imap: remove non-UID SEARCH for now

Supporting MSNs in long-lived connections beyond the lifetime of
a single request/response cycle is not scalable to a C10K
scenario.  It's probably not needed, since most clients seem to
use UIDs.

A somewhat efficient implementation I can come up uses
pack("S*" ...) (AKA "uint16_t mapping[50000]") has an overhead
of 100K per-client socket on a mailbox with 50K messages.  The
100K is a contiguous scalar, so it could be swapped out for
idle clients on most architectures if THP is disabled.

An alternative could be to use a tempfile as an allocator
partitioned into 100K chunks (or SQLite); but I'll only do that
if somebody presents a compelling case to support MSN SEARCH.

diff --git a/lib/PublicInbox/IMAP.pm b/lib/PublicInbox/IMAP.pm
index 1ba3a3ff1bb7cbb883cb1b85f462ab77ee94aa9c..7efe538764683deaec7400a9b9e2eff892d80a6c 100644 (file)
--- a/lib/PublicInbox/IMAP.pm
+++ b/lib/PublicInbox/IMAP.pm
@@ -986,21 +986,14 @@ sub parse_date ($) { # 02-Oct-1993
        timegm(0, 0, 0, $dd, $mm, $yyyy);
 }
 
-sub msn_convert ($$) {
-       my ($self, $uids) = @_;
-       my $adj = $self->{uid_base};
-       $_ -= $adj for @$uids;
-}
-
 sub search_uid_range { # long_response
-       my ($self, $tag, $sql, $range_info, $want_msn) = @_;
+       my ($self, $tag, $sql, $range_info) = @_;
        my $uids = [];
        if (defined(my $err = refill_uids($self, $uids, $range_info, $sql))) {
                $err ||= 'OK Search done';
                $self->write("\r\n$tag $err\r\n");
                return;
        }
-       msn_convert($self, $uids) if $want_msn;
        $self->msg_more(join(' ', '', @$uids));
        1; # more
 }
@@ -1162,46 +1155,38 @@ sub refill_xap ($$$$) {
 }
 
 sub search_xap_range { # long_response
-       my ($self, $tag, $q, $range_info, $want_msn) = @_;
+       my ($self, $tag, $q, $range_info) = @_;
        my $uids = [];
        if (defined(my $err = refill_xap($self, $uids, $range_info, $q))) {
                $err ||= 'OK Search done';
                $self->write("\r\n$tag $err\r\n");
                return;
        }
-       msn_convert($self, $uids) if $want_msn;
        $self->msg_more(join(' ', '', @$uids));
        1; # more
 }
 
-sub search_common {
-       my ($self, $tag, $rest, $want_msn) = @_;
+sub cmd_uid_search ($$$;) {
+       my ($self, $tag) = splice(@_, 0, 2);
        my $ibx = $self->{ibx} or return "$tag BAD No mailbox selected\r\n";
-       my $q = parse_query($self, $rest);
+       my $q = parse_query($self, \@_);
        return "$tag $q\r\n" if !ref($q);
        my ($sql, $range_info) = delete @$q{qw(sql range_info)};
        if (!scalar(keys %$q)) { # overview.sqlite3
                $self->msg_more('* SEARCH');
                long_response($self, \&search_uid_range,
-                               $tag, $sql, $range_info, $want_msn);
+                               $tag, $sql, $range_info);
        } elsif ($q = $q->{xap}) {
                $self->msg_more('* SEARCH');
                long_response($self, \&search_xap_range,
-                               $tag, $q, $range_info, $want_msn);
+                               $tag, $q, $range_info);
        } else {
                "$tag BAD Error\r\n";
        }
 }
 
-sub cmd_uid_search ($$$;) {
-       my ($self, $tag) = splice(@_, 0, 2);
-       search_common($self, $tag, \@_);
-}
-
-sub cmd_search ($$$;) {
-       my ($self, $tag) = splice(@_, 0, 2);
-       search_common($self, $tag, \@_, 1);
-}
+# note: MSN SEARCH is NOT supported.  Do any widely-used MUAs
+# rely on MSNs from SEARCH results?  Let us know at meta@public-inbox.org
 
 sub args_ok ($$) { # duplicated from PublicInbox::NNTP
        my ($cb, $argc) = @_;

diff --git a/t/imapd.t b/t/imapd.t
index c7e0baaa10b18d3cbfbe5593afebbffccf0fccb8..f5ca8b7eb03b2735be8c6cc5c56ddff7c0045014 100644 (file)
--- a/t/imapd.t
+++ b/t/imapd.t
@@ -360,43 +360,6 @@ is(scalar keys %$ret, 3, 'got all 3 messages with comma-separated sequence');
 $ret = $mic->fetch_hash('1:*', 'RFC822') or BAIL_OUT "FETCH $@";
 is(scalar keys %$ret, 3, 'got all 3 messages');
 
-SKIP: {
-       # do any clients use non-UID IMAP SEARCH?
-       skip 'Xapian missing', 2 if $level eq 'basic';
-       my $x = $mic->search('all');
-       is_deeply($x, [1, 2, 3], 'MSN SEARCH works before rm');
-       $x = $mic->search(qw(header subject embedded));
-       is_deeply($x, [2], 'MSN SEARCH on Subject works before rm');
-}
-
-{
-       my $rdr = { 0 => \($ret->{1}->{RFC822}) };
-       my $env = { HOME => $ENV{HOME} };
-       my @cmd = qw(-learn rm --all);
-       run_script(\@cmd, $env, $rdr) or BAIL_OUT('-learn rm');
-}
-
-SKIP: {
-       # do any clients use non-UID IMAP SEARCH?  We only ensure
-       # MSN "SEARCH" can return a result which can be retrieved
-       # via MSN "FETCH"
-       skip 'Xapian missing', 3 if $level eq 'basic';
-       my $x = $mic->search(qw(header subject embedded));
-       is(scalar(@$x), 1, 'MSN SEARCH on Subject works after rm');
-       $x = $mic->message_string($x->[0]);
-       is($x, $ret->{2}->{RFC822}, 'message 2 unchanged');
-}
-
-my $r2 = $mic->fetch_hash('1:*', 'BODY.PEEK[]') or BAIL_OUT "FETCH $@";
-is(scalar keys %$r2, 2, 'did not get all 3 messages');
-is($r2->{1}->{'BODY[]'}, $ret->{2}->{RFC822}, 'message 2 unchanged');
-is($r2->{2}->{'BODY[]'}, $ret->{3}->{RFC822}, 'message 3 unchanged');
-$r2 = $mic->fetch_hash(2, 'BODY.PEEK[HEADER.FIELDS (message-id)]')
-                       or BAIL_OUT "FETCH $@";
-is($r2->{2}->{'BODY[HEADER.FIELDS (MESSAGE-ID)]'},
-       'Message-ID: <20200418222508.GA13918@dcvr>'."\r\n\r\n",
-       'BODY.PEEK[HEADER.FIELDS ...] drops .PEEK');
-
 {
        my @new_list = $mic->list;
        # tag differs in [-1]