[PATCH] dir_idle: support IN_DELETE_SELF|IN_MOVE_SELF, too

[Eric Wong <e@80x24.org>]

We'll treat IN_MOVE_SELF as IN_DELETE_SELF since there
doesn't seem to be a reliable way to distinguish them
with FakeInotify, nor know the new name with kevent.
---
 lib/PublicInbox/DirIdle.pm     | 12 +++++++++---
 lib/PublicInbox/FakeInotify.pm | 23 ++++++++++++++++++++---
 lib/PublicInbox/KQNotify.pm    | 32 +++++++++++++++++++++++++-------
 t/dir_idle.t                   | 27 ++++++++++++++++++++++++---
 4 files changed, 78 insertions(+), 16 deletions(-)

diff --git a/lib/PublicInbox/DirIdle.pm b/lib/PublicInbox/DirIdle.pm
index e53fd9d1..5142d005 100644
--- a/lib/PublicInbox/DirIdle.pm
+++ b/lib/PublicInbox/DirIdle.pm
@@ -12,17 +12,23 @@ my ($MAIL_IN, $MAIL_GONE, $ino_cls);
 if ($^O eq 'linux' && eval { require Linux::Inotify2; 1 }) {
 	$MAIL_IN = Linux::Inotify2::IN_MOVED_TO() |
 		Linux::Inotify2::IN_CREATE();
-	$MAIL_GONE = Linux::Inotify2::IN_DELETE();
+	$MAIL_GONE = Linux::Inotify2::IN_DELETE() |
+			Linux::Inotify2::IN_DELETE_SELF() |
+			Linux::Inotify2::IN_MOVE_SELF();
 	$ino_cls = 'Linux::Inotify2';
 # Perl 5.22+ is needed for fileno(DIRHANDLE) support:
 } elsif ($^V ge v5.22 && eval { require PublicInbox::KQNotify }) {
 	$MAIL_IN = PublicInbox::KQNotify::MOVED_TO_OR_CREATE();
-	$MAIL_GONE = PublicInbox::KQNotify::NOTE_DELETE();
+	$MAIL_GONE = PublicInbox::KQNotify::NOTE_DELETE() |
+		PublicInbox::KQNotify::NOTE_REVOKE() |
+		PublicInbox::KQNotify::NOTE_RENAME();
 	$ino_cls = 'PublicInbox::KQNotify';
 } else {
 	require PublicInbox::FakeInotify;
 	$MAIL_IN = PublicInbox::FakeInotify::MOVED_TO_OR_CREATE();
-	$MAIL_GONE = PublicInbox::FakeInotify::IN_DELETE();
+	$MAIL_GONE = PublicInbox::FakeInotify::IN_DELETE() |
+			PublicInbox::FakeInotify::IN_DELETE_SELF() |
+			PublicInbox::FakeInotify::IN_MOVE_SELF();
 }
 
 sub new {
diff --git a/lib/PublicInbox/FakeInotify.pm b/lib/PublicInbox/FakeInotify.pm
index 644f5b5b..641bc5bd 100644
--- a/lib/PublicInbox/FakeInotify.pm
+++ b/lib/PublicInbox/FakeInotify.pm
@@ -13,7 +13,9 @@ sub IN_MODIFY () { 0x02 } # match Linux inotify
 # my $IN_MOVED_TO = 0x80;
 # my $IN_CREATE = 0x100;
 sub MOVED_TO_OR_CREATE () { 0x80 | 0x100 }
-sub IN_DELETE () { 0x00000200 }
+sub IN_DELETE () { 0x200 }
+sub IN_DELETE_SELF () { 0x400 }
+sub IN_MOVE_SELF () { 0x800 }
 
 our @EXPORT_OK = qw(fill_dirlist on_dir_change);
 
@@ -44,7 +46,7 @@ sub watch {
 
 # also used by KQNotify since it kevent requires readdir on st_nlink
 # count changes.
-sub on_dir_change ($$$$;$) {
+sub on_dir_change ($$$$$) {
 	my ($events, $dh, $path, $old_ctime, $dirlist) = @_;
 	my $oldlist = $dirlist->{$path};
 	my $newlist = $oldlist ? {} : undef;
@@ -79,7 +81,14 @@ sub read {
 	my @watch_gone;
 	for my $x (keys %$watch) {
 		my ($path, $mask) = split(/\0/, $x, 2);
-		my @now = stat($path) or next;
+		my @now = stat($path);
+		if (!@now && $!{ENOENT} && ($mask & IN_DELETE_SELF)) {
+			push @$events, bless(\$path,
+				'PublicInbox::FakeInotify::SelfGoneEvent');
+			push @watch_gone, $x;
+			delete $self->{dirlist}->{$path};
+		}
+		next if !@now;
 		my $old_ctime = $watch->{$x};
 		$watch->{$x} = $now[10];
 		next if $old_ctime == $now[10];
@@ -92,6 +101,7 @@ sub read {
 						$self->{dirlist});
 			} elsif ($!{ENOENT}) {
 				push @watch_gone, $x;
+				delete $self->{dirlist}->{$path};
 			} else {
 				warn "W: opendir $path: $!\n";
 			}
@@ -126,6 +136,7 @@ use strict;
 sub fullname { ${$_[0]} }
 
 sub IN_DELETE { 0 }
+sub IN_DELETE_SELF { 0 }
 
 package PublicInbox::FakeInotify::GoneEvent;
 use strict;
@@ -133,4 +144,10 @@ our @ISA = qw(PublicInbox::FakeInotify::Event);
 
