xcpdb: remove temporary directories on aborts

Cleanup temporary directories on common termination signals
(INT, HUP, PIPE, TERM), but only if it's not in the process
of being committed via rename() sequence.

diff --git a/lib/PublicInbox/Xapcmd.pm b/lib/PublicInbox/Xapcmd.pm
index 0e4480473b86ddfb9047d69d0d4ff273b49c2a1d..06389dd0fdef53fa8b03613d8538b3e0e5950fd8 100644 (file)
--- a/lib/PublicInbox/Xapcmd.pm
+++ b/lib/PublicInbox/Xapcmd.pm
@@ -31,13 +31,15 @@ sub commit_changes ($$$) {
                        $over->connect->sqlite_backup_to_file($tmp_over);
                        $over = undef;
                }
+               chmod($st[2] & 07777, $new) or die "chmod $old: $!\n";
 
+               # Xtmpdir->DESTROY won't remove $new after this:
                rename($old, "$new/old") or die "rename $old => $new/old: $!\n";
-               chmod($st[2] & 07777, $new) or die "chmod $old: $!\n";
                rename($new, $old) or die "rename $new => $old: $!\n";
                my $prev = "$old/old";
                remove_tree($prev) or die "failed to remove $prev: $!\n";
        }
+       $tmp->done;
        if ($reindex) {
                $opt->{-skip_lock} = 1;
                PublicInbox::Admin::index_inbox($ibx, $opt);
@@ -126,7 +128,7 @@ sub run {
        my $old = $ibx->search->xdir(1);
        -d $old or die "$old does not exist\n";
 
-       my $tmp = {}; # old partition => new (tmp) partition
+       my $tmp = PublicInbox::Xtmpdirs->new;
        my $v = $ibx->{version} ||= 1;
        my @cmds;
 
@@ -286,4 +288,37 @@ sub cpdb {
        remove_tree($tmp) or die "failed to remove $tmp: $!\n";
 }
 
+# slightly easier-to-manage manage than END{} blocks
+package PublicInbox::Xtmpdirs;
+use strict;
+use warnings;
+use File::Path qw(remove_tree);
+my %owner;
+
+sub new {
+       # http://www.tldp.org/LDP/abs/html/exitcodes.html
+       $SIG{INT} = sub { exit(130) };
+       $SIG{HUP} = $SIG{PIPE} = $SIG{TERM} = sub { exit(1) };
+       my $self = bless {}, $_[0]; # old partition => new (tmp) partition
+       $owner{"$self"} = $$;
+       $self;
+}
+
+sub done {
+       my ($self) = @_;
+       delete $owner{"$self"};
+       $SIG{INT} = $SIG{HUP} = $SIG{PIPE} = $SIG{TERM} = 'DEFAULT';
+       %$self = ();
+}
+
+sub DESTROY {
+       my ($self) = @_;
+       my $owner_pid = delete $owner{"$self"} or return;
+       return if $owner_pid != $$;
+       foreach my $new (values %$self) {
+               remove_tree($new) unless -d "$new/old";
+       }
+       $SIG{INT} = $SIG{HUP} = $SIG{PIPE} = $SIG{TERM} = 'DEFAULT';
+}
+
 1;