From: Eric Wong <e@yhbt.net>
To: meta@public-inbox.org
Subject: [PATCH 1/3] eml: reduce RE captures and possible side effects
Date: Sat, 9 May 2020 08:27:36 +0000 [thread overview]
Message-ID: <20200509082738.23602-2-e@yhbt.net> (raw)
In-Reply-To: <20200509082738.23602-1-e@yhbt.net>
Since Perl 5.6, the `@-' (aka @LAST_MATCH_START) and `@+' (aka
@LAST_MATCH_END) arrays provides integer offsets for every match
as documented in perlvar(1), regardless of regexp modifiers.
We can avoid relying on $1 in the epilogue scan, entirely.
So use these instead of relying on m//g and pos(), since the `g'
modifier can be affected by m//g matches performed in other
places.
Unrelated, but while we're in the area: remove some unnecessary
use of (?:...), too.
---
lib/PublicInbox/Eml.pm | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/lib/PublicInbox/Eml.pm b/lib/PublicInbox/Eml.pm
index 4508bd84..80e7c1af 100644
--- a/lib/PublicInbox/Eml.pm
+++ b/lib/PublicInbox/Eml.pm
@@ -71,11 +71,11 @@ sub re_memo ($) {
# compatible with our uses of Email::MIME
sub new {
my $ref = ref($_[1]) ? $_[1] : \(my $cpy = $_[1]);
- if ($$ref =~ /(?:\r?\n(\r?\n))/gs) { # likely
+ if ($$ref =~ /\r?\n(\r?\n)/s) { # 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 $$ref
+ my $hdr = substr($$ref, 0, $+[0], ''); # 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 && $$ref =~ /(\r?\n)\z/s) {
@@ -90,8 +90,8 @@ sub new {
sub new_sub {
my (undef, $ref) = @_;
# special case for messages like <85k5su9k59.fsf_-_@lola.goethe.zz>
- $$ref =~ /\A(?:(\r?\n))/gs or goto &new;
- my $hdr = substr($$ref, 0, pos($$ref), ''); # sv_chop on $$ref
+ $$ref =~ /\A(\r?\n)/s or goto &new;
+ my $hdr = substr($$ref, 0, $+[0], ''); # sv_chop on $$ref
bless { hdr => \$hdr, crlf => $1, bdy => $ref }, __PACKAGE__;
}
@@ -132,8 +132,8 @@ sub mp_descend ($$) {
# *sigh* just the regexp match alone seems to bump RSS by
# length($$bdy) on a ~30M string:
my $epilogue_missing;
- if ($$bdy =~ /((?:\r?\n)?^--$bnd--[ \t]*\r?$)/gsm) {
- substr($$bdy, pos($$bdy) - length($1)) = '';
+ if ($$bdy =~ /(?:\r?\n)?^--$bnd--[ \t]*\r?$/sm) {
+ substr($$bdy, $-[0]) = '';
} else {
$epilogue_missing = 1;
}
next prev parent reply other threads:[~2020-05-09 8:27 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-09 8:27 [PATCH 0/3] eml: some fixes and speedups Eric Wong
2020-05-09 8:27 ` Eric Wong [this message]
2020-05-09 8:27 ` [PATCH 2/3] eml: speed up common LF-only emails Eric Wong
2020-05-09 8:27 ` [PATCH 3/3] emlcontentfoo: quiet warning on missing attributes Eric Wong
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