http: use writev for known Content-Length responses

We could use sendmsg(2) without MSG_MORE here, too, but
writev(2) is simpler to setup and call and we may want to use it
with pipes or regular files in the future, too, not just sockets.

diff --git a/devel/sysdefs-list b/devel/sysdefs-list
index ba51de6c7c15ad3fe75baf7e3a9e24b7a77a516b..1345e0ba24a718d8c636a0441c2350e8dbfb9013 100755 (executable)
--- a/devel/sysdefs-list
+++ b/devel/sysdefs-list
@@ -152,6 +152,7 @@ int main(void)
 
        D(SYS_sendmsg);
        D(SYS_recvmsg);
+       D(SYS_writev);
 
        STRUCT_BEGIN(struct flock);
                PR_NUM(l_start);

diff --git a/lib/PublicInbox/DS.pm b/lib/PublicInbox/DS.pm
index c5f448606f3d352d1bf9e3bec2f79b951c122250..f807c6269c5014f862ac1cf6f614e76c766efb0d 100644 (file)
--- a/lib/PublicInbox/DS.pm
+++ b/lib/PublicInbox/DS.pm
@@ -38,6 +38,7 @@ use Carp qw(carp croak);
 use List::Util qw(sum);
 our @EXPORT_OK = qw(now msg_more awaitpid add_timer add_uniq_timer);
 my $sendmsg_more = PublicInbox::Syscall->can('sendmsg_more');
+my $writev = PublicInbox::Syscall->can('writev');
 
 my $nextq; # queue for next_tick
 my $reap_armed;
@@ -551,41 +552,54 @@ sub write {
        }
 }
 
+sub _iov_write ($$@) {
+       my ($self, $cb) = (shift, shift);
+       my ($tip, $tmpio, $s, $exp);
+       $s = $cb->($self->{sock}, @_);
+       if (defined $s) {
+               $exp = sum(map length, @_);
+               return 1 if $s == $exp;
+               while (@_) {
+                       $tip = shift;
+                       if ($s >= length($tip)) { # fully written
+                               $s -= length($tip);
+                       } else { # first partial write
+                               $tmpio = tmpio $self, \$tip, $s, @_ or return 0;
+                               last;
+                       }
+               }
+               $tmpio // return drop $self, "BUG: tmpio on $s != $exp";
+       } elsif ($! == EAGAIN) {
+               $tip = shift;
+               $tmpio = tmpio $self, \$tip, 0, @_ or return 0;
+       } else { # client disconnected
+               return $self->close;
+       }
+       push @{$self->{wbuf}}, $tmpio; # autovivifies
+       epwait $self->{sock}, EPOLLOUT|EPOLLONESHOT;
+       0;
+}
+
 sub msg_more ($@) {
        my $self = shift;
-       my ($sock, $wbuf);
-       $sock = $self->{sock} or return 1;
-       $wbuf = $self->{wbuf};
-
+       my $sock = $self->{sock} or return 1;
+       my $wbuf = $self->{wbuf};
        if ($sendmsg_more && (!defined($wbuf) || !scalar(@$wbuf)) &&
-               !$sock->can('stop_SSL')) {
-               my ($s, $tip, $tmpio);
-               $s = $sendmsg_more->($sock, @_);
-               if (defined $s) {
-                       my $exp = sum(map length, @_);
-                       return 1 if $s == $exp;
-                       while (@_) {
-                               $tip = shift;
-                               if ($s >= length($tip)) { # fully written
-                                       $s -= length($tip);
-                               } else { # first partial write
-                                       $tmpio = tmpio $self, \$tip, $s, @_
-                                               or return 0;
-                                       last;
-                               }
-                       }
-                       $tmpio // return drop $self, "BUG: tmpio on $s != $exp";
-               } elsif ($! == EAGAIN) {
-                       $tip = shift;
-                       $tmpio = tmpio $self, \$tip, 0, @_ or return 0;
-               } else { # client disconnected
-                       return $self->close;
-               }
-               push @{$self->{wbuf}}, $tmpio; # autovivifies
-               epwait $sock, EPOLLOUT|EPOLLONESHOT;
-               0;
-       } else {
-               # don't redispatch into NNTPdeflate::write
+                       !$sock->can('stop_SSL')) {
+               _iov_write $self, $sendmsg_more, @_;
+       } else { # don't redispatch into NNTPdeflate::write
+               PublicInbox::DS::write($self, join('', @_));
+       }
+}
+
+sub writev ($@) {
+       my $self = shift;
+       my $sock = $self->{sock} or return 1;
+       my $wbuf = $self->{wbuf};
+       if ($writev && (!defined($wbuf) || !scalar(@$wbuf)) &&
+                       !$sock->can('stop_SSL')) {
+               _iov_write $self, $writev, @_;
+       } else { # don't redispatch into NNTPdeflate::write
                PublicInbox::DS::write($self, join('', @_));
        }
 }

