@@ -1,8 +1,9 @@
11{-# LANGUAGE TemplateHaskell #-}
22{-# LANGUAGE CPP #-}
3+{-# LANGUAGE OverloadedStrings #-}
34-- | This module uses template Haskell. Following is a simplified explanation of usage for those unfamiliar with calling Template Haskell functions.
45--
5−-- The function @embedFile@ in this modules embeds a file into the exceutable
6+-- The function @embedFile@ in this modules embeds a file into the executable
67-- that you can use it at runtime. A file is represented as a @ByteString@.
78-- However, as you can see below, the type signature indicates a value of type
89-- @Q Exp@ will be returned. In order to convert this into a @ByteString@, you
@@ -18,43 +19,63 @@
1819module Data.FileEmbed
1920 ( -- * Embed at compile time
2021 embedFile
22+ , embedFileIfExists
2123 , embedOneFileOf
2224 , embedDir
25+ , embedDirListing
2326 , getDir
27+ -- * Embed as a IsString
28+ , embedStringFile
29+ , embedOneStringFileOf
2430 -- * Inject into an executable
31+ -- $inject
2532#if MIN_VERSION_template_haskell(2,5,0)
2633 , dummySpace
34+ , dummySpaceWith
2735#endif
2836 , inject
2937 , injectFile
38+ , injectWith
39+ , injectFileWith
40+ -- * Relative path manipulation
41+ , makeRelativeToProject
42+ , makeRelativeToLocationPredicate
3043 -- * Internal
3144 , stringToBs
45+ , bsToExp
46+ , strToExp
3247 ) where
3348
3449import Language.Haskell.TH.Syntax
35− ( Exp (AppE, ListE, LitE, TupE, SigE)
36−#if MIN_VERSION_template_haskell(2,5,0)
37− , Lit (StringL, StringPrimL, IntegerL)
38−#else
39− , Lit (StringL, IntegerL)
40−#endif
50+ ( Exp (AppE, ListE, LitE, TupE, SigE, VarE)
51+ , Lit (..)
4152 , Q
4253 , runIO
54+ , qLocation, loc_filename
4355#if MIN_VERSION_template_haskell(2,7,0)
4456 , Quasi(qAddDependentFile)
4557#endif
4658 )
59+#if MIN_VERSION_template_haskell(2,16,0)
60+import Language.Haskell.TH ( mkBytes, bytesPrimL )
61+import qualified Data.ByteString.Internal as B
62+#endif
4763import System.Directory (doesDirectoryExist, doesFileExist,
48− getDirectoryContents)
49−import Control.Exception (throw, ErrorCall(..))
50−import Control.Monad (filterM)
64+ getDirectoryContents, canonicalizePath)
65+import Control.Exception (throw, tryJust, ErrorCall(..))
66+import Control.Monad (filterM, guard)
5167import qualified Data.ByteString as B
5268import qualified Data.ByteString.Char8 as B8
5369import Control.Arrow ((&&&), second)
5470import Control.Applicative ((<$>))
5571import Data.ByteString.Unsafe (unsafePackAddressLen)
72+import System.IO.Error (isDoesNotExistError)
5673import System.IO.Unsafe (unsafePerformIO)
57−import System.FilePath ((</>))
74+import System.FilePath ((</>), takeDirectory, takeExtension)
75+import Data.String (fromString)
76+import Prelude as P
77+import Data.List (sortBy)
78+import Data.Ord (comparing)
5879
5980-- | Embed a single file in your source code.
6081--
@@ -69,13 +90,40 @@ embedFile fp =
6990#endif
7091 (runIO $ B.readFile fp) >>= bsToExp
7192
93+-- | Maybe embed a single file in your source code depending on whether or not file exists.
94+--
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.
