% Copyright (C) 20022004,2007 David Roundy
%
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\subsection{darcs rollback}
\begin{code}
module Darcs.Commands.Rollback ( rollback ) where
import Control.Monad ( when, filterM )
import System.Exit ( exitWith, ExitCode(..) )
import Data.List ( sort )
import Data.Maybe ( isJust )
import System.Directory ( removeFile )
import Darcs.Commands ( DarcsCommand(..), nodefaults, loggers )
import Darcs.Arguments ( DarcsFlag(MarkConflicts), fixSubPaths, get_author,
definePatches,
working_repo_dir, nocompress,
author, patchname_option, ask_long_comment,
leave_test_dir, notest, list_registered_files,
match_several_or_last, all_interactive, umask_option
)
import Darcs.RepoPath ( toFilePath )
import Darcs.Repository ( amInRepository, withRepoLock, ($-), applyToWorking,
slurp_recorded_and_unrecorded, read_repo, slurp_recorded,
tentativelyMergePatches, withGutsOf,
finalizeRepositoryChanges, sync_repo )
import Darcs.Patch ( summary, invert, namepatch, effect, fromPrims, sort_coalesceFL )
import Darcs.Ordered
import Darcs.Hopefully ( n2pia )
import Darcs.Lock ( world_readable_temp )
import Darcs.SlurpDirectory ( empty_slurpy, wait_a_moment )
import Darcs.Match ( first_match )
import Darcs.SelectChanges ( with_selected_last_changes_to_files_reversed,
with_selected_last_changes_to_files' )
import Darcs.Commands.Record ( file_exists, get_log )
import Darcs.Commands.Unrecord ( get_last_patches )
import Darcs.Utils ( clarify_errors )
import Progress ( debugMessage )
import Darcs.Sealed ( Sealed(..), FlippedSeal(..) )
import IsoDate ( getIsoDateTime )
#include "impossible.h"
rollback_description :: String
rollback_description =
"Record a new patch reversing some recorded changes."
\end{code}
\options{rollback}
\haskell{rollback_help} If you decide you didn't want to roll back a patch
after all, you can reverse its effect by obliterating the rolledback patch.
Rollback can actually allow you to roll back a subset of the changes made
by the selected patch or patches. Many of the options available in
rollback behave similarly to the options for unrecord~\ref{unrecord} and
record~\ref{record}.
\begin{code}
rollback_help :: String
rollback_help =
"Rollback is used to undo the effects of one or more patches without actually\n"++
"deleting them. Instead, it creates a new patch reversing selected portions.\n"++
"of those changes. Unlike obliterate and unrecord (which accomplish a similar\n"++
"goal) rollback is perfectly safe, since it leaves in the repository a record\n"++
"of its changes.\n"
rollback :: DarcsCommand
rollback = DarcsCommand {command_name = "rollback",
command_help = rollback_help,
command_description = rollback_description,
command_extra_args = 1,
command_extra_arg_help = ["[FILE or DIRECTORY]..."],
command_command = rollback_cmd,
command_prereq = amInRepository,
command_get_arg_possibilities = list_registered_files,
command_argdefaults = nodefaults,
command_advanced_options = [nocompress,umask_option],
command_basic_options = [match_several_or_last,
all_interactive,
author, patchname_option, ask_long_comment,
notest, leave_test_dir,
working_repo_dir]}
rollback_cmd :: [DarcsFlag] -> [String] -> IO ()
rollback_cmd opts args = withRepoLock opts $- \repository -> do
let (logMessage,_,_) = loggers opts
rec <- if null args then return empty_slurpy
else slurp_recorded repository
files <- sort `fmap` fixSubPaths opts args
existing_files <- map toFilePath `fmap` filterM (file_exists rec) files
non_existent_files <- map toFilePath `fmap` filterM (fmap not . file_exists rec) files
when (not $ null existing_files) $
logMessage $ "Recording changes in "++unwords existing_files++":\n"
when (not $ null non_existent_files) $
logMessage $ "Non existent files or directories: "++unwords non_existent_files++"\n"
when ((not $ null non_existent_files) && null existing_files) $
fail "None of the files you specified exist!"
(recorded, working_dir) <- slurp_recorded_and_unrecorded repository
allpatches <- read_repo repository
FlippedSeal patches <- return $ if first_match opts
then get_last_patches opts allpatches
else FlippedSeal $ concatRL allpatches
with_selected_last_changes_to_files_reversed "rollback" opts recorded existing_files
(reverseRL patches) $
\ (_ :> ps) ->
do when (nullFL ps) $ do logMessage "No patches selected!"
exitWith ExitSuccess
definePatches ps
with_selected_last_changes_to_files' "rollback" opts working_dir
existing_files (sort_coalesceFL $ effect ps) $ \ (_:>ps'') ->
do when (nullFL ps'') $ do logMessage "No changes selected!"
exitWith ExitSuccess
let make_log = world_readable_temp "darcs-rollback"
newlog = Just ("", "":"rolling back:":"":lines (show $ summary ps ))
(name, my_log, logf) <- get_log opts newlog make_log $ invert ps''
date <- getIsoDateTime
my_author <- get_author opts
rbp <- n2pia `fmap` namepatch date name my_author my_log
(fromPrims $ invert ps'')
debugMessage "Adding rollback patch to repository."
Sealed pw <- tentativelyMergePatches repository "rollback" (MarkConflicts : opts)
NilFL (rbp :>: NilFL)
debugMessage "Finalizing rollback changes..."
withGutsOf repository $ do
finalizeRepositoryChanges repository
debugMessage "About to apply rolled-back changes to working directory."
revertable $ do wait_a_moment
applyToWorking repository opts pw
when (isJust logf) $ removeFile (fromJust logf)
sync_repo repository
logMessage $ "Finished rolling back."
where revertable x = x `clarify_errors` unlines
["Error applying patch to the working directory.","",
"This may have left your working directory an inconsistent",
"but recoverable state. If you had no un-recorded changes",
"by using 'darcs revert' you should be able to make your",
"working directory consistent again."]
\end{code}