Allow to control the metadata cache, fixes #278

app/ghcup/BrickMain.hs

@@ -536,17 +536,7 @@ settings' = unsafePerformIO $ do
                                   , fileOutter    = \_ -> pure ()
                                   , fancyColors   = True
                                   }
-  newIORef $ AppState (Settings { cache      = True
-                                , noVerify   = False
-                                , keepDirs   = Never
-                                , downloader = Curl
-                                , verbose    = False
-                                , urlSource  = GHCupURL
-                                , noNetwork  = False
-                                , gpgSetting = GPGNone
-                                , noColor    = False
-                                , ..
-                                })
+  newIORef $ AppState defaultSettings
                       dirs
                       defaultKeyBindings
                       (GHCupInfo mempty mempty mempty)

app/ghcup/GHCup/OptParse.hs

@@ -67,6 +67,7 @@ data Options = Options
   -- global options
     optVerbose     :: Maybe Bool
   , optCache       :: Maybe Bool
+  , optMetaCache   :: Maybe Integer
   , optUrlSource   :: Maybe URI
   , optNoVerify    :: Maybe Bool
   , optKeepDirs    :: Maybe KeepDirs
@@ -105,6 +106,7 @@ opts =
   Options
     <$> invertableSwitch "verbose" 'v' False (help "Enable verbosity (default: disabled)")
     <*> invertableSwitch "cache" 'c' False (help "Cache downloads in ~/.ghcup/cache (default: disabled)")
+    <*> optional (option auto (long "metadata-caching" <> help "How long the yaml metadata caching interval is (in seconds), 0 to disable" <> internal))
     <*> optional
           (option
             (eitherReader parseUri)

app/ghcup/GHCup/OptParse/Common.hs

@@ -299,7 +299,7 @@ tagCompleter tool add = listIOCompleter $ do
         , fancyColors    = False
         }
   let appState = LeanAppState
-        (Settings True False Never Curl False GHCupURL True GPGNone False)
+        (defaultSettings { noNetwork = True })
         dirs'
         defaultKeyBindings
         loggerConfig
@@ -322,7 +322,7 @@ versionCompleter criteria tool = listIOCompleter $ do
         , fileOutter     = mempty
         , fancyColors    = False
         }
-  let settings = Settings True False Never Curl False GHCupURL True GPGNone False
+  let settings = defaultSettings { noNetwork = True }
   let leanAppState = LeanAppState
                    settings
                    dirs'

app/ghcup/GHCup/OptParse/Config.hs

@@ -122,6 +122,7 @@ updateSettings config' settings = do
    mergeConf :: UserSettings -> Settings -> Settings
    mergeConf UserSettings{..} Settings{..} =
      let cache'      = fromMaybe cache uCache
+         metaCache'  = fromMaybe metaCache uMetaCache
          noVerify'   = fromMaybe noVerify uNoVerify
          keepDirs'   = fromMaybe keepDirs uKeepDirs
          downloader' = fromMaybe downloader uDownloader
@@ -129,7 +130,7 @@ updateSettings config' settings = do
          urlSource'  = fromMaybe urlSource uUrlSource
          noNetwork'  = fromMaybe noNetwork uNoNetwork
          gpgSetting' = fromMaybe gpgSetting uGPGSetting
-     in Settings cache' noVerify' keepDirs' downloader' verbose' urlSource' noNetwork' gpgSetting' noColor
+     in Settings cache' metaCache' noVerify' keepDirs' downloader' verbose' urlSource' noNetwork' gpgSetting' noColor
 
 
 

app/ghcup/GHCup/OptParse/DInfo.hs

@@ -51,7 +51,7 @@ describe_result = $( LitE . StringL <$>
                      runIO (do
                              CapturedProcess{..} <-  do
                               dirs <- liftIO getAllDirs
-                              let settings = AppState (Settings True False Never Curl False GHCupURL False GPGNone False)
+                              let settings = AppState (defaultSettings { noNetwork = True })
                                                dirs
                                                defaultKeyBindings
                               flip runReaderT settings $ executeOut "git" ["describe"] Nothing

app/ghcup/Main.hs

@@ -55,6 +55,7 @@ import qualified Data.ByteString               as B
 import qualified Data.Text                     as T
 import qualified Data.Text.IO                  as T
 import qualified Data.Text.Encoding            as E
+import qualified GHCup.Types                   as Types
 
 
 