97+--
98+-- > import qualified Data.ByteString
99+-- >
100+-- > maybeMyFile :: Maybe Data.ByteString.ByteString
101+-- > maybeMyFile = $(embedFileIfExists "dirName/fileName")
102+--
103+-- @since 0.0.14.0
104+embedFileIfExists :: FilePath -> Q Exp
105+embedFileIfExists fp = do
106+ mbs <- runIO maybeFile
107+ case mbs of
108+ Nothing -> [| Nothing |]
109+ Just bs -> do
110+#if MIN_VERSION_template_haskell(2,7,0)
111+ qAddDependentFile fp
112+#endif
113+ [| Just $(bsToExp bs) |]
114+ where
115+ maybeFile :: IO (Maybe B.ByteString)
116+ maybeFile =
117+ either (const Nothing) Just <$>
118+ tryJust (guard . isDoesNotExistError) (B.readFile fp)
119+
72120-- | Embed a single existing file in your source code
73121-- out of list a list of paths supplied.
74122--
75123-- > import qualified Data.ByteString
76124-- >
77125-- > myFile :: Data.ByteString.ByteString
78−-- > myFile = $(embedFile' [ "dirName/fileName", "src/dirName/fileName" ])
126+-- > myFile = $(embedOneFileOf [ "dirName/fileName", "src/dirName/fileName" ])
79127embedOneFileOf :: [FilePath] -> Q Exp
80128embedOneFileOf ps =
81129 (runIO $ readExistingFile ps) >>= \ ( path, content ) -> do
@@ -103,6 +151,18 @@ embedDir fp = do
103151 e <- ListE <$> ((runIO $ fileList fp) >>= mapM (pairToExp fp))
104152 return $ SigE e typ
105153
154+-- | Embed a directory listing recursively in your source code.
155+--
156+-- > myFiles :: [FilePath]
157+-- > myFiles = $(embedDirListing "dirName")
158+--
159+-- @since 0.0.11
160+embedDirListing :: FilePath -> Q Exp
161+embedDirListing fp = do
162+ typ <- [t| [FilePath] |]
163+ e <- ListE <$> ((runIO $ fmap fst <$> fileList fp) >>= mapM strToExp)
164+ return $ SigE e typ
165+
106166-- | Get a directory tree in the IO monad.
107167--
108168-- This is the workhorse of 'embedDir'
@@ -115,17 +175,82 @@ pairToExp _root (path, bs) = do
115175 qAddDependentFile $ _root ++ '/' : path
116176#endif
117177 exp' <- bsToExp bs
118− return $! TupE [LitE $ StringL path, exp']
178+ return $! TupE
179+#if MIN_VERSION_template_haskell(2,16,0)
180+ $ map Just
181+#endif
182+ [LitE $ StringL path, exp']
119183
120184bsToExp :: B.ByteString -> Q Exp
185+#if MIN_VERSION_template_haskell(2, 5, 0)
186+bsToExp bs =
187+ return $ VarE 'unsafePerformIO
188+ `AppE` (VarE 'unsafePackAddressLen
189+ `AppE` LitE (IntegerL $ fromIntegral $ B8.length bs)
190+#if MIN_VERSION_template_haskell(2, 16, 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))
196+#else
197+ `AppE` LitE (StringPrimL $ B8.unpack bs))
198+#endif
199+#else
121200bsToExp bs = do
122201 helper <- [| stringToBs |]
123202 let chars = B8.unpack bs
124203 return $! AppE helper $! LitE $! StringL chars
204+#endif
125205
126206stringToBs :: String -> B.ByteString
127207stringToBs = B8.pack
128208
209+-- | Embed a single file in your source code.
210+--
211+-- > import Data.String
212+-- >
213+-- > myFile :: IsString a => a
214+-- > myFile = $(embedStringFile "dirName/fileName")
215+--
216+-- Since 0.0.9
217+embedStringFile :: FilePath -> Q Exp
218+embedStringFile fp =
219+#if MIN_VERSION_template_haskell(2,7,0)
220+ qAddDependentFile fp >>
221+#endif
222+ (runIO $ P.readFile fp) >>= strToExp
223+
224+-- | Embed a single existing string file in your source code
225+-- out of list a list of paths supplied.
