perl / Git / SVN / Ra.pmon commit git-svn: replace URL escapes with canonicalization (9c27a57)
   1package Git::SVN::Ra;
   2use vars qw/@ISA $config_dir $_ignore_refs_regex $_log_window_size/;
   3use strict;
   4use warnings;
   5use SVN::Client;
   6use Git::SVN::Utils qw(
   7        canonicalize_url
   8);
   9
  10use SVN::Ra;
  11BEGIN {
  12        @ISA = qw(SVN::Ra);
  13}
  14
  15my ($ra_invalid, $can_do_switch, %ignored_err, $RA);
  16
  17BEGIN {
  18        # enforce temporary pool usage for some simple functions
  19        no strict 'refs';
  20        for my $f (qw/rev_proplist get_latest_revnum get_uuid get_repos_root
  21                      get_file/) {
  22                my $SUPER = "SUPER::$f";
  23                *$f = sub {
  24                        my $self = shift;
  25                        my $pool = SVN::Pool->new;
  26                        my @ret = $self->$SUPER(@_,$pool);
  27                        $pool->clear;
  28                        wantarray ? @ret : $ret[0];
  29                };
  30        }
  31}
  32
  33sub _auth_providers () {
  34        my @rv = (
  35          SVN::Client::get_simple_provider(),
  36          SVN::Client::get_ssl_server_trust_file_provider(),
  37          SVN::Client::get_simple_prompt_provider(
  38            \&Git::SVN::Prompt::simple, 2),
  39          SVN::Client::get_ssl_client_cert_file_provider(),
  40          SVN::Client::get_ssl_client_cert_prompt_provider(
  41            \&Git::SVN::Prompt::ssl_client_cert, 2),
  42          SVN::Client::get_ssl_client_cert_pw_file_provider(),
  43          SVN::Client::get_ssl_client_cert_pw_prompt_provider(
  44            \&Git::SVN::Prompt::ssl_client_cert_pw, 2),
  45          SVN::Client::get_username_provider(),
  46          SVN::Client::get_ssl_server_trust_prompt_provider(
  47            \&Git::SVN::Prompt::ssl_server_trust),
  48          SVN::Client::get_username_prompt_provider(
  49            \&Git::SVN::Prompt::username, 2)
  50        );
  51
  52        # earlier 1.6.x versions would segfault, and <= 1.5.x didn't have
  53        # this function
  54        if (::compare_svn_version('1.6.15') >= 0) {
  55                my $config = SVN::Core::config_get_config($config_dir);
  56                my ($p, @a);
  57                # config_get_config returns all config files from
  58                # ~/.subversion, auth_get_platform_specific_client_providers
  59                # just wants the config "file".
  60                @a = ($config->{'config'}, undef);
  61                $p = SVN::Core::auth_get_platform_specific_client_providers(@a);
  62                # Insert the return value from
  63                # auth_get_platform_specific_providers
  64                unshift @rv, @$p;
  65        }
  66        \@rv;
  67}
  68
  69
  70sub new {
  71        my ($class, $url) = @_;
  72        $url =~ s!/+$!!;
  73        return $RA if ($RA && $RA->url eq $url);
  74
  75        ::_req_svn();
  76
  77        SVN::_Core::svn_config_ensure($config_dir, undef);
  78        my ($baton, $callbacks) = SVN::Core::auth_open_helper(_auth_providers);
  79        my $config = SVN::Core::config_get_config($config_dir);
  80        $RA = undef;
  81        my $dont_store_passwords = 1;
  82        my $conf_t = ${$config}{'config'};
  83        {
  84                no warnings 'once';
  85                # The usage of $SVN::_Core::SVN_CONFIG_* variables
  86                # produces warnings that variables are used only once.
  87                # I had not found the better way to shut them up, so
  88                # the warnings of type 'once' are disabled in this block.
