diff options
Diffstat (limited to 'lib/PublicInbox/LeiStoreErr.pm')
-rw-r--r-- | lib/PublicInbox/LeiStoreErr.pm | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/lib/PublicInbox/LeiStoreErr.pm b/lib/PublicInbox/LeiStoreErr.pm new file mode 100644 index 00000000..c8bc72b6 --- /dev/null +++ b/lib/PublicInbox/LeiStoreErr.pm @@ -0,0 +1,62 @@ +# Copyright (C) all contributors <meta@public-inbox.org> +# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt> + +# forwards stderr from lei/store process to any lei clients using +# the same store, falls back to syslog if no matching clients exist. +package PublicInbox::LeiStoreErr; +use v5.12; +use parent qw(PublicInbox::DS); +use PublicInbox::Syscall qw(EPOLLIN); +use Sys::Syslog qw(openlog syslog closelog); +use IO::Handle (); # ->blocking +use Time::HiRes (); +use autodie qw(open); +our $err_wr; + +# We don't want blocked stderr on clients to block lei/store or lei-daemon. +# We can't make stderr non-blocking since it can break MUAs or anything +# lei might spawn. So we setup a timer to wake us up after a second if +# printing to a user's stderr hasn't completed, yet. Unfortunately, +# EINTR alone isn't enough since Perl auto-restarts writes on signals, +# so to interrupt writes to clients with blocked stderr, we dup the +# error output to $err_wr ahead-of-time and close $err_wr in the +# SIGALRM handler to ensure `print' gets aborted: + +sub abort_err_wr { close($err_wr) if $err_wr; undef $err_wr } + +sub emit ($@) { + my ($efh, @msg) = @_; + open(local $err_wr, '>&', $efh); # fdopen(dup(fileno($efh)), "w") + local $SIG{ALRM} = \&abort_err_wr; + Time::HiRes::alarm(1.0, 0.1); + my $ret = print $err_wr @msg; + Time::HiRes::alarm(0); + $ret; +} + +sub new { + my ($cls, $rd, $lei) = @_; + my $self = bless { sock => $rd, store_path => $lei->store_path }, $cls; + $rd->blocking(0); + $self->SUPER::new($rd, EPOLLIN); # level-trigger +} + +sub event_step { + my ($self) = @_; + my $n = sysread($self->{sock}, my $buf, 8192); + return ($!{EAGAIN} ? 0 : $self->close) if !defined($n); + return $self->close if !$n; + my $printed; + for my $lei (grep defined, @PublicInbox::DS::FD_MAP) { + my $cb = $lei->can('store_path') // next; + next if $cb->($lei) ne $self->{store_path}; + emit($lei->{2} // next, $buf) and $printed = 1; + } + if (!$printed) { + openlog('lei/store', 'pid,nowait,nofatal,ndelay', 'user'); + for my $l (split(/\n/, $buf)) { syslog('warning', '%s', $l) } + closelog(); # don't share across fork + } +} + +1; |