git-svnimport.perl - jrn/git - Git at Google

 #!/usr/bin/perl -w

 # This tool is copyright (c) 2005, Matthias Urlichs.
 # It is released under the Gnu Public License, version 2.
 #
 # The basic idea is to pull and analyze SVN changes.
 #
 # Checking out the files is done by a single long-running CVS connection
 # / server process.
 #
 # The head revision is on branch "origin" by default.
 # You can change that with the '-o' option.

 require v5.8.0; # for shell-safe open("-|",LIST)
 use strict;
 use warnings;
 use Getopt::Std;
 use File::Spec;
 use File::Temp qw(tempfile);
 use File::Path qw(mkpath);
 use File::Basename qw(basename dirname);
 use Time::Local;
 use IO::Pipe;
 use POSIX qw(strftime dup2);
 use IPC::Open2;
 use SVN::Core;
 use SVN::Ra;

 die "Need CVN:COre 1.2.1 or better" if $SVN::Core::VERSION lt "1.2.1";

 $SIG{'PIPE'}="IGNORE";
 $ENV{'TZ'}="UTC";

 our($opt_h,$opt_o,$opt_v,$opt_u,$opt_C,$opt_i,$opt_m,$opt_M,$opt_t,$opt_T,$opt_b);

 sub usage() {
 	print STDERR <<END;
 Usage: ${\basename $0}     # fetch/update GIT from CVS
        [-o branch-for-HEAD] [-h] [-v]
        [-C GIT_repository] [-t tagname] [-T trunkname] [-b branchname]
        [-i] [-u] [-s subst] [-m] [-M regex] [SVN_URL]
 END
 	exit(1);
 }

 getopts("b:C:hivmM:o:t:T:u") or usage();
 usage if $opt_h;

 my $tag_name = $opt_t || "tags";
 my $trunk_name = $opt_T || "trunk";
 my $branch_name = $opt_b || "branches";

 @ARGV <= 1 or usage();

 $opt_o ||= "origin";
 my $git_tree = $opt_C;
 $git_tree ||= ".";

 my $cvs_tree;
 if ($#ARGV == 0) {
 	$cvs_tree = $ARGV[0];
 } elsif (-f 'CVS/Repository') {
 	open my $f, '<', 'CVS/Repository' or
 	    die 'Failed to open CVS/Repository';
 	$cvs_tree = <$f>;
 	chomp $cvs_tree;
 	close $f;
 } else {
 	usage();
 }

 our @mergerx = ();
 if ($opt_m) {
 	@mergerx = ( qr/\W(?:from|of|merge|merging|merged) (\w+)/i );
 }
 if ($opt_M) {
 	push (@mergerx, qr/$opt_M/);
 }

 select(STDERR); $|=1; select(STDOUT);


 package SVNconn;
 # Basic SVN connection.
 # We're only interested in connecting and downloading, so ...

 use File::Spec;
 use File::Temp qw(tempfile);
 use POSIX qw(strftime dup2);

 sub new {
 	my($what,$repo) = @_;
 	$what=ref($what) if ref($what);

 	my $self = {};
 	$self->{'buffer'} = "";
 	bless($self,$what);

 	$repo =~ s#/+$##;
 	$self->{'fullrep'} = $repo;
 	$self->conn();

 	return $self;
 }

 sub conn {
 	my $self = shift;
 	my $repo = $self->{'fullrep'};
 	my $s = SVN::Ra->new($repo);

 	die "SVN connection to $repo: $!\n" unless defined $s;
 	$self->{'svn'} = $s;
 	$self->{'repo'} = $repo;
 	$self->{'maxrev'} = $s->get_latest_revnum();
 }

 sub file {
 	my($self,$path,$rev) = @_;
 	my $res;

 	my ($fh, $name) = tempfile('gitsvn.XXXXXX',
 		    DIR => File::Spec->tmpdir(), UNLINK => 1);

 	print "... $rev $path ...\n" if $opt_v;
 	eval { $self->{'svn'}->get_file($path,$rev,$fh); };
 	if ($@ and $@ !~ /Attempted to get checksum/) {
 	    # retry
 	    $self->conn();
 		eval { $self->{'svn'}->get_file($path,$rev,$fh); };
 	};
 	return () if $@ and $@ !~ /Attempted to get checksum/;
 	die $@ if $@;
 	close ($fh);

 	return ($name, $res);
 }


 package main;

 my $svn = SVNconn->new($cvs_tree);


 sub pdate($) {
 	my($d) = @_;
 	$d =~ m#(\d\d\d\d)-(\d\d)-(\d\d)T(\d\d):(\d\d):(\d\d)#
 		or die "Unparseable date: $d\n";
 	my $y=$1; $y-=1900 if $y>1900;
 	return timegm($6||0,$5,$4,$3,$2-1,$y);
 }

 sub getwd() {
 	my $pwd = `pwd`;
 	chomp $pwd;
 	return $pwd;
 }


 sub get_headref($$) {
     my $name    = shift;
     my $git_dir = shift;
     my $sha;

     if (open(C,"$git_dir/refs/heads/$name")) {
 	chomp($sha = <C>);
 	close(C);
 	length($sha) == 40
 	    or die "Cannot get head id for $name ($sha): $!\n";
     }
     return $sha;
 }


