83 lines
3.2 KiB
Haskell
83 lines
3.2 KiB
Haskell
|
--------------------------------------------------------------------------------
|
||
|
|
module Hakyll.Core.Resource.Modified
|
||
|
|
( resourceModified
|
||
|
|
, resourceModificationTime
|
||
|
|
) where
|
||
|
|
|
||
|
|
|
||
|
|
--------------------------------------------------------------------------------
|
||
|
|
import Control.Applicative ((<$>), (<*>))
|
||
|
|
import Control.Monad (when)
|
||
|
|
import qualified Crypto.Hash.MD5 as MD5
|
||
|
|
import qualified Data.ByteString as B
|
||
|
|
import qualified Data.ByteString.Lazy as BL
|
||
|
|
import Data.IORef
|
||
|
|
import qualified Data.Map as M
|
||
|
|
import Data.Time (UTCTime)
|
||
|
|
import System.Directory (getModificationTime)
|
||
|
|
|
||
|
|
|
||
|
|
--------------------------------------------------------------------------------
|
||
|
|
import Hakyll.Core.Resource
|
||
|
|
import Hakyll.Core.Resource.MetadataCache
|
||
|
|
import Hakyll.Core.Resource.Provider.Internal
|
||
|
|
import Hakyll.Core.Store (Store)
|
||
|
|
import qualified Hakyll.Core.Store as Store
|
||
|
|
|
||
|
|
|
||
|
|
--------------------------------------------------------------------------------
|
||
|
|
-- | A resource is modified if it or its metadata has changed
|
||
|
|
resourceModified :: ResourceProvider -> Resource -> IO Bool
|
||
|
|
resourceModified rp r
|
||
|
|
| not exists = return False
|
||
|
|
| otherwise = do
|
||
|
|
cache <- readIORef cacheRef
|
||
|
|
case M.lookup r cache of
|
||
|
|
Just m -> return m
|
||
|
|
Nothing -> do
|
||
|
|
-- Check if the actual file was modified, and do a recursive
|
||
|
|
-- call to check if the metadata file was modified
|
||
|
|
m <- (||)
|
||
|
|
<$> fileDigestModified store (unResource r)
|
||
|
|
<*> resourceModified rp (resourceMetadataResource r)
|
||
|
|
modifyIORef cacheRef (M.insert r m)
|
||
|
|
|
||
|
|
-- Important!
|
||
|
|
when m $ resourceInvalidateMetadataCache rp r
|
||
|
|
|
||
|
|
return m
|
||
|
|
where
|
||
|
|
exists = resourceExists rp r
|
||
|
|
store = resourceStore rp
|
||
|
|
cacheRef = resourceModifiedCache rp
|
||
|
|
|
||
|
|
|
||
|
|
--------------------------------------------------------------------------------
|
||
|
|
-- | Utility: Check if a the digest of a file was modified
|
||
|
|
fileDigestModified :: Store -> FilePath -> IO Bool
|
||
|
|
fileDigestModified store fp = do
|
||
|
|
-- Get the latest seen digest from the store, and calculate the current
|
||
|
|
-- digest for the
|
||
|
|
lastDigest <- Store.get store key
|
||
|
|
newDigest <- fileDigest fp
|
||
|
|
if Store.Found newDigest == lastDigest
|
||
|
|
-- All is fine, not modified
|
||
|
|
then return False
|
||
|
|
-- Resource modified; store new digest
|
||
|
|
else do
|
||
|
|
Store.set store key newDigest
|
||
|
|
return True
|
||
|
|
where
|
||
|
|
key = ["Hakyll.Core.Resource.Provider.fileModified", fp]
|
||
|
|
|
||
|
|
|
||
|
|
--------------------------------------------------------------------------------
|
||
|
|
-- | Utility: Retrieve a digest for a given file
|
||
|
|
fileDigest :: FilePath -> IO B.ByteString
|
||
|
|
fileDigest = fmap MD5.hashlazy . BL.readFile
|
||
|
|
|
||
|
|
|
||
|
|
--------------------------------------------------------------------------------
|
||
|
|
resourceModificationTime :: Resource -> IO UTCTime
|
||
|
|
resourceModificationTime = getModificationTime . unResource
|