1 # Copyright (C) 2019 all contributors <meta@public-inbox.org>
2 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
4 # RFC 8054 NNTP COMPRESS DEFLATE implementation
6 # RSS usage for 10K idle-but-did-something NNTP clients on 64-bit:
7 # TLS + DEFLATE[a] : 1.8 GB (MemLevel=9, 1.2 GB with MemLevel=8)
8 # TLS + DEFLATE[b] : ~300MB
12 # [a] - initial implementation using per-client Deflate contexts and buffer
14 # [b] - memory-optimized implementation using a global deflate context.
15 # It's less efficient in terms of compression, but way more
16 # efficient in terms of server memory usage.
17 package PublicInbox::NNTPdeflate;
21 use base qw(PublicInbox::NNTP);
22 use Compress::Raw::Zlib;
23 use Hash::Util qw(unlock_hash); # dependency of fields for perl 5.10+, anyways
26 -Bufsize => PublicInbox::NNTP::LINE_MAX,
27 -WindowBits => -15, # RFC 1951
31 # global deflate context and buffer
32 my $zbuf = \(my $buf = '');
33 my $zout = Compress::Raw::Zlib::Deflate->new(
34 # nnrpd (INN) and Compress::Raw::Zlib favor MemLevel=9,
35 # but the zlib C library and git use MemLevel=8 as the default.
36 # FIXME: sometimes clients fail with 8, so we use 9
39 # needs more testing, nothing obviously different in terms of memory
42 -WindowBits => -15, # RFC 1951
47 my ($class, $self) = @_;
50 $self->{zin} = [ Compress::Raw::Zlib::Inflate->new(%IN_OPT), '' ];
53 # overrides PublicInbox::NNTP::compressed
56 # SUPER is PublicInbox::DS::do_read, so $_[1] may be a reference or not
58 my ($self, $rbuf, $len, $off) = @_;
60 my $zin = $self->{zin} or return; # closed
61 my $deflated = \($zin->[1]);
62 my $r = $self->SUPER::do_read($deflated, $len) or return;
64 # assert(length($$rbuf) == $off) as far as NNTP.pm is concerned
65 # -ConsumeInput is true, so $deflated is automatically emptied
66 my $err = $zin->[0]->inflate($deflated, $rbuf);
68 $r = length($$rbuf) and return $r;
69 # nothing ready, yet, get more, later
78 # override PublicInbox::DS::msg_more
82 # $_[1] may be a reference or not for ->deflate
83 my $err = $zout->deflate($_[1], $zbuf);
84 $err == Z_OK or die "->deflate failed $err";
92 $zbuf = \(my $next = '');
94 my $err = $zout->flush($deflated, Z_FULL_FLUSH);
95 $err == Z_OK or die "->flush failed $err";
97 # We can still let the lower socket layer do buffering:
98 PublicInbox::DS::msg_more($self, $$deflated);
101 # compatible with PublicInbox::DS::write, so $_[1] may be a reference or not
104 return PublicInbox::DS::write($self, $_[1]) if ref($_[1]) eq 'CODE';
106 my $deflated = $zbuf;
107 $zbuf = \(my $next = '');
109 # $_[1] may be a reference or not for ->deflate
110 my $err = $zout->deflate($_[1], $deflated);
111 $err == Z_OK or die "->deflate failed $err";
112 $err = $zout->flush($deflated, Z_FULL_FLUSH);
113 $err == Z_OK or die "->flush failed $err";
115 # We can still let the socket layer do buffering:
116 PublicInbox::DS::write($self, $deflated);