 -d $git_tree
 	or mkdir($git_tree,0777)
 	or die "Could not create $git_tree: $!";
 chdir($git_tree);

 my $orig_branch = "";
 my $forward_master = 0;
 my %branches;

 my $git_dir = $ENV{"GIT_DIR"} || ".git";
 $git_dir = getwd()."/".$git_dir unless $git_dir =~ m#^/#;
 $ENV{"GIT_DIR"} = $git_dir;
 my $orig_git_index;
 $orig_git_index = $ENV{GIT_INDEX_FILE} if exists $ENV{GIT_INDEX_FILE};
 my ($git_ih, $git_index) = tempfile('gitXXXXXX', SUFFIX => '.idx',
 				    DIR => File::Spec->tmpdir());
 close ($git_ih);
 $ENV{GIT_INDEX_FILE} = $git_index;
 my $maxnum = 0;
 my $last_rev = "";
 my $last_branch;
 my $current_rev = 0;
 unless(-d $git_dir) {
 	system("git-init-db");
 	die "Cannot init the GIT db at $git_tree: $?\n" if $?;
 	system("git-read-tree");
 	die "Cannot init an empty tree: $?\n" if $?;

 	$last_branch = $opt_o;
 	$orig_branch = "";
 } else {
 	-f "$git_dir/refs/heads/$opt_o"
 		or die "Branch '$opt_o' does not exist.\n".
 		       "Either use the correct '-o branch' option,\n".
 		       "or import to a new repository.\n";

 	-f "$git_dir/svn2git"
 		or die "'$git_dir/svn2git' does not exist.\n".
 		       "You need that file for incremental imports.\n";
 	$last_branch = basename(readlink("$git_dir/HEAD"));
 	unless($last_branch) {
 		warn "Cannot read the last branch name: $! -- assuming 'master'\n";
 		$last_branch = "master";
 	}
 	$orig_branch = $last_branch;
 	$last_rev = get_headref($orig_branch, $git_dir);
 	if (-f "$git_dir/SVN2GIT_HEAD") {
 		die <<EOM;
 SVN2GIT_HEAD exists.
 Make sure your working directory corresponds to HEAD and remove SVN2GIT_HEAD.
 You may need to run

     git-read-tree -m -u SVN2GIT_HEAD HEAD
 EOM
 	}
 	system('cp', "$git_dir/HEAD", "$git_dir/SVN2GIT_HEAD");

 	$forward_master =
 	    $opt_o ne 'master' && -f "$git_dir/refs/heads/master" &&
 	    system('cmp', '-s', "$git_dir/refs/heads/master",
 				"$git_dir/refs/heads/$opt_o") == 0;

 	# populate index
 	system('git-read-tree', $last_rev);
 	die "read-tree failed: $?\n" if $?;

 	# Get the last import timestamps
 	open my $B,"<", "$git_dir/svn2git";
 	while(<$B>) {
 		chomp;
 		my($num,$branch,$ref) = split;
 		$branches{$branch}{$num} = $ref;
 		$branches{$branch}{"LAST"} = $ref;
 		$current_rev = $num+1 if $current_rev < $num+1;
 	}
 	close($B);
 }
 -d $git_dir
 	or die "Could not create git subdir ($git_dir).\n";

 open BRANCHES,">>", "$git_dir/svn2git";


 ## cvsps output:
 #---------------------
 #PatchSet 314
 #Date: 1999/09/18 13:03:59
 #Author: wkoch
 #Branch: STABLE-BRANCH-1-0
 #Ancestor branch: HEAD
 #Tag: (none)
 #Log:
 #    See ChangeLog: Sat Sep 18 13:03:28 CEST 1999  Werner Koch
 #Members:
 #	README:1.57->1.57.2.1
 #	VERSION:1.96->1.96.2.1
 #
 #---------------------

 my $state = 0;

 sub get_file($$$) {
 	my($rev,$branch,$path) = @_;

 	# revert split_path(), below
 	my $svnpath;
 	$path = "" if $path eq "/"; # this should not happen, but ...
 	if($branch eq "/") {
 		$svnpath = "/$trunk_name/$path";
 	} elsif($branch =~ m#^/#) {
 		$svnpath = "/$tag_name$branch/$path";
 	} else {
 		$svnpath = "/$branch_name/$branch/$path";
 	}

 	# now get it
 	my ($name, $res) = eval { $svn->file($svnpath,$rev); };
 	return () unless defined $name;

 	open my $F, '-|', "git-hash-object", "-w", $name
 		or die "Cannot create object: $!\n";
 	my $sha = <$F>;
 	chomp $sha;
 	close $F;
 	my $mode = "0644"; # SV does not seem to store any file modes
 	return [$mode, $sha, $path];
 }

 sub split_path($$) {
 	my($rev,$path) = @_;
 	my $branch;

 	if($path =~ s#^/\Q$tag_name\E/([^/]+)/?##) {
 		$branch = "/$1";
 	} elsif($path =~ s#^/\Q$trunk_name\E/?##) {
 		$branch = "/";
 	} elsif($path =~ s#^/\Q$branch_name\E/([^/]+)/?##) {
 		$branch = $1;
 	} else {
 		print STDERR "$rev: Unrecognized path: $path\n";
 		return ()
 	}
 	$path = "/" if $path eq "";
 	return ($branch,$path);
 }

 sub commit {
 	my($branch, $changed_paths, $revision, $author, $date, $message) = @_;
 	my($author_name,$author_email,$dest);
 	my(@old,@new);

 	if (not defined $author) {
 		$author_name = $author_email = "unknown";
 	} elsif ($author =~ /^(.*?)\s+<(.*)>$/) {
 		($author_name, $author_email) = ($1, $2);
 	} else {
 		$author =~ s/^<(.*)>$/$1/;
 		$author_name = $author_email = $author;
 	}
 	$date = pdate($date);