@@ -72,15 +73,16 @@ toSettings options = do
  where
    mergeConf :: Options -> UserSettings -> Bool -> (Settings, KeyBindings)
    mergeConf Options{..} UserSettings{..} noColor =
-     let cache       = fromMaybe (fromMaybe False uCache) optCache
-         noVerify    = fromMaybe (fromMaybe False uNoVerify) optNoVerify
-         verbose     = fromMaybe (fromMaybe False uVerbose) optVerbose
-         keepDirs    = fromMaybe (fromMaybe Errors uKeepDirs) optKeepDirs
+     let cache       = fromMaybe (fromMaybe (Types.cache defaultSettings) uCache) optCache
+         metaCache   = fromMaybe (fromMaybe (Types.metaCache defaultSettings) uMetaCache) optMetaCache
+         noVerify    = fromMaybe (fromMaybe (Types.noVerify defaultSettings) uNoVerify) optNoVerify
+         verbose     = fromMaybe (fromMaybe (Types.verbose defaultSettings) uVerbose) optVerbose
+         keepDirs    = fromMaybe (fromMaybe (Types.keepDirs defaultSettings) uKeepDirs) optKeepDirs
          downloader  = fromMaybe (fromMaybe defaultDownloader uDownloader) optsDownloader
          keyBindings = maybe defaultKeyBindings mergeKeys uKeyBindings
-         urlSource   = maybe (fromMaybe GHCupURL uUrlSource) OwnSource optUrlSource
-         noNetwork   = fromMaybe (fromMaybe False uNoNetwork) optNoNetwork
-         gpgSetting  = fromMaybe (fromMaybe GPGNone uGPGSetting) optGpg
+         urlSource   = maybe (fromMaybe (Types.urlSource defaultSettings) uUrlSource) OwnSource optUrlSource
+         noNetwork   = fromMaybe (fromMaybe (Types.noNetwork defaultSettings) uNoNetwork) optNoNetwork
+         gpgSetting  = fromMaybe (fromMaybe (Types.gpgSetting defaultSettings) uGPGSetting) optGpg
      in (Settings {..}, keyBindings)
 #if defined(INTERNAL_DOWNLOADER)
    defaultDownloader = Internal

data/config.yaml

@@ -36,6 +36,10 @@ key-bindings:
   show-all-tools:
     KChar: 't'
 
+# The caching for the metadata files containing download info, depending on last access time
+# of the file. These usually are in '~/.ghcup/cache/ghcup-<ver>.yaml'.
+meta-cache: 300 # in seconds
+
 # Where to get GHC/cabal/hls download info/versions from. For more detailed explanation
 # check the 'URLSource' type in the code.
 url-source:

docs/guide.md

@@ -53,6 +53,25 @@ as e.g. `/etc/bash_completion.d/ghcup` (depending on distro)
 and make sure your bashrc sources the startup script
 (`/usr/share/bash-completion/bash_completion` on some distros).
 
+## Caching
+
+GHCup has a few caching mechanisms to avoid redownloads. All cached files end up in `~/.ghcup/cache` by default.
+
+### Downloads cache
+
+Downloaded tarballs (such as GHC, cabal, etc.) are not cached by default unless you pass `ghcup --cache` or set caching
+in your [config](#configuration) via `ghcup config set cache true`.
+
+### Metadata cache
+
+The metadata files (also see [github.com/haskell/ghcup-metadata](https://github.com/haskell/ghcup-metadata))
+have a 5 minutes cache per default depending on the last access time of the file. That means if you run
+`ghcup list` 10 times in a row, only the first time will trigger a download attempt.
+
+### Clearing the cache
+
+If you experience problems, consider clearing the cache via `ghcup gc --cache`.
+
 ## Compiling GHC from source
 
 Compiling from source is supported for both source tarballs and arbitrary git refs. See `ghcup compile ghc --help`

lib/GHCup/Download.hs

@@ -242,14 +242,18 @@ getBase uri = do
     e <- liftIO $ doesFileExist json_file
     currentTime <- liftIO getCurrentTime
     Dirs { cacheDir } <- lift getDirs
+    Settings { metaCache } <- lift getSettings
 