  89                if (SVN::_Core::svn_config_get_bool($conf_t,
  90                    $SVN::_Core::SVN_CONFIG_SECTION_AUTH,
  91                    $SVN::_Core::SVN_CONFIG_OPTION_STORE_PASSWORDS,
  92                    1) == 0) {
  93                        SVN::_Core::svn_auth_set_parameter($baton,
  94                            $SVN::_Core::SVN_AUTH_PARAM_DONT_STORE_PASSWORDS,
  95                            bless (\$dont_store_passwords, "_p_void"));
  96                }
  97                if (SVN::_Core::svn_config_get_bool($conf_t,
  98                    $SVN::_Core::SVN_CONFIG_SECTION_AUTH,
  99                    $SVN::_Core::SVN_CONFIG_OPTION_STORE_AUTH_CREDS,
 100                    1) == 0) {
 101                        $Git::SVN::Prompt::_no_auth_cache = 1;
 102                }
 103        } # no warnings 'once'
 104        my $self = SVN::Ra->new(url => canonicalize_url($url), auth => $baton,
 105                              config => $config,
 106                              pool => SVN::Pool->new,
 107                              auth_provider_callbacks => $callbacks);
 108        $RA = bless $self, $class;
 109
 110        # Make sure its canonicalized
 111        $self->url($url);
 112        $self->{svn_path} = $url;
 113        $self->{repos_root} = $self->get_repos_root;
 114        $self->{svn_path} =~ s#^\Q$self->{repos_root}\E(/|$)##;
 115        $self->{cache} = { check_path => { r => 0, data => {} },
 116                           get_dir => { r => 0, data => {} } };
 117
 118        return $RA;
 119}
 120
 121sub url {
 122        my $self = shift;
 123
 124        if (@_) {
 125                my $url = shift;
 126                $self->{url} = canonicalize_url($url);
 127                return;
 128        }
 129
 130        return $self->{url};
 131}
 132
 133sub check_path {
 134        my ($self, $path, $r) = @_;
 135        my $cache = $self->{cache}->{check_path};
 136        if ($r == $cache->{r} && exists $cache->{data}->{$path}) {
 137                return $cache->{data}->{$path};
 138        }
 139        my $pool = SVN::Pool->new;
 140        my $t = $self->SUPER::check_path($path, $r, $pool);
 141        $pool->clear;
 142        if ($r != $cache->{r}) {
 143                %{$cache->{data}} = ();
 144                $cache->{r} = $r;
 145        }
 146        $cache->{data}->{$path} = $t;
 147}
 148
 149sub get_dir {
 150        my ($self, $dir, $r) = @_;
 151        my $cache = $self->{cache}->{get_dir};
 152        if ($r == $cache->{r}) {
 153                if (my $x = $cache->{data}->{$dir}) {
 154                        return wantarray ? @$x : $x->[0];
 155                }
 156        }
 157        my $pool = SVN::Pool->new;
 158        my ($d, undef, $props) = $self->SUPER::get_dir($dir, $r, $pool);
 159        my %dirents = map { $_ => { kind => $d->{$_}->kind } } keys %$d;
 160        $pool->clear;
 161        if ($r != $cache->{r}) {
 162                %{$cache->{data}} = ();
 163                $cache->{r} = $r;
 164        }
 165        $cache->{data}->{$dir} = [ \%dirents, $r, $props ];
 166        wantarray ? (\%dirents, $r, $props) : \%dirents;
 167}
 168
 169sub DESTROY {
 170        # do not call the real DESTROY since we store ourselves in $RA
 171}
 172
 173# get_log(paths, start, end, limit,
 174#         discover_changed_paths, strict_node_history, receiver)
 175sub get_log {
 176        my ($self, @args) = @_;
 177        my $pool = SVN::Pool->new;
 178
 179        # svn_log_changed_path_t objects passed to get_log are likely to be
 180        # overwritten even if only the refs are copied to an external variable,
 181        # so we should dup the structures in their entirety.  Using an
 182        # externally passed pool (instead of our temporary and quickly cleared
 183        # pool in Git::SVN::Ra) does not help matters at all...
 184        my $receiver = pop @args;
 185        my $prefix = "/".$self->{svn_path};
 186        $prefix =~ s#/+($)##;
 187        my $prefix_regex = qr#^\Q$prefix\E#;
 188        push(@args, sub {
 189                my ($paths) = $_[0];
 190                return &$receiver(@_) unless $paths;
 191                $_[0] = ();
 192                foreach my $p (keys %$paths) {
 193                        my $i = $paths->{$p};
 194                        # Make path relative to our url, not repos_root
 195                        $p =~ s/$prefix_regex//;
 196                        my %s = map { $_ => $i->$_; }
 197                                qw/copyfrom_path copyfrom_rev action/;
 198                        if ($s{'copyfrom_path'}) {
 199                                $s{'copyfrom_path'} =~ s/$prefix_regex//;
 200                        }
 201                        $_[0]{$p} = \%s;
 202                }
 203                &$receiver(@_);
 204        });
 205
 206
 207        # the limit parameter was not supported in SVN 1.1.x, so we
 208        # drop it.  Therefore, the receiver callback passed to it
 209        # is made aware of this limitation by being wrapped if
 210        # the limit passed to is being wrapped.
