git-annex/Database/Keys.hs

266 lines
8.1 KiB
Haskell
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

{- Sqlite database of information about Keys
-
- Copyright 2015-2016 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE QuasiQuotes, TypeFamilies, TemplateHaskell #-}
{-# LANGUAGE OverloadedStrings, GADTs, FlexibleContexts #-}
{-# LANGUAGE MultiParamTypeClasses, GeneralizedNewtypeDeriving #-}
{-# LANGUAGE RankNTypes, ScopedTypeVariables #-}
module Database.Keys (
DbHandle,
addAssociatedFile,
getAssociatedFiles,
getAssociatedKey,
removeAssociatedFile,
scanAssociatedFiles,
storeInodeCaches,
addInodeCaches,
getInodeCaches,
removeInodeCaches,
AssociatedId,
ContentId,
) where
import Database.Types
import Database.Keys.Handle
import qualified Database.Queue as H
import Locations
import Common.Annex hiding (delete)
import qualified Annex
import Annex.Perms
import Annex.LockFile
import Utility.InodeCache
import Annex.InodeSentinal
import qualified Git.Types
import qualified Git.LsTree
import qualified Git.Branch
import Git.Ref
import Git.FilePath
import Annex.CatFile
import Database.Persist.TH
import Database.Esqueleto hiding (Key)
import Data.Time.Clock
share [mkPersist sqlSettings, mkMigrate "migrateKeysDb"] [persistLowerCase|
Associated
key SKey
file FilePath
KeyFileIndex key file
Content
key SKey
cache SInodeCache
KeyCacheIndex key cache
|]
newtype ReadHandle = ReadHandle H.DbQueue
type Reader v = ReadHandle -> Annex v
{- Runs an action that reads from the database.
-
- If the database doesn't already exist, it's not created; mempty is
- returned instead. This way, when the keys database is not in use,
- there's minimal overhead in checking it.
-
- If the database is already open, any writes are flushed to it, to ensure
- consistency.
-
- Any queued writes will be flushed before the read.
-}
runReader :: Monoid v => Reader v -> Annex v
runReader a = do
h <- getDbHandle
withDbState h go
where
go DbEmpty = return (mempty, DbEmpty)
go st@(DbOpen qh) = do
liftIO $ H.flushDbQueue qh
v <- a (ReadHandle qh)
return (v, st)
go DbClosed = do
st' <- openDb False DbClosed
v <- case st' of
(DbOpen qh) -> a (ReadHandle qh)
_ -> return mempty
return (v, st')
readDb :: SqlPersistM a -> ReadHandle -> Annex a
readDb a (ReadHandle h) = liftIO $ H.queryDbQueue h a
newtype WriteHandle = WriteHandle H.DbQueue
type Writer = WriteHandle -> Annex ()
{- Runs an action that writes to the database. Typically this is used to
- queue changes, which will be flushed at a later point.
-
- The database is created if it doesn't exist yet. -}
runWriter :: Writer -> Annex ()
runWriter a = do
h <- getDbHandle
withDbState h go
where
go st@(DbOpen qh) = do
v <- a (WriteHandle qh)
return (v, st)
go st = do
st' <- openDb True st
v <- case st' of
DbOpen qh -> a (WriteHandle qh)
_ -> error "internal"
return (v, st')
queueDb :: SqlPersistM () -> WriteHandle -> Annex ()
queueDb a (WriteHandle h) = liftIO $ H.queueDb h checkcommit a
where
-- commit queue after 1000 changes or 5 minutes, whichever comes first
checkcommit sz lastcommittime
| sz > 1000 = return True
| otherwise = do
now <- getCurrentTime
return $ diffUTCTime lastcommittime now > 300
{- Gets the handle cached in Annex state; creates a new one if it's not yet
- available, but doesn't open the database. -}
getDbHandle :: Annex DbHandle
getDbHandle = go =<< Annex.getState Annex.keysdbhandle
where
go (Just h) = pure h
go Nothing = do
h <- liftIO newDbHandle
Annex.changeState $ \s -> s { Annex.keysdbhandle = Just h }
return h
{- Opens the database, perhaps creating it if it doesn't exist yet.
-
- Multiple readers and writers can have the database open at the same
- time. Database.Handle deals with the concurrency issues.
- The lock is held while opening the database, so that when
- the database doesn't exist yet, one caller wins the lock and
- can create it undisturbed.
