+sub cmt_sha2rev_batch {
+ my %s2r;
+ my ($pid, $in, $out, $ctx) = command_bidi_pipe(qw/cat-file --batch/);
+ my $list = shift;
+
+ foreach my $sha (@{$list}) {
+ my $first = 1;
+ my $size = 0;
+ print $out $sha, "\n";
+
+ while (my $line = <$in>) {
+ if ($first && $line =~ /^[[:xdigit:]]{40}\smissing$/) {
+ last;
+ } elsif ($first &&
+ $line =~ /^[[:xdigit:]]{40}\scommit\s(\d+)$/) {
+ $first = 0;
+ $size = $1;
+ next;
+ } elsif ($line =~ /^(git-svn-id: )/) {
+ my (undef, $rev, undef) =
+ extract_metadata($line);
+ $s2r{$sha} = $rev;
+ }
+
+ $size -= length($line);
+ last if ($size == 0);
+ }
+ }
+
+ command_close_bidi_pipe($pid, $in, $out, $ctx);
+
+ return \%s2r;
+}
+