# Copyright (C) all contributors
# License: AGPL-3.0+
# for systems lacking Linux::Inotify2 or IO::KQueue, just emulates
# enough of Linux::Inotify2 we use.
package PublicInbox::FakeInotify;
use v5.12;
use Time::HiRes qw(stat);
use PublicInbox::DS qw(add_timer);
use Errno qw(ENOTDIR ENOENT);
sub IN_MODIFY () { 0x02 } # match Linux inotify
# my $IN_MOVED_FROM 0x00000040 /* File was moved from X. */
# my $IN_MOVED_TO = 0x80;
# my $IN_CREATE = 0x100;
sub MOVED_TO_OR_CREATE () { 0x80 | 0x100 }
sub IN_DELETE () { 0x200 }
sub IN_DELETE_SELF () { 0x400 }
sub IN_MOVE_SELF () { 0x800 }
my $poll_intvl = 2; # same as Filesys::Notify::Simple
sub new { bless {}, __PACKAGE__ }
sub on_dir_change ($$$$$) { # used by KQNotify subclass
my ($self, $events, $dh, $path, $dir_delete) = @_;
my $old = $self->{dirlist}->{$path};
my @cur = grep(!/\A\.\.?\z/, readdir($dh));
$self->{dirlist}->{$path} = \@cur;
# new files:
my %tmp = map { $_ => undef } @cur;
delete @tmp{@$old};
push(@$events, map {
bless \"$path/$_", 'PublicInbox::FakeInotify::Event'
} keys %tmp);
if ($dir_delete) {
%tmp = map { $_ => undef } @$old;
delete @tmp{@cur};
push(@$events, map {
bless \"$path/$_", 'PublicInbox::FakeInotify::GoneEvent'
} keys %tmp);
}
}
sub watch_open ($$$) { # used by KQNotify subclass
my ($self, $path, $dir_delete) = @_;
my ($fh, @st, @st0, $tries);
do {
again:
unless (@st0 = stat($path)) {
warn "W: stat($path): $!" if $! != ENOENT;
return;
}
if (!(-d _ ? opendir($fh, $path) : open($fh, '<', $path))) {
goto again if $! == ENOTDIR && ++$tries < 10;
warn "W: open($path): $!" if $! != ENOENT;
return;
}
@st = stat($fh) or die "fstat($path): $!";
} while ("@st[0,1]" ne "@st0[0,1]" &&
((++$tries < 10) || (warn(<{dirlist}->{$path} = [];
on_dir_change($self, [], $fh, $path, $$dir_delete);
} else {
$$dir_delete = 0;
}
bless [ @st[0, 1, 10], $path, $fh ], 'PublicInbox::FakeInotify::Watch'
}
# behaves like Linux::Inotify2->watch
sub watch {
my ($self, $path, $mask) = @_; # mask is ignored
my $dir_delete = $mask & IN_DELETE ? 1 : 0;
my $w = watch_open($self, $path, \$dir_delete) or return;
pop @$w; # no need to keep $fh open for non-kqueue
$self->{watch}->{"$path\0$dir_delete"} = $w;
}
sub gone ($$$) { # used by KQNotify subclass
my ($self, $ident, $path) = @_;
delete $self->{watch}->{$ident};
delete $self->{dirlist}->{$path};
bless(\$path, 'PublicInbox::FakeInotify::SelfGoneEvent');
}
# fuzz the time for freshly modified directories for low-res VFS
sub dir_adj ($) {
my ($old_ctime) = @_;
my $now = Time::HiRes::time;
my $diff = $now - $old_ctime;
my $adj = $poll_intvl + 1;
($diff > -$adj && $diff < $adj) ? 1 : 0;
}
# behaves like non-blocking Linux::Inotify2->read
sub read {
my ($self) = @_;
my $ret = [];
while (my ($ident, $w) = each(%{$self->{watch}})) {
if (!@$w) { # cancelled
delete($self->{watch}->{$ident});
next;
}
my $dir_delete = (split(/\0/, $ident, 2))[1];
my ($old_dev, $old_ino, $old_ctime, $path) = @$w;
my @new_st = stat($path);
warn "W: stat($path): $!\n" if !@new_st && $! != ENOENT;
if (!@new_st || "$old_dev $old_ino" ne "@new_st[0,1]") {
push @$ret, gone($self, $ident, $path);
next;
}
if (-d _ && $new_st[10] > ($old_ctime - dir_adj($old_ctime))) {
opendir(my $fh, $path) or do {
if ($! == ENOENT || $! == ENOTDIR) {
push @$ret, gone($self, $ident, $path);
} else {
warn "W: opendir($path): $!";
}
next;
};
@new_st = stat($fh) or die "fstat($path): $!";
if ("$old_dev $old_ino" ne "@new_st[0,1]") {
push @$ret, gone($self, $ident, $path);
next;
}
$w->[2] = $new_st[10];
on_dir_change($self, $ret, $fh, $path, $dir_delete);
} elsif ($new_st[10] > $old_ctime) { # regular files, etc
$w->[2] = $new_st[10];
push @$ret, bless(\$path,
'PublicInbox::FakeInotify::Event');
}
}
@$ret;
}
sub poll_once {
my ($obj) = @_;
$obj->event_step; # PublicInbox::InboxIdle::event_step
add_timer($poll_intvl, \&poll_once, $obj);
}
package PublicInbox::FakeInotify::Watch;
use v5.12;
sub cancel { @{$_[0]} = () }
sub name { $_[0]->[3] }
package PublicInbox::FakeInotify::Event;
use v5.12;
sub fullname { ${$_[0]} }
sub IN_DELETE { 0 }
sub IN_MOVED_FROM { 0 }
sub IN_DELETE_SELF { 0 }
package PublicInbox::FakeInotify::GoneEvent;
use v5.12;
our @ISA = qw(PublicInbox::FakeInotify::Event);
sub IN_DELETE { 1 }
sub IN_MOVED_FROM { 0 }
package PublicInbox::FakeInotify::SelfGoneEvent;
use v5.12;
our @ISA = qw(PublicInbox::FakeInotify::GoneEvent);
sub IN_DELETE_SELF { 1 }
1;