Andrew's git - gitweb.git/blob - perl/Git/SVN/Migration.pm

   1package Git::SVN::Migration;
   2# these version numbers do NOT correspond to actual version numbers
   3# of git nor git-svn.  They are just relative.
   4#
   5# v0 layout: .git/$id/info/url, refs/heads/$id-HEAD
   6#
   7# v1 layout: .git/$id/info/url, refs/remotes/$id
   8#
   9# v2 layout: .git/svn/$id/info/url, refs/remotes/$id
  10#
  11# v3 layout: .git/svn/$id, refs/remotes/$id
  12#            - info/url may remain for backwards compatibility
  13#            - this is what we migrate up to this layout automatically,
  14#            - this will be used by git svn init on single branches
  15# v3.1 layout (auto migrated):
  16#            - .rev_db => .rev_db.$UUID, .rev_db will remain as a symlink
  17#              for backwards compatibility
  18#
  19# v4 layout: .git/svn/$repo_id/$id, refs/remotes/$repo_id/$id
  20#            - this is only created for newly multi-init-ed
  21#              repositories.  Similar in spirit to the
  22#              --use-separate-remotes option in git-clone (now default)
  23#            - we do not automatically migrate to this (following
  24#              the example set by core git)
  25#
  26# v5 layout: .rev_db.$UUID => .rev_map.$UUID
  27#            - newer, more-efficient format that uses 24-bytes per record
  28#              with no filler space.
  29#            - use xxd -c24 < .rev_map.$UUID to view and debug
  30#            - This is a one-way migration, repositories updated to the
  31#              new format will not be able to use old git-svn without
  32#              rebuilding the .rev_db.  Rebuilding the rev_db is not
  33#              possible if noMetadata or useSvmProps are set; but should
  34#              be no problem for users that use the (sensible) defaults.
  35use strict;
  36use warnings;
  37use Carp qw/croak/;
  38use File::Path qw/mkpath/;
  39use File::Basename qw/dirname basename/;
  40
  41our $_minimize;
  42use Git qw(
  43        command
  44        command_noisy
  45        command_output_pipe
  46        command_close_pipe
  47);
  48
  49sub migrate_from_v0 {
  50        my $git_dir = $ENV{GIT_DIR};
  51        return undef unless -d $git_dir;
  52        my ($fh, $ctx) = command_output_pipe(qw/rev-parse --symbolic --all/);
  53        my $migrated = 0;
  54        while (<$fh>) {
  55                chomp;
  56                my ($id, $orig_ref) = ($_, $_);
  57                next unless $id =~ s#^refs/heads/(.+)-HEAD$#$1#;
  58                next unless -f "$git_dir/$id/info/url";
  59                my $new_ref = "refs/remotes/$id";
  60                if (::verify_ref("$new_ref^0")) {
  61                        print STDERR "W: $orig_ref is probably an old ",
  62                                     "branch used by an ancient version of ",
  63                                     "git-svn.\n",
  64                                     "However, $new_ref also exists.\n",
  65                                     "We will not be able ",
  66                                     "to use this branch until this ",
  67                                     "ambiguity is resolved.\n";
  68                        next;
  69                }
  70                print STDERR "Migrating from v0 layout...\n" if !$migrated;
  71                print STDERR "Renaming ref: $orig_ref => $new_ref\n";
  72                command_noisy('update-ref', $new_ref, $orig_ref);
  73                command_noisy('update-ref', '-d', $orig_ref, $orig_ref);
  74                $migrated++;
  75        }
  76        command_close_pipe($fh, $ctx);
  77        print STDERR "Done migrating from v0 layout...\n" if $migrated;
  78        $migrated;
  79}
  80
  81sub migrate_from_v1 {
  82        my $git_dir = $ENV{GIT_DIR};
  83        my $migrated = 0;
  84        return $migrated unless -d $git_dir;
  85        my $svn_dir = "$git_dir/svn";
  86
  87        # just in case somebody used 'svn' as their $id at some point...
  88        return $migrated if -d $svn_dir && ! -f "$svn_dir/info/url";
  89
  90        print STDERR "Migrating from a git-svn v1 layout...\n";
  91        mkpath([$svn_dir]);
  92        print STDERR "Data from a previous version of git-svn exists, but\n\t",
  93                     "$svn_dir\n\t(required for this version ",
  94                     "($::VERSION) of git-svn) does not exist.\n";
  95        my ($fh, $ctx) = command_output_pipe(qw/rev-parse --symbolic --all/);
  96        while (<$fh>) {
  97                my $x = $_;
  98                next unless $x =~ s#^refs/remotes/##;
  99                chomp $x;
 100                next unless -f "$git_dir/$x/info/url";
 101                my $u = eval { ::file_to_s("$git_dir/$x/info/url") };
 102                next unless $u;
 103                my $dn = dirname("$git_dir/svn/$x");
 104                mkpath([$dn]) unless -d $dn;
 105                if ($x eq 'svn') { # they used 'svn' as GIT_SVN_ID:
 106                        mkpath(["$git_dir/svn/svn"]);
 107                        print STDERR " - $git_dir/$x/info => ",
 108                                        "$git_dir/svn/$x/info\n";
 109                        rename "$git_dir/$x/info", "$git_dir/svn/$x/info" or
 110                               croak "$!: $x";
 111                        # don't worry too much about these, they probably
 112                        # don't exist with repos this old (save for index,
 113                        # and we can easily regenerate that)
 114                        foreach my $f (qw/unhandled.log index .rev_db/) {
 115                                rename "$git_dir/$x/$f", "$git_dir/svn/$x/$f";
 116                        }
 117                } else {
 118                        print STDERR " - $git_dir/$x => $git_dir/svn/$x\n";
