ds: remove fields.pm usage

Since the removal of pseudo-hash support in Perl 5.10, the
"fields" module no longer provides the space or speed benefits
it did in 5.8.  It also does not allow for compile-time checks,
only run-time checks.

To me, the extra developer overhead in maintaining "use fields"
args has become a hassle.  None of our non-DS-related code uses
fields.pm, nor do any of our current dependencies.  In fact,
Danga::Socket (which DS was originally forked from) and its
subclasses are the only fields.pm users I've ever encountered in
the wild.  Removing fields may make our code more approachable
to other Perl hackers.

So stop using fields.pm and locked hashes, but continue to
document what fields do for non-trivial classes.

1 files changed, 11 insertions, 8 deletions

diff --git a/lib/PublicInbox/IMAP.pm b/lib/PublicInbox/IMAP.pm
index 9ad74de8..e0602143 100644
--- a/lib/PublicInbox/IMAP.pm
+++ b/lib/PublicInbox/IMAP.pm
@@ -21,12 +21,18 @@
 #   as a 50K uint16_t array (via pack("S*", ...)).  "UID offset"
 #   is the offset from {uid_base} which determines the start of
 #   the mailbox slice.
-
+#
+# fields:
+# imapd: PublicInbox::IMAPD ref
+# ibx: PublicInbox::Inbox ref
+# long_cb: long_response private data
+# uid_base: base UID for mailbox slice (0-based)
+# -login_tag: IMAP TAG for LOGIN
+# -idle_tag: IMAP response tag for IDLE
+# uo2m: UID-to-MSN mapping
 package PublicInbox::IMAP;
 use strict;
-use base qw(PublicInbox::DS);
-use fields qw(imapd ibx long_cb -login_tag
-        uid_base -idle_tag uo2m);
+use parent qw(PublicInbox::DS);
 use PublicInbox::Eml;
 use PublicInbox::EmlContentFoo qw(parse_content_disposition);
 use PublicInbox::DS qw(now);
@@ -34,7 +40,6 @@ use PublicInbox::Syscall qw(EPOLLIN EPOLLONESHOT);
 use PublicInbox::GitAsyncCat;
 use Text::ParseWords qw(parse_line);
 use Errno qw(EAGAIN);
-use Hash::Util qw(unlock_hash); # dependency of fields for perl 5.10+, anyways
 use PublicInbox::Search;
 use PublicInbox::IMAPsearchqp;
 *mdocid = \&PublicInbox::Search::mdocid;
@@ -107,8 +112,7 @@ sub greet ($) {
 
 sub new ($$$) {
         my ($class, $sock, $imapd) = @_;
-        my $self = fields::new('PublicInbox::IMAP_preauth');
-        unlock_hash(%$self);
+        my $self = bless { imapd => $imapd }, 'PublicInbox::IMAP_preauth';
         my $ev = EPOLLIN;
         my $wbuf;
         if ($sock->can('accept_SSL') && !$sock->accept_SSL) {
@@ -117,7 +121,6 @@ sub new ($$$) {
                 $wbuf = [ \&PublicInbox::DS::accept_tls_step, \&greet ];
         }
         $self->SUPER::new($sock, $ev | EPOLLONESHOT);
-        $self->{imapd} = $imapd;
         if ($wbuf) {
                 $self->{wbuf} = $wbuf;
         } else {