From 57af9c8d0bedafac3267b5b42f963bb8aa5c2ea1 Mon Sep 17 00:00:00 2001 From: Eric Wong Date: Thu, 7 May 2020 21:05:48 +0000 Subject: eml: pure-Perl replacement for Email::MIME Email::MIME eats memory, wastes time parsing out all the headers, and some problems can't be fixed without breaking compatibility for other projects which depend on it. Informal benchmarks show a ~2x improvement in general stats gathering scripts and ~10% improvement in HTML view rendering. We also don't need the ability to create MIME messages, just parse them and maybe drop an attachment. While this isn't the zero-copy or streaming MIME parser of my dreams; it's still an improvement in that it doesn't keep a scalar copy of the raw body around along with subparts. It also doesn't parse subparts up front, so it can also replace our uses of Email::Simple. --- lib/PublicInbox/Eml.pm | 393 ++++++++++++++++++++++++++++++++++++++++++ lib/PublicInbox/TestCommon.pm | 9 +- 2 files changed, 401 insertions(+), 1 deletion(-) create mode 100644 lib/PublicInbox/Eml.pm (limited to 'lib') diff --git a/lib/PublicInbox/Eml.pm b/lib/PublicInbox/Eml.pm new file mode 100644 index 00000000..0c23bed0 --- /dev/null +++ b/lib/PublicInbox/Eml.pm @@ -0,0 +1,393 @@ +# Copyright (C) 2020 all contributors +# License: AGPL-3.0+ +# +# Lazy MIME parser, it still slurps the full message but keeps short +# lifetimes. Unlike Email::MIME, it doesn't pre-split multipart +# messages or do any up-front parsing of headers besides splitting +# the header string from the body. +# +# Contains ideas and code from Email::Simple and Email::MIME +# (Perl Artistic License, GPL-1+) +# +# This aims to replace Email::MIME for our purposes, similar API +# but internal field names are differ if they're not 100%-compatible. +# +# Includes some proposed fixes for Email::MIME: +# - header-less sub parts - https://github.com/rjbs/Email-MIME/issues/14 +# - "0" as boundary - https://github.com/rjbs/Email-MIME/issues/63 +# +# $self = { +# bdy => scalar ref for body (may be undef), +# hdr => scalar ref for header, +# crlf => "\n" or "\r\n" (scalar, not a ref), +# +# # filled in during ->each_part +# ct => hash ref returned by parse_content_type +# } +package PublicInbox::Eml; +use strict; +use v5.10.1; +use Carp qw(croak); +use Encode qw(find_encoding decode encode); # stdlib +use Text::Wrap qw(wrap); # stdlib, we need Perl 5.6+ for $huge + +my $MIME_Header = find_encoding('MIME-Header'); + +# TODO remove these dependencies +use Email::MIME::ContentType; +use Email::MIME::Encodings; +$Email::MIME::ContentType::STRICT_PARAMS = 0; + +our $MAXPARTS = 1000; # same as SpamAssassin +our $MAXDEPTH = 20; # seems enough, Perl sucks, here +our $MAXBOUNDLEN = 2048; # same as postfix + +my $NO_ENCODE_RE = qr/\A(?:7bit|8bit|binary)[ \t]*(?:;|$)?/i; +my %DECODE_ADDRESS = map { $_ => 1 } qw(From To Cc Sender Reply-To); +my %DECODE_FULL = ( + Subject => 1, + 'Content-Description' => 1, + 'Content-Type' => 1, # not correct, but needed, oh well +); +our %STR_TYPE = (text => 1); +our %STR_SUBTYPE = (plain => 1, html => 1); + +my %re_memo; +sub re_memo ($) { + my ($k) = @_; + # Do not normalize $k with lc/uc; instead strive to keep + # capitalization in our codebase consistent. + $re_memo{$k} ||= qr/^\Q$k\E:[ \t]*([^\n]*\r?\n # 1st line + # continuation lines: + (?:[^:\n]*?[ \t]+[^\n]*\r?\n)*) + /ismx +} + +# compatible with our uses of Email::MIME +sub new { + my $ref = ref($_[1]) ? $_[1] : \(my $cpy = $_[1]); + if ($$ref =~ /(?:\r?\n(\r?