 119                        rename "$git_dir/$x", "$git_dir/svn/$x" or
 120                               croak "$!: $x";
 121                }
 122                $migrated++;
 123        }
 124        command_close_pipe($fh, $ctx);
 125        print STDERR "Done migrating from a git-svn v1 layout\n";
 126        $migrated;
 127}
 128
 129sub read_old_urls {
 130        my ($l_map, $pfx, $path) = @_;
 131        my @dir;
 132        foreach (<$path/*>) {
 133                if (-r "$_/info/url") {
 134                        $pfx .= '/' if $pfx && $pfx !~ m!/$!;
 135                        my $ref_id = $pfx . basename $_;
 136                        my $url = ::file_to_s("$_/info/url");
 137                        $l_map->{$ref_id} = $url;
 138                } elsif (-d $_) {
 139                        push @dir, $_;
 140                }
 141        }
 142        foreach (@dir) {
 143                my $x = $_;
 144                $x =~ s!^\Q$ENV{GIT_DIR}\E/svn/!!o;
 145                read_old_urls($l_map, $x, $_);
 146        }
 147}
 148
 149sub migrate_from_v2 {
 150        my @cfg = command(qw/config -l/);
 151        return if grep /^svn-remote\..+\.url=/, @cfg;
 152        my %l_map;
 153        read_old_urls(\%l_map, '', "$ENV{GIT_DIR}/svn");
 154        my $migrated = 0;
 155
 156        require Git::SVN;
 157        foreach my $ref_id (sort keys %l_map) {
 158                eval { Git::SVN->init($l_map{$ref_id}, '', undef, $ref_id) };
 159                if ($@) {
 160                        Git::SVN->init($l_map{$ref_id}, '', $ref_id, $ref_id);
 161                }
 162                $migrated++;
 163        }
 164        $migrated;
 165}
 166
 167sub minimize_connections {
 168        require Git::SVN;
 169        require Git::SVN::Ra;
 170
 171        my $r = Git::SVN::read_all_remotes();
 172        my $new_urls = {};
 173        my $root_repos = {};
 174        foreach my $repo_id (keys %$r) {
 175                my $url = $r->{$repo_id}->{url} or next;
 176                my $fetch = $r->{$repo_id}->{fetch} or next;
 177                my $ra = Git::SVN::Ra->new($url);
 178
 179                # skip existing cases where we already connect to the root
 180                if (($ra->url eq $ra->{repos_root}) ||
 181                    ($ra->{repos_root} eq $repo_id)) {
 182                        $root_repos->{$ra->url} = $repo_id;
 183                        next;
 184                }
 185
 186                my $root_ra = Git::SVN::Ra->new($ra->{repos_root});
 187                my $root_path = $ra->url;
 188                $root_path =~ s#^\Q$ra->{repos_root}\E(/|$)##;
 189                foreach my $path (keys %$fetch) {
 190                        my $ref_id = $fetch->{$path};
 191                        my $gs = Git::SVN->new($ref_id, $repo_id, $path);
 192
 193                        # make sure we can read when connecting to
 194                        # a higher level of a repository
 195                        my ($last_rev, undef) = $gs->last_rev_commit;
 196                        if (!defined $last_rev) {
 197                                $last_rev = eval {
 198                                        $root_ra->get_latest_revnum;
 199                                };
 200                                next if $@;
 201                        }
 202                        my $new = $root_path;
 203                        $new .= length $path ? "/$path" : '';
 204                        eval {
 205                                $root_ra->get_log([$new], $last_rev, $last_rev,
 206                                                  0, 0, 1, sub { });
 207                        };
 208                        next if $@;
 209                        $new_urls->{$ra->{repos_root}}->{$new} =
 210                                { ref_id => $ref_id,
 211                                  old_repo_id => $repo_id,
 212                                  old_path => $path };
 213                }
 214        }
 215
 216        my @emptied;
 217        foreach my $url (keys %$new_urls) {
 218                # see if we can re-use an existing [svn-remote "repo_id"]
 219                # instead of creating a(n ugly) new section:
 220                my $repo_id = $root_repos->{$url} || $url;
 221
 222                my $fetch = $new_urls->{$url};
 223                foreach my $path (keys %$fetch) {
 224                        my $x = $fetch->{$path};
 225                        Git::SVN->init($url, $path, $repo_id, $x->{ref_id});
 226                        my $pfx = "svn-remote.$x->{old_repo_id}";
 227
 228                        my $old_fetch = quotemeta("$x->{old_path}:".
 229                                                  "$x->{ref_id}");
 230                        command_noisy(qw/config --unset/,
 231                                      "$pfx.fetch", '^'. $old_fetch . '$');
 232                        delete $r->{$x->{old_repo_id}}->
 233                               {fetch}->{$x->{old_path}};
 234                        if (!keys %{$r->{$x->{old_repo_id}}->{fetch}}) {
 235                                command_noisy(qw/config --unset/,
 236                                              "$pfx.url");
 237                                push @emptied, $x->{old_repo_id}
 238                        }
 239                }
 240        }
 241        if (@emptied) {
 242                my $file = $ENV{GIT_CONFIG} || "$ENV{GIT_DIR}/config";
 243                print STDERR <<EOF;
 244The following [svn-remote] sections in your config file ($file) are empty
 245and can be safely removed:
 246EOF
 247                print STDERR "[svn-remote \"$_\"]\n" foreach @emptied;
 248        }
 249}
 250
 251sub migration_check {
 252        migrate_from_v0();
 253        migrate_from_v1();
 254        migrate_from_v2();
 255        minimize_connections() if $_minimize;
 256}
 257
 2581;