 	my $tag;
 	my $parent;
 	if($branch eq "/") { # trunk
 		$parent = $opt_o;
 	} elsif($branch =~ m#^/(.+)#) { # tag
 		$tag = 1;
 		$parent = $1;
 	} else { # "normal" branch
 		# nothing to do
 		$parent = $branch;
 	}
 	$dest = $parent;

 	my $prev = $changed_paths->{"/"};
 	if($prev and $prev->[0] eq "A") {
 		delete $changed_paths->{"/"};
 		my $oldpath = $prev->[1];
 		my $rev;
 		if(defined $oldpath) {
 			my $p;
 			($parent,$p) = split_path($revision,$oldpath);
 			if($parent eq "/") {
 				$parent = $opt_o;
 			} else {
 				$parent =~ s#^/##; # if it's a tag
 			}
 		} else {
 			$parent = undef;
 		}
 	}

 	my $rev;
 	if(defined $parent) {
 		open(H,"git-rev-parse --verify $parent |");
 		$rev = <H>;
 		close(H) or do {
 			print STDERR "$revision: cannot find commit '$parent'!\n";
 			return;
 		};
 		chop $rev;
 		if(length($rev) != 40) {
 			print STDERR "$revision: cannot find commit '$parent'!\n";
 			return;
 		}
 		$rev = $branches{($parent eq $opt_o) ? "/" : $parent}{"LAST"};
 		if($revision != 1 and not $rev) {
 			print STDERR "$revision: do not know ancestor for '$parent'!\n";
 			return;
 		}
 	} else {
 		$rev = undef;
 	}

 #	if($prev and $prev->[0] eq "A") {
 #		if(not $tag) {
 #			unless(open(H,"> $git_dir/refs/heads/$branch")) {
 #				print STDERR "$revision: Could not create branch $branch: $!\n";
 #				$state=11;
 #				next;
 #			}
 #			print H "$rev\n"
 #				or die "Could not write branch $branch: $!";
 #			close(H)
 #				or die "Could not write branch $branch: $!";
 #		}
 #	}
 	if(not defined $rev) {
 		unlink($git_index);
 	} elsif ($rev ne $last_rev) {
 		print "Switching from $last_rev to $rev ($branch)\n" if $opt_v;
 		system("git-read-tree", $rev);
 		die "read-tree failed for $rev: $?\n" if $?;
 		$last_rev = $rev;
 	}

 	my $cid;
 	if($tag and not %$changed_paths) {
 		$cid = $rev;
 	} else {
 		while(my($path,$action) = each %$changed_paths) {
 			if ($action->[0] eq "A") {
 				my $f = get_file($revision,$branch,$path);
 				push(@new,$f) if $f;
 			} elsif ($action->[0] eq "D") {
 				push(@old,$path);
 			} elsif ($action->[0] eq "M") {
 				my $f = get_file($revision,$branch,$path);
 				push(@new,$f) if $f;
 			} elsif ($action->[0] eq "R") {
 				# refer to a file/tree in an earlier commit
 				push(@old,$path); # remove any old stuff

 				# ... and add any new stuff
 				my($b,$p) = split_path($revision,$action->[1]);
 				open my $F,"-|","git-ls-tree","-r","-z", $branches{$b}{$action->[2]}, $p;
 				local $/ = '\0';
 				while(<$F>) {
 					chomp;
 					my($m,$p) = split(/\t/,$_,2);
 					my($mode,$type,$sha1) = split(/ /,$m);
 					next if $type ne "blob";
 					push(@new,[$mode,$sha1,$p]);
 				}
 			} else {
 				die "$revision: unknown action '".$action->[0]."' for $path\n";
 			}
 		}

 		if(@old) {
 			open my $F, "-|", "git-ls-files", "-z", @old or die $!;
 			@old = ();
 			local $/ = '\0';
 			while(<$F>) {
 				chomp;
 				push(@old,$_);
 			}
 			close($F);

 			while(@old) {
 				my @o2;
 				if(@old > 55) {
 					@o2 = splice(@old,0,50);
 				} else {
 					@o2 = @old;
 					@old = ();
 				}
 				system("git-update-index","--force-remove","--",@o2);
 				die "Cannot remove files: $?\n" if $?;
 			}
 		}
 		while(@new) {
 			my @n2;
 			if(@new > 12) {
 				@n2 = splice(@new,0,10);
 			} else {
 				@n2 = @new;
 				@new = ();
 			}
 			system("git-update-index","--add",
 				(map { ('--cacheinfo', @$_) } @n2));
 			die "Cannot add files: $?\n" if $?;
 		}

 		my $pid = open(C,"-|");
 		die "Cannot fork: $!" unless defined $pid;
 		unless($pid) {
 			exec("git-write-tree");
 			die "Cannot exec git-write-tree: $!\n";
 		}
 		chomp(my $tree = <C>);
 		length($tree) == 40
 			or die "Cannot get tree id ($tree): $!\n";
 		close(C)
 			or die "Error running git-write-tree: $?\n";
 		print "Tree ID $tree\n" if $opt_v;

 		my $pr = IO::Pipe->new() or die "Cannot open pipe: $!\n";
 		my $pw = IO::Pipe->new() or die "Cannot open pipe: $!\n";
 		$pid = fork();
 		die "Fork: $!\n" unless defined $pid;
 		unless($pid) {
 			$pr->writer();
 			$pw->reader();
 			open(OUT,">&STDOUT");
 			dup2($pw->fileno(),0);
 			dup2($pr->fileno(),1);
 			$pr->close();
 			$pw->close();

 			my @par = ();
 			@par = ("-p",$rev) if defined $rev;

