[PATCH 01/18] limiter: split out from qspawn

[Eric Wong <e@80x24.org>]

It's slightly better organized this way, especially since
`publicinboxLimiter' has its own user-facing config section
and knobs.  I may use it in LeiMirror and CodeSearchIdx for
process management.
---
 MANIFEST                          |  1 +
 lib/PublicInbox/Config.pm         |  4 +--
 lib/PublicInbox/GitHTTPBackend.pm |  3 +-
 lib/PublicInbox/Inbox.pm          |  4 +--
 lib/PublicInbox/Limiter.pm        | 47 +++++++++++++++++++++++++++++++
 lib/PublicInbox/MailDiff.pm       |  1 +
 lib/PublicInbox/Qspawn.pm         | 47 ++-----------------------------
 t/qspawn.t                        |  3 +-
 8 files changed, 60 insertions(+), 50 deletions(-)
 create mode 100644 lib/PublicInbox/Limiter.pm

diff --git a/MANIFEST b/MANIFEST
index 791d91a7..dcce801c 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -287,6 +287,7 @@ lib/PublicInbox/LeiUp.pm
 lib/PublicInbox/LeiViewText.pm
 lib/PublicInbox/LeiWatch.pm
 lib/PublicInbox/LeiXSearch.pm
+lib/PublicInbox/Limiter.pm
 lib/PublicInbox/Linkify.pm
 lib/PublicInbox/Listener.pm
 lib/PublicInbox/Lock.pm
diff --git a/lib/PublicInbox/Config.pm b/lib/PublicInbox/Config.pm
index 15e0872e..d156b2d3 100644
--- a/lib/PublicInbox/Config.pm
+++ b/lib/PublicInbox/Config.pm
@@ -124,9 +124,9 @@ sub lookup_newsgroup {
 sub limiter {
 	my ($self, $name) = @_;
 	$self->{-limiters}->{$name} //= do {
-		require PublicInbox::Qspawn;
+		require PublicInbox::Limiter;
 		my $max = $self->{"publicinboxlimiter.$name.max"} || 1;
-		my $limiter = PublicInbox::Qspawn::Limiter->new($max);
+		my $limiter = PublicInbox::Limiter->new($max);
 		$limiter->setup_rlimit($name, $self);
 		$limiter;
 	};
diff --git a/lib/PublicInbox/GitHTTPBackend.pm b/lib/PublicInbox/GitHTTPBackend.pm
index 74432429..d69f5f8b 100644
--- a/lib/PublicInbox/GitHTTPBackend.pm
+++ b/lib/PublicInbox/GitHTTPBackend.pm
@@ -9,13 +9,14 @@ use v5.10.1;
 use Fcntl qw(:seek);
 use IO::Handle; # ->flush
 use HTTP::Date qw(time2str);
+use PublicInbox::Limiter;
 use PublicInbox::Qspawn;
 use PublicInbox::Tmpfile;
 use PublicInbox::WwwStatic qw(r @NO_CACHE);
 use Carp ();
 
 # 32 is same as the git-daemon connection limit
-my $default_limiter = PublicInbox::Qspawn::Limiter->new(32);
+my $default_limiter = PublicInbox::Limiter->new(32);
 
 # n.b. serving "description" and "cloneurl" should be innocuous enough to
 # not cause problems.  serving "config" might...
diff --git a/lib/PublicInbox/Inbox.pm b/lib/PublicInbox/Inbox.pm
index 9afbb478..3dad7004 100644
--- a/lib/PublicInbox/Inbox.pm
+++ b/lib/PublicInbox/Inbox.pm
@@ -55,8 +55,8 @@ sub _set_limiter ($$$) {
 		my $val = $self->{$mkey} or return;
 		my $lim;
 		if ($val =~ /\A[0-9]+\z/) {
-			require PublicInbox::Qspawn;
-			$lim = PublicInbox::Qspawn::Limiter->new($val);
+			require PublicInbox::Limiter;
+			$lim = PublicInbox::Limiter->new($val);
 		} elsif ($val =~ /\A[a-z][a-z0-9]*\z/) {
 			$lim = $pi_cfg->limiter($val);
 			warn "$mkey limiter=$val not found\n" if !$lim;
diff --git a/lib/PublicInbox/Limiter.pm b/lib/PublicInbox/Limiter.pm
new file mode 100644
index 00000000..48a2b6a3
--- /dev/null
+++ b/lib/PublicInbox/Limiter.pm
@@ -0,0 +1,47 @@
+# Copyright (C) all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+
+package PublicInbox::Limiter;
+use v5.12;
+use PublicInbox::Spawn;
+
+sub new {
+	my ($class, $max) = @_;
+	bless {
+		# 32 is same as the git-daemon connection limit
+		max => $max || 32,
+		running => 0,
+		run_queue => [],
+		# RLIMIT_CPU => undef,
+		# RLIMIT_DATA => undef,
+		# RLIMIT_CORE => undef,
+	}, $class;
+}
+
+sub setup_rlimit {
+	my ($self, $name, $cfg) = @_;
+	for my $rlim (@PublicInbox::Spawn::RLIMITS) {
+		my $k = lc($rlim);
+		$k =~ tr/_//d;
+		$k = "publicinboxlimiter.$name.$k";
+		my $v = $cfg->{$k} // next;
+		my @rlimit = split(/\s*,\s*/, $v);
+		if (scalar(@rlimit) == 1) {
+			push @rlimit, $rlimit[0];
+		} elsif (scalar(@rlimit) != 2) {
+			warn "could not parse $k: $v\n";
+		}
+		eval { require BSD::Resource };
+		if ($@) {
+			warn "BSD::Resource missing for $rlim";
+			next;
+		}
+		for my $i (0..$#rlimit) {
+			next if $rlimit[$i] ne 'INFINITY';
+			$rlimit[$i] = BSD::Resource::RLIM_INFINITY();
+		}
+		$self->{$rlim} = \@rlimit;
+	}
+}
+
+1;
diff --git a/lib/PublicInbox/MailDiff.pm b/lib/PublicInbox/MailDiff.pm
index 994c7851..c3ce9365 100644
--- a/lib/PublicInbox/MailDiff.pm
+++ b/lib/PublicInbox/MailDiff.pm
@@ -8,6 +8,7 @@ use PublicInbox::MsgIter qw(msg_part_text);
 use PublicInbox::ViewDiff qw(flush_diff);
 use PublicInbox::GitAsyncCat;
 use PublicInbox::ContentDigestDbg;
+use PublicInbox::Qspawn;
 
