src/Text/Hakyll/Internal/Cache.hs · hakyll

on ee682ab help sign in

30 lines 1.2 kB history raw

1module Text.Hakyll.Internal.Cache

2 ( storeInCache

3 , getFromCache

4 , isCacheMoreRecent

5 ) where

7import Control.Monad ((<=<))

8import Control.Monad.Reader (liftIO)

9import Text.Hakyll.Hakyll (Hakyll)

10import Text.Hakyll.File

11import Data.Binary

13-- | We can store all datatypes instantiating @Binary@ to the cache. The cache

14-- directory is specified by the @HakyllConfiguration@, usually @_cache@.

15storeInCache :: (Binary a) => a -> FilePath -> Hakyll ()

16storeInCache value path = do

17 cachePath <- toCache path

18 makeDirectories cachePath

19 liftIO $ encodeFile cachePath value

21-- | Get a value from the cache. The filepath given should not be located in the

22-- cache. This function performs a timestamp check on the filepath and the

23-- filepath in the cache, and only returns the cached value when it is still

24-- up-to-date.

25getFromCache :: (Binary a) => FilePath -> Hakyll a

26getFromCache = liftIO . decodeFile <=< toCache

28-- | Check if a file in the cache is more recent than a number of other files.

29isCacheMoreRecent :: FilePath -> [FilePath] -> Hakyll Bool

30isCacheMoreRecent file depends = toCache file >>= flip isMoreRecent depends