git-annex/Annex/Import.hs
2020-02-21 10:04:44 -04:00

505 lines
18 KiB
Haskell

{- git-annex import from remotes
-
- Copyright 2019 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
{-# LANGUAGE OverloadedStrings #-}
module Annex.Import (
ImportTreeConfig(..),
ImportCommitConfig(..),
buildImportCommit,
buildImportTrees,
downloadImport,
filterImportableContents,
makeImportMatcher,
listImportableContents,
) where
import Annex.Common
import Types.Import
import qualified Types.Remote as Remote
import Git.Types
import Git.Tree
import Git.Sha
import Git.FilePath
import Git.History
import qualified Git.Ref
import qualified Git.Branch
import qualified Annex
import Annex.Link
import Annex.LockFile
import Annex.Content
import Annex.Export
import Annex.RemoteTrackingBranch
import Command
import Backend
import Types.Key
import Types.KeySource
import Messages.Progress
import Utility.DataUnits
import Utility.Metered
import Logs.Export
import Logs.Location
import Logs.PreferredContent
import Types.FileMatcher
import Annex.FileMatcher
import Utility.Matcher (isEmpty)
import qualified Database.Export as Export
import qualified Database.ContentIdentifier as CIDDb
import qualified Logs.ContentIdentifier as CIDLog
import Control.Concurrent.STM
import qualified Data.Map.Strict as M
import qualified Data.Set as S
import qualified System.FilePath.Posix as Posix
import qualified System.FilePath.ByteString as P
{- Configures how to build an import tree. -}
data ImportTreeConfig
= ImportTree
-- ^ Import the tree as-is from the remote.
| ImportSubTree TopFilePath Sha
-- ^ Import a tree from the remote and graft it into a subdirectory
-- of the existing tree whose Sha is provided, replacing anything
-- that was there before.
deriving (Show)
{- Configures how to build an import commit. -}
data ImportCommitConfig = ImportCommitConfig
{ importCommitTracking :: Maybe Sha
-- ^ Current commit on the remote tracking branch.
, importCommitMode :: Git.Branch.CommitMode
, importCommitMessage :: String
}
{- Buils a commit for an import from a special remote.
-
- When there are no changes to make (importCommitTracking
- already matches what was imported), returns Nothing.
-
- After importing from a remote, exporting the same thing back to the
- remote should be a no-op. So, the export log and database are
- updated to reflect the imported tree.
-
- This does not download any content from a remote. But since it needs the
- Key of imported files to be known, its caller will have to first download
- new files in order to generate keys for them.
-}
buildImportCommit
:: Remote
-> ImportTreeConfig
-> ImportCommitConfig
-> ImportableContents Key
-> Annex (Maybe Ref)
buildImportCommit remote importtreeconfig importcommitconfig importable =
case importCommitTracking importcommitconfig of
Nothing -> go Nothing
Just trackingcommit -> inRepo (Git.Ref.tree trackingcommit) >>= \case
Nothing -> go Nothing
Just _ -> go (Just trackingcommit)
where
basetree = case importtreeconfig of
ImportTree -> emptyTree
ImportSubTree _ sha -> sha
subdir = case importtreeconfig of
ImportTree -> Nothing
ImportSubTree dir _ -> Just dir
go trackingcommit = do
imported@(History finaltree _) <-
buildImportTrees basetree subdir importable
buildImportCommit' remote importcommitconfig trackingcommit imported >>= \case
Just finalcommit -> do
updatestate finaltree
return (Just finalcommit)
Nothing -> return Nothing
updatestate committedtree = do
importedtree <- case subdir of
Nothing -> pure committedtree
Just dir ->
let subtreeref = Ref $
fromRef committedtree ++ ":" ++ fromRawFilePath (getTopFilePath dir)
in fromMaybe emptyTree
<$> inRepo (Git.Ref.tree subtreeref)
updateexportdb importedtree
oldexport <- updateexportlog importedtree
updatelocationlog oldexport importedtree
updateexportdb importedtree = do
db <- Export.openDb (Remote.uuid remote)
Export.writeLockDbWhile db $ do
prevtree <- liftIO $ fromMaybe emptyTree
<$> Export.getExportTreeCurrent db
when (importedtree /= prevtree) $ do
Export.updateExportDb db prevtree importedtree
liftIO $ Export.recordExportTreeCurrent db importedtree
Export.closeDb db
updateexportlog importedtree = do
oldexport <- getExport (Remote.uuid remote)
recordExport (Remote.uuid remote) $ ExportChange
{ oldTreeish = exportedTreeishes oldexport
, newTreeish = importedtree
}
return oldexport
-- downloadImport takes care of updating the location log
-- for the local repo when keys are downloaded, and also updates
-- the location log for the remote for keys that are present in it.