 211        if (::compare_svn_version('1.2.0') <= 0) {
 212                my $limit = splice(@args, 3, 1);
 213                if ($limit > 0) {
 214                        my $receiver = pop @args;
 215                        push(@args, sub { &$receiver(@_) if (--$limit >= 0) });
 216                }
 217        }
 218        my $ret = $self->SUPER::get_log(@args, $pool);
 219        $pool->clear;
 220        $ret;
 221}
 222
 223sub trees_match {
 224        my ($self, $url1, $rev1, $url2, $rev2) = @_;
 225        my $ctx = SVN::Client->new(auth => _auth_providers);
 226        my $out = IO::File->new_tmpfile;
 227
 228        # older SVN (1.1.x) doesn't take $pool as the last parameter for
 229        # $ctx->diff(), so we'll create a default one
 230        my $pool = SVN::Pool->new_default_sub;
 231
 232        $ra_invalid = 1; # this will open a new SVN::Ra connection to $url1
 233        $ctx->diff([], $url1, $rev1, $url2, $rev2, 1, 1, 0, $out, $out);
 234        $out->flush;
 235        my $ret = (($out->stat)[7] == 0);
 236        close $out or croak $!;
 237
 238        $ret;
 239}
 240
 241sub get_commit_editor {
 242        my ($self, $log, $cb, $pool) = @_;
 243
 244        my @lock = (::compare_svn_version('1.2.0') >= 0) ? (undef, 0) : ();
 245        $self->SUPER::get_commit_editor($log, $cb, @lock, $pool);
 246}
 247
 248sub gs_do_update {
 249        my ($self, $rev_a, $rev_b, $gs, $editor) = @_;
 250        my $new = ($rev_a == $rev_b);
 251        my $path = $gs->path;
 252
 253        if ($new && -e $gs->{index}) {
 254                unlink $gs->{index} or die
 255                  "Couldn't unlink index: $gs->{index}: $!\n";
 256        }
 257        my $pool = SVN::Pool->new;
 258        $editor->set_path_strip($path);
 259        my (@pc) = split m#/#, $path;
 260        my $reporter = $self->do_update($rev_b, (@pc ? shift @pc : ''),
 261                                        1, $editor, $pool);
 262        my @lock = (::compare_svn_version('1.2.0') >= 0) ? (undef) : ();
 263
 264        # Since we can't rely on svn_ra_reparent being available, we'll
 265        # just have to do some magic with set_path to make it so
 266        # we only want a partial path.
 267        my $sp = '';
 268        my $final = join('/', @pc);
 269        while (@pc) {
 270                $reporter->set_path($sp, $rev_b, 0, @lock, $pool);
 271                $sp .= '/' if length $sp;
 272                $sp .= shift @pc;
 273        }
 274        die "BUG: '$sp' != '$final'\n" if ($sp ne $final);
 275
 276        $reporter->set_path($sp, $rev_a, $new, @lock, $pool);
 277
 278        $reporter->finish_report($pool);
 279        $pool->clear;
 280        $editor->{git_commit_ok};
 281}
 282
 283# this requires SVN 1.4.3 or later (do_switch didn't work before 1.4.3, and
 284# svn_ra_reparent didn't work before 1.4)
 285sub gs_do_switch {
 286        my ($self, $rev_a, $rev_b, $gs, $url_b, $editor) = @_;
 287        my $path = $gs->path;
 288        my $pool = SVN::Pool->new;
 289
 290        my $full_url = $self->url;
 291        my $old_url = $full_url;
 292        $full_url .= '/' . $path if length $path;
 293        my ($ra, $reparented);
 294
 295        if ($old_url =~ m#^svn(\+ssh)?://# ||
 296            ($full_url =~ m#^https?://# &&
 297             canonicalize_url($full_url) ne $full_url)) {
 298                $_[0] = undef;
 299                $self = undef;
 300                $RA = undef;
 301                $ra = Git::SVN::Ra->new($full_url);
 302                $ra_invalid = 1;
 303        } elsif ($old_url ne $full_url) {
 304                SVN::_Ra::svn_ra_reparent($self->{session}, $full_url, $pool);
 305                $self->url($full_url);
 306                $reparented = 1;
 307        }
 308
 309        $ra ||= $self;
 310        $url_b = canonicalize_url($url_b);
 311        my $reporter = $ra->do_switch($rev_b, '', 1, $url_b, $editor, $pool);
 312        my @lock = (::compare_svn_version('1.2.0') >= 0) ? (undef) : ();
 313        $reporter->set_path('', $rev_a, 0, @lock, $pool);
 314        $reporter->finish_report($pool);
 315
 316        if ($reparented) {
 317                SVN::_Ra::svn_ra_reparent($self->{session}, $old_url, $pool);
 318                $self->url($old_url);
 319        }
 320
 321        $pool->clear;
 322        $editor->{git_commit_ok};
 323}
 324
 325sub longest_common_path {
 326        my ($gsv, $globs) = @_;
 327        my %common;
 328        my $common_max = scalar @$gsv;
 329
 330        foreach my $gs (@$gsv) {
 331                my @tmp = split m#/#, $gs->path;
 332                my $p = '';
 333                foreach (@tmp) {
 334                        $p .= length($p) ? "/$_" : $_;
