@@ -1,9 +1,8 @@
1{-# LANGUAGE TemplateHaskell #-}
1{-# LANGUAGE TemplateHaskell #-}
2{-# LANGUAGE CPP #-}
2{-# LANGUAGE CPP #-}
3−{-# LANGUAGE OverloadedStrings #-}
4-- | This module uses template Haskell. Following is a simplified explanation of usage for those unfamiliar with calling Template Haskell functions.
3-- | This module uses template Haskell. Following is a simplified explanation of usage for those unfamiliar with calling Template Haskell functions.
6−-- The function @embedFile@ in this modules embeds a file into the executable
5+-- The function @embedFile@ in this modules embeds a file into the exceutable
7-- that you can use it at runtime. A file is represented as a @ByteString@.
6-- that you can use it at runtime. A file is represented as a @ByteString@.
8-- However, as you can see below, the type signature indicates a value of type
7-- However, as you can see below, the type signature indicates a value of type
9-- @Q Exp@ will be returned. In order to convert this into a @ByteString@, you
8-- @Q Exp@ will be returned. In order to convert this into a @ByteString@, you
@@ -19,63 +18,44 @@
19module Data.FileEmbed
18module Data.FileEmbed
20 ( -- * Embed at compile time
19 ( -- * Embed at compile time
23 , embedOneFileOf
21 , embedOneFileOf
24 , embedDir
22 , embedDir
27− -- * Embed as a IsString
29− , embedOneStringFileOf
30 -- * Inject into an executable
24 -- * Inject into an executable
32#if MIN_VERSION_template_haskell(2,5,0)
25#if MIN_VERSION_template_haskell(2,5,0)
33 , dummySpace
26 , dummySpace
37 , injectFile
29 , injectFile
40− -- * Relative path manipulation
41− , makeRelativeToProject
42− , makeRelativeToLocationPredicate
43 -- * Internal
30 -- * Internal
44 , stringToBs
31 , stringToBs
49import Language.Haskell.TH.Syntax
35import Language.Haskell.TH.Syntax
50 ( Exp (AppE, ListE, LitE, TupE, SigE, VarE)
36 ( Exp (AppE, ListE, LitE, TupE, SigE, VarE)
51− , Lit (..)
37+#if MIN_VERSION_template_haskell(2,5,0)
38+ , Lit (StringL, StringPrimL, IntegerL)
40+ , Lit (StringL, IntegerL)
54− , qLocation, loc_filename
55#if MIN_VERSION_template_haskell(2,7,0)
44#if MIN_VERSION_template_haskell(2,7,0)
56 , Quasi(qAddDependentFile)
45 , Quasi(qAddDependentFile)
59−#if MIN_VERSION_template_haskell(2,16,0)
60−import Language.Haskell.TH ( mkBytes, bytesPrimL )
61−import qualified Data.ByteString.Internal as B
63import System.Directory (doesDirectoryExist, doesFileExist,
48import System.Directory (doesDirectoryExist, doesFileExist,
64− getDirectoryContents, canonicalizePath)
49+ getDirectoryContents)
65−import Control.Exception (throw, tryJust, ErrorCall(..))
50+import Control.Exception (throw, ErrorCall(..))
66−import Control.Monad (filterM, guard)
51+import Control.Monad (filterM)
67import qualified Data.ByteString as B
52import qualified Data.ByteString as B
68import qualified Data.ByteString.Char8 as B8
53import qualified Data.ByteString.Char8 as B8
69import Control.Arrow ((&&&), second)
54import Control.Arrow ((&&&), second)
70import Control.Applicative ((<$>))
55import Control.Applicative ((<$>))
71import Data.ByteString.Unsafe (unsafePackAddressLen)
56import Data.ByteString.Unsafe (unsafePackAddressLen)
72−import System.IO.Error (isDoesNotExistError)
73import System.IO.Unsafe (unsafePerformIO)
57import System.IO.Unsafe (unsafePerformIO)
74−import System.FilePath ((</>), takeDirectory, takeExtension)
58+import System.FilePath ((</>))
75−import Data.String (fromString)
77−import Data.List (sortBy)
78−import Data.Ord (comparing)
80-- | Embed a single file in your source code.
