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-rw-r--r--src/Hakyll/Core/Resource/Provider.hs39
1 files changed, 27 insertions, 12 deletions
diff --git a/src/Hakyll/Core/Resource/Provider.hs b/src/Hakyll/Core/Resource/Provider.hs
index ebd5984..2ed7797 100644
--- a/src/Hakyll/Core/Resource/Provider.hs
+++ b/src/Hakyll/Core/Resource/Provider.hs
@@ -1,3 +1,4 @@
+--------------------------------------------------------------------------------
-- | This module provides an API for resource providers. Resource providers
-- allow Hakyll to get content from resources; the type of resource depends on
-- the concrete instance.
@@ -19,22 +20,30 @@ module Hakyll.Core.Resource.Provider
, resourceModified
) where
+
+--------------------------------------------------------------------------------
import Control.Applicative ((<$>))
import Control.Concurrent (MVar, readMVar, modifyMVar_, newMVar)
import Data.Map (Map)
import qualified Data.Map as M
import qualified Data.Set as S
+
+--------------------------------------------------------------------------------
import Data.Time (UTCTime)
import qualified Crypto.Hash.MD5 as MD5
import qualified Data.ByteString as B
import qualified Data.ByteString.Lazy as LB
-import Hakyll.Core.Store
+
+--------------------------------------------------------------------------------
+import Hakyll.Core.Store (Store)
import Hakyll.Core.Resource
+import qualified Hakyll.Core.Store as Store
+
+--------------------------------------------------------------------------------
-- | A value responsible for retrieving and listing resources
---
data ResourceProvider = ResourceProvider
{ -- | A set of all resources this provider is able to provide
resourceSet :: S.Set Resource
@@ -48,8 +57,9 @@ data ResourceProvider = ResourceProvider
resourceModifiedCache :: MVar (Map Resource Bool)
}
+
+--------------------------------------------------------------------------------
-- | Create a resource provider
---
makeResourceProvider :: [Resource] -- ^ Resource list
-> (Resource -> IO String) -- ^ String reader
-> (Resource -> IO LB.ByteString) -- ^ ByteString reader
@@ -58,22 +68,27 @@ makeResourceProvider :: [Resource] -- ^ Resource list
makeResourceProvider l s b t =
ResourceProvider (S.fromList l) s b t <$> newMVar M.empty
+
+--------------------------------------------------------------------------------
-- | Get the list of all resources
resourceList :: ResourceProvider -> [Resource]
resourceList = S.toList . resourceSet
+
+--------------------------------------------------------------------------------
-- | Check if a given identifier has a resource
---
resourceExists :: ResourceProvider -> Resource -> Bool
resourceExists provider = flip S.member $ resourceSet provider
+
+--------------------------------------------------------------------------------
-- | Retrieve a digest for a given resource
---
resourceDigest :: ResourceProvider -> Resource -> IO B.ByteString
resourceDigest provider = fmap MD5.hashlazy . resourceLBS provider
+
+--------------------------------------------------------------------------------
-- | Check if a resource was modified
---
resourceModified :: ResourceProvider -> Store -> Resource -> IO Bool
resourceModified provider store r = do
cache <- readMVar mvar
@@ -90,21 +105,21 @@ resourceModified provider store r = do
where
mvar = resourceModifiedCache provider
+
+--------------------------------------------------------------------------------
-- | Check if a resource digest was modified
---
digestModified :: ResourceProvider -> Store -> Resource -> IO Bool
digestModified provider store r = do
-- Get the latest seen digest from the store
- lastDigest <- storeGet store itemName identifier
+ lastDigest <- Store.get store key
-- Calculate the digest for the resource
newDigest <- resourceDigest provider r
-- Check digests
- if Found newDigest == lastDigest
+ if Store.Found newDigest == lastDigest
-- All is fine, not modified
then return False
-- Resource modified; store new digest
- else do storeSet store itemName identifier newDigest
+ else do Store.set store key newDigest
return True
where
- identifier = toIdentifier r
- itemName = "Hakyll.Core.ResourceProvider.digestModified"
+ key = ["Hakyll.Core.ResourceProvider.digestModified", unResource r]