git/perl/Git/SVN/Fetcher.pm

623 lines
18 KiB
Perl

package Git::SVN::Fetcher;
use vars qw/@ISA $_ignore_regex $_include_regex $_preserve_empty_dirs
$_placeholder_filename @deleted_gpath %added_placeholder
$repo_id/;
use strict;
use warnings $ENV{GIT_PERL_FATAL_WARNINGS} ? qw(FATAL all) : ();
use SVN::Delta;
use Carp qw/croak/;
use File::Basename qw/dirname/;
use Git qw/command command_oneline command_noisy command_output_pipe
command_input_pipe command_close_pipe
command_bidi_pipe command_close_bidi_pipe
get_record/;
BEGIN {
@ISA = qw(SVN::Delta::Editor);
}
# file baton members: path, mode_a, mode_b, pool, fh, blob, base
sub new {
my ($class, $git_svn, $switch_path) = @_;
my $self = SVN::Delta::Editor->new;
bless $self, $class;
if (exists $git_svn->{last_commit}) {
$self->{c} = $git_svn->{last_commit};
$self->{empty_symlinks} =
_mark_empty_symlinks($git_svn, $switch_path);
}
# some options are read globally, but can be overridden locally
# per [svn-remote "..."] section. Command-line options will *NOT*
# override options set in an [svn-remote "..."] section
$repo_id = $git_svn->{repo_id};
my $k = "svn-remote.$repo_id.ignore-paths";
my $v = eval { command_oneline('config', '--get', $k) };
$self->{ignore_regex} = $v;
$k = "svn-remote.$repo_id.include-paths";
$v = eval { command_oneline('config', '--get', $k) };
$self->{include_regex} = $v;
$k = "svn-remote.$repo_id.preserve-empty-dirs";
$v = eval { command_oneline('config', '--get', '--bool', $k) };
if ($v && $v eq 'true') {
$_preserve_empty_dirs = 1;
$k = "svn-remote.$repo_id.placeholder-filename";
$v = eval { command_oneline('config', '--get', $k) };
$_placeholder_filename = $v;
}
# Load the list of placeholder files added during previous invocations.
$k = "svn-remote.$repo_id.added-placeholder";
$v = eval { command_oneline('config', '--get-all', $k) };
if ($_preserve_empty_dirs && $v) {
# command() prints errors to stderr, so we only call it if
# command_oneline() succeeded.
my @v = command('config', '--get-all', $k);
$added_placeholder{ dirname($_) } = $_ foreach @v;
}
$self->{empty} = {};
$self->{dir_prop} = {};
$self->{file_prop} = {};
$self->{absent_dir} = {};
$self->{absent_file} = {};
require Git::IndexInfo;
$self->{gii} = $git_svn->tmp_index_do(sub { Git::IndexInfo->new });
$self->{pathnameencoding} = Git::config('svn.pathnameencoding');
$self;
}
# this uses the Ra object, so it must be called before do_{switch,update},
# not inside them (when the Git::SVN::Fetcher object is passed) to
# do_{switch,update}
sub _mark_empty_symlinks {
my ($git_svn, $switch_path) = @_;
my $bool = Git::config_bool('svn.brokenSymlinkWorkaround');
return {} if (!defined($bool)) || (defined($bool) && ! $bool);
my %ret;
my ($rev, $cmt) = $git_svn->last_rev_commit;
return {} unless ($rev && $cmt);