 sub write_part { # Eml->each_part callback
 	my ($ary, $self) = @_;
diff --git a/lib/PublicInbox/Qspawn.pm b/lib/PublicInbox/Qspawn.pm
index 0e52617c..a4d78e49 100644
--- a/lib/PublicInbox/Qspawn.pm
+++ b/lib/PublicInbox/Qspawn.pm
@@ -29,6 +29,7 @@ use v5.12;
 use PublicInbox::Spawn qw(popen_rd);
 use PublicInbox::GzipFilter;
 use Scalar::Util qw(blessed);
+use PublicInbox::Limiter;
 
 # n.b.: we get EAGAIN with public-inbox-httpd, and EINTR on other PSGI servers
 use Errno qw(EAGAIN EINTR);
@@ -183,7 +184,7 @@ sub psgi_qx {
 	$self->{qx_arg} = $qx_arg;
 	$self->{qx_fh} = $qx_fh;
 	$self->{qx_buf} = \$qx_buf;
-	$limiter ||= $def_limiter ||= PublicInbox::Qspawn::Limiter->new(32);
+	$limiter ||= $def_limiter ||= PublicInbox::Limiter->new(32);
 	start($self, $limiter, \&psgi_qx_start);
 }
 
@@ -317,7 +318,7 @@ sub psgi_return {
 	$self->{psgi_env} = $env;
 	$self->{hdr_buf} = \(my $hdr_buf = '');
 	$self->{parse_hdr} = [ $parse_hdr, $hdr_arg ];
-	$limiter ||= $def_limiter ||= PublicInbox::Qspawn::Limiter->new(32);
+	$limiter ||= $def_limiter ||= PublicInbox::Limiter->new(32);
 
 	# the caller already captured the PSGI write callback from
 	# the PSGI server, so we can call ->start, here:
@@ -334,46 +335,4 @@ sub psgi_return {
 	}
 }
 
-package PublicInbox::Qspawn::Limiter;
-use v5.12;
-
-sub new {
-	my ($class, $max) = @_;
-	bless {
-		# 32 is same as the git-daemon connection limit
-		max => $max || 32,
-		running => 0,
-		run_queue => [],
-		# RLIMIT_CPU => undef,
-		# RLIMIT_DATA => undef,
-		# RLIMIT_CORE => undef,
-	}, $class;
-}
-
-sub setup_rlimit {
-	my ($self, $name, $cfg) = @_;
-	foreach my $rlim (@PublicInbox::Spawn::RLIMITS) {
-		my $k = lc($rlim);
-		$k =~ tr/_//d;
-		$k = "publicinboxlimiter.$name.$k";
-		defined(my $v = $cfg->{$k}) or next;
-		my @rlimit = split(/\s*,\s*/, $v);
-		if (scalar(@rlimit) == 1) {
-			push @rlimit, $rlimit[0];
-		} elsif (scalar(@rlimit) != 2) {
-			warn "could not parse $k: $v\n";
-		}
-		eval { require BSD::Resource };
-		if ($@) {
-			warn "BSD::Resource missing for $rlim";
-			next;
-		}
-		foreach my $i (0..$#rlimit) {
-			next if $rlimit[$i] ne 'INFINITY';
-			$rlimit[$i] = BSD::Resource::RLIM_INFINITY();
-		}
-		$self->{$rlim} = \@rlimit;
-	}
-}
-
 1;
diff --git a/t/qspawn.t b/t/qspawn.t
index 224e20db..507f86a5 100644
--- a/t/qspawn.t
+++ b/t/qspawn.t
@@ -3,6 +3,7 @@
 use v5.12;
 use Test::More;
 use_ok 'PublicInbox::Qspawn';
+use_ok 'PublicInbox::Limiter';
 
 {
 	my $cmd = [qw(sh -c), 'echo >&2 err; echo out'];
@@ -23,7 +24,7 @@ sub finish_err ($) {
 	$qsp->{qsp_err} && ${$qsp->{qsp_err}};
 }
 
-my $limiter = PublicInbox::Qspawn::Limiter->new(1);
+my $limiter = PublicInbox::Limiter->new(1);
 {
 	my $x = PublicInbox::Qspawn->new([qw(true)]);
 	$x->{qsp_err} = \(my $err = '');