diff --git a/lib/PublicInbox/HTTP.pm b/lib/PublicInbox/HTTP.pm
index d0e5aa291f42a03b2f113232c5301fbf15330890..73632aee2af0ebf64ed9e7573e3b9cb0b0f867a6 100644 (file)
--- a/lib/PublicInbox/HTTP.pm
+++ b/lib/PublicInbox/HTTP.pm
@@ -190,9 +190,10 @@ sub response_header_write ($$$) {
        my $conn = $env->{HTTP_CONNECTION} || '';
        my $term = defined($len) || $chunked;
        my $prot_persist = ($proto eq 'HTTP/1.1') && ($conn !~ /\bclose\b/i);
-       my $alive;
+       my ($alive, $res_body);
        if (!$term && ref($res->[2]) eq 'ARRAY') {
-               $len = sum0(map length, @{$res->[2]});
+               ($res_body, $res->[2]) = ($res->[2], []);
+               $len = sum0(map length, @$res_body);
                $h .= "Content-Length: $len\r\n";
                $term = 1;
        }
@@ -210,7 +211,9 @@ sub response_header_write ($$$) {
        }
        $h .= 'Date: ' . http_date() . "\r\n\r\n";
 
-       if (($len || $chunked) && $env->{REQUEST_METHOD} ne 'HEAD') {
+       if ($res_body) {
+               $self->writev($h, @$res_body);
+       } elsif (($len || $chunked) && $env->{REQUEST_METHOD} ne 'HEAD') {
                msg_more($self, $h);
        } else {
                $self->write(\$h);

diff --git a/lib/PublicInbox/Syscall.pm b/lib/PublicInbox/Syscall.pm
index 80b46c19cfb22797054b760f15ab73ebdaa481ba..ebcedb8909c1889b7abbe3bca9d9d988ee608ff0 100644 (file)
--- a/lib/PublicInbox/Syscall.pm
+++ b/lib/PublicInbox/Syscall.pm
@@ -61,7 +61,7 @@ our ($SYS_epoll_create,
        $SYS_recvmsg);
 
 my $SYS_fstatfs; # don't need fstatfs64, just statfs.f_type
-my ($FS_IOC_GETFLAGS, $FS_IOC_SETFLAGS);
+my ($FS_IOC_GETFLAGS, $FS_IOC_SETFLAGS, $SYS_writev);
 my $SFD_CLOEXEC = 02000000; # Perl does not expose O_CLOEXEC
 our $no_deprecated = 0;
 
@@ -95,6 +95,7 @@ if ($^O eq "linux") {
                $SYS_fstatfs = 100;
                $SYS_sendmsg = 370;
                $SYS_recvmsg = 372;
+               $SYS_writev = 146;
                $INOTIFY = { # usage: `use constant $PublicInbox::Syscall::INOTIFY'
                        SYS_inotify_init1 => 332,
                        SYS_inotify_add_watch => 292,
@@ -111,6 +112,7 @@ if ($^O eq "linux") {
                $SYS_fstatfs = 138;
                $SYS_sendmsg = 46;
                $SYS_recvmsg = 47;
+               $SYS_writev = 20;
                $INOTIFY = {
                        SYS_inotify_init1 => 294,
                        SYS_inotify_add_watch => 254,
@@ -127,6 +129,7 @@ if ($^O eq "linux") {
                $SYS_fstatfs = 138;
                $SYS_sendmsg = 0x40000206;
                $SYS_recvmsg = 0x40000207;
+               $SYS_writev = 0x40000204;
                $FS_IOC_GETFLAGS = 0x80046601;
                $FS_IOC_SETFLAGS = 0x40046602;
                $INOTIFY = {
@@ -164,6 +167,7 @@ if ($^O eq "linux") {
                $SYS_fstatfs = 100;
                $SYS_sendmsg = 341;
                $SYS_recvmsg = 342;
+               $SYS_writev = 146;
                $FS_IOC_GETFLAGS = 0x40086601;
                $FS_IOC_SETFLAGS = 0x80086602;
                $INOTIFY = {
@@ -179,6 +183,7 @@ if ($^O eq "linux") {
                $SYS_signalfd4 = 313;
                $SYS_renameat2 //= 357;
                $SYS_fstatfs = 100;
+               $SYS_writev = 146;
                $FS_IOC_GETFLAGS = 0x40086601;
                $FS_IOC_SETFLAGS = 0x80086602;
        } elsif ($machine =~ m/^s390/) { # untested, no machine on cfarm
@@ -191,6 +196,7 @@ if ($^O eq "linux") {
                $SYS_fstatfs = 100;
                $SYS_sendmsg = 370;
                $SYS_recvmsg = 372;
+               $SYS_writev = 146;
        } elsif ($machine eq 'ia64') { # untested, no machine on cfarm
                $SYS_epoll_create = 1243;
                $SYS_epoll_ctl = 1244;
@@ -216,6 +222,7 @@ if ($^O eq "linux") {
                $SYS_fstatfs = 44;
                $SYS_sendmsg = 211;
                $SYS_recvmsg = 212;
+               $SYS_writev = 66;
                $INOTIFY = {
                        SYS_inotify_init1 => 26,
                        SYS_inotify_add_watch => 27,
@@ -233,6 +240,7 @@ if ($^O eq "linux") {
                $SYS_fstatfs = 100;
                $SYS_sendmsg = 296;
                $SYS_recvmsg = 297;
+               $SYS_writev = 146;
        } elsif ($machine =~ m/^mips64/) { # cfarm only has 32-bit userspace
                $SYS_epoll_create = 5207;
                $SYS_epoll_ctl = 5208;
@@ -243,6 +251,7 @@ if ($^O eq "linux") {
                $SYS_fstatfs = 5135;
                $SYS_sendmsg = 5045;
                $SYS_recvmsg = 5046;
+               $SYS_writev = 5019;
                $FS_IOC_GETFLAGS = 0x40046601;
                $FS_IOC_SETFLAGS = 0x80046602;
        } elsif ($machine =~ m/^mips/) { # 32-bit, tested on mips64 cfarm host
@@ -255,6 +264,7 @@ if ($^O eq "linux") {
                $SYS_fstatfs = 4100;
                $SYS_sendmsg = 4179;
                $SYS_recvmsg = 4177;
+               $SYS_writev = 4146;
                $FS_IOC_GETFLAGS = 0x40046601;
                $FS_IOC_SETFLAGS = 0x80046602;
                $SIGNUM{WINCH} = 20;
@@ -287,6 +297,7 @@ EOM
 # (I'm assuming Dragonfly copies FreeBSD, here, too)
        $SYS_recvmsg = 27;
        $SYS_sendmsg = 28;
+       $SYS_writev = 121;
 }
 
