* [PATCH 0/2] http: remove most anonymous subs
@ 2019-12-21 23:53 Eric Wong
2019-12-21 23:53 ` [PATCH 1/2] http: get rid of anonymous subs for write/close Eric Wong
2019-12-21 23:53 ` [PATCH 2/2] http: avoid anonymous sub for getline callback Eric Wong
0 siblings, 2 replies; 3+ messages in thread
From: Eric Wong @ 2019-12-21 23:53 UTC (permalink / raw)
To: meta
subroutine allocation costs several thousand kilobytes every
response and their (temporary) self-referential usage increases
the likelyhood of memory leaks.
The only remaining anonymous sub in HTTP.pm is required by the
PSGI interface for push responses (e.g. Qspawn).
Eric Wong (2):
http: get rid of anonymous subs for write/close callbacks
http: avoid anonymous sub for getline callback
lib/PublicInbox/HTTP.pm | 160 +++++++++++++++++++++++-----------------
1 file changed, 92 insertions(+), 68 deletions(-)
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH 1/2] http: get rid of anonymous subs for write/close
2019-12-21 23:53 [PATCH 0/2] http: remove most anonymous subs Eric Wong
@ 2019-12-21 23:53 ` Eric Wong
2019-12-21 23:53 ` [PATCH 2/2] http: avoid anonymous sub for getline callback Eric Wong
1 sibling, 0 replies; 3+ messages in thread
From: Eric Wong @ 2019-12-21 23:53 UTC (permalink / raw)
To: meta
Each sub costs us several kilobytes of memory for every
response we make. An arrayref only costs 80 bytes on
64-bit, so bless that to packages with appropriate ->write
and ->close methods.
---
lib/PublicInbox/HTTP.pm | 91 ++++++++++++++++++++++++++---------------
1 file changed, 59 insertions(+), 32 deletions(-)
diff --git a/lib/PublicInbox/HTTP.pm b/lib/PublicInbox/HTTP.pm
index 53d50836..ad1a2f9f 100644
--- a/lib/PublicInbox/HTTP.pm
+++ b/lib/PublicInbox/HTTP.pm
@@ -222,22 +222,20 @@ sub response_header_write {
}
# middlewares such as Deflater may write empty strings
-sub chunked_wcb ($) {
- my ($self) = @_;
- sub {
- return if $_[0] eq '';
- msg_more($self, sprintf("%x\r\n", bytes::length($_[0])));
- msg_more($self, $_[0]);
-
- # use $self->write(\"\n\n") if you care about real-time
- # streaming responses, public-inbox WWW does not.
- msg_more($self, "\r\n");
- }
+sub chunked_write ($$) {
+ my $self = $_[0];
+ return if $_[1] eq '';
+ msg_more($self, sprintf("%x\r\n", bytes::length($_[1])));
+ msg_more($self, $_[1]);
+
+ # use $self->write(\"\n\n") if you care about real-time
+ # streaming responses, public-inbox WWW does not.
+ msg_more($self, "\r\n");
}
-sub identity_wcb ($) {
- my ($self) = @_;
- sub { $self->write(\($_[0])) if $_[0] ne '' }
+sub identity_write ($$) {
+ my $self = $_[0];
+ $self->write(\($_[1])) if $_[1] ne '';
}
sub next_request ($) {
@@ -251,17 +249,16 @@ sub next_request ($) {
}
}
-sub response_done_cb ($$) {
+sub response_done {
my ($self, $alive) = @_;
- sub {
- delete $self->{env}; # we're no longer busy
- $self->write(\"0\r\n\r\n") if $alive == 2;
- $self->write($alive ? \&next_request : \&close);
- }
+ delete $self->{env}; # we're no longer busy
+ $self->write(\"0\r\n\r\n") if $alive == 2;
+ $self->write($alive ? \&next_request : \&close);
}
-sub getline_response ($$$) {
- my ($self, $write, $close) = @_;
+sub getline_response ($$) {
+ my ($self, $alive) = @_;
+ my $write = $alive == 2 ? \&chunked_write : \&identity_write;
my $pull; # DANGER: self-referential
$pull = sub {
my $forward = $self->{forward};
@@ -273,13 +270,14 @@ sub getline_response ($$$) {
} if $forward;
if (defined $buf) {
- $write->($buf); # may close in PublicInbox::DS::write
+ # may close in PublicInbox::DS::write
+ $write->($self, $buf);
if ($self->{sock}) {
my $wbuf = $self->{wbuf} ||= [];
push @$wbuf, $pull;
- # wbuf may be populated by $write->($buf),
+ # wbuf may be populated by $write->(...$buf),
# no need to rearm if so:
$self->requeue if scalar(@$wbuf) == 1;
return; # likely
@@ -299,7 +297,7 @@ sub getline_response ($$$) {
}
}
$forward = undef;
- $close->(); # call response_done_cb
+ response_done($self, $alive);
};
$pull->(); # kick-off!
@@ -308,19 +306,23 @@ sub getline_response ($$$) {
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);
if (defined(my $body = $res->[2])) {
if (ref $body eq 'ARRAY') {
- $write->($_) foreach @$body;
- $close->();
+ if ($alive == 2) {
+ chunked_write($self, $_) for @$body;
+ } else {
+ identity_write($self, $_) for @$body;
+ }
+ response_done($self, $alive);
} else {
$self->{forward} = $body;
- getline_response($self, $write, $close);
+ getline_response($self, $alive);
}
+ # these are returned to the calling application:
+ } elsif ($alive == 2) {
+ bless [ $self, $alive ], 'PublicInbox::HTTP::Chunked';
} else {
- # this is returned to the calling application:
- Plack::Util::inline_object(write => $write, close => $close);
+ bless [ $self, $alive ], 'PublicInbox::HTTP::Identity';
}
}
@@ -466,4 +468,29 @@ sub busy () {
($self->{rbuf} || $self->{env} || $self->{wbuf});
}
+# Chunked and Identity packages are used for writing responses.