226+--
227+-- Since 0.0.9
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
233+#endif
234+ strToExp content
235+ where
236+ readExistingFile :: [FilePath] -> IO ( FilePath, String )
237+ readExistingFile xs = do
238+ ys <- filterM doesFileExist xs
239+ case ys of
240+ (p:_) -> P.readFile p >>= \ c -> return ( p, c )
241+ _ -> throw $ ErrorCall "Cannot find file to embed as resource"
242+
243+strToExp :: String -> Q Exp
244+#if MIN_VERSION_template_haskell(2, 5, 0)
245+strToExp s =
246+ return $ VarE 'fromString
247+ `AppE` LitE (StringL s)
248+#else
249+strToExp s = do
250+ helper <- [| fromString |]
251+ return $! AppE helper $! LitE $! StringL s
252+#endif
253+
129254notHidden :: FilePath -> Bool
130255notHidden ('.':_) = False
131256notHidden _ = True
@@ -141,20 +266,20 @@ fileList' realTop top = do
141266 mapM (liftPair2 . second B.readFile)
142267 dirs <- filterM (doesDirectoryExist . snd) all' >>=
143268 mapM (fileList' realTop . fst)
144− return $ concat $ files : dirs
269+ return $ sortBy (comparing fst) $ concat $ files : dirs
145270
146271liftPair2 :: Monad m => (a, m b) -> m (a, b)
147272liftPair2 (a, b) = b >>= \b' -> return (a, b')
148273
149−magic :: String
150−magic = concat ["fe", "MS"]
274+magic :: B.ByteString -> B.ByteString
275+magic x = B8.concat ["fe", x]
151276
152277sizeLen :: Int
153278sizeLen = 20
154279
155280getInner :: B.ByteString -> B.ByteString
156281getInner b =
157− let (sizeBS, rest) = B.splitAt sizeLen $ B.drop (length magic) b
282+ let (sizeBS, rest) = B.splitAt sizeLen b
158283 in case reads $ B8.unpack sizeBS of
159284 (i, _):_ -> B.take i rest
160285 [] -> error "Data.FileEmbed (getInner): Your dummy space has been corrupted."
@@ -165,44 +290,152 @@ padSize i =
165290 in replicate (sizeLen - length s) '0' ++ s
166291
167292#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.
168295dummySpace :: Int -> Q Exp
169−dummySpace space = do
296+dummySpace = dummySpaceWith "MS"
297+
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.
302+--
303+-- Since 0.0.8
304+dummySpaceWith :: B.ByteString -> Int -> Q Exp
305+dummySpaceWith postfix space = do
170306 let size = padSize space
171− let start = magic ++ size
172− let chars = LitE $ StringPrimL $
307+ magic' = magic postfix
308+ start = B8.unpack magic' ++ size
309+ magicLen = B8.length magic'
310+ len = magicLen + sizeLen + space
311+ chars = LitE $ StringPrimL $
173312#if MIN_VERSION_template_haskell(2,6,0)
174313 map (toEnum . fromEnum) $
175314#endif
176315 start ++ replicate space '0'
177− let len = LitE $ IntegerL $ fromIntegral $ length start + space
178− upi <- [|unsafePerformIO|]
179− pack <- [|unsafePackAddressLen|]
180− getInner' <- [|getInner|]
181− return $ getInner' `AppE` (upi `AppE` (pack `AppE` len `AppE` chars))
316+ [| getInner (B.drop magicLen (unsafePerformIO (unsafePackAddressLen len $(return chars)))) |]
182317#endif
183318
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.
184322inject :: B.ByteString -- ^ bs to inject
185323 -> B.ByteString -- ^ original BS containing dummy
186324 -> Maybe B.ByteString -- ^ new BS, or Nothing if there is insufficient dummy space
187−inject toInj orig =
325+inject = injectWith "MS"
326+
327+-- | Like 'inject', but takes a postfix for the magic string.
328+--
329+-- Since 0.0.8
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 =
188335 if toInjL > size
189336 then Nothing
190− else Just $ B.concat [before, B8.pack magic, B8.pack $ padSize toInjL, toInj, B8.pack $ replicate (size - toInjL) '0', after]
337+ else Just $ B.concat [before, magic', B8.pack $ padSize toInjL, toInj, B8.pack $ replicate (size - toInjL) '0', after]
191338 where
339+ magic' = magic postfix
192340 toInjL = B.length toInj
193− (before, rest) = B.breakSubstring (B8.pack magic) orig
194− (sizeBS, rest') = B.splitAt sizeLen $ B.drop (length magic) rest
341+ (before, rest) = B.breakSubstring magic' orig
342+ (sizeBS, rest') = B.splitAt sizeLen $ B.drop (B8.length magic') rest
195343 size = case reads $ B8.unpack sizeBS of
196344 (i, _):_ -> i
197345 [] -> error $ "Data.FileEmbed (inject): Your dummy space has been corrupted. Size is: " ++ show sizeBS
198346 after = B.drop size rest'
199347
200−injectFile :: B.ByteString
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
350+-- filesystem.
