ghcup-hs/lib/GHCup/Download.hs
2020-04-29 19:36:16 +02:00

484 lines
16 KiB
Haskell

{-# LANGUAGE CPP #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE QuasiQuotes #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE TypeApplications #-}
{-# LANGUAGE TypeFamilies #-}
module GHCup.Download where
#if defined(INTERNAL_DOWNLOADER)
import GHCup.Download.IOStreams
import GHCup.Download.Utils
#endif
import GHCup.Errors
import GHCup.Types
import GHCup.Types.JSON ( )
import GHCup.Types.Optics
import GHCup.Utils
import GHCup.Utils.File
import GHCup.Utils.Prelude
import GHCup.Version
import Control.Applicative
import Control.Exception.Safe
import Control.Monad
#if !MIN_VERSION_base(4,13,0)
import Control.Monad.Fail ( MonadFail )
#endif
import Control.Monad.Logger
import Control.Monad.Reader
import Control.Monad.Trans.Resource
hiding ( throwM )
import Data.Aeson
import Data.ByteString ( ByteString )
#if defined(INTERNAL_DOWNLOADER)
import Data.CaseInsensitive ( CI )
#endif
import Data.Maybe
import Data.String.Interpolate
import Data.Time.Clock
import Data.Time.Clock.POSIX
#if defined(INTERNAL_DOWNLOADER)
import Data.Time.Format
#endif
import Data.Versions
import Data.Word8
import GHC.IO.Exception
import HPath
import HPath.IO as HIO
import Haskus.Utils.Variant.Excepts
import Optics
import Prelude hiding ( abs
, readFile
, writeFile
)
import System.IO.Error
import System.Posix.Env.ByteString ( getEnv )
import URI.ByteString
import qualified Crypto.Hash.SHA256 as SHA256
import qualified Data.ByteString as BS
import qualified Data.ByteString.Base16 as B16
import qualified Data.ByteString.Lazy as L
#if defined(INTERNAL_DOWNLOADER)
import qualified Data.CaseInsensitive as CI
import qualified Data.Map.Strict as M
import qualified Data.Text as T
#endif
import qualified Data.Text.Encoding as E
import qualified System.Posix.Files.ByteString as PF
import qualified System.Posix.RawFilePath.Directory
as RD
------------------
--[ High-level ]--
------------------
-- | Like 'getDownloads', but tries to fall back to
-- cached ~/.ghcup/cache/ghcup-<format-ver>.json
getDownloadsF :: ( FromJSONKey Tool
, FromJSONKey Version
, FromJSON VersionInfo
, MonadIO m
, MonadCatch m
, MonadLogger m
, MonadThrow m
, MonadFail m
, MonadReader Settings m
)
=> URLSource
-> Excepts
'[JSONError , DownloadFailed , FileDoesNotExistError]
m
GHCupInfo
getDownloadsF urlSource = do
case urlSource of
GHCupURL ->
liftE
$ handleIO (\_ -> readFromCache)
$ catchE @_ @'[JSONError , FileDoesNotExistError]
(\(DownloadFailed _) -> readFromCache)
$ getDownloads urlSource
(OwnSource _) -> liftE $ getDownloads urlSource
(OwnSpec _) -> liftE $ getDownloads urlSource
where
readFromCache = do
lift $ $(logWarn)
[i|Could not get download info, trying cached version (this may not be recent!)|]
let path = view pathL' ghcupURL
cacheDir <- liftIO $ ghcupCacheDir
json_file <- (cacheDir </>) <$> urlBaseName path
bs <-
handleIO' NoSuchThing
(\_ -> throwE $ FileDoesNotExistError (toFilePath json_file))
$ liftIO
$ readFile json_file
lE' JSONDecodeError $ eitherDecode' bs
-- | Downloads the download information! But only if we need to ;P
getDownloads :: ( FromJSONKey Tool
, FromJSONKey Version
, FromJSON VersionInfo
, MonadIO m
, MonadCatch m
, MonadLogger m
, MonadThrow m
, MonadFail m
, MonadReader Settings m
)
=> URLSource
-> Excepts '[JSONError , DownloadFailed] m GHCupInfo
getDownloads urlSource = do
lift $ $(logDebug) [i|Receiving download info from: #{urlSource}|]
case urlSource of
GHCupURL -> do
bs <- reThrowAll DownloadFailed $ smartDl ghcupURL
lE' JSONDecodeError $ eitherDecode' bs
(OwnSource url) -> do
bs <- reThrowAll DownloadFailed $ downloadBS url
lE' JSONDecodeError $ eitherDecode' bs
(OwnSpec av) -> pure $ av
where
-- First check if the json file is in the ~/.ghcup/cache dir
-- and check it's access time. If it has been accessed within the
-- last 5 minutes, just reuse it.
