X-Git-Url: http://www.git.stargrave.org/?a=blobdiff_plain;f=lib%2FPublicInbox%2FQspawn.pm;h=5e4fd5cb8541a2a8202d188ae1fd73c88fe64188;hb=686fb938a2a27beca406af6e8ab819aad608b06e;hp=68b7111278f52626462a36f5263ccf4096c25b6d;hpb=af0b0fb7a454470a32c452119d0392e0dedb3fe1;p=public-inbox.git

diff --git a/lib/PublicInbox/Qspawn.pm b/lib/PublicInbox/Qspawn.pm
index 68b71112..5e4fd5cb 100644
--- a/lib/PublicInbox/Qspawn.pm
+++ b/lib/PublicInbox/Qspawn.pm
@@ -1,4 +1,4 @@
-# Copyright (C) 2016-2021 all contributors <meta@public-inbox.org>
+# Copyright (C) all contributors <meta@public-inbox.org>
 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
 
 # Like most Perl modules in public-inbox, this is internal and
@@ -12,7 +12,7 @@
 # operate in.  This can be useful to ensure smaller inboxes can
 # be cloned while cloning of large inboxes is maxed out.
 #
-# This does not depend on the PublicInbox::DS->EventLoop or any
+# This does not depend on the PublicInbox::DS::event_loop or any
 # other external scheduling mechanism, you just need to call
 # start() and finish() appropriately. However, public-inbox-httpd
 # (which uses PublicInbox::DS)  will be able to schedule this
@@ -25,10 +25,10 @@
 # processes such as git-apply(1).
 
 package PublicInbox::Qspawn;
-use strict;
+use v5.12;
 use PublicInbox::Spawn qw(popen_rd);
 use PublicInbox::GzipFilter;
-use PublicInbox::DS qw(dwaitpid); # doesn't need event loop
+use Scalar::Util qw(blessed);
 
 # n.b.: we get EAGAIN with public-inbox-httpd, and EINTR on other PSGI servers
 use Errno qw(EAGAIN EINTR);
@@ -39,7 +39,8 @@ my $def_limiter;
 # $cmd is the command to spawn
 # $cmd_env is the environ for the child process (not PSGI env)
 # $opt can include redirects and perhaps other process spawning options
-sub new ($$$;) {
+# {qsp_err} is an optional error buffer callers may access themselves
+sub new {
 	my ($class, $cmd, $cmd_env, $opt) = @_;
 	bless { args => [ $cmd, $cmd_env, $opt ] }, $class;
 }
@@ -55,41 +56,23 @@ sub _do_spawn {
 			$o{$k} = $rlimit;
 		}
 	}
-	$self->{cmd} = $o{quiet} ? undef : $cmd;
+	$self->{cmd} = $cmd;
+	$self->{-quiet} = 1 if $o{quiet};
+	$o{cb_arg} = [ \&waitpid_err, $self ];
 	eval {
 		# popen_rd may die on EMFILE, ENFILE
-		($self->{rpipe}, $self->{pid}) = popen_rd($cmd, $cmd_env, \%o);
-
-		die "E: $!" unless defined($self->{pid});
-
+		$self->{rpipe} = popen_rd($cmd, $cmd_env, \%o) // die "E: $!";
 		$limiter->{running}++;
 		$start_cb->($self); # EPOLL_CTL_ADD may ENOSPC/ENOMEM
 	};
 	finish($self, $@) if $@;
 }
 
-sub child_err ($) {
-	my ($child_error) = @_; # typically $?
-	my $exitstatus = ($child_error >> 8) or return;
-	my $sig = $child_error & 127;
-	my $msg = "exit status=$exitstatus";
-	$msg .= " signal=$sig" if $sig;
-	$msg;
-}
-
-sub log_err ($$) {
-	my ($env, $msg) = @_;
-	$env->{'psgi.errors'}->print($msg, "\n");
-}
-
-sub finalize ($$) {
-	my ($self, $err) = @_;
-
-	my ($env, $qx_cb, $qx_arg, $qx_buf) =
-		delete @$self{qw(psgi_env qx_cb qx_arg qx_buf)};
+sub finalize ($) {
+	my ($self) = @_;
 
