diff options
Diffstat (limited to 'perl/Git/SVN/Migration.pm')
| -rw-r--r-- | perl/Git/SVN/Migration.pm | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/perl/Git/SVN/Migration.pm b/perl/Git/SVN/Migration.pm new file mode 100644 index 000000000000..dc90f6a62142 --- /dev/null +++ b/perl/Git/SVN/Migration.pm @@ -0,0 +1,265 @@ +package Git::SVN::Migration; +# these version numbers do NOT correspond to actual version numbers +# of git or git-svn. They are just relative. +# +# v0 layout: .git/$id/info/url, refs/heads/$id-HEAD +# +# v1 layout: .git/$id/info/url, refs/remotes/$id +# +# v2 layout: .git/svn/$id/info/url, refs/remotes/$id +# +# v3 layout: .git/svn/$id, refs/remotes/$id +# - info/url may remain for backwards compatibility +# - this is what we migrate up to this layout automatically, +# - this will be used by git svn init on single branches +# v3.1 layout (auto migrated): +# - .rev_db => .rev_db.$UUID, .rev_db will remain as a symlink +# for backwards compatibility +# +# v4 layout: .git/svn/$repo_id/$id, refs/remotes/$repo_id/$id +# - this is only created for newly multi-init-ed +# repositories. Similar in spirit to the +# --use-separate-remotes option in git-clone (now default) +# - we do not automatically migrate to this (following +# the example set by core git) +# +# v5 layout: .rev_db.$UUID => .rev_map.$UUID +# - newer, more-efficient format that uses 24-bytes per record +# with no filler space. +# - use xxd -c24 < .rev_map.$UUID to view and debug +# - This is a one-way migration, repositories updated to the +# new format will not be able to use old git-svn without +# rebuilding the .rev_db. Rebuilding the rev_db is not +# possible if noMetadata or useSvmProps are set; but should +# be no problem for users that use the (sensible) defaults. +use strict; +use warnings; +use Carp qw/croak/; +use File::Path qw/mkpath/; +use File::Basename qw/dirname basename/; + +our $_minimize; +use Git qw( + command + command_noisy + command_output_pipe + command_close_pipe + command_oneline +); +use Git::SVN; + +sub migrate_from_v0 { + my $git_dir = $ENV{GIT_DIR}; + return undef unless -d $git_dir; + my ($fh, $ctx) = command_output_pipe(qw/rev-parse --symbolic --all/); + my $migrated = 0; + while (<$fh>) { + chomp; + my ($id, $orig_ref) = ($_, $_); + next unless $id =~ s#^refs/heads/(.+)-HEAD$#$1#; + my $info_url = command_oneline(qw(rev-parse --git-path), + "$id/info/url"); + next unless -f $info_url; + my $new_ref = "refs/remotes/$id"; + if (::verify_ref("$new_ref^0")) { + print STDERR "W: $orig_ref is probably an old ", + "branch used by an ancient version of ", + "git-svn.\n", + "However, $new_ref also exists.\n", + "We will not be able ", + "to use this branch until this ", + "ambiguity is resolved.\n"; + next; + } + print STDERR "Migrating from v0 layout...\n" if !$migrated; + print STDERR "Renaming ref: $orig_ref => $new_ref\n"; + command_noisy('update-ref', $new_ref, $orig_ref); + command_noisy('update-ref', '-d', $orig_ref, $orig_ref); + $migrated++; + } + command_close_pipe($fh, $ctx); + print STDERR "Done migrating from v0 layout...\n" if $migrated; + $migrated; +} + +sub migrate_from_v1 { + my $git_dir = $ENV{GIT_DIR}; + my $migrated = 0; + return $migrated unless -d $git_dir; + my $svn_dir = Git::SVN::svn_dir(); + + # just in case somebody used 'svn' as their $id at some point... + return $migrated if -d $svn_dir && ! -f "$svn_dir/info/url"; + + print STDERR "Migrating from a git-svn v1 layout...\n"; + mkpath([$svn_dir]); + print STDERR "Data from a previous version of git-svn exists, but\n\t", + "$svn_dir\n\t(required for this version ", + "($::VERSION) of git-svn) does not exist.