--
-- If not, then send a HEAD request and check for modification time.
-- Only download the file if the modification time is newer
-- than the local file.
--
-- Always save the local file with the mod time of the remote file.
smartDl :: forall m1
. ( MonadCatch m1
, MonadIO m1
, MonadFail m1
, MonadLogger m1
, MonadReader Settings m1
)
=> URI
-> Excepts
'[ FileDoesNotExistError
, HTTPStatusError
, URIParseError
, UnsupportedScheme
, NoLocationHeader
, TooManyRedirs
, ProcessError
]
m1
L.ByteString
smartDl uri' = do
let path = view pathL' uri'
cacheDir <- liftIO $ ghcupCacheDir
json_file <- (cacheDir </>) <$> urlBaseName path
e <- liftIO $ doesFileExist json_file
if e
then do
accessTime <-
PF.accessTimeHiRes
<$> (liftIO $ PF.getFileStatus (toFilePath json_file))
currentTime <- liftIO $ getPOSIXTime
-- access time won't work on most linuxes, but we can try regardless
if (currentTime - accessTime) > 300
then do -- no access in last 5 minutes, re-check upstream mod time
getModTime >>= \case
Just modTime -> do
fileMod <- liftIO $ getModificationTime json_file
if modTime > fileMod
then dlWithMod modTime json_file
else liftIO $ readFile json_file
Nothing -> do
lift $ $(logDebug) [i|Unable to get/parse Last-Modified header|]
dlWithoutMod json_file
else -- access in less than 5 minutes, re-use file
liftIO $ readFile json_file
else do
liftIO $ createDirIfMissing newDirPerms cacheDir
getModTime >>= \case
Just modTime -> dlWithMod modTime json_file
Nothing -> do
-- although we don't know last-modified, we still save
-- it to a file, so we might use it in offline mode
lift $ $(logDebug) [i|Unable to get/parse Last-Modified header|]
dlWithoutMod json_file
where
dlWithMod modTime json_file = do
bs <- liftE $ downloadBS uri'
liftIO $ writeFileWithModTime modTime json_file bs
pure bs
dlWithoutMod json_file = do
bs <- liftE $ downloadBS uri'
liftIO $ hideError doesNotExistErrorType $ deleteFile json_file
liftIO $ writeFileL json_file (Just newFilePerms) bs
liftIO $ setModificationTime json_file (fromIntegral @Int 0)
pure bs
getModTime = do
#if !defined(INTERNAL_DOWNLOADER)
pure Nothing
#else
headers <-
handleIO (\_ -> pure mempty)
$ liftE
$ ( catchAllE
(\_ ->
pure mempty :: Excepts '[] m1 (M.Map (CI ByteString) ByteString)
)
$ getHead uri'
)
pure $ parseModifiedHeader headers
parseModifiedHeader :: (M.Map (CI ByteString) ByteString) -> Maybe UTCTime
parseModifiedHeader headers =
(M.lookup (CI.mk "Last-Modified") headers) >>= \h -> parseTimeM
True
defaultTimeLocale
"%a, %d %b %Y %H:%M:%S %Z"
(T.unpack . decUTF8Safe $ h)
#endif
writeFileWithModTime :: UTCTime -> Path Abs -> L.ByteString -> IO ()
writeFileWithModTime utctime path content = do
let mod_time = utcTimeToPOSIXSeconds utctime
writeFileL path (Just newFilePerms) content
setModificationTimeHiRes path mod_time
getDownloadInfo :: Tool
-> Version
-- ^ tool version
-> PlatformRequest
-> GHCupDownloads
-> Either NoDownload DownloadInfo
getDownloadInfo t v (PlatformRequest a p mv) dls = maybe
(Left NoDownload)
Right
(with_distro <|> without_distro_ver <|> without_distro)
where
with_distro = distro_preview id id
without_distro_ver = distro_preview id (const Nothing)
without_distro = distro_preview (set _Linux UnknownLinux) (const Nothing)
distro_preview f g =
preview (ix t % ix v % viArch % ix a % ix (f p) % ix (g mv)) dls
-- | Tries to download from the given http or https url
-- and saves the result in continuous memory into a file.