60-- | Embed a single file in your source code.
@@ -90,40 +70,13 @@ embedFile fp =
91 (runIO $ B.readFile fp) >>= bsToExp
71 (runIO $ B.readFile fp) >>= bsToExp
93−-- | Maybe embed a single file in your source code depending on whether or not file exists.
95−-- Warning: When a build is compiled with the file missing, a recompile when the file exists might not trigger an embed of the file.
96−-- You might try to fix this by doing a clean build.
98−-- > import qualified Data.ByteString
100−-- > maybeMyFile :: Maybe Data.ByteString.ByteString
101−-- > maybeMyFile = $(embedFileIfExists "dirName/fileName")
104−embedFileIfExists :: FilePath -> Q Exp
105−embedFileIfExists fp = do
106− mbs <- runIO maybeFile
108− Nothing -> [| Nothing |]
110−#if MIN_VERSION_template_haskell(2,7,0)
111− qAddDependentFile fp
113− [| Just $(bsToExp bs) |]
115− maybeFile :: IO (Maybe B.ByteString)
117− either (const Nothing) Just <$>
118− tryJust (guard . isDoesNotExistError) (B.readFile fp)
120-- | Embed a single existing file in your source code
73-- | Embed a single existing file in your source code
121-- out of list a list of paths supplied.
74-- out of list a list of paths supplied.
123-- > import qualified Data.ByteString
76-- > import qualified Data.ByteString
125-- > myFile :: Data.ByteString.ByteString
78-- > myFile :: Data.ByteString.ByteString
126−-- > myFile = $(embedOneFileOf [ "dirName/fileName", "src/dirName/fileName" ])
79+-- > myFile = $(embedFile' [ "dirName/fileName", "src/dirName/fileName" ])
127embedOneFileOf :: [FilePath] -> Q Exp
80embedOneFileOf :: [FilePath] -> Q Exp
128embedOneFileOf ps =
81embedOneFileOf ps =
129 (runIO $ readExistingFile ps) >>= \ ( path, content ) -> do
82 (runIO $ readExistingFile ps) >>= \ ( path, content ) -> do
@@ -151,18 +104,6 @@ embedDir fp = do
151 e <- ListE <$> ((runIO $ fileList fp) >>= mapM (pairToExp fp))
104 e <- ListE <$> ((runIO $ fileList fp) >>= mapM (pairToExp fp))
152 return $ SigE e typ
105 return $ SigE e typ
154−-- | Embed a directory listing recursively in your source code.
156−-- > myFiles :: [FilePath]
157−-- > myFiles = $(embedDirListing "dirName")
160−embedDirListing :: FilePath -> Q Exp
161−embedDirListing fp = do
162− typ <- [t| [FilePath] |]
163− e <- ListE <$> ((runIO $ fmap fst <$> fileList fp) >>= mapM strToExp)
166-- | Get a directory tree in the IO monad.
107-- | Get a directory tree in the IO monad.
168-- This is the workhorse of 'embedDir'
109-- This is the workhorse of 'embedDir'
@@ -175,11 +116,7 @@ pairToExp _root (path, bs) = do
175 qAddDependentFile $ _root ++ '/' : path
116 qAddDependentFile $ _root ++ '/' : path
177 exp' <- bsToExp bs
118 exp' <- bsToExp bs
179−#if MIN_VERSION_template_haskell(2,16,0)
182− [LitE $ StringL path, exp']
119+ return $! TupE [LitE $ StringL path, exp']
184bsToExp :: B.ByteString -> Q Exp
121bsToExp :: B.ByteString -> Q Exp
185#if MIN_VERSION_template_haskell(2, 5, 0)
122#if MIN_VERSION_template_haskell(2, 5, 0)
@@ -187,11 +124,7 @@ bsToExp bs =
187 return $ VarE 'unsafePerformIO
124 return $ VarE 'unsafePerformIO
188 `AppE` (VarE 'unsafePackAddressLen
125 `AppE` (VarE 'unsafePackAddressLen
189 `AppE` LitE (IntegerL $ fromIntegral $ B8.length bs)
126 `AppE` LitE (IntegerL $ fromIntegral $ B8.length bs)
190−#if MIN_VERSION_template_haskell(2, 16, 0)
127+#if MIN_VERSION_template_haskell(2, 8, 0)
191− `AppE` LitE (bytesPrimL (
192− let B.PS ptr off sz = bs
193− in mkBytes ptr (fromIntegral off) (fromIntegral sz))))
194−#elif MIN_VERSION_template_haskell(2, 8, 0)
195 `AppE` LitE (StringPrimL $ B.unpack bs))
128 `AppE` LitE (StringPrimL $ B.unpack bs))
197 `AppE` LitE (StringPrimL $ B8.unpack bs))
130 `AppE` LitE (StringPrimL $ B8.unpack bs))
@@ -206,51 +139,6 @@ bsToExp bs = do
206stringToBs :: String -> B.ByteString
139stringToBs :: String -> B.ByteString
207stringToBs = B8.pack
140stringToBs = B8.pack
209−-- | Embed a single file in your source code.