-- That leaves updating the location log for the remote for keys
-- that have had the last copy of their content removed from it.
--
-- This must run after the export database has been updated
-- and flushed to disk, so it can query it.
updatelocationlog oldexport finaltree = do
let stillpresent db k = liftIO $ not . null
<$> Export.getExportedLocation db k
let updater db oldkey _newkey _ = case oldkey of
Just (AnnexKey k) -> unlessM (stillpresent db k) $
logChange k (Remote.uuid remote) InfoMissing
Just (GitKey _) -> noop
Nothing -> noop
db <- Export.openDb (Remote.uuid remote)
forM_ (exportedTreeishes oldexport) $ \oldtree ->
Export.runExportDiffUpdater updater db oldtree finaltree
Export.closeDb db
buildImportCommit' :: Remote -> ImportCommitConfig -> Maybe Sha -> History Sha -> Annex (Maybe Sha)
buildImportCommit' remote importcommitconfig mtrackingcommit imported@(History ti _) =
case mtrackingcommit of
Nothing -> Just <$> mkcommitsunconnected imported
Just trackingcommit -> do
-- Get history of tracking branch to at most
-- one more level deep than what was imported,
-- so we'll have enough history to compare,
-- but not spend too much time getting it.
let maxdepth = succ importeddepth
inRepo (getHistoryToDepth maxdepth trackingcommit)
>>= go trackingcommit
where
go _ Nothing = Just <$> mkcommitsunconnected imported
go trackingcommit (Just h)
-- If the tracking branch head is a merge commit
-- and one side of the merge matches the history,
-- nothing new needs to be committed.
| t == ti && any sametodepth (S.toList s) = return Nothing
-- If the tracking branch matches the history,
-- nothing new needs to be committed.
-- (This is unlikely to happen.)
| sametodepth h' = return Nothing
| otherwise = do
importedcommit <- case getRemoteTrackingBranchImportHistory h of
Nothing -> mkcommitsunconnected imported
Just oldimported@(History oldhc _)
| importeddepth == 1 ->
mkcommitconnected imported oldimported
| otherwise -> do
let oldimportedtrees = mapHistory historyCommitTree oldimported
mknewcommits oldhc oldimportedtrees imported
ti' <- addBackExportExcluded remote ti
Just <$> makeRemoteTrackingBranchMergeCommit'
trackingcommit importedcommit ti'
where
h'@(History t s) = mapHistory historyCommitTree h
importeddepth = historyDepth imported
sametodepth b = imported == truncateHistoryToDepth importeddepth b
mkcommit parents tree = inRepo $ Git.Branch.commitTree
(importCommitMode importcommitconfig)
(importCommitMessage importcommitconfig)
parents
tree
-- Start a new history of import commits, not connected to any
-- prior import commits.
mkcommitsunconnected (History importedtree hs) = do
parents <- mapM mkcommitsunconnected (S.toList hs)
mkcommit parents importedtree
-- Commit the new history connected with the old history.
-- Used when the import is not versioned, so the history depth is 1.
mkcommitconnected (History importedtree _) (History oldhc _) = do
let parents = [historyCommit oldhc]
mkcommit parents importedtree
-- Reuse the commits from the old imported History when possible.
mknewcommits oldhc old new@(History importedtree hs)
| old == new = return $ historyCommit oldhc
| otherwise = do
parents <- mapM (mknewcommits oldhc old) (S.toList hs)
mkcommit parents importedtree
{- Builds a history of git trees reflecting the ImportableContents.
-
- When a subdir is provided, imported tree is grafted into the basetree at
- that location, replacing any object that was there.
-}
buildImportTrees
:: Ref
-> Maybe TopFilePath
-> ImportableContents Key
-> Annex (History Sha)
buildImportTrees basetree msubdir importable = History
<$> (buildtree (importableContents importable) =<< Annex.gitRepo)
<*> buildhistory
where
buildhistory = S.fromList
<$> mapM (buildImportTrees basetree msubdir)
(importableHistory importable)
buildtree ls repo = withMkTreeHandle repo $ \hdl -> do
importtree <- liftIO . recordTree' hdl
. treeItemsToTree
=<< mapM mktreeitem ls
case msubdir of
Nothing -> return importtree
Just subdir -> liftIO $
graftTree' importtree subdir basetree repo hdl
mktreeitem (loc, k) = do
let lf = fromImportLocation loc
let treepath = asTopFilePath lf
let topf = asTopFilePath $
maybe lf (\sd -> getTopFilePath sd P.</> lf) msubdir
relf <- fromRepo $ fromTopFilePath topf
symlink <- calcRepo $ gitAnnexLink (fromRawFilePath relf) k
linksha <- hashSymlink symlink
return $ TreeItem treepath (fromTreeItemType TreeSymlink) linksha
{- Downloads all new ContentIdentifiers as needed to generate Keys.