-- If the filename is not provided, then we:
-- 1. try to guess the filename from the url path
-- 2. otherwise create a random file
--
-- The file must not exist.
download :: ( MonadMask m
, MonadReader Settings m
, MonadThrow m
, MonadLogger m
, MonadIO m
)
=> DownloadInfo
-> Path Abs -- ^ destination dir
-> Maybe (Path Rel) -- ^ optional filename
-> Excepts '[DigestError , DownloadFailed] m (Path Abs)
download dli dest mfn
| scheme == "https" = dl
| scheme == "http" = dl
| scheme == "file" = cp
| otherwise = throwE $ DownloadFailed (variantFromValue UnsupportedScheme)
where
scheme = view (dlUri % uriSchemeL' % schemeBSL') dli
cp = do
-- destination dir must exist
liftIO $ hideError AlreadyExists $ createDirRecursive newDirPerms dest
destFile <- getDestFile
fromFile <- parseAbs path
liftIO $ copyFile fromFile destFile Strict
pure destFile
dl = do
let uri' = decUTF8Safe (serializeURIRef' (view dlUri dli))
lift $ $(logInfo) [i|downloading: #{uri'}|]
-- destination dir must exist
liftIO $ hideError AlreadyExists $ createDirRecursive newDirPerms dest
destFile <- getDestFile
-- download
flip onException
(liftIO $ hideError doesNotExistErrorType $ deleteFile destFile)
$ catchAllE @_ @'[ProcessError, DownloadFailed, UnsupportedScheme]
(\e ->
(liftIO $ hideError doesNotExistErrorType $ deleteFile destFile)
>> (throwE . DownloadFailed $ e)
) $ do
lift getDownloader >>= \case
Curl -> do
o' <- liftIO getCurlOpts
liftE $ lEM @_ @'[ProcessError] $ liftIO $ exec "curl" True
(o' ++ ["-fL", "-o", toFilePath destFile, serializeURIRef' $ view dlUri dli]) Nothing Nothing
Wget -> do
o' <- liftIO getWgetOpts
liftE $ lEM @_ @'[ProcessError] $ liftIO $ exec "wget" True
(o' ++ ["-O", toFilePath destFile , serializeURIRef' $ view dlUri dli]) Nothing Nothing
#if defined(INTERNAL_DOWNLOADER)
Internal -> do
(https, host, fullPath, port) <- liftE $ uriToQuadruple (view dlUri dli)
liftE $ downloadToFile https host fullPath port destFile
#endif
liftE $ checkDigest dli destFile
pure destFile
-- Manage to find a file we can write the body into.
getDestFile :: MonadThrow m => m (Path Abs)
getDestFile = maybe (urlBaseName path <&> (dest </>)) (pure . (dest </>)) mfn
path = view (dlUri % pathL') dli
-- | Download into tmpdir or use cached version, if it exists. If filename
-- is omitted, infers the filename from the url.