-}
openDb :: Bool -> DbState -> Annex DbState
openDb _ st@(DbOpen _) = return st
openDb False DbEmpty = return DbEmpty
openDb createdb _ = withExclusiveLock gitAnnexKeysDbLock $ do
dbdir <- fromRepo gitAnnexKeysDb
let db = dbdir </> "db"
dbexists <- liftIO $ doesFileExist db
case (dbexists, createdb) of
(True, _) -> open db
(False, True) -> do
liftIO $ do
createDirectoryIfMissing True dbdir
H.initDb db $ void $
runMigrationSilent migrateKeysDb
setAnnexDirPerm dbdir
setAnnexFilePerm db
open db
(False, False) -> return DbEmpty
where
open db = liftIO $ DbOpen <$> H.openDbQueue db "content"
addAssociatedFile :: Key -> TopFilePath -> Annex ()
addAssociatedFile k f = runWriter $ addAssociatedFile' k f
addAssociatedFile' :: Key -> TopFilePath -> Writer
addAssociatedFile' k f = queueDb $ do
-- If the same file was associated with a different key before,
-- remove that.
delete $ from $ \r -> do
where_ (r ^. AssociatedFile ==. val (getTopFilePath f) &&. not_ (r ^. AssociatedKey ==. val sk))
void $ insertUnique $ Associated sk (getTopFilePath f)
where
sk = toSKey k
{- Note that the files returned were once associated with the key, but
- some of them may not be any longer. -}
getAssociatedFiles :: Key -> Annex [TopFilePath]
getAssociatedFiles = runReader . getAssociatedFiles' . toSKey
getAssociatedFiles' :: SKey -> Reader [TopFilePath]
getAssociatedFiles' sk = readDb $ do
l <- select $ from $ \r -> do
where_ (r ^. AssociatedKey ==. val sk)
return (r ^. AssociatedFile)
return $ map (asTopFilePath . unValue) l
{- Gets any keys that are on record as having a particular associated file.
- (Should be one or none but the database doesn't enforce that.) -}
getAssociatedKey :: TopFilePath -> Annex [Key]
getAssociatedKey = runReader . getAssociatedKey'
getAssociatedKey' :: TopFilePath -> Reader [Key]
getAssociatedKey' f = readDb $ do
l <- select $ from $ \r -> do
where_ (r ^. AssociatedFile ==. val (getTopFilePath f))
return (r ^. AssociatedKey)
return $ map (fromSKey . unValue) l
removeAssociatedFile :: Key -> TopFilePath -> Annex ()
removeAssociatedFile k = runWriter . removeAssociatedFile' (toSKey k)
removeAssociatedFile' :: SKey -> TopFilePath -> Writer
removeAssociatedFile' sk f = queueDb $
delete $ from $ \r -> do
where_ (r ^. AssociatedKey ==. val sk &&. r ^. AssociatedFile ==. val (getTopFilePath f))
{- Find all unlocked associated files. This is expensive, and so normally
- the associated files are updated incrementally when changes are noticed. -}
scanAssociatedFiles :: Annex ()
scanAssociatedFiles = whenM (isJust <$> inRepo Git.Branch.current) $
runWriter $ \h -> do
showSideAction "scanning for unlocked files"
dropallassociated h
(l, cleanup) <- inRepo $ Git.LsTree.lsTree headRef
forM_ l $ \i ->
when (isregfile i) $
maybe noop (add h i)
=<< catKey (Git.LsTree.sha i)
liftIO $ void cleanup
where
dropallassociated = queueDb $
delete $ from $ \(_r :: SqlExpr (Entity Associated)) ->
return ()
isregfile i = Git.Types.toBlobType (Git.LsTree.mode i) == Just Git.Types.FileBlob
add h i k = flip queueDb h $
void $ insertUnique $ Associated
(toSKey k)
(getTopFilePath $ Git.LsTree.file i)
{- Stats the files, and stores their InodeCaches. -}
storeInodeCaches :: Key -> [FilePath] -> Annex ()
storeInodeCaches k fs = withTSDelta $ \d ->
addInodeCaches k . catMaybes =<< liftIO (mapM (`genInodeCache` d) fs)
addInodeCaches :: Key -> [InodeCache] -> Annex ()
addInodeCaches k is = runWriter $ addInodeCaches' (toSKey k) is
addInodeCaches' :: SKey -> [InodeCache] -> Writer
addInodeCaches' sk is = queueDb $
forM_ is $ \i -> insertUnique $ Content sk (toSInodeCache i)
{- A key may have multiple InodeCaches; one for the annex object, and one
- for each pointer file that is a copy of it. -}
getInodeCaches :: Key -> Annex [InodeCache]
getInodeCaches = runReader . getInodeCaches' . toSKey
getInodeCaches' :: SKey -> Reader [InodeCache]
getInodeCaches' sk = readDb $ do
l <- select $ from $ \r -> do
where_ (r ^. ContentKey ==. val sk)
return (r ^. ContentCache)
return $ map (fromSInodeCache. unValue) l
removeInodeCaches :: Key -> Annex ()
removeInodeCaches = runWriter . removeInodeCaches' . toSKey
removeInodeCaches' :: SKey -> Writer
removeInodeCaches' sk = queueDb $
delete $ from $ \r -> do
where_ (r ^. ContentKey ==. val sk)