imap+nntp: share COMPRESS implementation

[public-inbox.git] / lib / PublicInbox / ProcessPipe.pm

diff --git a/lib/PublicInbox/ProcessPipe.pm b/lib/PublicInbox/ProcessPipe.pm
index c9234f4214d6f1f3a586370678301cd0c4107ff5..97e9c268f8d1e91aa0f8c1225112dc42cd623768 100644 (file)
--- a/lib/PublicInbox/ProcessPipe.pm
+++ b/lib/PublicInbox/ProcessPipe.pm
@@ -1,16 +1,20 @@
-# Copyright (C) 2016-2020 all contributors <meta@public-inbox.org>
+# Copyright (C) 2016-2021 all contributors <meta@public-inbox.org>
 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
 
 # a tied handle for auto reaping of children tied to a pipe, see perltie(1)
 package PublicInbox::ProcessPipe;
 use strict;
 use v5.10.1;
+use Carp qw(carp);
 
 sub TIEHANDLE {
        my ($class, $pid, $fh, $cb, $arg) = @_;
-       bless { pid => $pid, fh => $fh, cb => $cb, arg => $arg }, $class;
+       bless { pid => $pid, fh => $fh, ppid => $$, cb => $cb, arg => $arg },
+               $class;
 }
 
+sub BINMODE { binmode(shift->{fh}) } # for IO::Uncompress::Gunzip
+
 sub READ { read($_[0]->{fh}, $_[1], $_[2], $_[3] || 0) }
 
 sub READLINE { readline($_[0]->{fh}) }
@@ -25,30 +29,42 @@ sub PRINT {
        print { $self->{fh} } @_;
 }
 
-sub CLOSE {
-       my $fh = delete($_[0]->{fh});
-       my $ret = defined $fh ? close($fh) : '';
-       my ($pid, $cb, $arg) = delete @{$_[0]}{qw(pid cb arg)};
-       if (defined $pid) {
-               # PublicInbox::DS may not be loaded
-               eval { PublicInbox::DS::dwaitpid($pid, $cb, $arg) };
+sub FILENO { fileno($_[0]->{fh}) }
 
-               if ($@) { # ok, not in the event loop, work synchronously
-                       waitpid($pid, 0);
+sub _close ($;$) {
+       my ($self, $wait) = @_;
+       my $fh = delete $self->{fh};
+       my $ret = defined($fh) ? close($fh) : '';
+       my ($pid, $cb, $arg) = delete @$self{qw(pid cb arg)};
+       return $ret unless defined($pid) && $self->{ppid} == $$;
+       if ($wait) { # caller cares about the exit status:
+               my $wp = waitpid($pid, 0);
+               if ($wp == $pid) {
                        $ret = '' if $?;
-                       $cb->($arg, $pid) if $cb;
+                       if ($cb) {
+                               eval { $cb->($arg, $pid) };
+                               carp "E: cb(arg, $pid): $@" if $@;
+                       }
+               } else {
+                       carp "waitpid($pid, 0) = $wp, \$!=$!, \$?=$?";
                }
+       } else { # caller just undef-ed it, let event loop deal with it
+               require PublicInbox::DS;
+               PublicInbox::DS::dwaitpid($pid, $cb, $arg);
        }
        $ret;
 }
 
-sub FILENO { fileno($_[0]->{fh}) }
+# if caller uses close(), assume they want to check $? immediately so
+# we'll waitpid() synchronously.  n.b. wantarray doesn't seem to
+# propagate `undef' down to tied methods, otherwise I'd rely on that.
+sub CLOSE { _close($_[0], 1) }
 
+# if relying on DESTROY, assume the caller doesn't care about $? and
+# we can let the event loop call waitpid() whenever it gets SIGCHLD
 sub DESTROY {
-       CLOSE(@_);
+       _close($_[0]);
        undef;
 }
 
-sub pid { $_[0]->{pid} }
-
 1;