contrib/git-svn: optimize sequential commits to svn

Avoid running 'svn up' to a previous revision if we know the
revision we just committed is the first descendant of the
revision we came from.

This reduces the time to do a series of commits by about 25%.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>

contrib/git-svn/git-svn.perl

@@ -30,6 +30,7 @@ use File::Basename qw/dirname basename/;
 use File::Path qw/mkpath/;
 use Getopt::Long qw/:config gnu_getopt no_ignore_case auto_abbrev/;
 use File::Spec qw//;
+use POSIX qw/strftime/;
 my $sha1 = qr/[a-f\d]{40}/;
 my $sha1_short = qr/[a-f\d]{6,40}/;
 my ($_revision,$_stdin,$_no_ignore_ext,$_no_stop_copy,$_help,$_rmdir,$_edit,
@@ -591,6 +592,7 @@ sub handle_rmdir {
 sub svn_commit_tree {
 	my ($svn_rev, $commit) = @_;
 	my $commit_msg = "$GIT_DIR/$GIT_SVN/.svn-commit.tmp.$$";
+	my %log_msg = ( msg => '' );
 	open my $msg, '>', $commit_msg  or croak $!;
 
 	chomp(my $type = `git-cat-file -t $commit`);
@@ -606,6 +608,7 @@ sub svn_commit_tree {
 			if (!$in_msg) {
 				$in_msg = 1 if (/^\s*$/);
 			} else {
+				$log_msg{msg} .= $_;
 				print $msg $_ or croak $!;
 			}
 		}
@@ -625,9 +628,30 @@ sub svn_commit_tree {
 			join("\n",@ci_output),"\n";
 	my ($rev_committed) = ($committed =~ /^Committed revision (\d+)\./);
 
-	# resync immediately
-	my @svn_up = (qw(svn up), "-r$svn_rev");
+	my @svn_up = qw(svn up);
 	push @svn_up, '--ignore-externals' unless $_no_ignore_ext;
+	if ($rev_committed == ($svn_rev + 1)) {
+		push @svn_up, "-r$rev_committed";
+		sys(@svn_up);
+		my $info = svn_info('.');
+		my $date = $info->{'Last Changed Date'} or die "Missing date\n";
+		if ($info->{'Last Changed Rev'} != $rev_committed) {
+			croak "$info->{'Last Changed Rev'} != $rev_committed\n"
+		}
+		my ($Y,$m,$d,$H,$M,$S,$tz) = ($date =~
+					/(\d{4})\-(\d\d)\-(\d\d)\s
+					 (\d\d)\:(\d\d)\:(\d\d)\s([\-\+]\d+)/x)
+					 or croak "Failed to parse date: $date\n";
+		$log_msg{date} = "$tz $Y-$m-$d $H:$M:$S";
+		$log_msg{author} = $info->{'Last Changed Author'};
+		$log_msg{revision} = $rev_committed;
+		$log_msg{msg} .= "\n";
+		my $parent = file_to_s("$REV_DIR/$svn_rev");
+		git_commit(\%log_msg, $parent, $commit);
+		return $rev_committed;
+	}
+	# resync immediately
+	push @svn_up, "-r$svn_rev";
 	sys(@svn_up);
 	return fetch("$rev_committed=$commit")->{revision};
 }
@@ -724,7 +748,7 @@ sub svn_info {
 	# only single-lines seem to exist in svn info output
 	while (<$info_fh>) {
 		chomp $_;
-		if (m#^([^:]+)\s*:\s*(\S*)$#) {
+		if (m#^([^:]+)\s*:\s*(\S.*)$#) {
 			$ret->{$1} = $2;
 			push @{$ret->{-order}}, $1;
 		}