Merge pull request #142 from justnoxx/master

Added isMember function.

2 files changed, 24 insertions, 7 deletions

diff --git a/src/Hakyll/Core/Provider/MetadataCache.hs b/src/Hakyll/Core/Provider/MetadataCache.hs
index 077bad2..031960c 100644
--- a/src/Hakyll/Core/Provider/MetadataCache.hs
+++ b/src/Hakyll/Core/Provider/MetadataCache.hs
@@ -8,7 +8,7 @@ module Hakyll.Core.Provider.MetadataCache
 
 --------------------------------------------------------------------------------
 import qualified Data.Map                      as M
-
+import Control.Monad (unless)
 
 --------------------------------------------------------------------------------
 import           Hakyll.Core.Identifier
@@ -49,12 +49,8 @@ resourceInvalidateMetadataCache p r = do
 --------------------------------------------------------------------------------
 load :: Provider -> Identifier -> IO ()
 load p r = do
-    mmd <- Store.get store mdk :: IO (Store.Result Metadata)
-    case mmd of
-        -- Already loaded
-        Store.Found _  -> return ()
-        -- Not yet loaded
-        _ -> do
+    mmof <- Store.isMember store mdk
+    unless mmof $ do
             (md, body) <- loadMetadata p r
             Store.set store mdk md
             Store.set store bk  body
diff --git a/src/Hakyll/Core/Store.hs b/src/Hakyll/Core/Store.hs
index 1208c84..b2c61a0 100644
--- a/src/Hakyll/Core/Store.hs
+++ b/src/Hakyll/Core/Store.hs
@@ -9,6 +9,7 @@ module Hakyll.Core.Store
     , new
     , set
     , get
+    , isMember
     , delete
     , hash
     ) where
@@ -101,6 +102,16 @@ cacheLookup (Store _ (Just lru)) key = do
 
 
 --------------------------------------------------------------------------------
+cacheIsMember :: Store -> String -> IO Bool
+cacheIsMember (Store _ Nothing) _ =  return False
+cacheIsMember (Store _ (Just lru)) key = do
+    res <- Lru.lookup key lru
+    case res of
+        Nothing -> return False
+        _       -> return True
+
+
+--------------------------------------------------------------------------------
 -- | Auxiliary: delete an item from the in-memory cache
 cacheDelete :: Store -> String -> IO ()
 cacheDelete (Store _ Nothing)    _   = return ()
@@ -152,6 +163,16 @@ get store identifier = do
 
 
 --------------------------------------------------------------------------------
+-- | Strict function
+isMember :: Store -> [String] -> IO Bool
+isMember store identifier = do
+    inCache <- cacheIsMember store key
+    if inCache then return True else doesFileExist path
+    where
+        key = hash identifier
+        path = storeDirectory store </> key
+
+--------------------------------------------------------------------------------
 -- | Delete an item
 delete :: Store -> [String] -> IO ()
 delete store identifier = do