+# They may be exposed to the PSGI application when the PSGI app
+# returns a CODE ref for "push"-based responses
+package PublicInbox::HTTP::Chunked;
+use strict;
+
+sub write {
+ # ([$http], $buf) = @_;
+ PublicInbox::HTTP::chunked_write($_[0]->[0], $_[1])
+}
+
+sub close {
+ # $_[0] = [$http, $alive]
+ PublicInbox::HTTP::response_done(@{$_[0]});
+}
+
+package PublicInbox::HTTP::Identity;
+use strict;
+our @ISA = qw(PublicInbox::HTTP::Chunked);
+
+sub write {
+ # ([$http], $buf) = @_;
+ PublicInbox::HTTP::identity_write($_[0]->[0], $_[1]);
+}
+
1;
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH 2/2] http: avoid anonymous sub for getline callback
2019-12-21 23:53 [PATCH 0/2] http: remove most anonymous subs Eric Wong
2019-12-21 23:53 ` [PATCH 1/2] http: get rid of anonymous subs for write/close Eric Wong
@ 2019-12-21 23:53 ` Eric Wong
1 sibling, 0 replies; 3+ messages in thread
From: Eric Wong @ 2019-12-21 23:53 UTC (permalink / raw)
To: meta
We can avoid the danger of self-referential subs entirely for
code internal to PublicInbox::HTTP.
This change was only made possible by
commit 8e1c3155da4edc082e8e3d8b30351f0c861757a7
("ds: pass $self to code references")
---
lib/PublicInbox/HTTP.pm | 85 ++++++++++++++++++++---------------------
1 file changed, 41 insertions(+), 44 deletions(-)
diff --git a/lib/PublicInbox/HTTP.pm b/lib/PublicInbox/HTTP.pm
index ad1a2f9f..e350daaf 100644
--- a/lib/PublicInbox/HTTP.pm
+++ b/lib/PublicInbox/HTTP.pm
@@ -11,7 +11,7 @@ package PublicInbox::HTTP;
use strict;
use warnings;
use base qw(PublicInbox::DS);
-use fields qw(httpd env input_left remote_addr remote_port forward);
+use fields qw(httpd env input_left remote_addr remote_port forward alive);
use bytes (); # only for bytes::length
use Fcntl qw(:seek);
use Plack::HTTPParser qw(parse_http_request); # XS or pure Perl
@@ -256,51 +256,47 @@ sub response_done {
$self->write($alive ? \&next_request : \&close);
}
-sub getline_response ($$) {
- my ($self, $alive) = @_;
- my $write = $alive == 2 ? \&chunked_write : \&identity_write;
- my $pull; # DANGER: self-referential
- $pull = sub {
- my $forward = $self->{forward};
- # limit our own running time for fairness with other
- # clients and to avoid buffering too much:
- my $buf = eval {
- local $/ = \8192;
- $forward->getline;
- } if $forward;
-
- if (defined $buf) {
- # may close in PublicInbox::DS::write
- $write->($self, $buf);
-
- if ($self->{sock}) {
- my $wbuf = $self->{wbuf} ||= [];
- push @$wbuf, $pull;
-
- # wbuf may be populated by $write->(...$buf),
- # no need to rearm if so:
- $self->requeue if scalar(@$wbuf) == 1;
- return; # likely
- }
- } elsif ($@) {
- err($self, "response ->getline error: $@");
- $self->close;
+sub getline_pull {
+ my ($self) = @_;
+ my $forward = $self->{forward};
+
+ # limit our own running time for fairness with other
+ # clients and to avoid buffering too much:
+ my $buf = eval {
+ local $/ = \8192;
+ $forward->getline;
+ } if $forward;
+
+ if (defined $buf) {
+ # may close in PublicInbox::DS::write
+ if ($self->{alive} == 2) {
+ chunked_write($self, $buf);
+ } else {
+ identity_write($self, $buf);
}
- $pull = undef; # all done!
- # avoid recursion
- if (delete $self->{forward}) {
- eval { $forward->close };
- if ($@) {
- err($self, "response ->close error: $@");
- $self->close; # idempotent
- }
- }
- $forward = undef;
- response_done($self, $alive);
- };
+ if ($self->{sock}) {
+ my $wbuf = $self->{wbuf} //= [];
+ push @$wbuf, \&getline_pull;
- $pull->(); # kick-off!
+ # wbuf may be populated by {chunked,identity}_write()
+ # above, no need to rearm if so:
+ $self->requeue if scalar(@$wbuf) == 1;
+ return; # likely
+ }
+ } elsif ($@) {
+ err($self, "response ->getline error: $@");
+ $self->close;
+ }
+ # avoid recursion
+ if (delete $self->{forward}) {
+ eval { $forward->close };
+ if ($@) {
+ err($self, "response ->close error: $@");
+ $self->close; # idempotent
+ }
+ }
+ response_done($self, delete $self->{alive});
}
sub response_write {
@@ -316,7 +312,8 @@ sub response_write {
response_done($self, $alive);
} else {
$self->{forward} = $body;
- getline_response($self, $alive);
+ $self->{alive} = $alive;
+ getline_pull($self); # kick-off!
}
# these are returned to the calling application:
} elsif ($alive == 2) {
^ permalink raw reply related [flat|nested] 3+ messages in thread
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2019-12-21 23:53 [PATCH 0/2] http: remove most anonymous subs Eric Wong
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2019-12-21 23:53 ` [PATCH 2/2] http: avoid anonymous sub for getline callback Eric Wong
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