% Copyright (C) 2002-2005 David Roundy % % This program is free software; you can redistribute it and/or modify % it under the terms of the GNU General Public License as published by % the Free Software Foundation; either version 2, or (at your option) % any later version. % % This program is distributed in the hope that it will be useful, % but WITHOUT ANY WARRANTY; without even the implied warranty of % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the % GNU General Public License for more details. % % You should have received a copy of the GNU General Public License % along with this program; see the file COPYING. If not, write to % the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, % Boston, MA 02110-1301, USA. \darcsCommand{pull} \begin{code}
{-# OPTIONS_GHC -cpp #-}

module Darcs.Commands.Pull ( pull ) where
import System.Exit ( ExitCode(..), exitWith )
import Workaround ( getCurrentDirectory )
import Control.Monad ( when )
import Data.List ( nub )

import Darcs.Commands ( DarcsCommand(..), putVerbose, putInfo )
import Darcs.CommandsAux ( check_paths )
import Darcs.Arguments ( DarcsFlag( Verbose, DryRun, MarkConflicts,
                                   Intersection, Complement, AllowConflicts,
                                   NoAllowConflicts ),
                         nocompress, ignoretimes, definePatches,
                         depsSel, pullConflictOptions, useExternalMerge,
                         matchSeveral, fixUrl,
                         allInteractive, repoCombinator,
                         test, dryRun,
                         setDefault, summary, workingRepoDir, remoteRepo,
                         setScriptsExecutableOption, nolinks,
                         networkOptions, umaskOption, allowUnrelatedRepos, restrictPaths
import Darcs.Repository ( Repository, SealedPatchSet, identifyRepositoryFor, withGutsOf,
                          amInRepository, withRepoLock, ($-), tentativelyMergePatches,
                          finalizeRepositoryChanges, applyToWorking,
                          read_repo, checkUnrelatedRepos, invalidateIndex )
import Darcs.Hopefully ( info )
import Darcs.Patch ( RepoPatch, description )
import Darcs.Witnesses.Ordered ( (:>)(..), (:\/:)(..), RL(..),
                             mapFL, nullFL, reverseRL, mapRL )
import Darcs.Patch.Permutations ( partitionFL )
import Darcs.Repository.Prefs ( addToPreflist, defaultrepo, setDefaultrepo, getPreflist )
import Darcs.Repository.Motd (show_motd )
import Darcs.Patch.Depends ( get_common_and_uncommon,
                             patchset_intersection, patchset_union )
import Darcs.SelectChanges ( with_selected_changes, filterOutConflicts )
import Darcs.Utils ( clarifyErrors, formatPath )
import Darcs.Witnesses.Sealed ( Sealed(..), seal )
import Printer ( putDocLn, vcat, ($$), text )
#include "impossible.h"

#include "gadts.h"

pullDescription :: String
pullDescription =
 "Copy and apply patches from another repository to this one."

pullHelp :: String
pullHelp =
 "Pull is used to bring changes made in another repository into the current\n"++
 "repository (that is, either the one in the current directory, or the one\n"++
 "specified with the --repodir option). Pull allows you to bring over all or\n"++
 "some of the patches that are in that repository but not in this one. Pull\n"++
 "accepts arguments, which are URLs from which to pull, and when called\n"++
 "without an argument, pull will use the repository from which you have most\n"++
 "recently either pushed or pulled.\n"

pull :: DarcsCommand
pull = DarcsCommand {commandName = "pull",
                     commandHelp = pullHelp,
                     commandDescription = pullDescription,
                     commandExtraArgs = -1,
                     commandExtraArgHelp = ["[REPOSITORY]..."],
                     commandCommand = pullCmd,
                     commandPrereq = amInRepository,
                     commandGetArgPossibilities = getPreflist "repos",
                     commandArgdefaults = defaultrepo,
                     commandAdvancedOptions = [repoCombinator,
                                                 nocompress, nolinks,
                                                 restrictPaths] ++
                     commandBasicOptions = [matchSeveral,