211−-- > import Data.String
213−-- > myFile :: IsString a => a
214−-- > myFile = $(embedStringFile "dirName/fileName")
217−embedStringFile :: FilePath -> Q Exp
219−#if MIN_VERSION_template_haskell(2,7,0)
220− qAddDependentFile fp >>
222− (runIO $ P.readFile fp) >>= strToExp
224−-- | Embed a single existing string file in your source code
225−-- out of list a list of paths supplied.
228−embedOneStringFileOf :: [FilePath] -> Q Exp
229−embedOneStringFileOf ps =
230− (runIO $ readExistingFile ps) >>= \ ( path, content ) -> do
231−#if MIN_VERSION_template_haskell(2,7,0)
232− qAddDependentFile path
236− readExistingFile :: [FilePath] -> IO ( FilePath, String )
237− readExistingFile xs = do
238− ys <- filterM doesFileExist xs
240− (p:_) -> P.readFile p >>= \ c -> return ( p, c )
241− _ -> throw $ ErrorCall "Cannot find file to embed as resource"
243−strToExp :: String -> Q Exp
244−#if MIN_VERSION_template_haskell(2, 5, 0)
246− return $ VarE 'fromString
247− `AppE` LitE (StringL s)
250− helper <- [| fromString |]
251− return $! AppE helper $! LitE $! StringL s
254notHidden :: FilePath -> Bool
142notHidden :: FilePath -> Bool
255notHidden ('.':_) = False
143notHidden ('.':_) = False
256notHidden _ = True
144notHidden _ = True
@@ -266,20 +154,20 @@ fileList' realTop top = do
266 mapM (liftPair2 . second B.readFile)
154 mapM (liftPair2 . second B.readFile)
267 dirs <- filterM (doesDirectoryExist . snd) all' >>=
155 dirs <- filterM (doesDirectoryExist . snd) all' >>=
268 mapM (fileList' realTop . fst)
156 mapM (fileList' realTop . fst)
269− return $ sortBy (comparing fst) $ concat $ files : dirs
157+ return $ concat $ files : dirs
271liftPair2 :: Monad m => (a, m b) -> m (a, b)
159liftPair2 :: Monad m => (a, m b) -> m (a, b)
272liftPair2 (a, b) = b >>= \b' -> return (a, b')
160liftPair2 (a, b) = b >>= \b' -> return (a, b')
274−magic :: B.ByteString -> B.ByteString
162+magic :: String
275−magic x = B8.concat ["fe", x]
163+magic = concat ["fe", "MS"]
277sizeLen :: Int
165sizeLen :: Int
278sizeLen = 20
166sizeLen = 20
280getInner :: B.ByteString -> B.ByteString
168getInner :: B.ByteString -> B.ByteString
281getInner b =
169getInner b =
282− let (sizeBS, rest) = B.splitAt sizeLen b
170+ let (sizeBS, rest) = B.splitAt sizeLen $ B.drop (length magic) b
283 in case reads $ B8.unpack sizeBS of
171 in case reads $ B8.unpack sizeBS of
284 (i, _):_ -> B.take i rest
172 (i, _):_ -> B.take i rest
285 [] -> error "Data.FileEmbed (getInner): Your dummy space has been corrupted."