 335                        $common{$p} ||= 0;
 336                        $common{$p}++;
 337                }
 338        }
 339        $globs ||= [];
 340        $common_max += scalar @$globs;
 341        foreach my $glob (@$globs) {
 342                my @tmp = split m#/#, $glob->{path}->{left};
 343                my $p = '';
 344                foreach (@tmp) {
 345                        $p .= length($p) ? "/$_" : $_;
 346                        $common{$p} ||= 0;
 347                        $common{$p}++;
 348                }
 349        }
 350
 351        my $longest_path = '';
 352        foreach (sort {length $b <=> length $a} keys %common) {
 353                if ($common{$_} == $common_max) {
 354                        $longest_path = $_;
 355                        last;
 356                }
 357        }
 358        $longest_path;
 359}
 360
 361sub gs_fetch_loop_common {
 362        my ($self, $base, $head, $gsv, $globs) = @_;
 363        return if ($base > $head);
 364        my $inc = $_log_window_size;
 365        my ($min, $max) = ($base, $head < $base + $inc ? $head : $base + $inc);
 366        my $longest_path = longest_common_path($gsv, $globs);
 367        my $ra_url = $self->url;
 368        my $find_trailing_edge;
 369        while (1) {
 370                my %revs;
 371                my $err;
 372                my $err_handler = $SVN::Error::handler;
 373                $SVN::Error::handler = sub {
 374                        ($err) = @_;
 375                        skip_unknown_revs($err);
 376                };
 377                sub _cb {
 378                        my ($paths, $r, $author, $date, $log) = @_;
 379                        [ $paths,
 380                          { author => $author, date => $date, log => $log } ];
 381                }
 382                $self->get_log([$longest_path], $min, $max, 0, 1, 1,
 383                               sub { $revs{$_[1]} = _cb(@_) });
 384                if ($err) {
 385                        print "Checked through r$max\r";
 386                } else {
 387                        $find_trailing_edge = 1;
 388                }
 389                if ($err and $find_trailing_edge) {
 390                        print STDERR "Path '$longest_path' ",
 391                                     "was probably deleted:\n",
 392                                     $err->expanded_message,
 393                                     "\nWill attempt to follow ",
 394                                     "revisions r$min .. r$max ",
 395                                     "committed before the deletion\n";
 396                        my $hi = $max;
 397                        while (--$hi >= $min) {
 398                                my $ok;
 399                                $self->get_log([$longest_path], $min, $hi,
 400                                               0, 1, 1, sub {
 401                                               $ok = $_[1];
 402                                               $revs{$_[1]} = _cb(@_) });
 403                                if ($ok) {
 404                                        print STDERR "r$min .. r$ok OK\n";
 405                                        last;
 406                                }
 407                        }
 408                        $find_trailing_edge = 0;
 409                }
 410                $SVN::Error::handler = $err_handler;
 411
 412                my %exists = map { $_->{path} => $_ } @$gsv;
 413                foreach my $r (sort {$a <=> $b} keys %revs) {
 414                        my ($paths, $logged) = @{$revs{$r}};
 415
 416                        foreach my $gs ($self->match_globs(\%exists, $paths,
 417                                                           $globs, $r)) {
 418                                if ($gs->rev_map_max >= $r) {
 419                                        next;
 420                                }
 421                                next unless $gs->match_paths($paths, $r);
 422                                $gs->{logged_rev_props} = $logged;
 423                                if (my $last_commit = $gs->last_commit) {
 424                                        $gs->assert_index_clean($last_commit);
 425                                }
 426                                my $log_entry = $gs->do_fetch($paths, $r);
 427                                if ($log_entry) {
 428                                        $gs->do_git_commit($log_entry);
 429                                }
 430                                $Git::SVN::INDEX_FILES{$gs->{index}} = 1;
 431                        }
 432                        foreach my $g (@$globs) {
 433                                my $k = "svn-remote.$g->{remote}." .
