nntp: rework and simplify art_lookup response

We don't need some of the array elements returned from
art_lookup, anymore (and haven't used them in years).

We can also shorten the lifetime of the Email::Simple object by
relying on the fact Email::Simple->new will modify it's arg if
given a SCALARREF and allow us to avoid Email::Simple::body
calls.

Unfortunately, this doesn't seem to provide any noticeable
improvement in memory usage when dealing with a 30+ MB test
message, since our previous use of ->body_set('') was saving
some memory, but forcing a LF-only body to be CRLF was making
Perl allocate extra space for s///sg.

1 files changed, 22 insertions, 25 deletions

diff --git a/lib/PublicInbox/NNTP.pm b/lib/PublicInbox/NNTP.pm
index 53e18281..30d3dab6 100644
--- a/lib/PublicInbox/NNTP.pm
+++ b/lib/PublicInbox/NNTP.pm
@@ -510,24 +510,21 @@ find_mid:
 found:
         my $smsg = $ng->over->get_art($n) or return $err;
         my $msg = $ng->msg_by_smsg($smsg) or return $err;
-        my $s = Email::Simple->new($msg);
-        if ($set_headers) {
-                set_nntp_headers($self, $s->header_obj, $ng, $n, $mid);
 
-                # must be last
-                $s->body_set('') if ($set_headers == 2);
-        }
-        [ $n, $mid, $s, $smsg->bytes, $smsg->lines, $ng ];
+        # Email::Simple->new will modify $msg in-place as documented
+        # in its manpage, so what's left is the body and we won't need
+        # to call Email::Simple::body(), later
+        my $hdr = Email::Simple->new($msg)->header_obj;
+        set_nntp_headers($self, $hdr, $ng, $n, $mid) if $set_headers;
+        [ $n, $mid, $msg, $hdr ];
 }
 
-sub simple_body_write ($$) {
-        my ($self, $s) = @_;
-        my $body = $s->body;
-        $s->body_set('');
-        $body =~ s/^\./../smg;
-        $body =~ s/(?<!\r)\n/\r\n/sg;
-        msg_more($self, $body);
-        msg_more($self, "\r\n") unless $body =~ /\r\n\z/s;
+sub msg_body_write ($$) {
+        my ($self, $msg) = @_;
+        $$msg =~ s/^\./../smg;
+        $$msg =~ s/(?<!\r)\n/\r\n/sg;
+        msg_more($self, $$msg);
+        msg_more($self, "\r\n") unless $$msg =~ /\r\n\z/s;
         '.'
 }
 
@@ -537,7 +534,7 @@ sub set_art {
 }
 
 sub _header ($) {
-        my $hdr = $_[0]->header_obj->as_string;
+        my $hdr = $_[0]->as_string;
         utf8::encode($hdr);
         $hdr =~ s/(?<!\r)\n/\r\n/sg;
 
@@ -554,22 +551,22 @@ sub cmd_article ($;$) {
         my ($self, $art) = @_;
         my $r = art_lookup($self, $art, 1);
         return $r unless ref $r;
-        my ($n, $mid, $s) = @$r;
+        my ($n, $mid, $msg, $hdr) = @$r;
         set_art($self, $art);
         more($self, "220 $n <$mid> article retrieved - head and body follow");
-        msg_more($self, _header($s));
+        msg_more($self, _header($hdr));
         msg_more($self, "\r\n");
-        simple_body_write($self, $s);
+        msg_body_write($self, $msg);
 }
 
 sub cmd_head ($;$) {
         my ($self, $art) = @_;
         my $r = art_lookup($self, $art, 2);
         return $r unless ref $r;
-        my ($n, $mid, $s) = @$r;
+        my ($n, $mid, undef, $hdr) = @$r;
         set_art($self, $art);
         more($self, "221 $n <$mid> article retrieved - head follows");
-        msg_more($self, _header($s));
+        msg_more($self, _header($hdr));
         '.'
 }
 
@@ -577,17 +574,17 @@ sub cmd_body ($;$) {
         my ($self, $art) = @_;
         my $r = art_lookup($self, $art, 0);
         return $r unless ref $r;
-        my ($n, $mid, $s) = @$r;
+        my ($n, $mid, $msg) = @$r;
         set_art($self, $art);
         more($self, "222 $n <$mid> article retrieved - body follows");
-        simple_body_write($self, $s);
+        msg_body_write($self, $msg);
 }
 
 sub cmd_stat ($;$) {
         my ($self, $art) = @_;
         my $r = art_lookup($self, $art, 0);
         return $r unless ref $r;
-        my ($n, $mid, undef) = @$r;
+        my ($n, $mid) = @$r;
         set_art($self, $art);
         "223 $n <$mid> article retrieved - request text separately";
 }
@@ -815,7 +812,7 @@ sub hdr_mid_prefix ($$$$$) {
 }
 
 sub hdr_mid_response ($$$$$$) {
-        my ($self, $xhdr, $ng, $n, $mid, $v) = @_; # r: art_lookup result
+        my ($self, $xhdr, $ng, $n, $mid, $v) = @_;
         my $res = '';
         if ($xhdr) {
                 $res .= r221 . "\r\n";