\n"; + my ($fh, $ctx) = command_output_pipe(qw/rev-parse --symbolic --all/); + while (<$fh>) { + my $x = $_; + next unless $x =~ s#^refs/remotes/##; + chomp $x; + my $info_url = command_oneline(qw(rev-parse --git-path), + "$x/info/url"); + next unless -f $info_url; + my $u = eval { ::file_to_s($info_url) }; + next unless $u; + my $dn = dirname("$svn_dir/$x"); + mkpath([$dn]) unless -d $dn; + if ($x eq 'svn') { # they used 'svn' as GIT_SVN_ID: + mkpath(["$svn_dir/svn"]); + print STDERR " - $git_dir/$x/info => ", + "$svn_dir/$x/info\n"; + rename "$git_dir/$x/info", "$svn_dir/$x/info" or + croak "$!: $x"; + # don't worry too much about these, they probably + # don't exist with repos this old (save for index, + # and we can easily regenerate that) + foreach my $f (qw/unhandled.log index .rev_db/) { + rename "$git_dir/$x/$f", "$svn_dir/$x/$f"; + } + } else { + print STDERR " - $git_dir/$x => $svn_dir/$x\n"; + rename "$git_dir/$x", "$svn_dir/$x" or croak "$!: $x"; + } + $migrated++; + } + command_close_pipe($fh, $ctx); + print STDERR "Done migrating from a git-svn v1 layout\n"; + $migrated; +} + +sub read_old_urls { + my ($l_map, $pfx, $path) = @_; + my @dir; + foreach (<$path/*>) { + if (-r "$_/info/url") { + $pfx .= '/' if $pfx && $pfx !~ m!/$!; + my $ref_id = $pfx . basename $_; + my $url = ::file_to_s("$_/info/url"); + $l_map->{$ref_id} = $url; + } elsif (-d $_) { + push @dir, $_; + } + } + my $svn_dir = Git::SVN::svn_dir(); + foreach (@dir) { + my $x = $_; + $x =~ s!^\Q$svn_dir\E/!!o; + read_old_urls($l_map, $x, $_); + } +} + +sub migrate_from_v2 { + my @cfg = command(qw/config -l/); + return if grep /^svn-remote\..+\.url=/, @cfg; + my %l_map; + read_old_urls(\%l_map, '', Git::SVN::svn_dir()); + my $migrated = 0; + + require Git::SVN; + foreach my $ref_id (sort keys %l_map) { + eval { Git::SVN->init($l_map{$ref_id}, '', undef, $ref_id) }; + if ($@) { + Git::SVN->init($l_map{$ref_id}, '', $ref_id, $ref_id); + } + $migrated++; + } + $migrated; +} + +sub minimize_connections { + require Git::SVN; + require Git::SVN::Ra; + + my $r = Git::SVN::read_all_remotes(); + my $new_urls = {}; + my $root_repos = {}; + foreach my $repo_id (keys %$r) { + my $url = $r->{$repo_id}->{url} or next; + my $fetch = $r->{$repo_id}->{fetch} or next; + my $ra = Git::SVN::Ra->new($url); + + # skip existing cases where we already connect to the root + if (($ra->url eq $ra->{repos_root}) || + ($ra->{repos_root} eq $repo_id)) { + $root_repos->{$ra->url} = $repo_id; + next; + } + + my $root_ra = Git::SVN::Ra->new($ra->{repos_root}); + my $root_path = $ra->url; + $root_path =~ s#^\Q$ra->{repos_root}\E(/|$)##; + foreach my $path (keys %$fetch) { + my $ref_id = $fetch->{$path}; + my $gs = Git::SVN->new($ref_id, $repo_id, $path); + + # make sure we can read when connecting to + # a higher level of a repository + my ($last_rev, undef) = $gs->last_rev_commit; + if (!defined $last_rev) { + $last_rev = eval { + $root_ra->get_latest_revnum; + }; + next if $@; + } + my $new = $root_path; + $new .= length $path ? "/$path" : ''; + eval { + $root_ra->get_log([$new], $last_rev, $last_rev, + 0, 0, 1, sub { }); + }; + next if $@; + $new_urls->{$ra->{repos_root}}->{$new} = + { ref_id => $ref_id, + old_repo_id => $repo_id, + old_path => $path }; + } + } + + my @emptied; + foreach my $url (keys %$new_urls) { + # see if we can re-use an existing [svn-remote "repo_id"] + # instead of creating a(n ugly) new section: + my $repo_id = $root_repos->{$url} || $url; + + my $fetch = $new_urls->{$url}; + foreach my $path (keys %$fetch) { + my $x = $fetch->{$path}; + Git::SVN->init($url, $path, $repo_id, $x->{ref_id}); + my $pfx = "svn-remote.$x->{old_repo_id}"; + + my $old_fetch = quotemeta("$x->{old_path}:". + "$x->{ref_id}"); + command_noisy(qw/config --unset/, + "$pfx.fetch", '^'. $old_fetch . '$'); + delete $r->{$x->{old_repo_id}}-> + {fetch}->{$x->{old_path}}; + if (!keys %{$r->{$x->{old_repo_id}}->{fetch}}) { + command_noisy(qw/config --unset/, + "$pfx.url"); + push @emptied, $x->{old_repo_id} + } + } + } + if (@emptied) { + my $file = $ENV{GIT_CONFIG} || + command_oneline(qw(rev-parse --git-path config)); + print STDERR <<EOF; +The following [svn-remote] sections in your config file ($file) are empty +and can be safely removed: +EOF + print STDERR "[svn-remote \"$_\"]\n" foreach @emptied; + } +} + +sub migration_check { + migrate_from_v0(); + migrate_from_v1(); + migrate_from_v2(); + minimize_connections() if $_minimize; +} + +1; |