 434                                        "$g->{t}-maxRev";
 435                                Git::SVN::tmp_config($k, $r);
 436                        }
 437                        if ($ra_invalid) {
 438                                $_[0] = undef;
 439                                $self = undef;
 440                                $RA = undef;
 441                                $self = Git::SVN::Ra->new($ra_url);
 442                                $ra_invalid = undef;
 443                        }
 444                }
 445                # pre-fill the .rev_db since it'll eventually get filled in
 446                # with '0' x40 if something new gets committed
 447                foreach my $gs (@$gsv) {
 448                        next if $gs->rev_map_max >= $max;
 449                        next if defined $gs->rev_map_get($max);
 450                        $gs->rev_map_set($max, 0 x40);
 451                }
 452                foreach my $g (@$globs) {
 453                        my $k = "svn-remote.$g->{remote}.$g->{t}-maxRev";
 454                        Git::SVN::tmp_config($k, $max);
 455                }
 456                last if $max >= $head;
 457                $min = $max + 1;
 458                $max += $inc;
 459                $max = $head if ($max > $head);
 460        }
 461        Git::SVN::gc();
 462}
 463
 464sub get_dir_globbed {
 465        my ($self, $left, $depth, $r) = @_;
 466
 467        my @x = eval { $self->get_dir($left, $r) };
 468        return unless scalar @x == 3;
 469        my $dirents = $x[0];
 470        my @finalents;
 471        foreach my $de (keys %$dirents) {
 472                next if $dirents->{$de}->{kind} != $SVN::Node::dir;
 473                if ($depth > 1) {
 474                        my @args = ("$left/$de", $depth - 1, $r);
 475                        foreach my $dir ($self->get_dir_globbed(@args)) {
 476                                push @finalents, "$de/$dir";
 477                        }
 478                } else {
 479                        push @finalents, $de;
 480                }
 481        }
 482        @finalents;
 483}
 484
 485# return value: 0 -- don't ignore, 1 -- ignore
 486sub is_ref_ignored {
 487        my ($g, $p) = @_;
 488        my $refname = $g->{ref}->full_path($p);
 489        return 1 if defined($g->{ignore_refs_regex}) &&
 490                    $refname =~ m!$g->{ignore_refs_regex}!;
 491        return 0 unless defined($_ignore_refs_regex);
 492        return 1 if $refname =~ m!$_ignore_refs_regex!o;
 493        return 0;
 494}
 495
 496sub match_globs {
 497        my ($self, $exists, $paths, $globs, $r) = @_;
 498
 499        sub get_dir_check {
 500                my ($self, $exists, $g, $r) = @_;
 501
 502                my @dirs = $self->get_dir_globbed($g->{path}->{left},
 503                                                  $g->{path}->{depth},
 504                                                  $r);
 505
 506                foreach my $de (@dirs) {
 507                        my $p = $g->{path}->full_path($de);
 508                        next if $exists->{$p};
 509                        next if (length $g->{path}->{right} &&
 510                                 ($self->check_path($p, $r) !=
 511                                  $SVN::Node::dir));
 512                        next unless $p =~ /$g->{path}->{regex}/;
 513                        $exists->{$p} = Git::SVN->init($self->url, $p, undef,
 514                                         $g->{ref}->full_path($de), 1);
 515                }
 516        }
 517        foreach my $g (@$globs) {
 518                if (my $path = $paths->{"/$g->{path}->{left}"}) {
 519                        if ($path->{action} =~ /^[AR]$/) {
 520                                get_dir_check($self, $exists, $g, $r);
 521                        }
 522                }
 523                foreach (keys %$paths) {
 524                        if (/$g->{path}->{left_regex}/ &&
 525                            !/$g->{path}->{regex}/) {
 526                                next if $paths->{$_}->{action} !~ /^[AR]$/;
 527                                get_dir_check($self, $exists, $g, $r);
 528                        }
 529                        next unless /$g->{path}->{regex}/;
 530                        my $p = $1;
 531                        my $pathname = $g->{path}->full_path($p);
 532                        next if is_ref_ignored($g, $p);
 533                        next if $exists->{$pathname};
 534                        next if ($self->check_path($pathname, $r) !=
 535                                 $SVN::Node::dir);
