inbox: perform cleanup of Git objects for coderepos

Otherwise, long-running but idle git processes may keep unlinked
packs around indefinitely and waste disk space.

2 files changed, 29 insertions, 6 deletions

diff --git a/lib/PublicInbox/Git.pm b/lib/PublicInbox/Git.pm
index e844884a..a756684a 100644
--- a/lib/PublicInbox/Git.pm
+++ b/lib/PublicInbox/Git.pm
@@ -206,7 +206,15 @@ sub check {
 }
 
 sub _destroy {
-        my ($self, $in, $out, $pid) = @_;
+        my ($self, $in, $out, $pid, $expire) = @_;
+        my $rfh = $self->{$in} or return;
+        if (defined $expire) {
+                # at least FreeBSD 11.2 and Linux 4.20 update mtime of the
+                # read end of a pipe when the pipe is written to; dunno
+                # about other OSes.
+                my $mtime = (stat($rfh))[9];
+                return if $mtime > $expire;
+        }
         my $p = delete $self->{$pid} or return;
         foreach my $f ($in, $out) {
                 delete $self->{$f};
@@ -236,10 +244,12 @@ sub qx {
         <$fh>
 }
 
+# returns true if there are pending "git cat-file" processes
 sub cleanup {
-        my ($self) = @_;
-        _destroy($self, qw(in out pid));
-        _destroy($self, qw(in_c out_c pid_c));
+        my ($self, $expire) = @_;
+        _destroy($self, qw(in out pid), $expire);
+        _destroy($self, qw(in_c out_c pid_c), $expire);
+        !!($self->{pid} || $self->{pid_c});
 }
 
 # assuming a well-maintained repo, this should be a somewhat
diff --git a/lib/PublicInbox/Inbox.pm b/lib/PublicInbox/Inbox.pm
index d57e46d2..6fe896f4 100644
--- a/lib/PublicInbox/Inbox.pm
+++ b/lib/PublicInbox/Inbox.pm
@@ -22,12 +22,25 @@ my $cleanup_broken = $@;
 my $CLEANUP = {}; # string(inbox) -> inbox
 sub cleanup_task () {
         $cleanup_timer = undef;
+        my $next = {};
         for my $ibx (values %$CLEANUP) {
-                foreach my $f (qw(git mm search)) {
+                my $again;
+                foreach my $f (qw(mm search)) {
                         delete $ibx->{$f} if SvREFCNT($ibx->{$f}) == 1;
                 }
+                my $expire = time - 60;
+                if (my $git = $ibx->{git}) {
+                        $again = $git->cleanup($expire);
+                }
+                if (my $gits = $ibx->{-repo_objs}) {
+                        foreach my $git (@$gits) {
+                                $again = 1 if $git->cleanup($expire);
+                        }
+                }
+                $again ||= !!($ibx->{mm} || $ibx->{search});
+                $next->{"$ibx"} = $ibx if $again;
         }
-        $CLEANUP = {};
+        $CLEANUP = $next;
 }
 
 sub _cleanup_later ($) {