diff options
Diffstat (limited to 'Utility')
| -rw-r--r-- | Utility/InodeCache.hs | 60 |
1 files changed, 44 insertions, 16 deletions
diff --git a/Utility/InodeCache.hs b/Utility/InodeCache.hs index 1d3f17887..e08abc6ad 100644 --- a/Utility/InodeCache.hs +++ b/Utility/InodeCache.hs @@ -11,22 +11,46 @@ import Common import System.Posix.Types import Utility.QuickCheck -data InodeCache = InodeCache FileID FileOffset EpochTime +data InodeCachePrim = InodeCachePrim FileID FileOffset EpochTime + deriving (Show, Eq, Ord) + +newtype InodeCache = InodeCache InodeCachePrim deriving (Show) +{- Inode caches can be compared in two different ways, either weakly + - or strongly. -} +data InodeComparisonType = Weakly | Strongly + deriving (Eq, Ord) + +{- Strong comparison, including inodes. -} compareStrong :: InodeCache -> InodeCache -> Bool -compareStrong (InodeCache inode1 size1 mtime1) (InodeCache inode2 size2 mtime2) = - inode1 == inode2 && size1 == size2 && mtime1 == mtime2 +compareStrong (InodeCache x) (InodeCache y) = x == y -{- Weak comparison of the inode caches, comparing the size and mtime, but - - not the actual inode. Useful when inodes have changed, perhaps +{- Weak comparison of the inode caches, comparing the size and mtime, + - but not the actual inode. Useful when inodes have changed, perhaps - due to some filesystems being remounted. -} compareWeak :: InodeCache -> InodeCache -> Bool -compareWeak (InodeCache _ size1 mtime1) (InodeCache _ size2 mtime2) = +compareWeak (InodeCache (InodeCachePrim _ size1 mtime1)) (InodeCache (InodeCachePrim _ size2 mtime2)) = size1 == size2 && mtime1 == mtime2 +compareBy :: InodeComparisonType -> InodeCache -> InodeCache -> Bool +compareBy Strongly = compareStrong +compareBy Weakly = compareWeak + +{- For use in a Map; it's determined at creation time whether this + - uses strong or weak comparison for Eq. -} +data InodeCacheKey = InodeCacheKey InodeComparisonType InodeCachePrim + deriving (Ord) + +instance Eq InodeCacheKey where + (InodeCacheKey ctx x) == (InodeCacheKey cty y) = + compareBy (maximum [ctx,cty]) (InodeCache x ) (InodeCache y) + +inodeCacheToKey :: InodeComparisonType -> InodeCache -> InodeCacheKey +inodeCacheToKey ct (InodeCache prim) = InodeCacheKey ct prim + showInodeCache :: InodeCache -> String -showInodeCache (InodeCache inode size mtime) = unwords +showInodeCache (InodeCache (InodeCachePrim inode size mtime)) = unwords [ show inode , show size , show mtime @@ -34,10 +58,12 @@ showInodeCache (InodeCache inode size mtime) = unwords readInodeCache :: String -> Maybe InodeCache readInodeCache s = case words s of - (inode:size:mtime:_) -> InodeCache - <$> readish inode - <*> readish size - <*> readish mtime + (inode:size:mtime:_) -> + let prim = InodeCachePrim + <$> readish inode + <*> readish size + <*> readish mtime + in InodeCache <$> prim _ -> Nothing genInodeCache :: FilePath -> IO (Maybe InodeCache) @@ -45,17 +71,19 @@ genInodeCache f = catchDefaultIO Nothing $ toInodeCache <$> getFileStatus f toInodeCache :: FileStatus -> Maybe InodeCache toInodeCache s - | isRegularFile s = Just $ InodeCache + | isRegularFile s = Just $ InodeCache $ InodeCachePrim (fileID s) (fileSize s) (modificationTime s) | otherwise = Nothing instance Arbitrary InodeCache where - arbitrary = InodeCache - <$> arbitrary - <*> arbitrary - <*> arbitrary + arbitrary = + let prim = InodeCachePrim + <$> arbitrary + <*> arbitrary + <*> arbitrary + in InodeCache <$> prim prop_read_show_inodecache :: InodeCache -> Bool prop_read_show_inodecache c = case readInodeCache (showInodeCache c) of |