\n))/gs) { # likely + # This can modify $$ref in-place and to avoid memcpy/memmove + # on a potentially large $$ref. It does need to make a + # copy for $hdr, though. Idea stolen from Email::Simple + my $hdr = substr($$ref, 0, pos($$ref), ''); # sv_chop on $$ref + substr($hdr, -(length($1))) = ''; # lower SvCUR + bless { hdr => \$hdr, crlf => $1, bdy => $ref }, __PACKAGE__; + } elsif ($$ref =~ /^[a-z0-9-]+[ \t]*:/ims && $$ref =~ /(\r?\n)\z/s) { + # body is optional :P + bless { hdr => \($$ref), crlf => $1 }, __PACKAGE__; + } else { # nothing useful + my $hdr = $$ref = ''; + bless { hdr => \$hdr, crlf => "\n" }, __PACKAGE__; + } +} + +sub new_sub { + my (undef, $ref) = @_; + # special case for messages like <85k5su9k59.fsf_-_@lola.goethe.zz> + $$ref =~ /\A(?:(\r?\n))/gs or goto &new; + my $hdr = substr($$ref, 0, pos($$ref), ''); # sv_chop on $$ref + bless { hdr => \$hdr, crlf => $1, bdy => $ref }, __PACKAGE__; +} + +# same output as Email::Simple::Header::header_raw, but we extract +# headers on-demand instead of parsing them into a list which +# requires O(n) lookups anyways +sub header_raw { + my $re = re_memo($_[1]); + my @v = (${ $_[0]->{hdr} } =~ /$re/g); + for (@v) { + # for compatibility w/ Email::Simple::Header, + s/\s+\z//s; + s/\A\s+//s; + s/\r?\n[ \t]*/ /gs; + } + wantarray ? @v : $v[0]; +} + +# pick the first Content-Type header to match Email::MIME behavior. +# It's usually the right one based on historical archives. +sub ct ($) { + # Email::MIME::ContentType::content_type: + $_[0]->{ct} //= parse_content_type(header($_[0], 'Content-Type')); +} + +sub body_decode ($$) { + my $cte = header_raw($_[0], 'Content-Transfer-Encoding'); + ($cte) = ($cte =~ /([a-zA-Z0-9\-]+)/) if $cte; # For S/MIME, etc + (!$cte || $cte =~ $NO_ENCODE_RE) ? + $_[1] : Email::MIME::Encodings::decode($cte, $_[1], '7bit'); +} + +# returns a queue of sub-parts iff it's worth descending into +# TODO: descend into message/rfc822 parts (Email::MIME didn't) +sub mp_descend ($$) { + my ($self, $nr) = @_; # or $once for top-level + my $bnd = ct($self)->{attributes}->{boundary} // return; # single-part + return if $bnd eq '' || length($bnd) >= $MAXBOUNDLEN; + $bnd = quotemeta($bnd); + + # "multipart" messages can exist w/o a body + my $bdy = ($nr ? delete($self->{bdy}) : \(body_raw($self))) or return; + + # Cut at the the first epilogue, not subsequent ones. + # *sigh* just the regexp match alone seems to bump RSS by + # length($$bdy) on a ~30M string: + $$bdy =~ /((?:\r?\n)?^--$bnd--[ \t]*\r?$)/gsm and + substr($$bdy, pos($$bdy) - length($1)) = ''; + + # *Sigh* split() doesn't work in-place and return CoW strings + # because Perl wants to "\0"-terminate strings. So split() + # again bumps RSS by length($$bdy) + + # Quiet warning for "Complex regular subexpression recursion limit" + # in case we get many empty parts, it's harmless in this case + no warnings 'regexp'; + my ($pre, @parts) = split(/(?:\r?\n)?(?:^--$bnd[ \t]*\r?\n)+/ms, + $$bdy, + # + 3 since we don't want the last part + # processed to include any other excluded + # parts ($nr starts at 1, and I suck at math) + $MAXPARTS + 3 - $nr); + + if (@parts) { # the usual path if we got this far: + undef $bdy; # release memory ASAP if $nr > 0 + @parts = grep /[^ \t\r\n]/s, @parts; # ignore empty parts + + # Keep "From: someone..." from preamble in old, + # buggy versions of git-send-email, otherwise drop it + # There's also a case where quoted text showed up in the + # preamble + # <20060515162817.65F0F1BBAE@citi.umich.edu> + unshift(@parts, $pre) if $pre =~ /:/s; + return \@parts; + } + # "multipart", but no boundary found, treat as single part + $self->{bdy} //= $bdy; + undef; +} + +# $p = [ \@parts, $depth, $idx ] +# $idx[0] grows