yesod/yesod-static/Yesod/Static.hs
2012-01-05 15:27:16 +02:00

375 lines
13 KiB
Haskell

{-# LANGUAGE QuasiQuotes #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE OverloadedStrings #-}
---------------------------------------------------------
--
-- | Serve static files from a Yesod app.
--
-- This is great for developing your application, but also for a
-- dead-simple deployment. Caching headers are automatically
-- taken care of.
--
-- If you are running a proxy server (like Apache or Nginx),
-- you may want to have that server do the static serving instead.
--
-- In fact, in an ideal setup you'll serve your static files from
-- a separate domain name to save time on transmitting
-- cookies. In that case, you may wish to use 'urlRenderOverride'
-- to redirect requests to this subsite to a separate domain
-- name.
--
-- Note that this module's static subsite ignores all files and
-- directories that are hidden by Unix conventions (i.e. start
-- with a dot, such as @\".ssh\"@) and the directory "tmp" on the
-- root of the directory with static files.
module Yesod.Static
( -- * Subsite
Static (..)
, Route (..)
-- * Smart constructor
, static
, staticDevel
, embed
-- * Template Haskell helpers
, staticFiles
, staticFilesList
, publicFiles
-- * Hashing
, base64md5
#ifdef TEST
, getFileListPieces
#endif
) where
import Prelude hiding (FilePath)
import qualified Prelude
import System.Directory
import Control.Monad
import Data.FileEmbed (embedDir)
import Yesod.Core hiding (lift)
import Data.List (intercalate)
import Language.Haskell.TH
import Language.Haskell.TH.Syntax
import qualified Data.ByteString.Lazy as L
import Data.Digest.Pure.MD5
import qualified Data.ByteString.Base64
import qualified Data.ByteString.Char8 as S8
import qualified Data.Serialize
import Data.Text (Text, pack)
import Data.Monoid (mempty)
import qualified Data.Map as M
import Data.IORef (readIORef, newIORef, writeIORef)
import Network.Wai (pathInfo, rawPathInfo, responseLBS)
import Data.Char (isLower, isDigit)
import Data.List (foldl')
import qualified Data.ByteString as S
import Network.HTTP.Types (status301)
import System.PosixCompat.Files (getFileStatus, modificationTime)
import System.Posix.Types (EpochTime)
import qualified Data.Conduit as C
import qualified Data.Conduit.Binary as CB
import qualified Data.Conduit.List as CL
import Network.Wai.Application.Static
( StaticSettings (..)
, defaultWebAppSettings
, staticApp
, embeddedLookup
, toEmbedded
, toFilePath
, fromFilePath
, FilePath
, ETagLookup
, webAppSettingsWithLookup
)
-- | Type used for the subsite with static contents.
newtype Static = Static StaticSettings
-- | Produce a default value of 'Static' for a given file
-- folder.
--
-- Does not have index files or directory listings. The static
-- files' contents /must not/ change, however new files can be
-- added.
static :: Prelude.FilePath -> IO Static
static dir = do
hashLookup <- cachedETagLookup dir
return $ Static $ webAppSettingsWithLookup (toFilePath dir) hashLookup
-- | Same as 'static', but does not assumes that the files do not
-- change and checks their modification time whenever a request
-- is made.
staticDevel :: Prelude.FilePath -> IO Static
staticDevel dir = do
hashLookup <- cachedETagLookupDevel dir
return $ Static $ webAppSettingsWithLookup (toFilePath dir) hashLookup
-- | Produce a 'Static' based on embedding all of the static
-- files' contents in the executable at compile time.
embed :: Prelude.FilePath -> Q Exp
embed fp =
[|Static (defaultWebAppSettings
{ ssFolder = embeddedLookup (toEmbedded $(embedDir fp))
})|]
instance RenderRoute Static where
-- | A route on the static subsite (see also 'staticFiles').
