hakyll/src/Hakyll/Core/Resource/Provider/Internal.hs

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2012-11-08 11:45:26 +00:00
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module Hakyll.Core.Resource.Provider.Internal
( ResourceProvider (..)
, newResourceProvider
, resourceList
, resourceExists
, resourceMetadataResource
, resourceString
, resourceLBS
) where
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import Control.Applicative ((<$>))
import qualified Data.ByteString.Lazy as BL
import Data.IORef
import Data.Map (Map)
import qualified Data.Map as M
import Data.Set (Set)
import qualified Data.Set as S
import System.FilePath (addExtension)
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import Hakyll.Core.Resource
import Hakyll.Core.Store
import Hakyll.Core.Util.File
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-- | Responsible for retrieving and listing resources
data ResourceProvider = ResourceProvider
{ -- | A list of all files found
resourceSet :: Set Resource
, -- | Cache keeping track of modified files
resourceModifiedCache :: IORef (Map Resource Bool)
, -- | Underlying persistent store for caching
resourceStore :: Store
}
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-- | Create a resource provider
newResourceProvider :: Store -- ^ Store to use
-> (FilePath -> Bool) -- ^ Should we ignore this file?
-> FilePath -- ^ Search directory
-> IO ResourceProvider -- ^ Resulting provider
newResourceProvider store ignore directory = do
list <- map resource . filter (not . ignore) <$>
getRecursiveContents False directory
cache <- newIORef M.empty
return $ ResourceProvider (S.fromList list) cache store
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resourceList :: ResourceProvider -> [Resource]
resourceList = S.toList . resourceSet
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-- | Check if a given resiyrce exists
resourceExists :: ResourceProvider -> Resource -> Bool
resourceExists provider = (`S.member` resourceSet provider)
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-- | Each resource may have an associated metadata resource (with a @.metadata@
-- filename)
resourceMetadataResource :: Resource -> Resource
resourceMetadataResource = resource . flip addExtension "metadata" . unResource
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-- | Get the raw body of a resource as string
resourceString :: Resource -> IO String
resourceString = readFile . unResource
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-- | Get the raw body of a resource of a lazy bytestring
resourceLBS :: Resource -> IO BL.ByteString
resourceLBS = BL.readFile . unResource