 BEGIN {
@@ -466,8 +477,9 @@ sub CMSG_LEN ($) { CMSG_ALIGN_SIZEOF_cmsghdr + $_[0] }
 use constant msg_controllen_max =>
        CMSG_SPACE(10 * SIZEOF_int) + SIZEOF_cmsghdr; # space for 10 FDs
 
-if (defined($SYS_sendmsg) && defined($SYS_recvmsg)) {
 no warnings 'once';
+
+if (defined($SYS_sendmsg) && defined($SYS_recvmsg)) {
 require PublicInbox::CmdIPC4;
 
 *send_cmd4 = sub ($$$$;$) {
@@ -548,6 +560,19 @@ require PublicInbox::CmdIPC4;
 };
 }
 
+if (defined($SYS_writev)) {
+*writev = sub {
+       my $fh = shift;
+       use bytes qw(length substr);
+       my $iov = join('', map { pack 'P'.TMPL_size_t, $_, length } @_);
+       my $w;
+       do {
+               $w = syscall($SYS_writev, fileno($fh), $iov, scalar(@_));
+       } while ($w < 0 && $!{EINTR});
+       $w < 0 ? undef : $w;
+};
+}
+
 1;
 
 =head1 WARRANTY

diff --git a/t/syscall.t b/t/syscall.t
index 19390d090502812a70684241e8aa737e167aaf00..8f0e9efa9b8dba2357c9f840b7ec080d4900f059 100644 (file)
--- a/t/syscall.t
+++ b/t/syscall.t
@@ -4,11 +4,17 @@ use Test::More;
 use PublicInbox::Syscall;
 use Socket qw(AF_UNIX SOCK_STREAM);
 my $sendmsg_more = PublicInbox::Syscall->can('sendmsg_more') or
-       plan skip_all => "sendmsg syscalls not defined on $^O";
+       plan skip_all => "sendmsg syscall not defined on $^O";
+my $writev = PublicInbox::Syscall->can('writev') or
+       plan skip_all => "writev syscall not defined on $^O";
 
 socketpair(my $s1, my $s2, AF_UNIX, SOCK_STREAM, 0);
 is $sendmsg_more->($s1, 'hello', 'world'), 10, 'sendmsg_more expected size';
 is sysread($s2, my $buf, 11), 10, 'reader got expected size from sendmsg_more';
 is $buf, 'helloworld', 'sendmsg_more sent expected message';
 
+is $writev->($s1, 'hello', 'world'), 10, 'writev expected size';
+is sysread($s2, $buf, 11), 10, 'reader got expected size from writev';
+is $buf, 'helloworld', 'writev sent expected message';
+
 done_testing;