[PATCH 2/2] eml: rename limits to match postfix names

[Eric Wong <e@yhbt.net>]

They're still part of our internal API at this point, but
reusing the same names as those used by postfix makes sense for
now to reduce cognitive overheads of learning new things.

There's no "mime_parts_limit", but the name is consistent
with "mime_nesting_limit".
---
 lib/PublicInbox/Eml.pm | 18 +++++++++++-------
 t/eml.t                |  4 ++--
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/lib/PublicInbox/Eml.pm b/lib/PublicInbox/Eml.pm
index 2ccbb6597de..ef401141c13 100644
--- a/lib/PublicInbox/Eml.pm
+++ b/lib/PublicInbox/Eml.pm
@@ -38,9 +38,11 @@ my $MIME_Header = find_encoding('MIME-Header');
 use PublicInbox::EmlContentFoo qw(parse_content_type parse_content_disposition);
 $PublicInbox::EmlContentFoo::STRICT_PARAMS = 0;
 
-our $MAXPARTS = 1000; # same as SpamAssassin
-our $MAXDEPTH = 20; # seems enough, Perl sucks, here
-our $MAXBOUNDLEN = 2048; # same as postfix
+our $mime_parts_limit = 1000; # same as SpamAssassin (not in postfix AFAIK)
+
+# the rest of the limit names are taken from postfix:
+our $mime_nesting_limit = 20; # seems enough, Perl sucks, here
+our $mime_boundary_length_limit = 2048; # same as postfix
 our $header_size_limit = 102400; # same as postfix
 
 my %MIME_ENC = (qp => \&enc_qp, base64 => \&encode_base64);
@@ -151,7 +153,7 @@ sub ct ($) {
 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;
+	return if $bnd eq '' || length($bnd) >= $mime_boundary_length_limit;
 	$bnd = quotemeta($bnd);
 
 	# "multipart" messages can exist w/o a body
@@ -179,7 +181,7 @@ sub mp_descend ($$) {
 				# + 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);
+				$mime_parts_limit + 3 - $nr);
 
 	if (@parts) { # the usual path if we got this far:
 		undef $bdy; # release memory ASAP if $nr > 0
@@ -218,13 +220,15 @@ sub each_part {
 	$p = [ $p, 0 ];
 	my @s; # our virtual stack
 	my $nr = 0;
-	while ((scalar(@{$p->[0]}) || ($p = pop @s)) && ++$nr <= $MAXPARTS) {
+	while ((scalar(@{$p->[0]}) || ($p = pop @s)) &&
+			++$nr <= $mime_parts_limit) {
 		++$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, $nr))) {
+		if ($depth < $mime_nesting_limit &&
+				(my $nxt = mp_descend($sub, $nr))) {
 			push(@s, $p) if scalar @{$p->[0]};
 			$p = [ $nxt, @idx, 0 ];
 		} else { # a leaf node
diff --git a/t/eml.t b/t/eml.t
index d5e8cbcbbba..c91deb3ab29 100644
--- a/t/eml.t
+++ b/t/eml.t
@@ -282,7 +282,7 @@ if ('maxparts is a feature unique to us') {
 	my @orig;
 	$eml->each_part(sub { push @orig, $_[0]->[0] });
 
-	local $PublicInbox::Eml::MAXPARTS = scalar(@orig);
+	local $PublicInbox::Eml::mime_parts_limit = scalar(@orig);
 	my $i = 0;
 	$eml->each_part(sub {
 		my $cur = $_[0]->[0];
@@ -290,7 +290,7 @@ if ('maxparts is a feature unique to us') {
 		is($cur->body_raw, $prv->body_raw, "part #$i matches");
 	});
 	is($i, scalar(@orig), 'maxparts honored');
-	$PublicInbox::Eml::MAXPARTS--;
+	$PublicInbox::Eml::mime_parts_limit--;
 	my @ltd;
 	$eml->each_part(sub { push @ltd, $_[0]->[0] });
 	for ($i = 0; $i <= $#ltd; $i++) {