diff options
Diffstat (limited to 'Utility/InodeCache.hs')
| -rw-r--r-- | Utility/InodeCache.hs | 53 |
1 files changed, 31 insertions, 22 deletions
diff --git a/Utility/InodeCache.hs b/Utility/InodeCache.hs index b0718e0be..b3534487d 100644 --- a/Utility/InodeCache.hs +++ b/Utility/InodeCache.hs @@ -107,15 +107,17 @@ readInodeCache s = case words s of genInodeCache :: FilePath -> TSDelta -> IO (Maybe InodeCache) genInodeCache f delta = catchDefaultIO Nothing $ - toInodeCache delta <$> getFileStatus f - -toInodeCache :: TSDelta -> FileStatus -> Maybe InodeCache -toInodeCache (TSDelta delta) s - | isRegularFile s = Just $ InodeCache $ InodeCachePrim - (fileID s) - (fileSize s) - (modificationTime s + delta) - | otherwise = Nothing + toInodeCache delta =<< getFileStatus f + +toInodeCache :: TSDelta -> FileStatus -> IO (Maybe InodeCache) +toInodeCache (TSDelta getdelta) s + | isRegularFile s = do + delta <- getdelta + return $ Just $ InodeCache $ InodeCachePrim + (fileID s) + (fileSize s) + (modificationTime s + delta) + | otherwise = pure Nothing {- Some filesystem get new random inodes each time they are mounted. - To detect this and other problems, a sentinal file can be created. @@ -130,12 +132,13 @@ data SentinalFile = SentinalFile {- On Windows, the mtime of a file appears to change when the time zone is - changed. To deal with this, a TSDelta can be used; the delta is added to - the mtime when generating an InodeCache. The current delta can be found - - by looking at the SentinalFile. -} -newtype TSDelta = TSDelta EpochTime - deriving (Show) + - by looking at the SentinalFile. Effectively, this makes all InodeCaches + - use the same time zone that was in use when the sential file was + - originally written. -} +newtype TSDelta = TSDelta (IO EpochTime) noTSDelta :: TSDelta -noTSDelta = TSDelta 0 +noTSDelta = TSDelta (pure 0) writeSentinalFile :: SentinalFile -> IO () writeSentinalFile s = do @@ -147,16 +150,15 @@ data SentinalStatus = SentinalStatus { sentinalInodesChanged :: Bool , sentinalTSDelta :: TSDelta } - deriving (Show) {- Checks if the InodeCache of the sentinal file is the same - as it was when it was originally created. - - - On Windows, there's no change even when there is a nonzero - - TSDelta between the original and current InodeCaches. + - On Windows, time stamp differences are ignored, since they change + - with the timezone. - - - If the sential does not exist, returns a dummy value indicating - - that it's apparently changed. + - When the sential file does not exist, InodeCaches canot reliably be + - compared, so the assumption is that there is has been a change. -} checkSentinalFile :: SentinalFile -> IO SentinalStatus checkSentinalFile s = do @@ -172,14 +174,21 @@ checkSentinalFile s = do loadoldcache = catchDefaultIO Nothing $ readInodeCache <$> readFile (sentinalCacheFile s) gennewcache = genInodeCache (sentinalFile s) noTSDelta - calc (InodeCache (InodeCachePrim inode1 size1 mtime1)) (InodeCache (InodeCachePrim inode2 size2 mtime2)) = + calc (InodeCache (InodeCachePrim oldinode oldsize oldmtime)) (InodeCache (InodeCachePrim newinode newsize newmtime)) = SentinalStatus (not unchanged) tsdelta where #ifdef mingw32_HOST_OS - unchanged = inode1 == inode2 && size1 == size2 - tsdelta = TSDelta (mtime1 - mtime2) + unchanged = oldinode == newinode && oldsize == newsize + tsdelta = TSDelta $ do + -- Run when generating an InodeCache, + -- to get the current delta. + mnew <- gennewcache + return $ case mnew of + Just (InodeCache (InodeCachePrim _ _ currmtime)) -> + oldmtime - currmtime + Nothing -> 0 #else - unchanged = inode1 == inode2 && size1 == size2 && mtime1 == mtime2 + unchanged = oldinode == newinode && oldsize == newsize && oldmtime == newmtime tsdelta = noTSDelta #endif dummy = SentinalStatus True noTSDelta |