# allow the warning to be printed for each revision we fetch to
# ensure the user sees it. The user can also disable the workaround
# on the repository even while git svn is running and the next
# revision fetched will skip this expensive function.
my $printed_warning;
chomp(my $empty_blob = `git hash-object -t blob --stdin < /dev/null`);
my ($ls, $ctx) = command_output_pipe(qw/ls-tree -r -z/, $cmt);
my $pfx = defined($switch_path) ? $switch_path : $git_svn->path;
$pfx .= '/' if length($pfx);
while (defined($_ = get_record($ls, "\0"))) {
s/\A100644 blob $empty_blob\t//o or next;
unless ($printed_warning) {
print STDERR "Scanning for empty symlinks, ",
"this may take a while if you have ",
"many empty files\n",
"You may disable this with `",
"git config svn.brokenSymlinkWorkaround ",
"false'.\n",
"This may be done in a different ",
"terminal without restarting ",
"git svn\n";
$printed_warning = 1;
}
my $path = $_;
my (undef, $props) =
$git_svn->ra->get_file($pfx.$path, $rev, undef);
if ($props->{'svn:special'}) {
$ret{$path} = 1;
}
}
command_close_pipe($ls, $ctx);
\%ret;
}
# returns true if a given path is inside a ".git" directory
sub in_dot_git {
$_[0] =~ m{(?:^|/)\.git(?:/|$)};
}
# return value: 0 -- don't ignore, 1 -- ignore
# This will also check whether the path is explicitly included
sub is_path_ignored {
my ($self, $path) = @_;
return 1 if in_dot_git($path);
return 1 if defined($self->{ignore_regex}) &&
$path =~ m!$self->{ignore_regex}!;
return 0 if defined($self->{include_regex}) &&
$path =~ m!$self->{include_regex}!;
return 0 if defined($_include_regex) &&
$path =~ m!$_include_regex!;
return 1 if defined($self->{include_regex});
return 1 if defined($_include_regex);
return 0 unless defined($_ignore_regex);
return 1 if $path =~ m!$_ignore_regex!o;
return 0;
}
sub set_path_strip {
my ($self, $path) = @_;
$self->{path_strip} = qr/^\Q$path\E(\/|$)/ if length $path;
}
sub open_root {
{ path => '' };
}
sub open_directory {
my ($self, $path, $pb, $rev) = @_;
{ path => $path };
}
sub git_path {
my ($self, $path) = @_;
if (my $enc = $self->{pathnameencoding}) {
require Encode;
Encode::from_to($path, 'UTF-8', $enc);
}
if ($self->{path_strip}) {
$path =~ s!$self->{path_strip}!! or
die "Failed to strip path '$path' ($self->{path_strip})\n";
}
$path;
}
sub delete_entry {
my ($self, $path, $rev, $pb) = @_;
return undef if $self->is_path_ignored($path);
my $gpath = $self->git_path($path);
return undef if ($gpath eq '');
# remove entire directories.
my ($tree) = (command('ls-tree', '-z', $self->{c}, "./$gpath")
=~ /\A040000 tree ($::oid)\t\Q$gpath\E\0/);
if ($tree) {
my ($ls, $ctx) = command_output_pipe(qw/ls-tree
-r --name-only -z/,
$tree);
while (defined($_ = get_record($ls, "\0"))) {
my $rmpath = "$gpath/$_";
$self->{gii}->remove($rmpath);
print "\tD\t$rmpath\n" unless $::_q;
}
print "\tD\t$gpath/\n" unless $::_q;
command_close_pipe($ls, $ctx);
} else {
$self->{gii}->remove($gpath);
print "\tD\t$gpath\n" unless $::_q;
}
# Don't add to @deleted_gpath if we're deleting a placeholder file.
push @deleted_gpath, $gpath unless $added_placeholder{dirname($path)};
$self->{empty}->{$path} = 0;
undef;
}
sub open_file {
my ($self, $path, $pb, $rev) = @_;
my ($mode, $blob);
goto out if $self->is_path_ignored($path);
my $gpath = $self->git_path($path);
($mode, $blob) = (command('ls-tree', '-z', $self->{c}, "./$gpath")
=~ /\A(\d{6}) blob ($::oid)\t\Q$gpath\E\0/);
unless (defined $mode && defined $blob) {
die "$path was not found in commit $self->{c} (r$rev)\n";
}
if ($mode eq '100644' && $self->{empty_symlinks}->{$path}) {
$mode = '120000';
}
out:
{ path => $path, mode_a => $mode, mode_b => $mode, blob => $blob,
pool => SVN::Pool->new, action => 'M' };
}
sub add_file {
my ($self, $path, $pb, $cp_path, $cp_rev) = @_;
my $mode;
if (!$self->is_path_ignored($path)) {
my ($dir, $file) = ($path =~ m#^(.*?)/?([^/]+)$#);
delete $self->{empty}->{$dir};
$mode = '100644';