173 [] -> error "Data.FileEmbed (getInner): Your dummy space has been corrupted."
@@ -290,152 +178,41 @@ padSize i =
290 in replicate (sizeLen - length s) '0' ++ s
178 in replicate (sizeLen - length s) '0' ++ s
292#if MIN_VERSION_template_haskell(2,5,0)
180#if MIN_VERSION_template_haskell(2,5,0)
293−-- | Allocate the given number of bytes in the generate executable. That space
294−-- can be filled up with the 'inject' and 'injectFile' functions.
295dummySpace :: Int -> Q Exp
181dummySpace :: Int -> Q Exp
296−dummySpace = dummySpaceWith "MS"
182+dummySpace space = do
298−-- | Like 'dummySpace', but takes a postfix for the magic string. In
299−-- order for this to work, the same postfix must be used by 'inject' /
300−-- 'injectFile'. This allows an executable to have multiple
301−-- 'ByteString's injected into it, without encountering collisions.
304−dummySpaceWith :: B.ByteString -> Int -> Q Exp
305−dummySpaceWith postfix space = do
306 let size = padSize space
183 let size = padSize space
307− magic' = magic postfix
308− start = B8.unpack magic' ++ size
184+ let start = magic ++ size
309− magicLen = B8.length magic'
310− len = magicLen + sizeLen + space
311− chars = LitE $ StringPrimL $
185+ let chars = LitE $ StringPrimL $
312#if MIN_VERSION_template_haskell(2,6,0)
186#if MIN_VERSION_template_haskell(2,6,0)
313 map (toEnum . fromEnum) $
187 map (toEnum . fromEnum) $
315 start ++ replicate space '0'
189 start ++ replicate space '0'
190+ let len = fromIntegral $ length start + space :: Int
316− [| getInner (B.drop magicLen (unsafePerformIO (unsafePackAddressLen len $(return chars)))) |]
191+ [| getInner (unsafePerformIO (unsafePackAddressLen len $(return chars))) |]
319−-- | Inject some raw data inside a @ByteString@ containing empty, dummy space
320−-- (allocated with @dummySpace@). Typically, the original @ByteString@ is an
321−-- executable read from the filesystem.
322inject :: B.ByteString -- ^ bs to inject
194inject :: B.ByteString -- ^ bs to inject
323 -> B.ByteString -- ^ original BS containing dummy
195 -> B.ByteString -- ^ original BS containing dummy
324 -> Maybe B.ByteString -- ^ new BS, or Nothing if there is insufficient dummy space
196 -> Maybe B.ByteString -- ^ new BS, or Nothing if there is insufficient dummy space
325−inject = injectWith "MS"
327−-- | Like 'inject', but takes a postfix for the magic string.
330−injectWith :: B.ByteString -- ^ postfix of magic string
331− -> B.ByteString -- ^ bs to inject
332− -> B.ByteString -- ^ original BS containing dummy
333− -> Maybe B.ByteString -- ^ new BS, or Nothing if there is insufficient dummy space
334−injectWith postfix toInj orig =
197+inject toInj orig =
335 if toInjL > size
198 if toInjL > size
336 then Nothing
199 then Nothing
337− else Just $ B.concat [before, magic', B8.pack $ padSize toInjL, toInj, B8.pack $ replicate (size - toInjL) '0', after]
200+ else Just $ B.concat [before, B8.pack magic, B8.pack $ padSize toInjL, toInj, B8.pack $ replicate (size - toInjL) '0', after]
339− magic' = magic postfix
340 toInjL = B.length toInj
202 toInjL = B.length toInj
341− (before, rest) = B.breakSubstring magic' orig
203+ (before, rest) = B.breakSubstring (B8.pack magic) orig
342− (sizeBS, rest') = B.splitAt sizeLen $ B.drop (B8.length magic') rest
204+ (sizeBS, rest') = B.splitAt sizeLen $ B.drop (length magic) rest
343 size = case reads $ B8.unpack sizeBS of
205 size = case reads $ B8.unpack sizeBS of
344 (i, _):_ -> i
206 (i, _):_ -> i
345 [] -> error $ "Data.FileEmbed (inject): Your dummy space has been corrupted. Size is: " ++ show sizeBS
207 [] -> error $ "Data.FileEmbed (inject): Your dummy space has been corrupted. Size is: " ++ show sizeBS
346 after = B.drop size rest'
208 after = B.drop size rest'
348−-- | Same as 'inject', but instead of performing the injecting in memory, read
349−-- the contents from the filesystem and write back to a different file on the
351−injectFile :: B.ByteString -- ^ bs to inject
210+injectFile :: B.ByteString
352 -> FilePath -- ^ template file
211 -> FilePath -- ^ template file
353 -> FilePath -- ^ output file
212 -> FilePath -- ^ output file
355−injectFile = injectFileWith "MS"
357−-- | Like 'injectFile', but takes a postfix for the magic string.