- Supports concurrency when enabled.
-
- If any download fails, the whole thing fails with Nothing,
- but it will resume where it left off.
-}
downloadImport :: Remote -> ImportTreeConfig -> ImportableContents (ContentIdentifier, ByteSize) -> Annex (Maybe (ImportableContents Key))
downloadImport remote importtreeconfig importablecontents = do
-- This map is used to remember content identifiers that
-- were just downloaded, before they have necessarily been
-- stored in the database. This way, if the same content
-- identifier appears multiple times in the
-- importablecontents (eg when it has a history),
-- they will only be downloaded once.
cidmap <- liftIO $ newTVarIO M.empty
-- When concurrency is enabled, this set is needed to
-- avoid two threads both downloading the same content identifier.
downloading <- liftIO $ newTVarIO S.empty
withExclusiveLock gitAnnexContentIdentifierLock $
bracket CIDDb.openDb CIDDb.closeDb $ \db -> do
CIDDb.needsUpdateFromLog db
>>= maybe noop (CIDDb.updateFromLog db)
go False cidmap downloading importablecontents db
where
go oldversion cidmap downloading (ImportableContents l h) db = do
jobs <- forM l $ \i ->
startdownload cidmap downloading db i oldversion
l' <- liftIO $ forM jobs $
either pure (atomically . takeTMVar)
if any isNothing l'
then return Nothing
else do
h' <- mapM (\ic -> go True cidmap downloading ic db) h
if any isNothing h'
then return Nothing
else return $ Just $
ImportableContents
(catMaybes l')
(catMaybes h')
waitstart downloading cid = liftIO $ atomically $ do
s <- readTVar downloading
if S.member cid s
then retry
else writeTVar downloading $ S.insert cid s
signaldone downloading cid = liftIO $ atomically $ do
s <- readTVar downloading
writeTVar downloading $ S.delete cid s
startdownload cidmap downloading db i@(loc, (cid, _sz)) oldversion = getcidkey cidmap db cid >>= \case
(k:_) -> return $ Left $ Just (loc, k)
[] -> do
job <- liftIO $ newEmptyTMVarIO
let ai = ActionItemOther (Just (fromRawFilePath (fromImportLocation loc)))
let downloadaction = starting ("import " ++ Remote.name remote) ai $ do
when oldversion $
showNote "old version"
tryNonAsync (download cidmap db i) >>= \case
Left e -> next $ do
warning (show e)
liftIO $ atomically $
putTMVar job Nothing
return False
Right r -> next $ do
liftIO $ atomically $
putTMVar job r
return True
commandAction $ bracket_
(waitstart downloading cid)
(signaldone downloading cid)
downloadaction
return (Right job)
download cidmap db (loc, (cid, sz)) = do
let rundownload tmpfile p =
Remote.retrieveExportWithContentIdentifier ia loc cid tmpfile (mkkey loc tmpfile) p >>= \case
Just k -> tryNonAsync (moveAnnex k tmpfile) >>= \case
Right True -> do
recordcidkey cidmap db cid k
logStatus k InfoPresent
logChange k (Remote.uuid remote) InfoPresent
return $ Just (loc, k)
_ -> return Nothing
Nothing -> return Nothing
checkDiskSpaceToGet tmpkey Nothing $
withTmp tmpkey $ \tmpfile ->
metered Nothing tmpkey $
const (rundownload tmpfile)
where
ia = Remote.importActions remote
tmpkey = importKey cid sz
mkkey loc tmpfile = do
f <- fromRepo $ fromTopFilePath $ locworktreefilename loc
backend <- chooseBackend (fromRawFilePath f)
let ks = KeySource
{ keyFilename = f
, contentLocation = toRawFilePath tmpfile
, inodeCache = Nothing
}
fmap fst <$> genKey ks nullMeterUpdate backend
locworktreefilename loc = asTopFilePath $ case importtreeconfig of
ImportTree -> fromImportLocation loc
ImportSubTree subdir _ ->
getTopFilePath subdir P.</> fromImportLocation loc
getcidkey cidmap db cid = liftIO $
CIDDb.getContentIdentifierKeys db rs cid >>= \case
[] -> atomically $
maybeToList . M.lookup cid <$> readTVar cidmap
l -> return l
recordcidkey cidmap db cid k = do
liftIO $ atomically $ modifyTVar' cidmap $
M.insert cid k
liftIO $ CIDDb.recordContentIdentifier db rs cid k
CIDLog.recordContentIdentifier rs cid k
rs = Remote.remoteStateHandle remote
{- Temporary key used for import of a ContentIdentifier while downloading
- content, before generating its real key. -}
importKey :: ContentIdentifier -> Integer -> Key
importKey (ContentIdentifier cid) size = mkKey $ \k -> k
{ keyName = cid
, keyVariety = OtherKey "CID"
, keySize = Just size
}
{-- Export omits non-preferred content from the tree stored on the
-- remote. So the import will normally have that content
-- omitted (unless something else added files with the same names to the
-- special remote).
