imap: require ".$UID_MIN-$UID_END" suffix

Finish up the IMAP-only portion of iterative config reloading,
which allows us to create all sub-ranges of an inbox up front.
The InboxIdler still uses ->each_inbox which will struggle with
100K inboxes.

Having messages in the top-level newsgroup name of an inbox will
still waste bandwidth for clients which want to do full syncs
once there's a rollover to a new 50K range.  So instead, make
every inbox accessible exclusively via 50K slices in the form of
"$NEWSGROUP.$UID_MIN-$UID_END".

This introduces the DummyInbox, which makes $NEWSGROUP
and every parent component a selectable, empty inbox.
This aids navigation with mutt and possibly other MUAs.

Finally, the xt/perf-imap-list maintainer test is broken, now,
so remove it.  The grep perlfunc is already proven effective,
and we'll have separate tests for mocking out ~100k inboxes.

1 files changed, 21 insertions, 43 deletions

diff --git a/lib/PublicInbox/IMAP.pm b/lib/PublicInbox/IMAP.pm
index 959dcfbe..6f64dff9 100644
--- a/lib/PublicInbox/IMAP.pm
+++ b/lib/PublicInbox/IMAP.pm
@@ -192,26 +192,23 @@ sub cmd_done ($$) {
         "$idle_tag OK Idle done\r\n";
 }
 
-sub ensure_old_ranges_exist ($$$) {
-        my ($self, $ibx, $uid_min) = @_;
-        my $groups = $self->{imapd}->{groups};
-        my $mailbox = $ibx->{newsgroup};
+sub ensure_ranges_exist ($$$) {
+        my ($imapd, $ibx, $max) = @_;
+        my $mailboxes = $imapd->{mailboxes};
+        my $mb_top = $ibx->{newsgroup};
         my @created;
-        $uid_min -= UID_BLOCK;
+        my $uid_min = UID_BLOCK * int($max/UID_BLOCK) + 1;
         my $uid_end = $uid_min + UID_BLOCK - 1;
         while ($uid_min > 0) {
-                my $sub_mailbox = "$mailbox.$uid_min-$uid_end";
-                last if exists $groups->{$sub_mailbox};
-                $groups->{$sub_mailbox} = $ibx;
+                my $sub_mailbox = "$mb_top.$uid_min-$uid_end";
+                last if exists $mailboxes->{$sub_mailbox};
+                $mailboxes->{$sub_mailbox} = $ibx;
                 $uid_end -= UID_BLOCK;
                 $uid_min -= UID_BLOCK;
                 push @created, $sub_mailbox;
         }
         return unless @created;
-        my $l = $self->{imapd}->{inboxlist};
-        grep {
-                / \Q$mailbox\E\r\n\z/ and s/\(\\HasNoChildren/\(\\HasChildren/;
-        } @$l;
+        my $l = $imapd->{inboxlist} or return;
         push @$l, map { qq[* LIST (\\HasNoChildren) "." $_\r\n] } @created;
 }
 
@@ -222,41 +219,23 @@ sub cmd_examine ($$$) {
         if ($mailbox =~ /\A(.+)\.([0-9]+)-([0-9]+)\z/) {
                 # old mail: inbox.comp.foo.$uid_min-$uid_end
                 my ($mb_top, $uid_min, $uid_end) = ($1, $2 + 0, $3 + 0);
-                $ibx = $self->{imapd}->{groups}->{lc $mb_top};
-                if (!$ibx || ($uid_end % UID_BLOCK) != 0 ||
-                                ($uid_min + UID_BLOCK - 1) != $uid_end) {
-                        return "$tag NO Mailbox doesn't exist: $mailbox\r\n";
-                }
-                $mm = $ibx->mm;
-                $max = $mm->max // 0;
 
-                # don't let users create inboxes w/ not-yet-possible range:
-                $uid_min > $max and
+                $ibx = $self->{imapd}->{mailboxes}->{lc $mailbox} or
                         return "$tag NO Mailbox doesn't exist: $mailbox\r\n";
 
-                $max = $uid_min + UID_BLOCK + 1;
+                $mm = $ibx->mm;
+                $max = $mm->max // 0;
                 $self->{uid_min} = $uid_min;
-                ensure_old_ranges_exist($self, $ibx, $uid_min);
-        } else { # current mailbox (most recent UID_BLOCK messages)
-                $ibx = $self->{imapd}->{groups}->{lc $mailbox} or
+                ensure_ranges_exist($self->{imapd}, $ibx, $max);
+                $max = $uid_end if $max > $uid_end;
+        } else { # check for dummy inboxes
+                $ibx = $self->{imapd}->{mailboxes}->{lc $mailbox} or
                         return "$tag NO Mailbox doesn't exist: $mailbox\r\n";
-
+                delete $self->{uid_min};
+                $max = 0;
                 $mm = $ibx->mm;
-                $max = $mm->max // 0;
-
-                my $uid_min = UID_BLOCK * int($max/UID_BLOCK) + 1;
-                if ($uid_min == 1) { # normal inbox with <UID_BLOCK messages
-                        delete $self->{uid_min}; # implicit cmd_close
-                } else { # we have a giant inbox:
-                        $self->{uid_min} = $uid_min;
-                        ensure_old_ranges_exist($self, $ibx, $uid_min);
-                }
         }
 
-        # RFC 3501 2.3.1.1 -  "A good UIDVALIDITY value to use in
-        # this case is a 32-bit representation of the creation
-        # date/time of the mailbox"
-        my $uidvalidity = $mm->created_at or return "$tag BAD UIDVALIDITY\r\n";
         my $uidnext = $max + 1;
 
         # XXX: do we need this? RFC 5162/7162
@@ -269,7 +248,7 @@ sub cmd_examine ($$$) {
 * OK [PERMANENTFLAGS ()] Read-only mailbox\r
 * OK [UNSEEN $max]\r
 * OK [UIDNEXT $uidnext]\r
-* OK [UIDVALIDITY $uidvalidity]\r
+* OK [UIDVALIDITY $ibx->{uidvalidity}]\r
 $tag OK [READ-ONLY] EXAMINE/SELECT done\r
 EOF
 }
@@ -561,7 +540,7 @@ sub uid_fetch_m { # long_response
 
 sub cmd_status ($$$;@) {
         my ($self, $tag, $mailbox, @items) = @_;
-        my $ibx = $self->{imapd}->{groups}->{$mailbox} or
+        my $ibx = $self->{imapd}->{mailboxes}->{$mailbox} or
                 return "$tag NO Mailbox doesn't exist: $mailbox\r\n";
         return "$tag BAD no items\r\n" if !scalar(@items);
         ($items[0] !~ s/\A\(//s || $items[-1] !~ s/\)\z//s) and
@@ -577,8 +556,7 @@ sub cmd_status ($$$;@) {
                 } elsif ($it eq 'UIDNEXT') {
                         push(@it, ($max //= $mm->max // 0) + 1);
                 } elsif ($it eq 'UIDVALIDITY') {
-                        push(@it, $mm->created_at //
-                                return("$tag BAD UIDVALIDITY\r\n"));
+                        push(@it, $ibx->{uidvalidity});
                 } else {
                         return "$tag BAD invalid item\r\n";
                 }