 			# loose detection of merges
 			# based on the commit msg
 			foreach my $rx (@mergerx) {
 				if ($message =~ $rx) {
 					my $mparent = $1;
 					if ($mparent eq 'HEAD') { $mparent = $opt_o };
 					if ( -e "$git_dir/refs/heads/$mparent") {
 						$mparent = get_headref($mparent, $git_dir);
 						push @par, '-p', $mparent;
 						print OUT "Merge parent branch: $mparent\n" if $opt_v;
 					}
 				}
 			}

 			exec("env",
 				"GIT_AUTHOR_NAME=$author_name",
 				"GIT_AUTHOR_EMAIL=$author_email",
 				"GIT_AUTHOR_DATE=".strftime("+0000 %Y-%m-%d %H:%M:%S",gmtime($date)),
 				"GIT_COMMITTER_NAME=$author_name",
 				"GIT_COMMITTER_EMAIL=$author_email",
 				"GIT_COMMITTER_DATE=".strftime("+0000 %Y-%m-%d %H:%M:%S",gmtime($date)),
 				"git-commit-tree", $tree,@par);
 			die "Cannot exec git-commit-tree: $!\n";
 		}
 		$pw->writer();
 		$pr->reader();

 		$message =~ s/[\s\n]+\z//;

 		print $pw "$message\n"
 			or die "Error writing to git-commit-tree: $!\n";
 		$pw->close();

 		print "Committed change $revision:$branch ".strftime("%Y-%m-%d %H:%M:%S",gmtime($date)).")\n" if $opt_v;
 		chomp($cid = <$pr>);
 		length($cid) == 40
 			or die "Cannot get commit id ($cid): $!\n";
 		print "Commit ID $cid\n" if $opt_v;
 		$pr->close();

 		waitpid($pid,0);
 		die "Error running git-commit-tree: $?\n" if $?;
 	}

 	if(not defined $dest) {
 		print "... no known parent\n" if $opt_v;
 	} elsif(not $tag) {
 		print "Writing to refs/heads/$dest\n" if $opt_v;
 		open(C,">$git_dir/refs/heads/$dest") and
 		print C ("$cid\n") and
 		close(C)
 			or die "Cannot write branch $dest for update: $!\n";
 	}
 	$branches{$branch}{"LAST"} = $cid;
 	$branches{$branch}{$revision} = $cid;
 	$last_rev = $cid;
 	print BRANCHES "$revision $branch $cid\n";
 	print "DONE: $revision $dest $cid\n" if $opt_v;

 	if($tag) {
 		my($in, $out) = ('','');
 		$last_rev = "-" if %$changed_paths;
 		# the tag was 'complex', i.e. did not refer to a "real" revision

 		$dest =~ tr/_/\./ if $opt_u;

 		my $pid = open2($in, $out, 'git-mktag');
 		print $out ("object $cid\n".
 		    "type commit\n".
 		    "tag $dest\n".
 		    "tagger $author_name <$author_email>\n") and
 		close($out)
 		    or die "Cannot create tag object $dest: $!\n";

 		my $tagobj = <$in>;
 		chomp $tagobj;

 		if ( !close($in) or waitpid($pid, 0) != $pid or
 				$? != 0 or $tagobj !~ /^[0123456789abcdef]{40}$/ ) {
 			die "Cannot create tag object $dest: $!\n";
 		}

 		open(C,">$git_dir/refs/tags/$dest") and
 		print C ("$tagobj\n") and
 		close(C)
 			or die "Cannot create tag $branch: $!\n";

 		print "Created tag '$dest' on '$branch'\n" if $opt_v;
 	}
 }

 my ($changed_paths, $revision, $author, $date, $message, $pool) = @_;
 sub _commit_all {
 	($changed_paths, $revision, $author, $date, $message, $pool) = @_;
 	my %p;
 	while(my($path,$action) = each %$changed_paths) {
 		$p{$path} = [ $action->action,$action->copyfrom_path, $action->copyfrom_rev ];
 	}
 	$changed_paths = \%p;
 }

 sub commit_all {
 	my %done;
 	my @col;
 	my $pref;
 	my $branch;

 	while(my($path,$action) = each %$changed_paths) {
 		($branch,$path) = split_path($revision,$path);
 		next if not defined $branch;
 		$done{$branch}{$path} = $action;
 	}
 	while(($branch,$changed_paths) = each %done) {
 		commit($branch, $changed_paths, $revision, $author, $date, $message);
 	}
 }

 while(++$current_rev < $svn->{'maxrev'}) {
 	$svn->{'svn'}->get_log("/",$current_rev,$current_rev,$current_rev,1,1,\&_commit_all,"");
 	commit_all();
 }


 unlink($git_index);

 if (defined $orig_git_index) {
 	$ENV{GIT_INDEX_FILE} = $orig_git_index;
 } else {
 	delete $ENV{GIT_INDEX_FILE};
 }