downloadCached :: ( MonadMask m
, MonadResource m
, MonadThrow m
, MonadLogger m
, MonadIO m
, MonadReader Settings m
)
=> DownloadInfo
-> Maybe (Path Rel) -- ^ optional filename
-> Excepts '[DigestError , DownloadFailed] m (Path Abs)
downloadCached dli mfn = do
cache <- lift getCache
case cache of
True -> do
cachedir <- liftIO $ ghcupCacheDir
fn <- maybe (urlBaseName $ view (dlUri % pathL') dli) pure mfn
let cachfile = cachedir </> fn
fileExists <- liftIO $ doesFileExist cachfile
if
| fileExists -> do
liftE $ checkDigest dli cachfile
pure $ cachfile
| otherwise -> liftE $ download dli cachedir mfn
False -> do
tmp <- lift withGHCupTmpDir
liftE $ download dli tmp mfn
------------------
--[ Low-level ]--
------------------
-- | This is used for downloading the JSON.
downloadBS :: (MonadReader Settings m, MonadCatch m, MonadIO m, MonadLogger m)
=> URI
-> Excepts
'[ FileDoesNotExistError
, HTTPStatusError
, URIParseError
, UnsupportedScheme
, NoLocationHeader
, TooManyRedirs
, ProcessError
]
m
L.ByteString
downloadBS uri'
| scheme == "https"
= dl True
| scheme == "http"
= dl False
| scheme == "file"
= liftIOException doesNotExistErrorType (FileDoesNotExistError path)
$ (liftIO $ RD.readFile path)
| otherwise
= throwE UnsupportedScheme
where
scheme = view (uriSchemeL' % schemeBSL') uri'
path = view pathL' uri'
#if defined(INTERNAL_DOWNLOADER)
dl https = do
#else
dl _ = do
#endif
lift $ $(logDebug) [i|downloading: #{serializeURIRef' uri'}|]
lift getDownloader >>= \case
Curl -> do
o' <- liftIO getCurlOpts
let exe = [rel|curl|]
args = o' ++ ["-sSfL", serializeURIRef' uri']
liftIO (executeOut exe args Nothing) >>= \case
CapturedProcess ExitSuccess stdout _ -> do
pure $ L.fromStrict stdout
CapturedProcess (ExitFailure i') _ _ -> throwE $ NonZeroExit i' (toFilePath exe) args
Wget -> do
o' <- liftIO getWgetOpts
let exe = [rel|wget|]
args = o' ++ ["-qO-", serializeURIRef' uri']
liftIO (executeOut exe args Nothing) >>= \case
CapturedProcess ExitSuccess stdout _ -> do
pure $ L.fromStrict stdout
CapturedProcess (ExitFailure i') _ _ -> throwE $ NonZeroExit i' (toFilePath exe) args
#if defined(INTERNAL_DOWNLOADER)
Internal -> do
(_, host', fullPath', port') <- liftE $ uriToQuadruple uri'
liftE $ downloadBS' https host' fullPath' port'
#endif
checkDigest :: (MonadIO m, MonadThrow m, MonadLogger m, MonadReader Settings m)
=> DownloadInfo
-> Path Abs
-> Excepts '[DigestError] m ()
checkDigest dli file = do
verify <- lift ask <&> (not . noVerify)
when verify $ do
p' <- toFilePath <$> basename file
lift $ $(logInfo) [i|verifying digest of: #{p'}|]
c <- liftIO $ readFile file
cDigest <- throwEither . E.decodeUtf8' . B16.encode . SHA256.hashlazy $ c
let eDigest = view dlHash dli
when ((cDigest /= eDigest) && verify) $ throwE (DigestError cDigest eDigest)
-- | Get additional curl args from env. This is an undocumented option.
getCurlOpts :: IO [ByteString]
getCurlOpts =
getEnv "GHCUP_CURL_OPTS" >>= \case
Just r -> pure $ BS.split _space r
Nothing -> pure []
-- | Get additional wget args from env. This is an undocumented option.
getWgetOpts :: IO [ByteString]
getWgetOpts =
getEnv "GHCUP_WGET_OPTS" >>= \case
Just r -> pure $ BS.split _space r
Nothing -> pure []