--
-- That presents a problem: Merging the imported tree would result
-- in deletion of the files that were excluded from export.
-- To avoid that happening, this adds them back to the imported tree.
--}
addBackExportExcluded :: Remote -> Sha -> Annex Sha
addBackExportExcluded remote importtree =
getExportExcluded (Remote.uuid remote) >>= \case
[] -> return importtree
excludedlist -> inRepo $
adjustTree
-- don't remove any
(pure . Just)
excludedlist
-- if something was imported with the same
-- name as a file that was previously
-- excluded from import, use what was imported
(\imported _excluded -> imported)
[]
importtree
{- Match the preferred content of the remote at import time.
-
- Only keyless tokens are supported, because the keys are not known
- until an imported file is downloaded, which is too late to bother
- excluding it from an import.
-}
makeImportMatcher :: Remote -> Annex (Either String (FileMatcher Annex))
makeImportMatcher r = load preferredContentKeylessTokens >>= \case
Nothing -> return $ Right matchAll
Just (Right v) -> return $ Right v
Just (Left err) -> load preferredContentTokens >>= \case
Just (Left err') -> return $ Left err'
_ -> return $ Left $
"The preferred content expression contains terms that cannot be checked when importing: " ++ err
where
load t = M.lookup (Remote.uuid r) . fst <$> preferredRequiredMapsLoad' t
wantImport :: FileMatcher Annex -> ImportLocation -> ByteSize -> Annex Bool
wantImport matcher loc sz = checkMatcher' matcher mi mempty
where
mi = MatchingInfo $ ProvidedInfo
{ providedFilePath = Right $ fromRawFilePath $ fromImportLocation loc
, providedKey = unavail "key"
, providedFileSize = Right sz
, providedMimeType = unavail "mime"
, providedMimeEncoding = unavail "mime"
}
-- This should never run, as long as the FileMatcher was generated
-- using the preferredContentKeylessTokens.
unavail v = Left $ error $ "Internal error: unavailable " ++ v
{- If a file is not preferred content, but it was previously exported or
- imported to the remote, not importing it would result in a remote
- tracking branch that, when merged, would delete the file.
-
- To avoid that problem, such files are included in the import.
- The next export will remove them from the remote.
-}
shouldImport :: Export.ExportHandle -> FileMatcher Annex -> ImportLocation -> ByteSize -> Annex Bool
shouldImport dbhandle matcher loc sz =
wantImport matcher loc sz
<||>
liftIO (not . null <$> Export.getExportTreeKey dbhandle loc)
filterImportableContents :: Remote -> FileMatcher Annex -> ImportableContents (ContentIdentifier, ByteSize) -> Annex (ImportableContents (ContentIdentifier, ByteSize))
filterImportableContents r matcher importable
| isEmpty matcher = return importable
| otherwise = do
dbhandle <- Export.openDb (Remote.uuid r)
go dbhandle importable
where
go dbhandle ic = ImportableContents
<$> filterM (match dbhandle) (importableContents ic)
<*> mapM (go dbhandle) (importableHistory ic)
match dbhandle (loc, (_cid, sz)) = shouldImport dbhandle matcher loc sz
{- Gets the ImportableContents from the remote.
-
- Filters out any paths that include a ".git" component, because git does
- not allow storing ".git" in a git repository. While it is possible to
- write a git tree that contains that, git will complain and refuse to
- check it out.
-}
listImportableContents :: Remote -> Annex (Maybe (ImportableContents (ContentIdentifier, ByteSize)))
listImportableContents r = fmap removegitspecial
<$> Remote.listImportableContents (Remote.importActions r)
where
removegitspecial ic = ImportableContents
{ importableContents =
filter (not . gitspecial . fst) (importableContents ic)
, importableHistory =
map removegitspecial (importableHistory ic)
}
gitspecial l = ".git" `elem` Posix.splitDirectories (fromRawFilePath (fromImportLocation l))