 # Now switch back to the branch we were in before all of this happened
 if($orig_branch) {
 	print "DONE\n" if $opt_v;
 	system("cp","$git_dir/refs/heads/$opt_o","$git_dir/refs/heads/master")
 		if $forward_master;
 	unless ($opt_i) {
 		system('git-read-tree', '-m', '-u', 'SVN2GIT_HEAD', 'HEAD');
 		die "read-tree failed: $?\n" if $?;
 	}
 } else {
 	$orig_branch = "master";
 	print "DONE; creating $orig_branch branch\n" if $opt_v;
 	system("cp","$git_dir/refs/heads/$opt_o","$git_dir/refs/heads/master")
 		unless -f "$git_dir/refs/heads/master";
 	unlink("$git_dir/HEAD");
 	symlink("refs/heads/$orig_branch","$git_dir/HEAD");
 	unless ($opt_i) {
 		system('git checkout');
 		die "checkout failed: $?\n" if $?;
 	}
 }
 unlink("$git_dir/SVN2GIT_HEAD");
 close(BRANCHES);
	#!/usr/bin/perl -w

	# This tool is copyright (c) 2005, Matthias Urlichs.
	# It is released under the Gnu Public License, version 2.
	#
	# The basic idea is to pull and analyze SVN changes.
	#
	# Checking out the files is done by a single long-running CVS connection
	# / server process.
	#
	# The head revision is on branch "origin" by default.
	# You can change that with the '-o' option.

	require v5.8.0; # for shell-safe open("-\|",LIST)
	use strict;
	use warnings;
	use Getopt::Std;
	use File::Spec;
	use File::Temp qw(tempfile);
	use File::Path qw(mkpath);
	use File::Basename qw(basename dirname);
	use Time::Local;
	use IO::Pipe;
	use POSIX qw(strftime dup2);
	use IPC::Open2;
	use SVN::Core;
	use SVN::Ra;

	die "Need CVN:COre 1.2.1 or better" if $SVN::Core::VERSION lt "1.2.1";

	$SIG{'PIPE'}="IGNORE";
	$ENV{'TZ'}="UTC";

	our($opt_h,$opt_o,$opt_v,$opt_u,$opt_C,$opt_i,$opt_m,$opt_M,$opt_t,$opt_T,$opt_b);

	sub usage() {
	print STDERR <<END;
	Usage: ${\basename $0} # fetch/update GIT from CVS
	[-o branch-for-HEAD] [-h] [-v]
	[-C GIT_repository] [-t tagname] [-T trunkname] [-b branchname]
	[-i] [-u] [-s subst] [-m] [-M regex] [SVN_URL]
	END
	exit(1);
	}

	getopts("b:C:hivmM:o:t:T:u") or usage();
	usage if $opt_h;

	my $tag_name = $opt_t \|\| "tags";
	my $trunk_name = $opt_T \|\| "trunk";
	my $branch_name = $opt_b \|\| "branches";

	@ARGV <= 1 or usage();

	$opt_o \|\|= "origin";
	my $git_tree = $opt_C;
	$git_tree \|\|= ".";

	my $cvs_tree;
	if ($#ARGV == 0) {
	$cvs_tree = $ARGV[0];
	} elsif (-f 'CVS/Repository') {
	open my $f, '<', 'CVS/Repository' or
	die 'Failed to open CVS/Repository';
	$cvs_tree = <$f>;
	chomp $cvs_tree;
	close $f;
	} else {
	usage();
	}

	our @mergerx = ();
	if ($opt_m) {
	@mergerx = ( qr/\W(?:from\|of\|merge\|merging\|merged) (\w+)/i );
	}
	if ($opt_M) {
	push (@mergerx, qr/$opt_M/);
	}

	select(STDERR); $\|=1; select(STDOUT);


	package SVNconn;
	# Basic SVN connection.
	# We're only interested in connecting and downloading, so ...

	use File::Spec;
	use File::Temp qw(tempfile);
	use POSIX qw(strftime dup2);

	sub new {
	my($what,$repo) = @_;
	$what=ref($what) if ref($what);

	my $self = {};
	$self->{'buffer'} = "";
	bless($self,$what);

	$repo =~ s#/+$##;
	$self->{'fullrep'} = $repo;
	$self->conn();

	return $self;
	}

	sub conn {
	my $self = shift;
	my $repo = $self->{'fullrep'};
	my $s = SVN::Ra->new($repo);

	die "SVN connection to $repo: $!\n" unless defined $s;
	$self->{'svn'} = $s;
	$self->{'repo'} = $repo;
	$self->{'maxrev'} = $s->get_latest_revnum();
	}

	sub file {
	my($self,$path,$rev) = @_;
	my $res;

	my ($fh, $name) = tempfile('gitsvn.XXXXXX',
	DIR => File::Spec->tmpdir(), UNLINK => 1);

	print "... $rev $path ...\n" if $opt_v;
	eval { $self->{'svn'}->get_file($path,$rev,$fh); };
	if ($@ and $@ !~ /Attempted to get checksum/) {
	# retry
	$self->conn();
	eval { $self->{'svn'}->get_file($path,$rev,$fh); };
	};
	return () if $@ and $@ !~ /Attempted to get checksum/;
	die $@ if $@;
	close ($fh);

	return ($name, $res);
	}


	package main;

	my $svn = SVNconn->new($cvs_tree);


	sub pdate($) {
	my($d) = @_;
	$d =~ m#(\d\d\d\d)-(\d\d)-(\d\d)T(\d\d):(\d\d):(\d\d)#
	or die "Unparseable date: $d\n";
	my $y=$1; $y-=1900 if $y>1900;
	return timegm($6\|\|0,$5,$4,$3,$2-1,$y);
	}

	sub getwd() {
	my $pwd = `pwd`;
	chomp $pwd;
	return $pwd;
	}


	sub get_headref($$) {
	my $name = shift;
	my $git_dir = shift;
	my $sha;

	if (open(C,"$git_dir/refs/heads/$name")) {
	chomp($sha = <C>);
	close(C);
	length($sha) == 40
	or die "Cannot get head id for $name ($sha): $!\n";
	}
	return $sha;
	}


