git-annex/Remotes.hs
2010-12-02 17:54:08 -04:00

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{- git-annex remote repositories
-
- Copyright 2010 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Remotes (
list,
keyPossibilities,
tryGitConfigRead,
inAnnex,
same,
commandLineRemote,
copyFromRemote,
copyToRemote,
runCmd
) where
import Control.Exception.Extensible
import Control.Monad.State (liftIO)
import qualified Data.Map as Map
import Data.String.Utils
import System.Directory hiding (copyFile)
import System.Posix.Directory
import Data.List
import Control.Monad (when, unless, filterM)
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 qualified SysConfig
{- Human visible list of remotes. -}
list :: [Git.Repo] -> String
list remotes = join ", " $ map Git.repoDescribe remotes
{- Cost ordered list of remotes that the LocationLog indicate may have a key. -}
keyPossibilities :: Key -> Annex [Git.Repo]
keyPossibilities key = do
g <- Annex.gitRepo
uuids <- liftIO $ keyLocations g key
allremotes <- remotesByCost
-- To determine if a remote has a key, its UUID needs to be known.
-- The locally cached UUIDs of remotes can fall out of date if
-- eg, a different drive is mounted at the same location.
-- But, reading the config of remotes can be expensive, so make
-- sure we only do it once per git-annex run.
remotesread <- Annex.flagIsSet "remotesread"
if remotesread
then reposByUUID allremotes uuids
else do
-- We assume that it's cheap to read the config
-- of non-URL remotes, so that is done each time.
-- But reading the config of an URL remote is
-- only done when there is no cached UUID value.
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
if not $ null todo
then do
_ <- mapM tryGitConfigRead todo
Annex.flagChange "remotesread" $ FlagBool True
keyPossibilities key
else reposByUUID allremotes uuids
where
cachedUUID r = do
u <- getUUID r
return $ null u
{- 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 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 <- runCmd r "test" ["-e", annexLocation r key]
-- XXX Note that ssh failing and the file not existing
-- are not currently differentiated.
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
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
{- 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 = do
sshoptions <- repoConfig r "ssh-options" ""
if Map.null $ Git.configMap r
then do
-- configRead can fail due to IO error or
-- for other reasons; catch all possible exceptions
result <- liftIO (try (Git.configRead r $ Just $ words sshoptions)::IO (Either SomeException Git.Repo))
case result of
Left _ -> return $ Left r
Right r' -> do
g <- Annex.gitRepo
let l = Git.remotes g
let g' = Git.remotesAdd g $
exchange l r'
Annex.gitRepoChange g'
return $ Right r'
else return $ Right r -- config already read
where
exchange [] _ = []
exchange (old:ls) new =
if Git.repoRemoteName old == Git.repoRemoteName new
then new : exchange ls new
else old : exchange ls new
{- Tries to copy a key's content from a remote to a file. -}
copyFromRemote :: Git.Repo -> Key -> FilePath -> Annex Bool
copyFromRemote r key file
| not $ Git.repoIsUrl r = getlocal
| Git.repoIsSsh r = getssh
| otherwise = error "copying from non-ssh repo not supported"
where
keyloc = annexLocation r key
getlocal = liftIO $ copyFile keyloc file
getssh = remoteCopyFile r (sshLocation r keyloc) file
{- Tries to copy a key's content to a file on a remote. -}
copyToRemote :: Git.Repo -> Key -> FilePath -> Annex Bool
copyToRemote r key file = do
g <- Annex.gitRepo
let keyloc = annexLocation g key
if not $ Git.repoIsUrl r
then putlocal keyloc
else if Git.repoIsSsh r
then putssh keyloc
else error "copying to non-ssh repo not supported"
where
putlocal src = liftIO $ copyFile src file
putssh src = remoteCopyFile r src (sshLocation r file)
sshLocation :: Git.Repo -> FilePath -> FilePath
sshLocation r file = Git.urlHost r ++ ":" ++ shellEscape file
{- Copys a file from or to a remote, using rsync (when available) or scp. -}
remoteCopyFile :: Git.Repo -> String -> String -> Annex Bool
remoteCopyFile r src dest = do
showProgress -- make way for progress bar
o <- repoConfig r configopt ""
res <- liftIO $ boolSystem cmd $ options ++ words o ++ [src, dest]
if res
then return res
else do
when rsync $
showLongNote "rsync failed -- run git annex again to resume file transfer"
return res
where
cmd
| rsync = "rsync"
| otherwise = "scp"
configopt
| rsync = "rsync-options"
| otherwise = "scp-options"
options
-- inplace makes rsync resume partial files
| rsync = ["-p", "--progress", "--inplace"]
| otherwise = ["-p"]
rsync = SysConfig.rsync
{- Runs a command in a remote, using ssh if necessary.
- (Honors annex-ssh-options.) -}
runCmd :: Git.Repo -> String -> [String] -> Annex Bool
runCmd r command params = do
sshoptions <- repoConfig r "ssh-options" ""
if not $ Git.repoIsUrl r
then do
cwd <- liftIO getCurrentDirectory
liftIO $ bracket_
(changeWorkingDirectory (Git.workTree r))
(changeWorkingDirectory cwd)
(boolSystem command params)
else if Git.repoIsSsh r
then liftIO $ boolSystem "ssh" $
words sshoptions ++ [Git.urlHost r, sshcmd]
else error "running command in non-ssh repo not supported"
where
sshcmd = "cd " ++ shellEscape (Git.workTree r) ++
" && " ++ shellEscape command ++ " " ++
unwords (map shellEscape params)
{- 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