pullCmd :: [DarcsFlag] -> [String] -> IO ()
pullCmd opts unfixedrepodirs@(_:_) = withRepoLock opts $- \repository -> do
  here <- getCurrentDirectory
  repodirs <- (nub . filter (/= here)) `fmap` mapM (fixUrl opts) unfixedrepodirs
  -- Test to make sure we aren't trying to pull from the current repo
  when (null repodirs) $
        fail "Can't pull from current repository!"
  (Sealed them, Sealed compl) <- readRepos repository opts repodirs
  old_default <- getPreflist "defaultrepo"
  setDefaultrepo (head repodirs) opts
  mapM_ (addToPreflist "repos") repodirs
  when (old_default == repodirs) $
      let pulling = if DryRun `elem` opts then "Would pull" else "Pulling"
      in  putInfo opts $ text $ pulling++" from "++concatMap formatPath repodirs++"..."
  mapM_ (show_motd opts) repodirs
  us <- read_repo repository
  (common, us' :\/: them'') <- return $ get_common_and_uncommon (us, them)
  (_     ,   _ :\/: compl') <- return $ get_common_and_uncommon (us, compl)
  checkUnrelatedRepos opts common us them
  let avoided = mapRL info compl'
  ps :> _ <- return $ partitionFL (not . (`elem` avoided) . info) $ reverseRL them''
  do when (Verbose `elem` opts) $
          do case us' of
               (x@(_:<:_)) -> putDocLn $ text "We have the following new (to them) patches:"
                                         $$ (vcat $ mapRL description x)
               _ -> return ()
             when (not $ nullFL ps) $ putDocLn $ text "They have the following patches to pull:"
                      $$ (vcat $ mapFL description ps)
     let merge_opts | NoAllowConflicts `elem` opts = opts
                    | AllowConflicts   `elem` opts = opts
                    | otherwise                    = MarkConflicts : opts
     (hadConflicts, Sealed psFiltered) <- filterOutConflicts merge_opts us' repository ps
     when hadConflicts $ putStrLn "Skipping some patches which would cause conflicts."
     when (nullFL psFiltered)
                      $ do putInfo opts $ text "No remote changes to pull in!"
                           definePatches psFiltered
                           exitWith ExitSuccess
     with_selected_changes "pull" opts Nothing psFiltered $
      \ (to_be_pulled:>_) ->
           printDryRunMessageAndExit "pull" opts to_be_pulled
           definePatches to_be_pulled
           when (nullFL to_be_pulled) $ do
                               putStrLn "You don't want to pull any patches, and that's fine with me!"
                               exitWith ExitSuccess
           check_paths opts to_be_pulled
           putVerbose opts $ text "Getting and merging the following patches:"
           putVerbose opts $ vcat $ mapFL description to_be_pulled
           Sealed pw <- tentativelyMergePatches repository "pull" merge_opts
                       (reverseRL us') to_be_pulled
           invalidateIndex repository
           withGutsOf repository $ do finalizeRepositoryChanges repository
                                      revertable $ applyToWorking repository opts pw
           putInfo opts $ text "Finished pulling and applying."

pullCmd _ [] = fail "No default repository to pull from, please specify one"

revertable :: IO a -> IO a
revertable x =
    x `clarifyErrors` 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."]

{- Read in the specified pull-from repositories.  Perform
Intersection, Union, or Complement read.  In patch-theory terms
(stated in set algebra, where + is union and & is intersection
and \ is complement):

    Union =         ((R1 + R2 + ... + Rn) \ Rc)
    Intersection =  ((R1 & R2 & ... & Rn) \ Rc)
    Complement =    (R1 \ Rc) \ ((R2 + R3 + ... + Rn) \ Rc)

                        where Rc = local repo
                              R1 = 1st specified pull repo
                              R2, R3, Rn = other specified pull repo

Since Rc is not provided here yet, the result of readRepos is a
tuple: the first patchset(s) to be complemented against Rc and then
the second patchset(s) to be complemented against Rc.

readRepos :: RepoPatch p => Repository p C(r u t) -> [DarcsFlag] -> [String] -> IO (SealedPatchSet p,SealedPatchSet p)
readRepos _ _ [] = impossible
readRepos to_repo opts us =
    do rs <- mapM (\u -> do r <- identifyRepositoryFor to_repo u
                            ps <- read_repo r
                            return $ seal ps) us
       return $ if Intersection `elem` opts
                then (patchset_intersection rs, seal NilRL)
                else if Complement `elem` opts
                     then (head rs, patchset_union $ tail rs)
                     else (patchset_union rs, seal NilRL)

\end{code} \begin{options} --intersection, --union [DEFAULT], --complement \end{options} If you provide more than one repository as an argument to pull, darcs' behavior is determined by the presence of the \verb!--complement!, \verb!--intersection!, and \verb!--union! flags. \begin{itemize} \item The default (\verb!--union!) behavior is to pull any patches that are in any of the specified repositories ($ R_1 \bigcup R_2 \bigcup R_3 \ldots$). \item If you instead specify the \verb!--intersection! flag, darcs will only pull those patches which are present in all source repositories ($ R_1 \bigcap R_2 \bigcap R_3 \ldots$). \item If you specify the \verb!--complement! flag, darcs will only pull elements in the first repository that do not exist in any of the remaining repositories\footnote{The first thing darcs will do is remove duplicates, keeping only the first specification. This is noticeable for the complement operation, since mathematically $ S \backslash S \rightarrow \emptyset $, one would expect that ``\texttt{darcs pull --complement repo1 repo1}'' would result in no pulls, but the duplicate elimination removes the second \texttt{repo1}, reducing the above to effectively ``\texttt{darcs pull repo1}''. The expected functionality could be seen via ``\texttt{darcs get -a repo1 repo2; darcs pull --complement repo1 repo2}'', but there are easier ways of doing nothing!} ($ R_1 \backslash (R_2 \bigcup R_3 \bigcup \ldots$)). \end{itemize} \begin{options} --external-merge \end{options} You can use an external interactive merge tool to resolve conflicts with the flag \verb!--external-merge!. For more details see subsection~\ref{resolution}. \begin{options} --matches, --patches, --tags, --no-deps \end{options} The \verb!--patches!, \verb!--matches!, \verb!--tags!, and \verb!--no-deps! options can be used to select which patches to pull, as described in subsection~\ref{selecting}. \begin{options} --no-test, --test \end{options} If you specify the \verb!--test! option, pull will run the test (if a test exists) on a scratch copy of the repository contents prior to actually performing the pull. If the test fails, the pull will be aborted. \begin{options} --verbose \end{options} Adding the \verb!--verbose! option causes another section to appear in the output which also displays a summary of patches that you have and the remote repository lacks. Thus, the following syntax can be used to show you all the patch differences between two repositories: \begin{verbatim} darcs pull --dry-run --verbose \end{verbatim}