        -- for local files, let's short-circuit and ignore access time
     if | scheme == "file" -> liftE $ download uri' Nothing Nothing cacheDir Nothing True
        | e -> do
-          accessTime <- liftIO $ getAccessTime json_file
-
+          accessTime <- fmap utcTimeToPOSIXSeconds $ liftIO $ getAccessTime json_file
+          let sinceLastAccess = utcTimeToPOSIXSeconds currentTime - accessTime
+          let cacheInterval = fromInteger metaCache
+          lift $ logDebug $ "last access was " <> T.pack (show sinceLastAccess) <> " ago, cache interval is " <> T.pack (show cacheInterval)
           -- access time won't work on most linuxes, but we can try regardless
-          if | ((utcTimeToPOSIXSeconds currentTime - utcTimeToPOSIXSeconds accessTime) > 300) ->
+          if | metaCache <= 0 -> dlWithMod currentTime json_file
+             | (sinceLastAccess > cacheInterval) ->
                 -- no access in last 5 minutes, re-check upstream mod time
                 dlWithMod currentTime json_file
              | otherwise -> pure json_file

lib/GHCup/Types.hs

@@ -294,6 +294,7 @@ instance NFData (URIRef Absolute) where
 
 data UserSettings = UserSettings
   { uCache       :: Maybe Bool
+  , uMetaCache   :: Maybe Integer
   , uNoVerify    :: Maybe Bool
   , uVerbose     :: Maybe Bool
   , uKeepDirs    :: Maybe KeepDirs
@@ -306,12 +307,13 @@ data UserSettings = UserSettings
   deriving (Show, GHC.Generic)
 
 defaultUserSettings :: UserSettings
-defaultUserSettings = UserSettings Nothing Nothing Nothing Nothing Nothing Nothing Nothing Nothing Nothing
+defaultUserSettings = UserSettings Nothing Nothing Nothing Nothing Nothing Nothing Nothing Nothing Nothing Nothing
 
 fromSettings :: Settings -> Maybe KeyBindings -> UserSettings
 fromSettings Settings{..} Nothing =
   UserSettings {
       uCache = Just cache
+    , uMetaCache = Just metaCache
     , uNoVerify = Just noVerify
     , uVerbose = Just verbose
     , uKeepDirs = Just keepDirs
@@ -335,6 +337,7 @@ fromSettings Settings{..} (Just KeyBindings{..}) =
             }
   in UserSettings {
       uCache = Just cache
+    , uMetaCache = Just metaCache
     , uNoVerify = Just noVerify
     , uVerbose = Just verbose
     , uKeepDirs = Just keepDirs
@@ -410,6 +413,7 @@ instance NFData LeanAppState
 
 data Settings = Settings
   { cache      :: Bool
+  , metaCache  :: Integer
   , noVerify   :: Bool
   , keepDirs   :: KeepDirs
   , downloader :: Downloader
@@ -421,6 +425,12 @@ data Settings = Settings
   }
   deriving (Show, GHC.Generic)
 
+defaultMetaCache :: Integer
+defaultMetaCache = 300 -- 5 minutes
+
+defaultSettings :: Settings
+defaultSettings = Settings False defaultMetaCache False Never Curl False GHCupURL False GPGNone False
+
 instance NFData Settings
 
 data Dirs = Dirs

lib/GHCup/Utils.hs

@@ -111,7 +111,7 @@ import qualified Data.List.NonEmpty            as NE
 -- >>> let lc = LoggerConfig { lcPrintDebug = False, consoleOutter = mempty, fileOutter = mempty, fancyColors = False }
 -- >>> dirs' <- getAllDirs
 -- >>> let installedVersions = [ ([pver|8.10.7|], Nothing), ([pver|8.10.4|], Nothing), ([pver|8.8.4|], Nothing), ([pver|8.8.3|], Nothing) ]
--- >>> let settings = Settings True False Never Curl False GHCupURL True GPGNone False
+-- >>> let settings = Settings True 0 False Never Curl False GHCupURL True GPGNone False
 -- >>> let leanAppState = LeanAppState settings dirs' defaultKeyBindings lc
 -- >>> cwd <- getCurrentDirectory
 -- >>> (Right ref) <- pure $ parseURI strictURIParserOptions $ "file://" <> E.encodeUtf8 (T.pack cwd) <> "/data/metadata/" <> (urlBaseName . view pathL' $ ghcupURL)

test/GHCup/Types/JSONSpec.hs

@@ -3,7 +3,7 @@
 module GHCup.Types.JSONSpec where
 
 import           GHCup.ArbitraryTypes ()
-import           GHCup.Types
+import           GHCup.Types hiding ( defaultSettings )
 import           GHCup.Types.JSON ()
 
 import           Test.Aeson.GenericSpecs