if ($added_placeholder{$dir}) {
# Remove our placeholder file, if we created one.
delete_entry($self, $added_placeholder{$dir})
unless $path eq $added_placeholder{$dir};
delete $added_placeholder{$dir}
}
}
{ path => $path, mode_a => $mode, mode_b => $mode,
pool => SVN::Pool->new, action => 'A' };
}
sub add_directory {
my ($self, $path, $cp_path, $cp_rev) = @_;
goto out if $self->is_path_ignored($path);
my $gpath = $self->git_path($path);
if ($gpath eq '') {
my ($ls, $ctx) = command_output_pipe(qw/ls-tree
-r --name-only -z/,
$self->{c});
while (defined($_ = get_record($ls, "\0"))) {
$self->{gii}->remove($_);
print "\tD\t$_\n" unless $::_q;
push @deleted_gpath, $gpath;
}
command_close_pipe($ls, $ctx);
$self->{empty}->{$path} = 0;
}
my ($dir, $file) = ($path =~ m#^(.*?)/?([^/]+)$#);
delete $self->{empty}->{$dir};
$self->{empty}->{$path} = 1;
if ($added_placeholder{$dir}) {
# Remove our placeholder file, if we created one.
delete_entry($self, $added_placeholder{$dir});
delete $added_placeholder{$dir}
}
out:
{ path => $path };
}
sub change_dir_prop {
my ($self, $db, $prop, $value) = @_;
return undef if $self->is_path_ignored($db->{path});
$self->{dir_prop}->{$db->{path}} ||= {};
$self->{dir_prop}->{$db->{path}}->{$prop} = $value;
undef;
}
sub absent_directory {
my ($self, $path, $pb) = @_;
return undef if $self->is_path_ignored($path);
$self->{absent_dir}->{$pb->{path}} ||= [];
push @{$self->{absent_dir}->{$pb->{path}}}, $path;
undef;
}
sub absent_file {
my ($self, $path, $pb) = @_;
return undef if $self->is_path_ignored($path);
$self->{absent_file}->{$pb->{path}} ||= [];
push @{$self->{absent_file}->{$pb->{path}}}, $path;
undef;
}
sub change_file_prop {
my ($self, $fb, $prop, $value) = @_;
return undef if $self->is_path_ignored($fb->{path});
if ($prop eq 'svn:executable') {
if ($fb->{mode_b} != 120000) {
$fb->{mode_b} = defined $value ? 100755 : 100644;
}
} elsif ($prop eq 'svn:special') {
$fb->{mode_b} = defined $value ? 120000 : 100644;
} else {
$self->{file_prop}->{$fb->{path}} ||= {};
$self->{file_prop}->{$fb->{path}}->{$prop} = $value;
}
undef;
}
sub apply_textdelta {
my ($self, $fb, $exp) = @_;
return undef if $self->is_path_ignored($fb->{path});
my $suffix = 0;
++$suffix while $::_repository->temp_is_locked("svn_delta_${$}_$suffix");
my $fh = $::_repository->temp_acquire("svn_delta_${$}_$suffix");
# $fh gets auto-closed() by SVN::TxDelta::apply(),
# (but $base does not,) so dup() it for reading in close_file
open my $dup, '<&', $fh or croak $!;
my $base = $::_repository->temp_acquire("git_blob_${$}_$suffix");
# close_file may call temp_acquire on 'svn_hash', but because of the
# call chain, if the temp_acquire call from close_file ends up being the
# call that first creates the 'svn_hash' temp file, then the FileHandle
# that's created as a result will end up in an SVN::Pool that we clear
# in SVN::Ra::gs_fetch_loop_common. Avoid that by making sure the
# 'svn_hash' FileHandle is already created before close_file is called.
my $tmp_fh = $::_repository->temp_acquire('svn_hash');
$::_repository->temp_release($tmp_fh, 1);
if ($fb->{blob}) {
my ($base_is_link, $size);
if ($fb->{mode_a} eq '120000' &&
! $self->{empty_symlinks}->{$fb->{path}}) {
print $base 'link ' or die "print $!\n";
$base_is_link = 1;
}
retry:
$size = $::_repository->cat_blob($fb->{blob}, $base);
die "Failed to read object $fb->{blob}" if ($size < 0);
if (defined $exp) {
seek $base, 0, 0 or croak $!;
my $got = ::md5sum($base);
if ($got ne $exp) {
my $err = "Checksum mismatch: ".