 sub IN_DELETE { 1 }
 
+package PublicInbox::FakeInotify::SelfGoneEvent;
+use strict;
+our @ISA = qw(PublicInbox::FakeInotify::GoneEvent);
+
+sub IN_DELETE_SELF { 1 }
+
 1;
diff --git a/lib/PublicInbox/KQNotify.pm b/lib/PublicInbox/KQNotify.pm
index fc321a16..7efb8b60 100644
--- a/lib/PublicInbox/KQNotify.pm
+++ b/lib/PublicInbox/KQNotify.pm
@@ -33,14 +33,16 @@ sub watch {
 			'PublicInbox::KQNotify::Watch';
 	}
 	my $ident = fileno($fh);
-	$self->{dskq}->{kq}->EV_SET($ident, # ident
+	$self->{dskq}->{kq}->EV_SET($ident, # ident (fd)
 		EVFILT_VNODE, # filter
 		EV_ADD | EV_CLEAR, # flags
 		$mask, # fflags
 		0, 0); # data, udata
-	if ($mask & (MOVED_TO_OR_CREATE | NOTE_DELETE)) {
+	if ($mask & (MOVED_TO_OR_CREATE|NOTE_DELETE|NOTE_LINK|NOTE_REVOKE)) {
 		$self->{watch}->{$ident} = $watch;
-		fill_dirlist($self, $path, $fh) if $mask & NOTE_DELETE;
+		if ($mask & (NOTE_DELETE|NOTE_LINK|NOTE_REVOKE)) {
+			fill_dirlist($self, $path, $fh)
+		}
 	} else {
 		die "TODO Not implemented: $mask";
 	}
@@ -63,21 +65,37 @@ sub read {
 	my ($self) = @_;
 	my @kevents = $self->{dskq}->{kq}->kevent(0);
 	my $events = [];
+	my @gone;
+	my $watch = $self->{watch};
 	for my $kev (@kevents) {
 		my $ident = $kev->[KQ_IDENT];
 		my $mask = $kev->[KQ_FFLAGS];
-		my ($dh, $path, $old_ctime) = @{$self->{watch}->{$ident}};
+		my ($dh, $path, $old_ctime) = @{$watch->{$ident}};
 		if (!defined($old_ctime)) {
 			push @$events,
 				bless(\$path, 'PublicInbox::FakeInotify::Event')
-		} elsif ($mask & (MOVED_TO_OR_CREATE | NOTE_DELETE)) {
-			my @new_st = stat($path) or next;
-			$self->{watch}->{$ident}->[3] = $new_st[10]; # ctime
+		} elsif ($mask & (MOVED_TO_OR_CREATE|NOTE_DELETE|NOTE_LINK|
+				NOTE_REVOKE|NOTE_RENAME)) {
+			my @new_st = stat($path);
+			if (!@new_st && $!{ENOENT}) {
+				push @$events, bless(\$path,
+						'PublicInbox::FakeInotify::'.
+						'SelfGoneEvent');
+				push @gone, $ident;
+				delete $self->{dirlist}->{$path};
+				next;
+			}
+			if (!@new_st) {
+				warn "unhandled stat($path) error: $!\n";
+				next;
+			}
+			$watch->{$ident}->[3] = $new_st[10]; # ctime
 			rewinddir($dh);
 			on_dir_change($events, $dh, $path, $old_ctime,
 					$self->{dirlist});
 		}
 	}
+	delete @$watch{@gone};
 	@$events;
 }
 
diff --git a/t/dir_idle.t b/t/dir_idle.t
index 969c16e9..0bb3b758 100644
--- a/t/dir_idle.t
+++ b/t/dir_idle.t
@@ -6,10 +6,10 @@ use PublicInbox::DS qw(now);
 use File::Path qw(make_path);
 use_ok 'PublicInbox::DirIdle';
 my ($tmpdir, $for_destroy) = tmpdir();
-make_path("$tmpdir/a/b");
+make_path("$tmpdir/a/b", "$tmpdir/c");
 my @x;
 my $cb = sub { push @x, \@_ };
-my $di = PublicInbox::DirIdle->new(["$tmpdir/a"], $cb, 1);
+my $di = PublicInbox::DirIdle->new(["$tmpdir/a", "$tmpdir/c"], $cb, 1);
 PublicInbox::DS->SetLoopTimeout(1000);
 my $end = 3 + now;
 PublicInbox::DS->SetPostLoopCallback(sub { scalar(@x) == 0 && now < $end });
@@ -17,6 +17,27 @@ tick(0.011);
 rmdir("$tmpdir/a/b") or xbail "rmdir $!";
 PublicInbox::DS->EventLoop;
 is(scalar(@x), 1, 'got an event') and
-	is($x[0]->[0]->fullname, "$tmpdir/a/b", 'got expected fullname');
+	is($x[0]->[0]->fullname, "$tmpdir/a/b", 'got expected fullname') and
+	ok($x[0]->[0]->IN_DELETE, 'IN_DELETE set');
+
+tick(0.011);
+rmdir("$tmpdir/a") or xbail "rmdir $!";
+@x = ();
+$end = 3 + now;
+PublicInbox::DS->EventLoop;
+is(scalar(@x), 1, 'got an event') and
+	is($x[0]->[0]->fullname, "$tmpdir/a", 'got expected fullname') and
+	ok($x[0]->[0]->IN_DELETE_SELF, 'IN_DELETE_SELF set');
+
+tick(0.011);
+rename("$tmpdir/c", "$tmpdir/j") or xbail "rmdir $!";
+@x = ();
+$end = 3 + now;
+PublicInbox::DS->EventLoop;
+is(scalar(@x), 1, 'got an event') and
+	is($x[0]->[0]->fullname, "$tmpdir/c", 'got expected fullname') and
+	ok($x[0]->[0]->IN_DELETE_SELF || $x[0]->[0]->IN_MOVE_SELF,
+		'IN_DELETE_SELF set on move');
+
 PublicInbox::DS->Reset;
 done_testing;