 536                        $exists->{$pathname} = Git::SVN->init(
 537                                              $self->url, $pathname, undef,
 538                                              $g->{ref}->full_path($p), 1);
 539                }
 540                my $c = '';
 541                foreach (split m#/#, $g->{path}->{left}) {
 542                        $c .= "/$_";
 543                        next unless ($paths->{$c} &&
 544                                     ($paths->{$c}->{action} =~ /^[AR]$/));
 545                        get_dir_check($self, $exists, $g, $r);
 546                }
 547        }
 548        values %$exists;
 549}
 550
 551sub minimize_url {
 552        my ($self) = @_;
 553        return $self->url if ($self->url eq $self->{repos_root});
 554        my $url = $self->{repos_root};
 555        my @components = split(m!/!, $self->{svn_path});
 556        my $c = '';
 557        do {
 558                $url .= "/$c" if length $c;
 559                eval {
 560                        my $ra = (ref $self)->new($url);
 561                        my $latest = $ra->get_latest_revnum;
 562                        $ra->get_log("", $latest, 0, 1, 0, 1, sub {});
 563                };
 564        } while ($@ && ($c = shift @components));
 565
 566        return canonicalize_url($url);
 567}
 568
 569sub can_do_switch {
 570        my $self = shift;
 571        unless (defined $can_do_switch) {
 572                my $pool = SVN::Pool->new;
 573                my $rep = eval {
 574                        $self->do_switch(1, '', 0, $self->url,
 575                                         SVN::Delta::Editor->new, $pool);
 576                };
 577                if ($@) {
 578                        $can_do_switch = 0;
 579                } else {
 580                        $rep->abort_report($pool);
 581                        $can_do_switch = 1;
 582                }
 583                $pool->clear;
 584        }
 585        $can_do_switch;
 586}
 587
 588sub skip_unknown_revs {
 589        my ($err) = @_;
 590        my $errno = $err->apr_err();
 591        # Maybe the branch we're tracking didn't
 592        # exist when the repo started, so it's
 593        # not an error if it doesn't, just continue
 594        #
 595        # Wonderfully consistent library, eh?
 596        # 160013 - svn:// and file://
 597        # 175002 - http(s)://
 598        # 175007 - http(s):// (this repo required authorization, too...)
 599        #   More codes may be discovered later...
 600        if ($errno == 175007 || $errno == 175002 || $errno == 160013) {
 601                my $err_key = $err->expanded_message;
 602                # revision numbers change every time, filter them out
 603                $err_key =~ s/\d+/\0/g;
 604                $err_key = "$errno\0$err_key";
 605                unless ($ignored_err{$err_key}) {
 606                        warn "W: Ignoring error from SVN, path probably ",
 607                             "does not exist: ($errno): ",
 608                             $err->expanded_message,"\n";
 609                        warn "W: Do not be alarmed at the above message ",
 610                             "git-svn is just searching aggressively for ",
 611                             "old history.\n",
 612                             "This may take a while on large repositories\n";
 613                        $ignored_err{$err_key} = 1;
 614                }
 615                return;
 616        }
 617        die "Error from SVN, ($errno): ", $err->expanded_message,"\n";
 618}
 619
 6201;
 621__END__
 622
 623Git::SVN::Ra - Subversion remote access functions for git-svn
 624
 625=head1 SYNOPSIS
 626
 627    use Git::SVN::Ra;
 628
 629    my $ra = Git::SVN::Ra->new($branchurl);
 630    my ($dirents, $fetched_revnum, $props) =
 631        $ra->get_dir('.', $SVN::Core::INVALID_REVNUM);
 632
 633=head1 DESCRIPTION
 634
 635This is a wrapper around the L<SVN::Ra> module for use by B<git-svn>.
 636It fills in some default parameters (such as the authentication
 637scheme), smooths over incompatibilities between libsvn versions, adds
 638caching, and implements some functions specific to B<git-svn>.
 639
 640Do not use it unless you are developing git-svn.  The interface will
 641change as git-svn evolves.
 642
 643=head1 DEPENDENCIES
 644
 645Subversion perl bindings,
 646L<Git::SVN>.
 647
 648C<Git::SVN::Ra> has not been tested using callers other than
 649B<git-svn> itself.
 650
 651=head1 SEE ALSO
 652
 653L<SVN::Ra>.
 654
 655=head1 INCOMPATIBILITIES
 656
 657None reported.
 658
 659=head1 BUGS
 660
 661None.