"$fb->{path} $fb->{blob}\n" .
"expected: $exp\n" .
" got: $got\n";
if ($base_is_link) {
warn $err,
"Retrying... (possibly ",
"a bad symlink from SVN)\n";
$::_repository->temp_reset($base);
$base_is_link = 0;
goto retry;
}
die $err;
}
}
}
seek $base, 0, 0 or croak $!;
$fb->{fh} = $fh;
$fb->{base} = $base;
[ SVN::TxDelta::apply($base, $dup, undef, $fb->{path}, $fb->{pool}) ];
}
sub close_file {
my ($self, $fb, $exp) = @_;
return undef if $self->is_path_ignored($fb->{path});
my $hash;
my $path = $self->git_path($fb->{path});
if (my $fh = $fb->{fh}) {
if (defined $exp) {
seek($fh, 0, 0) or croak $!;
my $got = ::md5sum($fh);
if ($got ne $exp) {
die "Checksum mismatch: $path\n",
"expected: $exp\n got: $got\n";
}
}
if ($fb->{mode_b} == 120000) {
sysseek($fh, 0, 0) or croak $!;
my $rd = sysread($fh, my $buf, 5);
if (!defined $rd) {
croak "sysread: $!\n";
} elsif ($rd == 0) {
warn "$path has mode 120000",
" but it points to nothing\n",
"converting to an empty file with mode",
" 100644\n";
$fb->{mode_b} = '100644';
} elsif ($buf ne 'link ') {
warn "$path has mode 120000",
" but is not a link\n";
} else {
my $tmp_fh = $::_repository->temp_acquire(
'svn_hash');
my $res;
while ($res = sysread($fh, my $str, 1024)) {
my $out = syswrite($tmp_fh, $str, $res);
defined($out) && $out == $res
or croak("write ",
Git::temp_path($tmp_fh),
": $!\n");
}
defined $res or croak $!;
($fh, $tmp_fh) = ($tmp_fh, $fh);
Git::temp_release($tmp_fh, 1);
}
}
$hash = $::_repository->hash_and_insert_object(
Git::temp_path($fh));
$hash =~ /^$::oid$/ or die "not an object ID: $hash\n";
Git::temp_release($fb->{base}, 1);
Git::temp_release($fh, 1);
} else {
$hash = $fb->{blob} or die "no blob information\n";
}
$fb->{pool}->clear;
$self->{gii}->update($fb->{mode_b}, $hash, $path) or croak $!;
print "\t$fb->{action}\t$path\n" if $fb->{action} && ! $::_q;
undef;
}
sub abort_edit {
my $self = shift;
$self->{nr} = $self->{gii}->{nr};
delete $self->{gii};
$self->SUPER::abort_edit(@_);
}
sub close_edit {
my $self = shift;
if ($_preserve_empty_dirs) {
my @empty_dirs;
# Any entry flagged as empty that also has an associated
# dir_prop represents a newly created empty directory.
foreach my $i (keys %{$self->{empty}}) {
push @empty_dirs, $i if exists $self->{dir_prop}->{$i};
}
# Search for directories that have become empty due subsequent
# file deletes.
push @empty_dirs, $self->find_empty_directories();
# Finally, add a placeholder file to each empty directory.
$self->add_placeholder_file($_) foreach (@empty_dirs);
$self->stash_placeholder_list();
}
$self->{git_commit_ok} = 1;
$self->{nr} = $self->{gii}->{nr};
delete $self->{gii};
$self->SUPER::close_edit(@_);
}
sub find_empty_directories {
my ($self) = @_;
my @empty_dirs;
my %dirs = map { dirname($_) => 1 } @deleted_gpath;
foreach my $dir (sort keys %dirs) {
next if $dir eq ".";
# If there have been any additions to this directory, there is
# no reason to check if it is empty.
my $skip_added = 0;
foreach my $t (qw/dir_prop file_prop/) {
foreach my $path (keys %{ $self->{$t} }) {
if (exists $self->{$t}->{dirname($path)}) {
$skip_added = 1;
last;
}
}
last if $skip_added;
}
next if $skip_added;
