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
5 # Warning, enabling compression for C10K NNTP clients is rather
6 # expensive in terms of memory use.
8 # RSS usage for 10K idle-but-did-something NNTP clients on 64-bit:
9 # TLS + DEFLATE : 1.8 GB (MemLevel=9, 1.2 GB with MemLevel=8)
12 package PublicInbox::NNTPdeflate;
16 use base qw(PublicInbox::NNTP);
17 use Compress::Raw::Zlib;
18 use Hash::Util qw(unlock_hash); # dependency of fields for perl 5.10+, anyways
21 -Bufsize => PublicInbox::NNTP::LINE_MAX,
22 -WindowBits => -15, # RFC 1951
27 # nnrpd (INN) and Compress::Raw::Zlib favor MemLevel=9,
28 # but the zlib C library and git use MemLevel=8
29 # as the default. Using 8 drops our memory use with 10K
30 # TLS clients from 1.8 GB to 1.2 GB, but...
31 # FIXME: sometimes clients fail with 8, so we use 9
34 # needs more testing, nothing obviously different in terms of memory
37 -WindowBits => -15, # RFC 1951
42 my ($class, $self) = @_;
45 $self->{zin} = [ Compress::Raw::Zlib::Inflate->new(%IN_OPT), '' ];
46 $self->{zout} = [ Compress::Raw::Zlib::Deflate->new(%OUT_OPT), '' ];
49 # overrides PublicInbox::NNTP::compressed
52 # SUPER is PublicInbox::DS::do_read, so $_[1] may be a reference or not
54 my ($self, $rbuf, $len, $off) = @_;
56 my $zin = $self->{zin} or return; # closed
57 my $deflated = \($zin->[1]);
58 my $r = $self->SUPER::do_read($deflated, $len) or return;
60 # assert(length($$rbuf) == $off) as far as NNTP.pm is concerned
61 # -ConsumeInput is true, so $deflated is automatically emptied
62 my $err = $zin->[0]->inflate($deflated, $rbuf);
64 $r = length($$rbuf) and return $r;
65 # nothing ready, yet, get more, later
74 # override PublicInbox::DS::msg_more
77 my $zout = $self->{zout};
79 # $_[1] may be a reference or not for ->deflate
80 my $err = $zout->[0]->deflate($_[1], $zout->[1]);
81 $err == Z_OK or die "->deflate failed $err";
85 # SUPER is PublicInbox::DS::write, so $_[1] may be a reference or not
88 return $self->SUPER::write($_[1]) if ref($_[1]) eq 'CODE';
89 my $zout = $self->{zout};
90 my $deflated = pop @$zout;
92 # $_[1] may be a reference or not for ->deflate
93 my $err = $zout->[0]->deflate($_[1], $deflated);
94 $err == Z_OK or die "->deflate failed $err";
95 $err = $zout->[0]->flush($deflated, Z_PARTIAL_FLUSH);
96 $err == Z_OK or die "->flush failed $err";
98 # PublicInbox::DS::write puts partial writes into another buffer,
99 # so we can prepare the next deflate buffer:
101 $self->SUPER::write(\$deflated);