[PATCH 2/5] daemon: use per-listener SIG{__WARN__} callbacks

[Eric Wong]

This allows "-l $ADDRESS?err=/path/to/err.log to isolate normal
warn() (and carp()) messages for a particular listen address to
track down errors more easily.
---
 lib/PublicInbox/Daemon.pm | 2 ++
 lib/PublicInbox/HTTP.pm   | 2 +-
 lib/PublicInbox/HTTPD.pm  | 1 +
 lib/PublicInbox/IMAP.pm   | 2 +-
 lib/PublicInbox/NNTP.pm   | 2 +-
 lib/PublicInbox/POP3.pm   | 1 +
 6 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/lib/PublicInbox/Daemon.pm b/lib/PublicInbox/Daemon.pm
index 0043d21e..bb140640 100644
--- a/lib/PublicInbox/Daemon.pm
+++ b/lib/PublicInbox/Daemon.pm
@@ -134,6 +134,8 @@ sub load_mod ($;$$) {
                $tlsd->{$f} = $logs{$p} //= open_log_path(my $fh, $p);
                warn "# $scheme://$addr $f=$p\n";
        }
+       my $err = $tlsd->{err};
+       $tlsd->{warn_cb} = sub { print $err @_ }; # for local $SIG{__WARN__}
        \%xn;
 }
 
diff --git a/lib/PublicInbox/HTTP.pm b/lib/PublicInbox/HTTP.pm
index 3d4e3499..0dba425d 100644
--- a/lib/PublicInbox/HTTP.pm
+++ b/lib/PublicInbox/HTTP.pm
@@ -69,7 +69,7 @@ sub new ($$$) {
 
 sub event_step { # called by PublicInbox::DS
        my ($self) = @_;
-
+       local $SIG{__WARN__} = $self->{srv_env}->{'pi-httpd.warn_cb'};
        return unless $self->flush_write && $self->{sock};
 
        # only read more requests if we've drained the write buffer,
diff --git a/lib/PublicInbox/HTTPD.pm b/lib/PublicInbox/HTTPD.pm
index e531ee70..bae7281b 100644
--- a/lib/PublicInbox/HTTPD.pm
+++ b/lib/PublicInbox/HTTPD.pm
@@ -47,6 +47,7 @@ sub env_for ($$$) {
                # detect when to use async paths for slow blobs
                'pi-httpd.async' => \&pi_httpd_async,
                'pi-httpd.app' => $self->{app},
+               'pi-httpd.warn_cb' => $self->{warn_cb},
        }
 }
 
diff --git a/lib/PublicInbox/IMAP.pm b/lib/PublicInbox/IMAP.pm
index 605c5e51..2be1b763 100644
--- a/lib/PublicInbox/IMAP.pm
+++ b/lib/PublicInbox/IMAP.pm
@@ -1186,7 +1186,7 @@ sub out ($$;@) {
 # callback used by PublicInbox::DS for any (e)poll (in/out/hup/err)
 sub event_step {
        my ($self) = @_;
-
+       local $SIG{__WARN__} = $self->{imapd}->{warn_cb};
        return unless $self->flush_write && $self->{sock} && !$self->{long_cb};
 
        # only read more requests if we've drained the write buffer,
diff --git a/lib/PublicInbox/NNTP.pm b/lib/PublicInbox/NNTP.pm
index 524784cb..ef01f448 100644
--- a/lib/PublicInbox/NNTP.pm
+++ b/lib/PublicInbox/NNTP.pm
@@ -958,7 +958,7 @@ sub out ($$;@) {
 # callback used by PublicInbox::DS for any (e)poll (in/out/hup/err)
 sub event_step {
        my ($self) = @_;
-
+       local $SIG{__WARN__} = $self->{nntpd}->{warn_cb};
        return unless $self->flush_write && $self->{sock} && !$self->{long_cb};
 
        # only read more requests if we've drained the write buffer,
diff --git a/lib/PublicInbox/POP3.pm b/lib/PublicInbox/POP3.pm
index 7469922b..53fb2e05 100644
--- a/lib/PublicInbox/POP3.pm
+++ b/lib/PublicInbox/POP3.pm
@@ -351,6 +351,7 @@ sub process_line ($$) {
 # callback used by PublicInbox::DS for any (e)poll (in/out/hup/err)
 sub event_step {
        my ($self) = @_;
+       local $SIG{__WARN__} = $self->{pop3d}->{warn_cb};
        return unless $self->flush_write && $self->{sock} && !$self->{long_cb};
 
        # only read more requests if we've drained the write buffer,