351+injectFile :: B.ByteString -- ^ bs to inject
201352 -> FilePath -- ^ template file
202353 -> FilePath -- ^ output file
203354 -> IO ()
204−injectFile inj srcFP dstFP = do
355+injectFile = injectFileWith "MS"
356+
357+-- | Like 'injectFile', but takes a postfix for the magic string.
358+--
359+-- Since 0.0.8
360+injectFileWith :: B.ByteString -- ^ postfix of magic string
361+ -> B.ByteString -- ^ bs to inject
362+ -> FilePath -- ^ template file
363+ -> FilePath -- ^ output file
364+ -> IO ()
365+injectFileWith postfix inj srcFP dstFP = do
205366 src <- B.readFile srcFP
206− case inject inj src of
367+ case injectWith postfix inj src of
207368 Nothing -> error "Insufficient dummy space"
208369 Just dst -> B.writeFile dstFP dst
370+
371+{- $inject
372+
373+The inject system allows arbitrary content to be embedded inside a Haskell
374+executable, post compilation. Typically, file-embed allows you to read some
375+contents from the file system at compile time and embed them inside your
376+executable. Consider a case, instead, where you would want to embed these
377+contents after compilation. Two real-world examples are:
378+
379+* You would like to embed a hash of the executable itself, for sanity checking in a network protocol. (Obviously the hash will change after you embed the hash.)
380+
381+* You want to create a self-contained web server that has a set of content, but will need to update the content on machines that do not have access to GHC.
382+
383+The typical workflow use:
384+
385+* Use 'dummySpace' or 'dummySpaceWith' to create some empty space in your executable
386+
387+* Use 'injectFile' or 'injectFileWith' from a separate utility to modify that executable to have the updated content.
388+
389+The reason for the @With@-variant of the functions is for cases where you wish
390+to inject multiple different kinds of content, and therefore need control over
391+the magic key. If you know for certain that there will only be one dummy space
392+available, you can use the non-@With@ variants.
393+
394+-}
395+
396+-- | Take a relative file path and attach it to the root of the current
397+-- project.
398+--
399+-- The idea here is that, when building with Stack, the build will always be
400+-- executed with a current working directory of the root of the project (where
401+-- your .cabal file is located). However, if you load up multiple projects with
402+-- @stack ghci@, the working directory may be something else entirely.
403+--
404+-- This function looks at the source location of the Haskell file calling it,
405+-- finds the first parent directory with a .cabal file, and uses that as the
406+-- root directory for fixing the relative path.
407+--
408+-- @$(makeRelativeToProject "data/foo.txt" >>= embedFile)@
409+--
410+-- @since 0.0.10
411+makeRelativeToProject :: FilePath -> Q FilePath
412+makeRelativeToProject = makeRelativeToLocationPredicate $ (==) ".cabal" . takeExtension
413+
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
415+--
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.
419+--
420+-- @$(makeRelativeToLocationPredicate ((==) ".cabal" . takeExtension) "data/foo.txt" >>= embedFile)@
421+--
422+-- @since 0.0.15.0
423+makeRelativeToLocationPredicate :: (FilePath -> Bool) -> FilePath -> Q FilePath
424+makeRelativeToLocationPredicate isTargetFile rel = do
425+ loc <- qLocation
426+ runIO $ do
427+ srcFP <- canonicalizePath $ loc_filename loc
428+ mdir <- findProjectDir srcFP
429+ case mdir of
430+ Nothing -> error $ "Could not find .cabal file for path: " ++ srcFP
431+ Just dir -> return $ dir </> rel
432+ where
433+ findProjectDir x = do
434+ let dir = takeDirectory x
435+ if dir == x
436+ then return Nothing
437+ else do
438+ contents <- getDirectoryContents dir
439+ if any isTargetFile contents
440+ then return (Just dir)
441+ else findProjectDir dir