceForkIO $ createHoogleDb dirs stackageEnt errorLog hoogletemp urlRender
 
                 -- Determine which packages have documentation and update the
                 -- database appropriately
@@ -396,33 +398,39 @@ getUploadDocMapR = do
 putUploadDocMapR :: Handler Html
 putUploadDocMapR = getUploadDocMapR
 
-copyHoogleTextFiles :: FilePath -- ^ raw unpacked Haddock files
+copyHoogleTextFiles :: Handle -- ^ error log handle
+                    -> FilePath -- ^ raw unpacked Haddock files
                     -> FilePath -- ^ temporary work directory
                     -> ResourceT IO ()
-copyHoogleTextFiles raw tmp = do
+copyHoogleTextFiles errorLog raw tmp = do
     let tmptext = tmp </> "text"
     liftIO $ createTree tmptext
     sourceDirectory raw $$ mapM_C (\fp ->
         forM_ (nameAndVersionFromPath fp) $ \(name, version) -> do
             let src = fp </> fpFromText name <.> "txt"
                 dst = tmptext </> fpFromText (name ++ "-" ++ version)
-            whenM (liftIO $ isFile src) $
+            exists <- liftIO $ isFile src
-                sourceFile src $$ (sinkFile dst :: Sink ByteString (ResourceT IO) ())
+            if exists
+                then sourceFile src $$ (sinkFile dst :: Sink ByteString (ResourceT IO) ())
+                else liftIO $ appendHoogleErrors errorLog $ HoogleErrors
+                    { packageName = name
+                    , packageVersion = version
+                    , errors = ["No textual Hoogle DB (use \"cabal haddock --hoogle\")"]
+                    }
             )
 
 createHoogleDb :: Dirs
                -> Entity Stackage
+               -> Handle -- ^ error log handle
                -> FilePath -- ^ temp directory
                -> (Route App -> [(Text, Text)] -> Text)
                -> ResourceT IO ()
-createHoogleDb dirs (Entity _ stackage) tmpdir urlRender = do
+createHoogleDb dirs (Entity _ stackage) errorLog tmpdir urlRender = do
     let ident = stackageIdent stackage
         tmpbin = tmpdir </> "binary"
-        hoogleDir = dirHoogleIdent dirs ident
+    liftIO $ createTree tmpbin
-    liftIO $ do
+    eres <- tryAny $ do
-        createTree hoogleDir
+        -- Create hoogle binary databases for each package.
-        createTree tmpbin
-    -- Create hoogle binary databases for each package
         sourceDirectory (tmpdir </> "text") $$ mapM_C
           ( \fp -> do
             (releaseKey, srcH) <- allocate (openBinaryFile (fpToString fp) ReadMode) hClose
@@ -434,30 +442,57 @@ createHoogleDb dirs (Entity _ stackage) tmpdir urlRender = do
                     urlPieces = [name <> "-" <> version, "index.html"]
                     -- Compute the filepath of the resulting hoogle
                     -- database.
-                out = fpToString $ tmpbin </> base <.> "hoo"
+                    out = fpToString $ tmpbin </> fpFromText base
-                base = F.dropExtension $ filename fp
+                    base = name <> "-" <> version <> ".hoo"
-            errs <- Hoogle.createDatabase "foo" Hoogle.Haskell [] src' out
+                errs <- Hoogle.createDatabase "" Hoogle.Haskell [] src' out
-            -- TODO: handle these more gracefully?
+                when (not $ null errs) $ do
-            when (not $ null errs) $ putStrLn $ concat
+                    -- TODO: remove this printing once errors are yielded
-                [ fpToText base
+                    -- to the user.
+                    putStrLn $ concat
+                        [ base
                         , " Hoogle errors: "
                         , tshow errs
                         ]
+                    appendHoogleErrors errorLog $ HoogleErrors
+                        { packageName = name
+                        , packageVersion = version
+                        , errors = map show errs
+                        }
             release releaseKey
             )
         -- Merge the individual binary databases into one big database.
         liftIO $ do
             dbs <- listDirectory tmpbin
-        let merged = hoogleDir </> "default.hoo"
             Hoogle.mergeDatabase
-            (map fpToString (filter (/= merged) dbs))
+                (map fpToString dbs)
-            (fpToString merged)
+                (fpToString (dirHoogleFp dirs ident ["default.hoo"]))
+    case eres of
+        Right () -> return ()
+        Left err -> liftIO $ appendHoogleErrors errorLog $ HoogleErrors
+             { packageName = "Exception thrown while building hoogle DB"
+             , packageVersion = ""
+             , errors = [show err]
+             }
+
+data HoogleErrors = HoogleErrors
+    { packageName :: Text
+    , packageVersion :: Text
+    , errors :: [String]
+    } deriving (Generic)
+
+instance ToJSON HoogleErrors where
+instance FromJSON HoogleErrors where
+
+-- Appends hoogle errors to a log file.  By encoding within a single
+-- list, the resulting file can be decoded as [HoogleErrors].
+appendHoogleErrors :: Handle -> HoogleErrors -> IO ()
+appendHoogleErrors h errs = hPut h (Y.encode [errs])
 
 nameAndVersionFromPath :: FilePath -> Maybe (Text, Text)
 nameAndVersionFromPath fp =
     (\name -> (name, version)) <$> stripSuffix "-" name'
   where
-    (name', version) = T.breakOnEnd "-" $ fpToText $ filename fp
+    (name', version) = T.breakOnEnd "-" $ fpToText $ F.dropExtension $ filename fp
 
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 -- HADDOCK HACKS