--
-- You may use this constructor directly to manually link to a
-- static file. The first argument is the sub-path to the file
-- being served whereas the second argument is the key-value
-- pairs in the query string. For example,
--
-- > StaticRoute $ StaticR [\"thumb001.jpg\"] [(\"foo\", \"5\"), (\"bar\", \"choc\")]
--
-- would generate a url such as
-- @http://www.example.com/static/thumb001.jpg?foo=5&bar=choc@
-- The StaticRoute constructor can be used when the URL cannot be
-- statically generated at compile-time (e.g. when generating
-- image galleries).
data Route Static = StaticRoute [Text] [(Text, Text)]
deriving (Eq, Show, Read)
renderRoute (StaticRoute x y) = (x, y)
instance Yesod master => YesodDispatch Static master where
-- Need to append trailing slash to make relative links work
yesodDispatch _ _ _ _ _ _ [] _ req =
return $ responseLBS status301 [("Location", rawPathInfo req `S.append` "/")] ""
yesodDispatch _ (Static set) _ _ _ _ textPieces _ req =
staticApp set req { pathInfo = textPieces }
notHidden :: Prelude.FilePath -> Bool
notHidden "tmp" = False
notHidden s =
case s of
'.':_ -> False
_ -> True
getFileListPieces :: Prelude.FilePath -> IO [[String]]
getFileListPieces = flip go id
where
go :: String -> ([String] -> [String]) -> IO [[String]]
go fp front = do
allContents <- filter notHidden `fmap` getDirectoryContents fp
let fullPath :: String -> String
fullPath f = fp ++ '/' : f
files <- filterM (doesFileExist . fullPath) allContents
let files' = map (front . return) files
dirs <- filterM (doesDirectoryExist . fullPath) allContents
dirs' <- mapM (\f -> go (fullPath f) (front . (:) f)) dirs
return $ concat $ files' : dirs'
-- | Template Haskell function that automatically creates routes
-- for all of your static files.
--
-- For example, if you used
--
-- > staticFiles "static/"
--
-- and you had files @\"static\/style.css\"@ and
-- @\"static\/js\/script.js\"@, then the following top-level
-- definitions would be created:
--
-- > style_css = StaticRoute ["style.css"] []
-- > js_script_js = StaticRoute ["js/script.js"] []
--
-- Note that dots (@.@), dashes (@-@) and slashes (@\/@) are
-- replaced by underscores (@\_@) to create valid Haskell
-- identifiers.
staticFiles :: Prelude.FilePath -> Q [Dec]
staticFiles dir = mkStaticFiles dir
-- | Same as 'staticFiles', but takes an explicit list of files
-- to create identifiers for. The files path given are relative
-- to the static folder. For example, to create routes for the
-- files @\"static/js/jquery.js\"@ and
-- @\"static/css/normalize.css\"@, you would use:
--
-- > staticFilesList \"static\" [\"js\/jquery.js\", \"css\/normalize.css\"]
--
-- This can be useful when you have a very large number of static
-- files, but only need to refer to a few of them from Haskell.
staticFilesList :: Prelude.FilePath -> [Prelude.FilePath] -> Q [Dec]
staticFilesList dir fs =
mkStaticFilesList dir (map split fs) "StaticRoute" True
where
split :: Prelude.FilePath -> [String]
split [] = []
split x =
let (a, b) = break (== '/') x
in a : split (drop 1 b)
-- | Same as 'staticFiles', but doesn't append an ETag to the
-- query string.
--
-- Using 'publicFiles' will speed up the compilation, since there
-- won't be any need for hashing files during compile-time.
-- However, since the ETag ceases to be part of the URL, the
-- 'Static' subsite won't be able to set the expire date too far
-- on the future. Browsers still will be able to cache the
-- contents, however they'll need send a request to the server to
-- see if their copy is up-to-date.
