+sub cat_async_begin {
+ my ($self) = @_;
+ cleanup($self) if $self->alternates_changed;
+ $self->batch_prepare;
+ die 'BUG: already in async' if $self->{inflight};
+ $self->{inflight} = [];
+}
+
+sub cat_async ($$$;$) {
+ my ($self, $oid, $cb, $arg) = @_;
+ my $inflight = $self->{inflight} // cat_async_begin($self);
+ while (scalar(@$inflight) >= MAX_INFLIGHT) {
+ cat_async_step($self, $inflight);
+ }
+ print { $self->{out} } $oid, "\n" or $self->fail("write error: $!");
+ push(@$inflight, $oid, $cb, $arg);
+}
+
+# returns the modified time of a git repo, same as the "modified" field
+# of a grokmirror manifest
+sub modified ($) {
+ # committerdate:unix is git 2.9.4+ (2017-05-05), so using raw instead
+ my $fh = popen($_[0], qw[for-each-ref --sort=-committerdate
+ --format=%(committerdate:raw) --count=1]);
+ (split(/ /, <$fh> // time))[0] + 0; # integerize for JSON
+}
+
+# for grokmirror, which doesn't read gitweb.description
+# templates/hooks--update.sample and git-multimail in git.git
+# only match "Unnamed repository", not the full contents of
+# templates/this--description in git.git
+sub manifest_entry {
+ my ($self, $epoch, $default_desc) = @_;
+ my $fh = $self->popen('show-ref');
+ my $dig = Digest::SHA->new(1);
+ while (read($fh, my $buf, 65536)) {
+ $dig->add($buf);
+ }
+ close $fh or return; # empty, uninitialized git repo
+ undef $fh; # for open, below
+ my $git_dir = $self->{git_dir};
+ my $ent = {
+ fingerprint => $dig->hexdigest,
+ reference => undef,
+ modified => modified($self),
+ };
+ chomp(my $owner = $self->qx('config', 'gitweb.owner'));
+ utf8::decode($owner);
+ $ent->{owner} = $owner eq '' ? undef : $owner;
+ my $desc = '';
+ if (open($fh, '<', "$git_dir/description")) {
+ local $/ = "\n";
+ chomp($desc = <$fh>);
+ utf8::decode($desc);
+ }
+ $desc = 'Unnamed repository' if $desc eq '';
+ if (defined $epoch && $desc =~ /\AUnnamed repository/) {
+ $desc = "$default_desc [epoch $epoch]";
+ }
+ $ent->{description} = $desc;
+ if (open($fh, '<', "$git_dir/objects/info/alternates")) {
+ # n.b.: GitPython doesn't seem to handle comments or C-quoted
+ # strings like native git does; and we don't for now, either.
+ local $/ = "\n";
+ chomp(my @alt = <$fh>);
+
+ # grokmirror only supports 1 alternate for "reference",
+ if (scalar(@alt) == 1) {
+ my $objdir = "$git_dir/objects";
+ my $ref = File::Spec->rel2abs($alt[0], $objdir);
+ $ref =~ s!/[^/]+/?\z!!; # basename
+ $ent->{reference} = $ref;
+ }
+ }
+ $ent;
+}
+
+# returns true if there are pending cat-file processes
+sub cleanup_if_unlinked {
+ my ($self) = @_;
+ return cleanup($self, 1) if $^O ne 'linux';
+ # Linux-specific /proc/$PID/maps access
+ # TODO: support this inside git.git
+ my $ret = 0;
+ for my $fld (qw(pid pid_c)) {
+ my $pid = $self->{$fld} // next;
+ open my $fh, '<', "/proc/$pid/maps" or return cleanup($self, 1);
+ while (<$fh>) {
+ # n.b. we do not restart for unlinked multi-pack-index
+ # since it's not too huge, and the startup cost may
+ # be higher.
+ /\.(?:idx|pack) \(deleted\)$/ and
+ return cleanup($self, 1);
+ }
+ ++$ret;
+ }
+ $ret;