git-annex/Remotes.hs
Joey Hess f1b747e6d9 bugfix: Running move --to with a remote whose UUID was not yet known
* bugfix: Running `move --to` with a remote whose UUID was not yet known
  could result in git-annex not recording on the local side where the
  file was moved to. This could not result in data loss, or even a
  significant problem, since the remote *did* record that it had the file.
* Also, add a general guard to detect attempts to record information
  about repositories with missing UUIDs.
2011-01-04 17:45:27 -04:00

336 lines
11 KiB
Haskell

{- git-annex remote repositories
-
- Copyright 2010 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Remotes (
list,
readConfigs,
keyPossibilities,
inAnnex,
same,
commandLineRemote,
byName,
copyFromRemote,
copyToRemote,
onRemote
) where
import Control.Exception.Extensible
import Control.Monad.State (liftIO)
import qualified Data.Map as Map
import Data.String.Utils
import System.Cmd.Utils
import Data.List (intersect, sortBy)
import Control.Monad (when, unless, filterM)
import Data.Maybe
import Types
import qualified GitRepo as Git
import qualified Annex
import LocationLog
import Locations
import UUID
import Utility
import qualified Core
import Messages
import CopyFile
import RsyncFile
{- Human visible list of remotes. -}
list :: [Git.Repo] -> String
list remotes = join ", " $ map Git.repoDescribe remotes
{- The git configs for the git repo's remotes is not read on startup
- because reading it may be expensive. This function tries to read the
- config for a specified remote, and updates state. If successful, it
- returns the updated git repo. -}
tryGitConfigRead :: Git.Repo -> Annex (Either Git.Repo Git.Repo)
tryGitConfigRead r
| not $ Map.null $ Git.configMap r = return $ Right r -- already read
| Git.repoIsSsh r = store $ onRemote r (pipedconfig, r) "configlist" []
| Git.repoIsUrl r = return $ Left r
| otherwise = store $ safely $ Git.configRead r
where
-- Reading config can fail due to IO error or
-- for other reasons; catch all possible exceptions.
safely a = do
result <- liftIO (try (a)::IO (Either SomeException Git.Repo))
case result of
Left _ -> return r
Right r' -> return r'
pipedconfig cmd params = safely $
pOpen ReadFromPipe cmd params $
Git.hConfigRead r
store a = do
r' <- a
g <- Annex.gitRepo
let l = Git.remotes g
let g' = Git.remotesAdd g $ exchange l r'
Annex.gitRepoChange g'
return $ Right r'
exchange [] _ = []
exchange (old:ls) new =
if Git.repoRemoteName old == Git.repoRemoteName new
then new : exchange ls new
else old : exchange ls new
{- Reads the configs of all remotes.
-
- This has to be called before things that rely on eg, the UUID of
- remotes. Most such things will take care of running this themselves.
-
- As reading the config of remotes can be expensive, this
- function will only read configs once per git-annex run. It's
- assumed to be cheap to read the config of non-URL remotes,
- so this is done each time git-annex is run. Conversely,
- the config of an URL remote is only read when there is no
- cached UUID value.
- -}
readConfigs :: Annex ()
readConfigs = do
g <- Annex.gitRepo
remotesread <- Annex.flagIsSet "remotesread"
unless remotesread $ do
let allremotes = Git.remotes g
let cheap = filter (not . Git.repoIsUrl) allremotes
let expensive = filter Git.repoIsUrl allremotes
doexpensive <- filterM cachedUUID expensive
unless (null doexpensive) $
showNote $ "getting UUID for " ++
list doexpensive ++ "..."
let todo = cheap ++ doexpensive
unless (null todo) $ do
_ <- mapM tryGitConfigRead todo
Annex.flagChange "remotesread" $ FlagBool True
where
cachedUUID r = do
u <- getUUID r
return $ null u
{- Cost ordered lists of remotes that the LocationLog indicate may have a key.
-
- The first list is of remotes that are trusted to have the key.
-
- The second is of untrusted remotes that may have the key.