	-d $git_tree
	or mkdir($git_tree,0777)
	or die "Could not create $git_tree: $!";
	chdir($git_tree);

	my $orig_branch = "";
	my $forward_master = 0;
	my %branches;

	my $git_dir = $ENV{"GIT_DIR"} \|\| ".git";
	$git_dir = getwd()."/".$git_dir unless $git_dir =~ m#^/#;
	$ENV{"GIT_DIR"} = $git_dir;
	my $orig_git_index;
	$orig_git_index = $ENV{GIT_INDEX_FILE} if exists $ENV{GIT_INDEX_FILE};
	my ($git_ih, $git_index) = tempfile('gitXXXXXX', SUFFIX => '.idx',
	DIR => File::Spec->tmpdir());
	close ($git_ih);
	$ENV{GIT_INDEX_FILE} = $git_index;
	my $maxnum = 0;
	my $last_rev = "";
	my $last_branch;
	my $current_rev = 0;
	unless(-d $git_dir) {
	system("git-init-db");
	die "Cannot init the GIT db at $git_tree: $?\n" if $?;
	system("git-read-tree");
	die "Cannot init an empty tree: $?\n" if $?;

	$last_branch = $opt_o;
	$orig_branch = "";
	} else {
	-f "$git_dir/refs/heads/$opt_o"
	or die "Branch '$opt_o' does not exist.\n".
	"Either use the correct '-o branch' option,\n".
	"or import to a new repository.\n";

	-f "$git_dir/svn2git"
	or die "'$git_dir/svn2git' does not exist.\n".
	"You need that file for incremental imports.\n";
	$last_branch = basename(readlink("$git_dir/HEAD"));
	unless($last_branch) {
	warn "Cannot read the last branch name: $! -- assuming 'master'\n";
	$last_branch = "master";
	}
	$orig_branch = $last_branch;
	$last_rev = get_headref($orig_branch, $git_dir);
	if (-f "$git_dir/SVN2GIT_HEAD") {
	die <<EOM;
	SVN2GIT_HEAD exists.
	Make sure your working directory corresponds to HEAD and remove SVN2GIT_HEAD.
	You may need to run

	git-read-tree -m -u SVN2GIT_HEAD HEAD
	EOM
	}
	system('cp', "$git_dir/HEAD", "$git_dir/SVN2GIT_HEAD");

	$forward_master =
	$opt_o ne 'master' && -f "$git_dir/refs/heads/master" &&
	system('cmp', '-s', "$git_dir/refs/heads/master",
	"$git_dir/refs/heads/$opt_o") == 0;

	# populate index
	system('git-read-tree', $last_rev);
	die "read-tree failed: $?\n" if $?;

	# Get the last import timestamps
	open my $B,"<", "$git_dir/svn2git";
	while(<$B>) {
	chomp;
	my($num,$branch,$ref) = split;
	$branches{$branch}{$num} = $ref;
	$branches{$branch}{"LAST"} = $ref;
	$current_rev = $num+1 if $current_rev < $num+1;
	}
	close($B);
	}
	-d $git_dir
	or die "Could not create git subdir ($git_dir).\n";

	open BRANCHES,">>", "$git_dir/svn2git";


	## cvsps output:
	#---------------------
	#PatchSet 314
	#Date: 1999/09/18 13:03:59
	#Author: wkoch
	#Branch: STABLE-BRANCH-1-0
	#Ancestor branch: HEAD
	#Tag: (none)
	#Log:
	# See ChangeLog: Sat Sep 18 13:03:28 CEST 1999 Werner Koch
	#Members:
	# README:1.57->1.57.2.1
	# VERSION:1.96->1.96.2.1
	#
	#---------------------

	my $state = 0;

	sub get_file($$$) {
	my($rev,$branch,$path) = @_;

	# revert split_path(), below
	my $svnpath;
	$path = "" if $path eq "/"; # this should not happen, but ...
	if($branch eq "/") {
	$svnpath = "/$trunk_name/$path";
	} elsif($branch =~ m#^/#) {
	$svnpath = "/$tag_name$branch/$path";
	} else {
	$svnpath = "/$branch_name/$branch/$path";
	}

	# now get it
	my ($name, $res) = eval { $svn->file($svnpath,$rev); };
	return () unless defined $name;

	open my $F, '-\|', "git-hash-object", "-w", $name
	or die "Cannot create object: $!\n";
	my $sha = <$F>;
	chomp $sha;
	close $F;
	my $mode = "0644"; # SV does not seem to store any file modes
	return [$mode, $sha, $path];
	}

	sub split_path($$) {
	my($rev,$path) = @_;
	my $branch;

	if($path =~ s#^/\Q$tag_name\E/([^/]+)/?##) {
	$branch = "/$1";
	} elsif($path =~ s#^/\Q$trunk_name\E/?##) {
	$branch = "/";
	} elsif($path =~ s#^/\Q$branch_name\E/([^/]+)/?##) {
	$branch = $1;
	} else {
	print STDERR "$rev: Unrecognized path: $path\n";
	return ()
	}
	$path = "/" if $path eq "";
	return ($branch,$path);
	}

	sub commit {
	my($branch, $changed_paths, $revision, $author, $date, $message) = @_;
	my($author_name,$author_email,$dest);
	my(@old,@new);

