82a239675f
Check just before running update-index if the worktree file's content is still the same, don't update it when it's been modified. This narrows the race window a lot, from possibly minutes or hours, to seconds or less. (Use replaceFile so that the worktree update happens atomically, allowing the InodeCache of the new worktree file to itself be gathered w/o any other race.) This doesn't eliminate the race; it can still occur in the window before update-index runs. When annex.queue is large, a lot of files will be statted by the checks, and so the window may still be large enough to be a problem. When only a few files are being processed, the window is as small as it is in the race where a modification gets overwritten by git-annex when it updates the worktree. Or maybe as small as whatever race git checkout/pull/merge may have when the worktree gets modified during it. Still, I've kept a todo about this race. This commit was supported by the NSF-funded DataLad project.
86 lines
2 KiB
Haskell
86 lines
2 KiB
Haskell
{- git-annex command queue
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-
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- Copyright 2011, 2012 Joey Hess <id@joeyh.name>
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-
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- Licensed under the GNU GPL version 3 or higher.
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-}
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{-# LANGUAGE BangPatterns #-}
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module Annex.Queue (
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addCommand,
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addCommandCond,
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addUpdateIndex,
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flush,
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flushWhenFull,
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size,
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get,
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mergeFrom,
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) where
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import Annex.Common
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import Annex hiding (new)
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import qualified Git.Queue
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import qualified Git.UpdateIndex
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{- Adds a git command to the queue. -}
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addCommand :: String -> [CommandParam] -> [FilePath] -> Annex ()
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addCommand command params files = do
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q <- get
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store <=< flushWhenFull <=< inRepo $
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Git.Queue.addCommand command params files q
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addCommandCond :: String -> [CommandParam] -> [(FilePath, IO Bool)] -> Annex ()
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addCommandCond command params files = do
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q <- get
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store <=< flushWhenFull <=< inRepo $
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Git.Queue.addCommandCond command params files q
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{- Adds an update-index stream to the queue. -}
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addUpdateIndex :: Git.UpdateIndex.Streamer -> Annex ()
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addUpdateIndex streamer = do
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q <- get
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store <=< flushWhenFull <=< inRepo $
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Git.Queue.addUpdateIndex streamer q
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{- Runs the queue if it is full. -}
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flushWhenFull :: Git.Queue.Queue -> Annex Git.Queue.Queue
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flushWhenFull q
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| Git.Queue.full q = flush' q
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| otherwise = return q
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{- Runs (and empties) the queue. -}
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flush :: Annex ()
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flush = do
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q <- get
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unless (0 == Git.Queue.size q) $ do
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store =<< flush' q
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flush' :: Git.Queue.Queue -> Annex Git.Queue.Queue
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flush' q = do
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showStoringStateAction
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inRepo $ Git.Queue.flush q
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{- Gets the size of the queue. -}
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size :: Annex Int
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size = Git.Queue.size <$> get
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get :: Annex Git.Queue.Queue
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get = maybe new return =<< getState repoqueue
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new :: Annex Git.Queue.Queue
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new = do
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q <- Git.Queue.new . annexQueueSize <$> getGitConfig
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store q
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return q
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store :: Git.Queue.Queue -> Annex ()
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store q = changeState $ \s -> s { repoqueue = Just q }
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mergeFrom :: AnnexState -> Annex ()
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mergeFrom st = case repoqueue st of
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Nothing -> noop
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Just newq -> do
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q <- get
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let !q' = Git.Queue.merge q newq
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store =<< flushWhenFull q'
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