-
- Also returns a list of UUIDs that are trusted to have the key
- (some may not have configured remotes).
-}
keyPossibilities :: Key -> Annex ([Git.Repo], [Git.Repo], [UUID])
keyPossibilities key = do
readConfigs
allremotes <- remotesByCost
g <- Annex.gitRepo
u <- getUUID g
trusted <- getTrusted
-- get uuids of other repositories that are
-- believed to have the key
uuids <- liftIO $ keyLocations g key
let validuuids = filter (/= u) uuids
-- get uuids trusted to have the key
-- note that validuuids is assumed to not have dups
let validtrusteduuids = intersect validuuids trusted
-- remotes that match uuids that have the key
validremotes <- reposByUUID allremotes validuuids
-- partition out the trusted and untrusted remotes
trustedremotes <- reposByUUID validremotes validtrusteduuids
untrustedremotes <- reposWithoutUUID validremotes trusted
return (trustedremotes, untrustedremotes, validtrusteduuids)
{- Checks if a given remote has the content for a key inAnnex.
- If the remote cannot be accessed, returns a Left error.
-}
inAnnex :: Git.Repo -> Key -> Annex (Either IOException Bool)
inAnnex r key = if Git.repoIsUrl r
then checkremote
else liftIO (try checklocal ::IO (Either IOException Bool))
where
checklocal = do
-- run a local check inexpensively,
-- by making an Annex monad using the remote
a <- Annex.new r []
Annex.eval a (Core.inAnnex key)
checkremote = do
showNote ("checking " ++ Git.repoDescribe r ++ "...")
inannex <- onRemote r (boolSystem, False) "inannex"
["--backend=" ++ backendName key, keyName key]
return $ Right inannex
{- Cost Ordered list of remotes. -}
remotesByCost :: Annex [Git.Repo]
remotesByCost = do
g <- Annex.gitRepo
reposByCost $ Git.remotes g
{- Orders a list of git repos by cost. Throws out ignored ones. -}
reposByCost :: [Git.Repo] -> Annex [Git.Repo]
reposByCost l = do
notignored <- filterM repoNotIgnored l
costpairs <- mapM costpair notignored
return $ fst $ unzip $ sortBy cmpcost costpairs
where
costpair r = do
cost <- repoCost r
return (r, cost)
cmpcost (_, c1) (_, c2) = compare c1 c2
{- Calculates cost for a repo.
-
- The default cost is 100 for local repositories, and 200 for remote
- repositories; it can also be configured by remote.<name>.annex-cost
-}
repoCost :: Git.Repo -> Annex Int
repoCost r = do
cost <- repoConfig r "cost" ""
if not $ null cost
then return $ read cost
else if Git.repoIsUrl r
then return 200
else return 100
{- Checks if a repo should be ignored, based either on annex-ignore
- setting, or on command-line options. Allows command-line to override
- annex-ignore. -}
repoNotIgnored :: Git.Repo -> Annex Bool
repoNotIgnored r = do
ignored <- repoConfig r "ignore" "false"
fromName <- Annex.flagGet "fromrepository"
toName <- Annex.flagGet "torepository"
let name = if null fromName then toName else fromName
if not $ null name
then return $ match name
else return $ not $ Git.configTrue ignored
where
match name = name == Git.repoRemoteName r
{- Checks if two repos are the same, by comparing their remote names. -}
same :: Git.Repo -> Git.Repo -> Bool
same a b = Git.repoRemoteName a == Git.repoRemoteName b
{- Returns the remote specified by --from or --to, may fail with error. -}
commandLineRemote :: Annex Git.Repo
commandLineRemote = do
fromName <- Annex.flagGet "fromrepository"
toName <- Annex.flagGet "torepository"
let name = if null fromName then toName else fromName
byName name
{- Looks up a remote by name. -}
byName :: String -> Annex Git.Repo
byName name = do
when (null name) $ error "no remote specified"
g <- Annex.gitRepo
let match = filter (\r -> name == Git.repoRemoteName r) $
Git.remotes g