as $depth grows, $idx[1] == $p->[-1] == current part +# (callers need to be updated) +# \@parts is a queue which empties when we're done with a parent part + +# same usage as PublicInbox::MsgIter::msg_iter +# $cb - user-supplied callback sub +# $arg - user-supplied arg (think pthread_create) +# $once - unref body scalar during iteration +sub each_part { + my ($self, $cb, $arg, $once) = @_; + my $p = mp_descend($self, $once // 0) or + return $cb->([$self, 0, 0], $arg); + $p = [ $p, 0 ]; + my @s; # our virtual stack + my $nr = 0; + while ((scalar(@{$p->[0]}) || ($p = pop @s)) && ++$nr <= $MAXPARTS) { + ++$p->[-1]; # bump index + my (undef, @idx) = @$p; + @idx = (join('.', @idx)); + my $depth = ($idx[0] =~ tr/././) + 1; + my $sub = new_sub(undef, \(shift @{$p->[0]})); + if ($depth < $MAXDEPTH && (my $nxt = mp_descend($sub, $nr))) { + push(@s, $p) if scalar @{$p->[0]}; + $p = [ $nxt, @idx, 0 ]; + } else { # a leaf node + $cb->([$sub, $depth, @idx], $arg); + } + } +} + +########### compatibility section for existing Email::MIME uses ######### + +sub header_obj { + bless { hdr => $_[0]->{hdr}, crlf => $_[0]->{crlf} }, __PACKAGE__; +} + +sub subparts { + my ($self) = @_; + my $parts = mp_descend($self, 0) or return (); + my $bnd = ct($self)->{attributes}->{boundary} // die 'BUG: no boundary'; + my $bdy = $self->{bdy}; + if ($$bdy =~ /\A(.*?)(?:\r?\n)?^--\Q$bnd\E[ \t]*\r?$/sm) { + $self->{preamble} = $1; + } + if ($$bdy =~ /^--\Q$bnd\E--[ \t]*\r?\n(.+)\z/sm) { + $self->{epilogue} = $1; + } + map { new_sub(undef, \$_) } @$parts; +} + +sub parts_set { + my ($self, $parts) = @_; + + # we can't fully support what Email::MIME does, + # just what our filter code needs: + my $bnd = ct($self)->{attributes}->{boundary} // die <parts_set not supported for single-part messages +EOF + my $crlf = $self->{crlf}; + my $fin_bnd = "$crlf--$bnd--$crlf"; + $bnd = "$crlf--$bnd$crlf"; + ${$self->{bdy}} = join($bnd, + delete($self->{preamble}) // '', + map { $_->as_string } @$parts + ) . + $fin_bnd . + (delete($self->{epilogue}) // ''); + undef; +} + +sub body_set { + my ($self, $body) = @_; + my $bdy = $self->{bdy} = ref($body) ? $body : \$body; + my $cte = header_raw($self, 'Content-Transfer-Encoding'); + if ($cte && $cte !~ $NO_ENCODE_RE) { + $$bdy = Email::MIME::Encodings::encode($cte, $$bdy) + } + undef; +} + +sub body_str_set { + my ($self, $body_str) = @_; + my $charset = ct($self)->{attributes}->{charset} or + Carp::confess('body_str was given, but no charset is defined'); + body_set($self, \(encode($charset, $body_str, Encode::FB_CROAK))); +} + +sub content_type { scalar header($_[0], 'Content-Type') } + +# we only support raw header_set +sub header_set { + my ($self, $pfx, @vals) = @_; + my $re = re_memo($pfx); + my $hdr = $self->{hdr}; + return $$hdr =~ s!$re!!g if !@vals; + $pfx .= ': '; + my $len = 78 - length($pfx); + @vals = map {; + # folding differs from Email::Simple::Header, + # we favor tabs for visibility (and space savings :P) + if (length($_) >= $len && (/\n[^ \t]/s || !/\n/s)) { + local $Text::Wrap::columns = $len; + local $Text::Wrap::huge = 'overflow'; + $pfx . wrap('', "\t", $_) . $self->{crlf}; + } else { + $pfx . $_ . $self->{crlf}; + } + } @vals; + $$hdr =~ s!$re!shift(@vals) // ''!ge; # replace current headers, first + $$hdr .= join('', @vals); # append any leftovers not replaced + # wantarray ? @_[2..$#_] : $_[2]; # Email::Simple::Header compat + undef; # we don't care for the return value +} + +# note: we only call this method on Subject +sub header_str_set { + my ($self, $name, @vals) = @_; + for (@vals) { + next unless /[^\x20-\x7e]/; + utf8::encode($_); # to octets + # 39: int((75 - length("Subject: =?UTF-8?B?".'