-	# done, spawn whatever's in the queue
-	my $limiter = $self->{limiter};
+	# process is done, spawn whatever's in the queue
+	my $limiter = delete $self->{limiter} or return;
 	my $running = --$limiter->{running};
 
 	if ($running < $limiter->{max}) {
@@ -97,36 +80,54 @@ sub finalize ($$) {
 			_do_spawn(@$next, $limiter);
 		}
 	}
-
-	if ($err) {
-		if (defined $self->{err}) {
-			$self->{err} .= "; $err";
-		} else {
-			$self->{err} = $err;
-		}
-		if ($env && $self->{cmd}) {
-			log_err($env, join(' ', @{$self->{cmd}}) . ": $err");
+	if (my $err = $self->{_err}) { # set by finish or waitpid_err
+		utf8::decode($err);
+		if (my $dst = $self->{qsp_err}) {
+			$$dst .= $$dst ? " $err" : "; $err";
 		}
+		warn "@{$self->{cmd}}: $err\n" if !$self->{-quiet};
 	}
+
+	my ($env, $qx_cb, $qx_arg, $qx_buf) =
+		delete @$self{qw(psgi_env qx_cb qx_arg qx_buf)};
 	if ($qx_cb) {
 		eval { $qx_cb->($qx_buf, $qx_arg) };
-	} elsif (my $wcb = delete $env->{'qspawn.wcb'}) {
+		return unless $@;
+		warn "E: $@"; # hope qspawn.wcb can handle it
+	}
+	return if $self->{passed}; # another command chained it
+	if (my $wcb = delete $env->{'qspawn.wcb'}) {
 		# have we started writing, yet?
+		my $code = delete $env->{'qspawn.fallback'} // 500;
 		require PublicInbox::WwwStatic;
-		$wcb->(PublicInbox::WwwStatic::r(500));
+		$wcb->(PublicInbox::WwwStatic::r($code));
 	}
 }
 
-# callback for dwaitpid
-sub waitpid_err { finalize($_[0], child_err($?)) }
+sub DESTROY { finalize($_[0]) } # ->finalize is idempotent
+
+sub waitpid_err { # callback for awaitpid
+	my (undef, $self) = @_; # $_[0]: pid
+	$self->{_err} = ''; # for defined check in ->finish
+	if ($?) {
+		my $status = $? >> 8;
+		my $sig = $? & 127;
+		$self->{_err} .= "exit status=$status";
+		$self->{_err} .= " signal=$sig" if $sig;
+	}
+	finalize($self) if !$self->{rpipe};
+}
 
 sub finish ($;$) {
 	my ($self, $err) = @_;
-	if (delete $self->{rpipe}) {
-		dwaitpid $self->{pid}, \&waitpid_err, $self;
-	} else {
-		finalize($self, $err);
-	}
+	$self->{_err} //= $err; # only for $@
+
+	# we can safely finalize if pipe was closed before, or if
+	# {_err} is defined by waitpid_err.  Deleting {rpipe} will
+	# trigger PublicInbox::ProcessPipe::DESTROY -> waitpid_err,
+	# but it may not fire right away if inside the event loop.
+	my $closed_before = !delete($self->{rpipe});
+	finalize($self) if $closed_before || defined($self->{_err});
 }
 
 sub start ($$$) {
@@ -138,22 +139,22 @@ sub start ($$$) {
 	}
 }
 
-sub psgi_qx_init_cb {
+sub psgi_qx_init_cb { # this may be PublicInbox::HTTPD::Async {cb}
 	my ($self) = @_;
-	my $async = delete $self->{async};
 	my ($r, $buf);
-	my $qx_fh = $self->{qx_fh};
 reread:
 	$r = sysread($self->{rpipe}, $buf, 65536);
-	if ($async) {
-		$async->async_pass($self->{psgi_env}->{'psgix.io'},
-					$qx_fh, \$buf);
-	} elsif (defined $r) {
-		$r ? (print $qx_fh $buf) : event_step($self, undef);
-	} else {
+	if (!defined($r)) {
 		return if $! == EAGAIN; # try again when notified
 		goto reread if $! == EINTR;
 		event_step($self, $!);
+	} elsif (my $as = delete $self->{async}) { # PublicInbox::HTTPD::Async
+		$as->async_pass($self->{psgi_env}->{'psgix.io'},
+				$self->{qx_fh}, \$buf);
+	} elsif ($r) { # generic PSGI:
+		print { $self->{qx_fh} } $buf;
+	} else { # EOF
+		event_step($self, undef);
 	}
 }
 
@@ -191,82 +192,97 @@ sub psgi_qx {
 # PSGI servers.
 sub event_step {
 	my ($self, $err) = @_; # $err: $!
-	log_err($self->{psgi_env}, "psgi_{return,qx} $err") if defined($err);
+	warn "psgi_{return,qx} $err" if defined($err);
 	finish($self);
-	my ($fh, $qx_fh) = delete(@$self{qw(fh qx_fh)});
+	my ($fh, $qx_fh) = delete(@$self{qw(qfh qx_fh)});
 	$fh->close if $fh; # async-only (psgi_return)
 }
 