when (null match) $ error $
"there is no git remote named \"" ++ name ++ "\""
return $ head match
{- Tries to copy a key's content from a remote's annex to a file. -}
copyFromRemote :: Git.Repo -> Key -> FilePath -> Annex Bool
copyFromRemote r key file
| not $ Git.repoIsUrl r = liftIO $ copyFile (annexLocation r key) file
| Git.repoIsSsh r = rsynchelper r True key file
| otherwise = error "copying from non-ssh repo not supported"
{- Tries to copy a key's content to a remote's annex. -}
copyToRemote :: Git.Repo -> Key -> Annex Bool
copyToRemote r key
| not $ Git.repoIsUrl r = do
g <- Annex.gitRepo
let keysrc = annexLocation g key
let keydest = annexLocation r key
liftIO $ copyFile keysrc keydest
| Git.repoIsSsh r = do
g <- Annex.gitRepo
let keysrc = annexLocation g key
rsynchelper r False key keysrc
| otherwise = error "copying to non-ssh repo not supported"
rsynchelper :: Git.Repo -> Bool -> Key -> FilePath -> Annex (Bool)
rsynchelper r sending key file = do
showProgress -- make way for progress bar
p <- rsyncParams r sending key file
res <- liftIO $ boolSystem "rsync" p
if res
then return res
else do
showLongNote "rsync failed -- run git annex again to resume file transfer"
return res
{- Generates rsync parameters that ssh to the remote and asks it
- to either receive or send the key's content. -}
rsyncParams :: Git.Repo -> Bool -> Key -> FilePath -> Annex [String]
rsyncParams r sending key file = do
-- Note that the command is terminated with "--", because
-- rsync will tack on its own options to this command,
-- and they need to be ignored.
shellcmd <- git_annex_shell r
(if sending then "sendkey" else "recvkey")
["--backend=" ++ backendName key, keyName key, "--"]
-- Convert the ssh command into rsync command line.
let eparam = rsyncShell $ fromJust shellcmd
o <- repoConfig r "rsync-options" ""
let base = options ++ words o ++ eparam
if sending
then return $ base ++ [dummy, file]
else return $ base ++ [file, dummy]
where
-- inplace makes rsync resume partial files
options = ["-p", "--progress", "--inplace"]
-- the rsync shell parameter controls where rsync
-- does, so the source/dest parameter can be a dummy value,
-- that just enables remote rsync mode.
dummy = ":"
{- Uses a supplied function to run a git-annex-shell command on a remote.
-
- Or, if the remote does not support running remote commands, returns
- a specified error value. -}
onRemote
:: Git.Repo
-> (String -> [String] -> IO a, a)
-> String
-> [String]
-> Annex a
onRemote r (with, errorval) command params = do
s <- git_annex_shell r command params
case s of
Just shellcmd -> liftIO $ with (shellcmd !! 0) (tail shellcmd)
Nothing -> return errorval
{- Generates parameters to run a git-annex-shell command on a remote. -}
git_annex_shell :: Git.Repo -> String -> [String] -> Annex (Maybe [String])
git_annex_shell r command params
| not $ Git.repoIsUrl r = return $ Just (shellcmd:shellopts)
| Git.repoIsSsh r = do
sshoptions <- repoConfig r "ssh-options" ""
return $ Just $ ["ssh"] ++ words sshoptions ++
[Git.urlHost r, sshcmd]
| otherwise = return Nothing
where
dir = Git.workTree r
shellcmd = "git-annex-shell"
shellopts = command:dir:params
sshcmd = shellcmd ++ " " ++ unwords (map shellEscape shellopts)
{- Looks up a per-remote config option in git config.
- Failing that, tries looking for a global config option. -}
repoConfig :: Git.Repo -> String -> String -> Annex String
repoConfig r key def = do
g <- Annex.gitRepo
let def' = Git.configGet g global def
return $ Git.configGet g local def'
where
local = "remote." ++ Git.repoRemoteName r ++ ".annex-" ++ key
global = "annex." ++ key