# Use `git ls-tree` to get the filenames of this directory
# that existed prior to this particular commit.
my $ls = command('ls-tree', '-z', '--name-only',
$self->{c}, "$dir/");
my %files = map { $_ => 1 } split(/\0/, $ls);
# Remove the filenames that were deleted during this commit.
delete $files{$_} foreach (@deleted_gpath);
# Report the directory if there are no filenames left.
push @empty_dirs, $dir unless (scalar %files);
}
@empty_dirs;
}
sub add_placeholder_file {
my ($self, $dir) = @_;
my $path = "$dir/$_placeholder_filename";
my $gpath = $self->git_path($path);
my $fh = $::_repository->temp_acquire($gpath);
my $hash = $::_repository->hash_and_insert_object(Git::temp_path($fh));
Git::temp_release($fh, 1);
$self->{gii}->update('100644', $hash, $gpath) or croak $!;
# The directory should no longer be considered empty.
delete $self->{empty}->{$dir} if exists $self->{empty}->{$dir};
# Keep track of any placeholder files we create.
$added_placeholder{$dir} = $path;
}
sub stash_placeholder_list {
my ($self) = @_;
my $k = "svn-remote.$repo_id.added-placeholder";
my $v = eval { command_oneline('config', '--get-all', $k) };
command_noisy('config', '--unset-all', $k) if $v;
foreach (values %added_placeholder) {
command_noisy('config', '--add', $k, $_);
}
}
1;
__END__
=head1 NAME
Git::SVN::Fetcher - tree delta consumer for "git svn fetch"
=head1 SYNOPSIS
use SVN::Core;
use SVN::Ra;
use Git::SVN;
use Git::SVN::Fetcher;
use Git;
my $gs = Git::SVN->find_by_url($url);
my $ra = SVN::Ra->new(url => $url);
my $editor = Git::SVN::Fetcher->new($gs);
my $reporter = $ra->do_update($SVN::Core::INVALID_REVNUM, '',
1, $editor);
$reporter->set_path('', $old_rev, 0);
$reporter->finish_report;
my $tree = $gs->tmp_index_do(sub { command_oneline('write-tree') });
foreach my $path (keys %{$editor->{dir_prop}) {
my $props = $editor->{dir_prop}{$path};
foreach my $prop (keys %$props) {
print "property $prop at $path changed to $props->{$prop}\n";
}
}
foreach my $path (keys %{$editor->{empty}) {
my $action = $editor->{empty}{$path} ? 'added' : 'removed';
print "empty directory $path $action\n";
}
foreach my $path (keys %{$editor->{file_prop}) { ... }
foreach my $parent (keys %{$editor->{absent_dir}}) {
my @children = @{$editor->{abstent_dir}{$parent}};
print "cannot fetch directory $parent/$_: not authorized?\n"
foreach @children;
}
foreach my $parent (keys %{$editor->{absent_file}) { ... }
=head1 DESCRIPTION
This is a subclass of C<SVN::Delta::Editor>, which means it implements
callbacks to act as a consumer of Subversion tree deltas. This
particular implementation of those callbacks is meant to store
information about the resulting content which B<git svn fetch> could
use to populate new commits and new entries for F<unhandled.log>.
More specifically:
=over
=item * Additions, removals, and modifications of files are propagated
to git-svn's index file F<$GIT_DIR/svn/$refname/index> using
B<git update-index>.
=item * Changes in Subversion path properties are recorded in the
C<dir_prop> and C<file_prop> fields (which are hashes).
=item * Addition and removal of empty directories are indicated by
entries with value 1 and 0 respectively in the C<empty> hash.
=item * Paths that are present but cannot be conveyed (presumably due
to permissions) are recorded in the C<absent_file> and
C<absent_dirs> hashes. For each key, the corresponding value is
a list of paths under that directory that were present but
could not be conveyed.
=back
The interface is unstable. Do not use this module unless you are
developing git-svn.
=head1 DEPENDENCIES
L<SVN::Delta> from the Subversion perl bindings,
the core L<Carp> and L<File::Basename> modules,
and git's L<Git> helper module.
C<Git::SVN::Fetcher> has not been tested using callers other than
B<git-svn> itself.
=head1 SEE ALSO
L<SVN::Delta>,
L<Git::SVN::Editor>.
=head1 INCOMPATIBILITIES
None reported.
=head1 BUGS
None.