publicFiles :: Prelude.FilePath -> Q [Dec]
publicFiles dir = mkStaticFiles' dir "StaticRoute" False
mkHashMap :: Prelude.FilePath -> IO (M.Map FilePath S8.ByteString)
mkHashMap dir = do
fs <- getFileListPieces dir
hashAlist fs >>= return . M.fromList
where
hashAlist :: [[String]] -> IO [(FilePath, S8.ByteString)]
hashAlist fs = mapM hashPair fs
where
hashPair :: [String] -> IO (FilePath, S8.ByteString)
hashPair pieces = do let file = pathFromRawPieces dir pieces
h <- base64md5File file
return (toFilePath file, S8.pack h)
pathFromRawPieces :: Prelude.FilePath -> [String] -> Prelude.FilePath
pathFromRawPieces =
foldl' append
where
append a b = a ++ '/' : b
cachedETagLookupDevel :: Prelude.FilePath -> IO ETagLookup
cachedETagLookupDevel dir = do
etags <- mkHashMap dir
mtimeVar <- newIORef (M.empty :: M.Map FilePath EpochTime)
return $ \f ->
case M.lookup f etags of
Nothing -> return Nothing
Just checksum -> do
fs <- getFileStatus $ fromFilePath f
let newt = modificationTime fs
mtimes <- readIORef mtimeVar
oldt <- case M.lookup f mtimes of
Nothing -> writeIORef mtimeVar (M.insert f newt mtimes) >> return newt
Just oldt -> return oldt
return $ if newt /= oldt then Nothing else Just checksum
cachedETagLookup :: Prelude.FilePath -> IO ETagLookup
cachedETagLookup dir = do
etags <- mkHashMap dir
return $ (\f -> return $ M.lookup f etags)
mkStaticFiles :: Prelude.FilePath -> Q [Dec]
mkStaticFiles fp = mkStaticFiles' fp "StaticRoute" True
mkStaticFiles' :: Prelude.FilePath -- ^ static directory
-> String -- ^ route constructor "StaticRoute"
-> Bool -- ^ append checksum query parameter
-> Q [Dec]
mkStaticFiles' fp routeConName makeHash = do
fs <- qRunIO $ getFileListPieces fp
mkStaticFilesList fp fs routeConName makeHash
mkStaticFilesList
:: Prelude.FilePath -- ^ static directory
-> [[String]] -- ^ list of files to create identifiers for
-> String -- ^ route constructor "StaticRoute"
-> Bool -- ^ append checksum query parameter
-> Q [Dec]
mkStaticFilesList fp fs routeConName makeHash = do
concat `fmap` mapM mkRoute fs
where
replace' c
| 'A' <= c && c <= 'Z' = c
| 'a' <= c && c <= 'z' = c
| '0' <= c && c <= '9' = c
| otherwise = '_'
mkRoute f = do
let name' = intercalate "_" $ map (map replace') f
routeName = mkName $
case () of
()
| null name' -> error "null-named file"
| isDigit (head name') -> '_' : name'
| isLower (head name') -> name'
| otherwise -> '_' : name'
f' <- [|map pack $(lift f)|]
let route = mkName routeConName
pack' <- [|pack|]
qs <- if makeHash
then do hash <- qRunIO $ base64md5File $ pathFromRawPieces fp f
[|[(pack $(lift hash), mempty)]|]
else return $ ListE []
return
[ SigD routeName $ ConT route
, FunD routeName
[ Clause [] (NormalB $ (ConE route) `AppE` f' `AppE` qs) []
]
]
base64md5File :: Prelude.FilePath -> IO String
base64md5File file = do
bss <- C.runResourceT $ CB.sourceFile file C.$$ CL.consume
return $ base64md5 $ L.fromChunks bss
-- FIXME I'd like something streaming instead
{-
fmap (base64 . finalize) $ E.run_ $
EB.enumFile file E.$$ EL.fold go (md5InitialContext, "")
where
go (context, prev) next = (md5Update context prev, next)
finalize (context, end) = md5Finalize context end
-}
-- | Calculates the MD5 hash of the given lazy bytestring,
-- encodes it using Base64 and then return the 8 first
-- characters.
base64md5 :: L.ByteString -> String
base64md5 = base64 . md5
base64 :: MD5Digest -> String
base64 = map tr
. take 8
. S8.unpack
. Data.ByteString.Base64.encode
. Data.Serialize.encode
where
tr '+' = '-'
tr '/' = '_'
tr c = c
{- FIXME
-- | Dispatch static route for a subsite
--
-- Subsites with static routes can't (yet) define Static routes the same way "master" sites can.
-- Instead of a subsite route:
-- /static StaticR Static getStatic
-- Use a normal route:
-- /static/*Strings StaticR GET
--
-- Then, define getStaticR something like:
-- getStaticR = getStaticHandler ($(mkEmbedFiles "static") typeByExt) StaticR
-- */ end CPP comment
getStaticHandler :: Static -> (StaticRoute -> Route sub) -> [String] -> GHandler sub y ChooseRep
getStaticHandler static toSubR pieces = do
toMasterR <- getRouteToMaster
toMasterHandler (toMasterR . toSubR) toSub route handler
where route = StaticRoute pieces []
toSub _ = static
staticSite = getSubSite :: Site (Route Static) (String -> Maybe (GHandler Static y ChooseRep))
handler = fromMaybe notFound $ handleSite staticSite (error "Yesod.Static: getSTaticHandler") route "GET"
-}
{-
calcHash :: Prelude.FilePath -> IO String
calcHash fname =
withBinaryFile fname ReadMode hashHandle
where
hashHandle h = do s <- L.hGetContents h
return $! base64md5 s
-}