?=') ) / 4) * 3; + s/(.{1,39})/'=?UTF-8?B?'.encode_base64($1, '').'?='/ges; + } + header_set($self, $name, @vals); +} + +sub mhdr_decode ($) { eval { $MIME_Header->decode($_[0]) } // $_[0] } + +sub filename { + my $dis = header_raw($_[0], 'Content-Disposition'); + my $attrs = parse_content_disposition($dis)->{attributes}; + my $fn = $attrs->{filename}; + $fn = ct($_[0])->{attributes}->{name} if !defined($fn) || $fn eq ''; + (defined($fn) && $fn =~ /=\?/) ? mhdr_decode($fn) : $fn; +} + +sub xs_addr_str { # helper for ->header / ->header_str + for (@_) { # array from header_raw() + next unless /=\?/; + my @g = parse_email_groups($_); # [ foo => [ E::A::X, ... ] + for (my $i = 0; $i < @g; $i += 2) { + if (defined($g[$i]) && $g[$i] =~ /=\?/) { + $g[$i] = mhdr_decode($g[$i]); + } + my $addrs = $g[$i + 1]; + for my $eax (@$addrs) { + for my $m (qw(phrase comment)) { + my $v = $eax->$m; + $eax->$m(mhdr_decode($v)) if + $v && $v =~ /=\?/; + } + } + } + $_ = format_email_groups(@g); + } +} + +eval { + require Email::Address::XS; + Email::Address::XS->import(qw(parse_email_groups format_email_groups)); + 1; +} or do { + # fallback to just decoding everything, because parsing + # email addresses correctly w/o C/XS is slow + %DECODE_FULL = (%DECODE_FULL, %DECODE_ADDRESS); + %DECODE_ADDRESS = (); +}; + +*header = \&header_str; +sub header_str { + my ($self, $name) = @_; + my @v = header_raw($self, $name); + if ($DECODE_ADDRESS{$name}) { + xs_addr_str(@v); + } elsif ($DECODE_FULL{$name}) { + for (@v) { + $_ = mhdr_decode($_) if /=\?/; + } + } + wantarray ? @v : $v[0]; +} + +sub body_raw { ${$_[0]->{bdy} // \''}; } + +sub body { body_decode($_[0], body_raw($_[0])) } + +sub body_str { + my ($self) = @_; + my $ct = ct($self); + my $charset = $ct->{attributes}->{charset}; + if (!$charset) { + if ($STR_TYPE{$ct->{type}} && $STR_SUBTYPE{$ct->{subtype}}) { + return body($self); + } + Carp::confess("can't get body as a string for ", + join("\n\t", header_raw($self, 'Content-Type'))); + } + decode($charset, body($self), Encode::FB_CROAK); +} + +sub as_string { + my ($self) = @_; + my $ret = ${ $self->{hdr} }; + return $ret unless defined($self->{bdy}); + $ret .= $self->{crlf}; + $ret .= ${$self->{bdy}}; +} + +# Unlike Email::MIME::charset_set, this only changes the parsed +# representation of charset used for search indexing and HTML display. +# This does NOT affect what ->as_string returns. +sub charset_set { + ct($_[0])->{attributes}->{charset} = $_[1]; +} + +sub crlf { $_[0]->{crlf} // "\n" } + +sub willneed { re_memo($_) for @_ } + +willneed(qw(From To Cc Date Subject Content-Type In-Reply-To References + Message-ID X-Alt-Message-ID)); + +1; diff --git a/lib/PublicInbox/TestCommon.pm b/lib/PublicInbox/TestCommon.pm index cd73b5b6..600843f0 100644 --- a/lib/PublicInbox/TestCommon.pm +++ b/lib/PublicInbox/TestCommon.pm @@ -9,7 +9,7 @@ use Fcntl qw(FD_CLOEXEC F_SETFD F_GETFD :seek); use POSIX qw(dup2); use IO::Socket::INET; our @EXPORT = qw(tmpdir tcp_server tcp_connect require_git require_mods - run_script start_script key2sub xsys xqx mime_load); + run_script start_script key2sub xsys xqx mime_load eml_load); sub mime_load ($) { my ($path) = @_; @@ -17,6 +17,13 @@ sub mime_load ($) { PublicInbox::MIME->new(\(do { local $/; <$fh> })); } +sub eml_load ($) { + my ($path, $cb) = @_; + open(my $fh, '<', $path) or die "open $path: $!"; + binmode $fh; + PublicInbox::Eml->new(\(do { local $/; <$fh> })); +} + sub tmpdir (;$) { my ($base) = @_; require File::Temp; -- cgit v1.2.3-24-ge0c7