	if (not defined $author) {
	$author_name = $author_email = "unknown";
	} elsif ($author =~ /^(.?)\s+<(.)>$/) {
	($author_name, $author_email) = ($1, $2);
	} else {
	$author =~ s/^<(.*)>$/$1/;
	$author_name = $author_email = $author;
	}
	$date = pdate($date);

	my $tag;
	my $parent;
	if($branch eq "/") { # trunk
	$parent = $opt_o;
	} elsif($branch =~ m#^/(.+)#) { # tag
	$tag = 1;
	$parent = $1;
	} else { # "normal" branch
	# nothing to do
	$parent = $branch;
	}
	$dest = $parent;

	my $prev = $changed_paths->{"/"};
	if($prev and $prev->[0] eq "A") {
	delete $changed_paths->{"/"};
	my $oldpath = $prev->[1];
	my $rev;
	if(defined $oldpath) {
	my $p;
	($parent,$p) = split_path($revision,$oldpath);
	if($parent eq "/") {
	$parent = $opt_o;
	} else {
	$parent =~ s#^/##; # if it's a tag
	}
	} else {
	$parent = undef;
	}
	}

	my $rev;
	if(defined $parent) {
	open(H,"git-rev-parse --verify $parent \|");
	$rev = <H>;
	close(H) or do {
	print STDERR "$revision: cannot find commit '$parent'!\n";
	return;
	};
	chop $rev;
	if(length($rev) != 40) {
	print STDERR "$revision: cannot find commit '$parent'!\n";
	return;
	}
	$rev = $branches{($parent eq $opt_o) ? "/" : $parent}{"LAST"};
	if($revision != 1 and not $rev) {
	print STDERR "$revision: do not know ancestor for '$parent'!\n";
	return;
	}
	} else {
	$rev = undef;
	}

	# if($prev and $prev->[0] eq "A") {
	# if(not $tag) {
	# unless(open(H,"> $git_dir/refs/heads/$branch")) {
	# print STDERR "$revision: Could not create branch $branch: $!\n";
	# $state=11;
	# next;
	# }
	# print H "$rev\n"
	# or die "Could not write branch $branch: $!";
	# close(H)
	# or die "Could not write branch $branch: $!";
	# }
	# }
	if(not defined $rev) {
	unlink($git_index);
	} elsif ($rev ne $last_rev) {
	print "Switching from $last_rev to $rev ($branch)\n" if $opt_v;
	system("git-read-tree", $rev);
	die "read-tree failed for $rev: $?\n" if $?;
	$last_rev = $rev;
	}

	my $cid;
	if($tag and not %$changed_paths) {
	$cid = $rev;
	} else {
	while(my($path,$action) = each %$changed_paths) {
	if ($action->[0] eq "A") {
	my $f = get_file($revision,$branch,$path);
	push(@new,$f) if $f;
	} elsif ($action->[0] eq "D") {
	push(@old,$path);
	} elsif ($action->[0] eq "M") {
	my $f = get_file($revision,$branch,$path);
	push(@new,$f) if $f;
	} elsif ($action->[0] eq "R") {
	# refer to a file/tree in an earlier commit
	push(@old,$path); # remove any old stuff

	# ... and add any new stuff
	my($b,$p) = split_path($revision,$action->[1]);
	open my $F,"-\|","git-ls-tree","-r","-z", $branches{$b}{$action->[2]}, $p;
	local $/ = '\0';
	while(<$F>) {
	chomp;
	my($m,$p) = split(/\t/,$_,2);
	my($mode,$type,$sha1) = split(/ /,$m);
	next if $type ne "blob";
	push(@new,[$mode,$sha1,$p]);
	}
	} else {
	die "$revision: unknown action '".$action->[0]."' for $path\n";
	}
	}

	if(@old) {
	open my $F, "-\|", "git-ls-files", "-z", @old or die $!;
	@old = ();
	local $/ = '\0';
	while(<$F>) {
	chomp;
	push(@old,$_);
	}
	close($F);

	while(@old) {
	my @o2;
	if(@old > 55) {
	@o2 = splice(@old,0,50);
	} else {
	@o2 = @old;
	@old = ();
	}
	system("git-update-index","--force-remove","--",@o2);
	die "Cannot remove files: $?\n" if $?;
	}
	}
	while(@new) {
	my @n2;
	if(@new > 12) {
	@n2 = splice(@new,0,10);
	} else {
	@n2 = @new;
	@new = ();
	}
	system("git-update-index","--add",
	(map { ('--cacheinfo', @$_) } @n2));
	die "Cannot add files: $?\n" if $?;
	}

	my $pid = open(C,"-\|");
	die "Cannot fork: $!" unless defined $pid;
	unless($pid) {
	exec("git-write-tree");
	die "Cannot exec git-write-tree: $!\n";
	}
	chomp(my $tree = <C>);
	length($tree) == 40
	or die "Cannot get tree id ($tree): $!\n";
	close(C)
	or die "Error running git-write-tree: $?\n";
	print "Tree ID $tree\n" if $opt_v;

	my $pr = IO::Pipe->new() or die "Cannot open pipe: $!\n";
	my $pw = IO::Pipe->new() or die "Cannot open pipe: $!\n";
	$pid = fork();
	die "Fork: $!\n" unless defined $pid;
	unless($pid) {
	$pr->writer();
	$pw->reader();
	open(OUT,">&STDOUT");
	dup2($pw->fileno(),0);
	dup2($pr->fileno(),1);
	$pr->close();
	$pw->close();

	my @par = ();
	@par = ("-p",$rev) if defined $rev;

