http: chunk in the server, not middleware

Since PSGI does not require Transfer-Encoding: chunked or
Content-Length, we cannot expect random apps we host to chunk
their responses.

Thus, to improve interoperability, chunk at the HTTP layer like
other PSGI servers do.  I'm chosing a more syscall-intensive method
(via multiple send(...MSG_MORE) for now to reduce copy + packet
overhead.

diff --git a/examples/public-inbox.psgi b/examples/public-inbox.psgi
index 876fc76226d651d60dbe2901f89332fabcfd0f06..4edbf5e369914f3f12334b5aa4afa5f14f5bce4a 100644 (file)
--- a/examples/public-inbox.psgi
+++ b/examples/public-inbox.psgi
@@ -12,11 +12,6 @@ PublicInbox::WWW->preload;
 use Plack::Builder;
 my $www = PublicInbox::WWW->new;
 builder {
-       # Chunked middleware conflicts with Starman:
-       # https://github.com/miyagawa/Starman/issues/23
-       # However, it is strongly recommended to enable it if using
-       # public-inbox-httpd to allow persistent connections
-       # enable 'Chunked';
        eval {
                enable 'Deflater',
                        content_type => [ qw(

diff --git a/lib/PublicInbox/HTTP.pm b/lib/PublicInbox/HTTP.pm
index 480800bd90b00c51a747bf4cd3a0ff1957ab4f7e..77b178c07e6fea56cfe47c9b95a7358499f91088 100644 (file)
--- a/lib/PublicInbox/HTTP.pm
+++ b/lib/PublicInbox/HTTP.pm
@@ -180,12 +180,19 @@ sub response_header_write {
 
        my $conn = $env->{HTTP_CONNECTION} || '';
        my $term = defined($len) || $chunked;
-       my $alive = $term &&
-                       (($proto eq 'HTTP/1.1' && $conn !~ /\bclose\b/i) ||
-                        ($conn =~ /\bkeep-alive\b/i));
-
-       $h .= 'Connection: ' . ($alive ? 'keep-alive' : 'close');
-       $h .= "\r\nDate: " . http_date() . "\r\n\r\n";
+       my $prot_persist = ($proto eq 'HTTP/1.1') && ($conn !~ /\bclose\b/i);
+       my $alive;
+       if (!$term && $prot_persist) { # auto-chunk
+               $chunked = $alive = 2;
+               $h .= "Transfer-Encoding: chunked\r\n";
+               # no need for "Connection: keep-alive" with HTTP/1.1
+       } elsif ($term && ($prot_persist || ($conn =~ /\bkeep-alive\b/i))) {
+               $alive = 1;
+               $h .= "Connection: keep-alive\r\n";
+       } else {
+               $h .= "Connection: close\r\n";
+       }
+       $h .= 'Date: ' . http_date() . "\r\n\r\n";
 
        if (($len || $chunked) && $env->{REQUEST_METHOD} ne 'HEAD') {
                more($self, $h);
@@ -195,13 +202,29 @@ sub response_header_write {
        $alive;
 }
 
+# middlewares such as Deflater may write empty strings
+sub chunked_wcb ($) {
+       my ($self) = @_;
+       sub {
+               return if $_[0] eq '';
+               more($self, sprintf("%x\r\n", bytes::length($_[0])));
+               more($self, $_[0]);
+               $self->write("\r\n");
+       }
+}
+
+sub identity_wcb ($) {
+       my ($self) = @_;
+       sub { $self->write(\($_[0])) if $_[0] ne '' }
+}
+
 sub response_write {
        my ($self, $env, $res) = @_;
        my $alive = response_header_write($self, $env, $res);
 
-       # middlewares such as Deflater may write empty strings
-       my $write = sub { $self->write(\($_[0])) if $_[0] ne '' };
+       my $write = $alive == 2 ? chunked_wcb($self) : identity_wcb($self);
        my $close = sub {
+               $self->write("0\r\n\r\n") if $alive == 2;
                if ($alive) {
                        $self->event_write; # watch for readability if done
                } else {

diff --git a/script/public-inbox-httpd b/script/public-inbox-httpd
index b29effcccb4ff25c3966de527b271e92253cbaa3..f19582fafc600ccea7730ed98f45533ff8381ad6 100755 (executable)
--- a/script/public-inbox-httpd
+++ b/script/public-inbox-httpd
@@ -25,7 +25,6 @@ my $refresh = sub {
                PublicInbox::WWW->preload;
                my $www = PublicInbox::WWW->new;
                $app = builder {
-                       enable 'Chunked';
                        eval {
                                enable 'Deflater',
                                        content_type => [ qw(

diff --git a/t/git-http-backend.psgi b/t/git-http-backend.psgi
index 8cec7d35365b69ac1fd42fedbd585c92df0e39e3..c9607143e636a70a298e6072f5414912b496969a 100644 (file)
--- a/t/git-http-backend.psgi
+++ b/t/git-http-backend.psgi
@@ -11,7 +11,6 @@ use BSD::Resource qw(getrusage);
 my $git_dir = $ENV{GIANT_GIT_DIR} or die 'GIANT_GIT_DIR not defined in env';
 my $git = PublicInbox::Git->new($git_dir);
 builder {
-       enable 'Chunked' if $ENV{TEST_CHUNK};
        enable 'Head';
        sub {
                my ($env) = @_;