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From: Eric Wong <e@80x24.org>
To: meta@public-inbox.org
Subject: [PATCH 3/3] http: remove weaken usage, reduce anonsub capture scope
Date: Wed,  4 Jan 2017 11:20:51 +0000
Message-Id: <20170104112051.6804-4-e@80x24.org>
In-Reply-To: <20170104112051.6804-1-e@80x24.org>
References: <20170104112051.6804-1-e@80x24.org>
List-Id: <meta@public-inbox.org>

Avoiding weaken here is no more dangerous than the existing
circular refs (e.g. psgix.io) we create and manage throughout
the lifetime of the connection.  So, trust ourselves to maintain
the data structure properly and avoid triggering extra memory
usage.

While we're at it, avoid having anonymous subroutines capture
more variables than necessary to simplify reference auditing.
---
 lib/PublicInbox/HTTP.pm | 25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/lib/PublicInbox/HTTP.pm b/lib/PublicInbox/HTTP.pm
index 03ce4fe..3530f8b 100644
--- a/lib/PublicInbox/HTTP.pm
+++ b/lib/PublicInbox/HTTP.pm
@@ -16,7 +16,6 @@ use Fcntl qw(:seek);
 use Plack::HTTPParser qw(parse_http_request); # XS or pure Perl
 use HTTP::Status qw(status_message);
 use HTTP::Date qw(time2str);
-use Scalar::Util qw(weaken);
 use IO::Handle;
 use constant {
 	CHUNK_START => -1,   # [a-f0-9]+\r\n
@@ -237,12 +236,14 @@ sub next_request ($) {
 	}
 }
 
-sub response_done ($$) {
+sub response_done_cb ($$) {
 	my ($self, $alive) = @_;
-	my $env = $self->{env};
-	$self->{env} = undef;
-	$self->write("0\r\n\r\n") if $alive == 2;
-	$self->write(sub { $alive ? next_request($self) : $self->close });
+	sub {
+		my $env = $self->{env};
+		$self->{env} = undef;
+		$self->write("0\r\n\r\n") if $alive == 2;
+		$self->write(sub{$alive ? next_request($self) : $self->close});
+	}
 }
 
 sub getline_cb ($$$) {
@@ -283,10 +284,8 @@ sub getline_cb ($$$) {
 	$close->();
 }
 
-sub getline_response {
-	my ($self, $body, $write, $close) = @_;
-	$self->{forward} = $body;
-	weaken($self);
+sub getline_response ($$$) {
+	my ($self, $write, $close) = @_;
 	my $pull = $self->{pull} = sub { getline_cb($self, $write, $close) };
 	$pull->();
 }
@@ -294,15 +293,15 @@ sub getline_response {
 sub response_write {
 	my ($self, $env, $res) = @_;
 	my $alive = response_header_write($self, $env, $res);
-
+	my $close = response_done_cb($self, $alive);
 	my $write = $alive == 2 ? chunked_wcb($self) : identity_wcb($self);
-	my $close = sub { response_done($self, $alive) };
 	if (defined(my $body = $res->[2])) {
 		if (ref $body eq 'ARRAY') {
 			$write->($_) foreach @$body;
 			$close->();
 		} else {
-			getline_response($self, $body, $write, $close);
+			$self->{forward} = $body;
+			getline_response($self, $write, $close);
 		}
 	} else {
 		# this is returned to the calling application:
-- 
EW