git/perl/Git/SVN/Fetcher.pm

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package Git::SVN::Fetcher;
use vars qw/@ISA $_ignore_regex $_include_regex $_preserve_empty_dirs
$_placeholder_filename @deleted_gpath %added_placeholder
$repo_id/;
use strict;
use warnings;
use SVN::Delta;
use Carp qw/croak/;
use File::Basename qw/dirname/;
use Git qw/command command_oneline command_noisy command_output_pipe
command_input_pipe command_close_pipe
command_bidi_pipe command_close_bidi_pipe
get_record/;
BEGIN {
@ISA = qw(SVN::Delta::Editor);
}
# file baton members: path, mode_a, mode_b, pool, fh, blob, base
sub new {
my ($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 ([a-f\d]{40})\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 ([a-f\d]{40})\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");
Git::SVN::*: avoid premature FileHandle closure Since b19138b (git-svn: Make it incrementally faster by minimizing temp files, v1.6.0), git-svn has been using the Git.pm temp_acquire and temp_release mechanism to avoid unnecessary temp file churn and provide a speed boost. However, that change introduced a call to temp_acquire inside the Git::SVN::Fetcher::close_file function for an 'svn_hash' temp file. Because an SVN::Pool is active at the time this function is called, if the Git::temp_acquire function ends up actually creating a new FileHandle for the temp file (which it will the first time it's called with the name 'svn_hash') that FileHandle will end up in the SVN::Pool and should that pool have SVN::Pool::clear called on it that FileHandle will be closed out from under Git::temp_acquire. Since the only call site to Git::temp_acquire with the name 'svn_hash' is inside the close_file function, if an 'svn_hash' temp file is ever created its FileHandle is guaranteed to be created in the active SVN::Pool. This has not been a problem in the past because the SVN::Pool was not being cleared. However, since dfa72fdb (git-svn: reload RA every log-window-size, v2.2.0) the pool has been getting cleared periodically at which point the FileHandle for the 'svn_hash' temp file gets closed. Any subsequent calls to Git::temp_acquire for 'svn_hash', however, succeed without creating/opening a new temporary file since it still has the now invalid FileHandle in its cache. Callers that then attempt to use that FileHandle fail with an error. We avoid this problem by making sure the 'svn_hash' temp file is created in the same place the 'svn_delta_...' and 'git_blob_...' temp files are (and then temp_release'd) so that it can be safely used inside the close_file function without having its FileHandle end up in an SVN::Pool that gets cleared. Additionally the Git.pm cat_blob function creates a bidirectional pipe FileHandle using the IPC::Open2::open2 function. If that handle is created too late, it also gets caught up in the SVN::Pool and incorrectly closed by the SVN::Pool::clear call. But this only seems to happen with more recent versions of Perl and svn. To avoid this problem we add an explicit call to _open_cat_blob_if_needed before the first call to SVN::Pool->new_default to make sure the open2 handle does not end up in the SVN::Pool. Signed-off-by: Kyle J. McKay <mackyle@gmail.com> Signed-off-by: Eric Wong <normalperson@yhbt.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-02-26 13:49:34 +00:00
# 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));
$hash =~ /^[a-f\d]{40}$/ or die "not a sha1: $hash\n";
Git::temp_release($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.