	# loose detection of merges
	# based on the commit msg
	foreach my $rx (@mergerx) {
	if ($message =~ $rx) {
	my $mparent = $1;
	if ($mparent eq 'HEAD') { $mparent = $opt_o };
	if ( -e "$git_dir/refs/heads/$mparent") {
	$mparent = get_headref($mparent, $git_dir);
	push @par, '-p', $mparent;
	print OUT "Merge parent branch: $mparent\n" if $opt_v;
	}
	}
	}

	exec("env",
	"GIT_AUTHOR_NAME=$author_name",
	"GIT_AUTHOR_EMAIL=$author_email",
	"GIT_AUTHOR_DATE=".strftime("+0000 %Y-%m-%d %H:%M:%S",gmtime($date)),
	"GIT_COMMITTER_NAME=$author_name",
	"GIT_COMMITTER_EMAIL=$author_email",
	"GIT_COMMITTER_DATE=".strftime("+0000 %Y-%m-%d %H:%M:%S",gmtime($date)),
	"git-commit-tree", $tree,@par);
	die "Cannot exec git-commit-tree: $!\n";
	}
	$pw->writer();
	$pr->reader();

	$message =~ s/[\s\n]+\z//;

	print $pw "$message\n"
	or die "Error writing to git-commit-tree: $!\n";
	$pw->close();

	print "Committed change $revision:$branch ".strftime("%Y-%m-%d %H:%M:%S",gmtime($date)).")\n" if $opt_v;
	chomp($cid = <$pr>);
	length($cid) == 40
	or die "Cannot get commit id ($cid): $!\n";
	print "Commit ID $cid\n" if $opt_v;
	$pr->close();

	waitpid($pid,0);
	die "Error running git-commit-tree: $?\n" if $?;
	}

	if(not defined $dest) {
	print "... no known parent\n" if $opt_v;
	} elsif(not $tag) {
	print "Writing to refs/heads/$dest\n" if $opt_v;
	open(C,">$git_dir/refs/heads/$dest") and
	print C ("$cid\n") and
	close(C)
	or die "Cannot write branch $dest for update: $!\n";
	}
	$branches{$branch}{"LAST"} = $cid;
	$branches{$branch}{$revision} = $cid;
	$last_rev = $cid;
	print BRANCHES "$revision $branch $cid\n";
	print "DONE: $revision $dest $cid\n" if $opt_v;

	if($tag) {
	my($in, $out) = ('','');
	$last_rev = "-" if %$changed_paths;
	# the tag was 'complex', i.e. did not refer to a "real" revision

	$dest =~ tr/_/\./ if $opt_u;

	my $pid = open2($in, $out, 'git-mktag');
	print $out ("object $cid\n".
	"type commit\n".
	"tag $dest\n".
	"tagger $author_name <$author_email>\n") and
	close($out)
	or die "Cannot create tag object $dest: $!\n";

	my $tagobj = <$in>;
	chomp $tagobj;

	if ( !close($in) or waitpid($pid, 0) != $pid or
	$? != 0 or $tagobj !~ /^[0123456789abcdef]{40}$/ ) {
	die "Cannot create tag object $dest: $!\n";
	}

	open(C,">$git_dir/refs/tags/$dest") and
	print C ("$tagobj\n") and
	close(C)
	or die "Cannot create tag $branch: $!\n";

	print "Created tag '$dest' on '$branch'\n" if $opt_v;
	}
	}

	my ($changed_paths, $revision, $author, $date, $message, $pool) = @_;
	sub _commit_all {
	($changed_paths, $revision, $author, $date, $message, $pool) = @_;
	my %p;
	while(my($path,$action) = each %$changed_paths) {
	$p{$path} = [ $action->action,$action->copyfrom_path, $action->copyfrom_rev ];
	}
	$changed_paths = \%p;
	}

	sub commit_all {
	my %done;
	my @col;
	my $pref;
	my $branch;

	while(my($path,$action) = each %$changed_paths) {
	($branch,$path) = split_path($revision,$path);
	next if not defined $branch;
	$done{$branch}{$path} = $action;
	}
	while(($branch,$changed_paths) = each %done) {
	commit($branch, $changed_paths, $revision, $author, $date, $message);
	}
	}

	while(++$current_rev < $svn->{'maxrev'}) {
	$svn->{'svn'}->get_log("/",$current_rev,$current_rev,$current_rev,1,1,\&_commit_all,"");
	commit_all();
	}


	unlink($git_index);

	if (defined $orig_git_index) {
	$ENV{GIT_INDEX_FILE} = $orig_git_index;
	} else {
	delete $ENV{GIT_INDEX_FILE};
	}

	# Now switch back to the branch we were in before all of this happened
	if($orig_branch) {
	print "DONE\n" if $opt_v;
	system("cp","$git_dir/refs/heads/$opt_o","$git_dir/refs/heads/master")
	if $forward_master;
	unless ($opt_i) {
	system('git-read-tree', '-m', '-u', 'SVN2GIT_HEAD', 'HEAD');
	die "read-tree failed: $?\n" if $?;
	}
	} else {
	$orig_branch = "master";
	print "DONE; creating $orig_branch branch\n" if $opt_v;
	system("cp","$git_dir/refs/heads/$opt_o","$git_dir/refs/heads/master")
	unless -f "$git_dir/refs/heads/master";
	unlink("$git_dir/HEAD");
	symlink("refs/heads/$orig_branch","$git_dir/HEAD");
	unless ($opt_i) {
	system('git checkout');
	die "checkout failed: $?\n" if $?;
	}
	}
	unlink("$git_dir/SVN2GIT_HEAD");
	close(BRANCHES);