360−injectFileWith :: B.ByteString -- ^ postfix of magic string
361− -> B.ByteString -- ^ bs to inject
362− -> FilePath -- ^ template file
363− -> FilePath -- ^ output file
365−injectFileWith postfix inj srcFP dstFP = do
214+injectFile inj srcFP dstFP = do
366 src <- B.readFile srcFP
215 src <- B.readFile srcFP
367− case injectWith postfix inj src of
216+ case inject inj src of
368 Nothing -> error "Insufficient dummy space"
217 Nothing -> error "Insufficient dummy space"
369 Just dst -> B.writeFile dstFP dst
218 Just dst -> B.writeFile dstFP dst
373−The inject system allows arbitrary content to be embedded inside a Haskell
374−executable, post compilation. Typically, file-embed allows you to read some
375−contents from the file system at compile time and embed them inside your
376−executable. Consider a case, instead, where you would want to embed these
377−contents after compilation. Two real-world examples are:
379−* You would like to embed a hash of the executable itself, for sanity checking in a network protocol. (Obviously the hash will change after you embed the hash.)
381−* You want to create a self-contained web server that has a set of content, but will need to update the content on machines that do not have access to GHC.
383−The typical workflow use:
385−* Use 'dummySpace' or 'dummySpaceWith' to create some empty space in your executable
387−* Use 'injectFile' or 'injectFileWith' from a separate utility to modify that executable to have the updated content.
389−The reason for the @With@-variant of the functions is for cases where you wish
390−to inject multiple different kinds of content, and therefore need control over
391−the magic key. If you know for certain that there will only be one dummy space
392−available, you can use the non-@With@ variants.
396−-- | Take a relative file path and attach it to the root of the current
399−-- The idea here is that, when building with Stack, the build will always be
400−-- executed with a current working directory of the root of the project (where
401−-- your .cabal file is located). However, if you load up multiple projects with
402−-- @stack ghci@, the working directory may be something else entirely.
404−-- This function looks at the source location of the Haskell file calling it,
405−-- finds the first parent directory with a .cabal file, and uses that as the
406−-- root directory for fixing the relative path.
408−-- @$(makeRelativeToProject "data/foo.txt" >>= embedFile)@
411−makeRelativeToProject :: FilePath -> Q FilePath
412−makeRelativeToProject = makeRelativeToLocationPredicate $ (==) ".cabal" . takeExtension
414−-- | Take a predicate to infer the project root and a relative file path, the given file path is then attached to the inferred project root
416−-- This function looks at the source location of the Haskell file calling it,
417−-- finds the first parent directory with a file matching the given predicate, and uses that as the
418−-- root directory for fixing the relative path.
420−-- @$(makeRelativeToLocationPredicate ((==) ".cabal" . takeExtension) "data/foo.txt" >>= embedFile)@
423−makeRelativeToLocationPredicate :: (FilePath -> Bool) -> FilePath -> Q FilePath
424−makeRelativeToLocationPredicate isTargetFile rel = do
427− srcFP <- canonicalizePath $ loc_filename loc
428− mdir <- findProjectDir srcFP
430− Nothing -> error $ "Could not find .cabal file for path: " ++ srcFP
431− Just dir -> return $ dir </> rel
433− findProjectDir x = do
434− let dir = takeDirectory x
438− contents <- getDirectoryContents dir
439− if any isTargetFile contents
440− then return (Just dir)
441− else findProjectDir dir