+ $dst //= *STDERR{GLOB};
+ $opt->{-progress} = sub { print $dst @_ };
+ }
+}
+
+# same unit factors as git:
+sub parse_unsigned ($) {
+ my ($val) = @_;
+
+ $$val =~ /\A([0-9]+)([kmg])?\z/i or return;
+ my ($n, $unit_factor) = ($1, $2 // '');
+ my %u = ( k => 1024, m => 1024**2, g => 1024**3 );
+ $$val = $n * ($u{lc($unit_factor)} // 1);
+ 1;
+}
+
+sub index_prepare ($$) {
+ my ($opt, $cfg) = @_;
+ my $env;
+ if ($opt->{compact}) {
+ require PublicInbox::Xapcmd;
+ PublicInbox::Xapcmd::check_compact();
+ $opt->{compact_opt} = { -coarse_lock => 1, compact => 1 };
+ if (defined(my $jobs = $opt->{jobs})) {
+ $opt->{compact_opt}->{jobs} = $jobs;
+ }
+ }
+ for my $k (qw(max_size batch_size)) {
+ my $git_key = "publicInbox.index".ucfirst($k);
+ $git_key =~ s/_([a-z])/\U$1/g;
+ defined(my $v = $opt->{$k} // $cfg->{lc($git_key)}) or next;
+ parse_unsigned(\$v) or die "`$git_key=$v' not parsed\n";
+ $v > 0 or die "`$git_key=$v' must be positive\n";
+ $opt->{$k} = $v;
+ }
+
+ # out-of-the-box builds of Xapian 1.4.x are still limited to 32-bit
+ # https://getting-started-with-xapian.readthedocs.io/en/latest/concepts/indexing/limitations.html
+ $opt->{batch_size} and
+ $env = { XAPIAN_FLUSH_THRESHOLD => '4294967295' };
+
+ for my $k (qw(sequential-shard)) {
+ my $git_key = "publicInbox.index".ucfirst($k);
+ $git_key =~ s/-([a-z])/\U$1/g;
+ defined(my $s = $opt->{$k} // $cfg->{lc($git_key)}) or next;
+ defined(my $v = $cfg->git_bool($s))
+ or die "`$git_key=$s' not boolean\n";
+ $opt->{$k} = $v;
+ }
+ for my $k (qw(since until)) {
+ my $v = $opt->{$k} // next;
+ $opt->{reindex} or die "--$k=$v requires --reindex\n";
+ }
+ $env;
+}
+
+sub do_chdir ($) {
+ my $chdir = $_[0] // return;
+ for my $d (@$chdir) {
+ next if $d eq ''; # same as git(1)
+ chdir $d or die "cd $d: $!";