 sub rd_hdr ($) {
 	my ($self) = @_;
 	# typically used for reading CGI headers
-	# we must loop until EAGAIN for EPOLLET in HTTPD/Async.pm
 	# We also need to check EINTR for generic PSGI servers.
 	my $ret;
 	my $total_rd = 0;
 	my $hdr_buf = $self->{hdr_buf};
 	my ($ph_cb, $ph_arg) = @{$self->{parse_hdr}};
-	do {
+	until (defined($ret)) {
 		my $r = sysread($self->{rpipe}, $$hdr_buf, 4096,
 				length($$hdr_buf));
 		if (defined($r)) {
 			$total_rd += $r;
 			eval { $ret = $ph_cb->($total_rd, $hdr_buf, $ph_arg) };
 			if ($@) {
-				log_err($self->{psgi_env}, "parse_hdr: $@");
+				warn "parse_hdr: $@";
+				$ret = [ 500, [], [ "Internal error\n" ] ];
+			} elsif (!defined($ret) && !$r) {
+				warn <<EOM;
+EOF parsing headers from @{$self->{cmd}} ($self->{psgi_env}->{REQUEST_URI})
+EOM
 				$ret = [ 500, [], [ "Internal error\n" ] ];
 			}
 		} else {
 			# caller should notify us when it's ready:
 			return if $! == EAGAIN;
 			next if $! == EINTR; # immediate retry
-			log_err($self->{psgi_env}, "error reading header: $!");
+			warn "error reading header: $!";
 			$ret = [ 500, [], [ "Internal error\n" ] ];
 		}
-	} until (defined $ret);
+	}
 	delete $self->{parse_hdr}; # done parsing headers
 	$ret;
 }
 
-sub psgi_return_init_cb {
+sub psgi_return_init_cb { # this may be PublicInbox::HTTPD::Async {cb}
 	my ($self) = @_;
 	my $r = rd_hdr($self) or return;
 	my $env = $self->{psgi_env};
-	my $filter = delete $env->{'qspawn.filter'} //
-		PublicInbox::GzipFilter::qsp_maybe($r->[1], $env);
+	my $filter;
+
+	# this is for RepoAtom since that can fire after parse_cgi_headers
+	if (ref($r) eq 'ARRAY' && blessed($r->[2]) && $r->[2]->can('attach')) {
+		$filter = pop @$r;
+	}
+	$filter //= delete($env->{'qspawn.filter'}) // (ref($r) eq 'ARRAY' ?
+		PublicInbox::GzipFilter::qsp_maybe($r->[1], $env) : undef);
 
 	my $wcb = delete $env->{'qspawn.wcb'};
-	my $async = delete $self->{async};
-	if (scalar(@$r) == 3) { # error
-		if ($async) {
-			# calls rpipe->close && ->event_step
-			$async->close;
-		} else {
-			$self->{rpipe}->close;
+	my $async = delete $self->{async}; # PublicInbox::HTTPD::Async
+	if (ref($r) ne 'ARRAY' || scalar(@$r) == 3) { # error
+		if ($async) { # calls rpipe->close && ->event_step
+			$async->close; # PublicInbox::HTTPD::Async::close
+		} else { # generic PSGI, use PublicInbox::ProcessPipe::CLOSE
+			delete($self->{rpipe})->close;
 			event_step($self);
 		}
-		$wcb->($r);
+		if (ref($r) eq 'ARRAY') { # error
+			$wcb->($r)
+		} elsif (ref($r) eq 'CODE') { # chain another command
+			$r->($wcb);
+			$self->{passed} = 1;
+		}
+		# else do nothing
 	} elsif ($async) {
 		# done reading headers, handoff to read body
 		my $fh = $wcb->($r); # scalar @$r == 2
 		$fh = $filter->attach($fh) if $filter;
-		$self->{fh} = $fh;
+		$self->{qfh} = $fh;
 		$async->async_pass($env->{'psgix.io'}, $fh,
 					delete($self->{hdr_buf}));
 	} else { # for synchronous PSGI servers
 		require PublicInbox::GetlineBody;
+		my $buf = delete $self->{hdr_buf};
 		$r->[2] = PublicInbox::GetlineBody->new($self->{rpipe},
-					\&event_step, $self,
-					${$self->{hdr_buf}}, $filter);
+					\&event_step, $self, $$buf, $filter);
 		$wcb->($r);
 	}
 }
 
 sub psgi_return_start { # may run later, much later...
 	my ($self) = @_;
-	if (my $async = $self->{psgi_env}->{'pi-httpd.async'}) {
+	if (my $cb = $self->{psgi_env}->{'pi-httpd.async'}) {
 		# PublicInbox::HTTPD::Async->new(rpipe, $cb, $cb_arg, $end_obj)
-		$self->{async} = $async->($self->{rpipe},
+		$self->{async} = $cb->($self->{rpipe},
 					\&psgi_return_init_cb, $self, $self);
 	} else { # generic PSGI
 		psgi_return_init_cb($self) while $self->{parse_hdr};
@@ -319,8 +335,7 @@ sub psgi_return {
 }
 
 package PublicInbox::Qspawn::Limiter;
-use strict;
-use warnings;
+use v5.12;
 
 sub new {
 	my ($class, $max) = @_;