msgmap: split ->max into its own method

There's enough places where we only care about the max NNTP
article number to warrant avoiding a call into SQLite.

Using ->num_highwater in read-only packages such as
PublicInbox::IMAP is also incorrect, since that memoizes
and won't pick up changes made by other processes.

diff --git a/lib/PublicInbox/IMAP.pm b/lib/PublicInbox/IMAP.pm
index 99c6c817fd799b48995e068d232d09467d12770b..4a43185c51262baffb9abbafce7eea758c2c3447 100644 (file)
--- a/lib/PublicInbox/IMAP.pm
+++ b/lib/PublicInbox/IMAP.pm
@@ -146,7 +146,7 @@ sub cmd_noop ($$) { "$_[1] OK NOOP completed\r\n" }
 # called by PublicInbox::InboxIdle
 sub on_inbox_unlock {
        my ($self, $ibx) = @_;
-       my $new = ($ibx->mm->minmax)[1];
+       my $new = $ibx->mm->max;
        defined(my $old = $self->{-idle_max}) or die 'BUG: -idle_max unset';
        if ($new > $old) {
                $self->{-idle_max} = $new;
@@ -161,7 +161,7 @@ sub cmd_idle ($$) {
        my $ibx = $self->{ibx} or return "$tag BAD no mailbox selected\r\n";
        $ibx->subscribe_unlock(fileno($self->{sock}), $self);
        $self->{-idle_tag} = $tag;
-       $self->{-idle_max} = ($ibx->mm->minmax)[1] // 0;
+       $self->{-idle_max} = $ibx->mm->max // 0;
        "+ idling\r\n"
 }
 
@@ -182,7 +182,7 @@ sub cmd_examine ($$$) {
        my $ibx = $self->{imapd}->{groups}->{$mailbox} or
                return "$tag NO Mailbox doesn't exist: $mailbox\r\n";
        my $mm = $ibx->mm;
-       my $max = $mm->num_highwater // 0;
+       my $max = $mm->max // 0;
        # RFC 3501 2.3.1.1 -  "A good UIDVALIDITY value to use in
        # this case is a 32-bit representation of the creation
        # date/time of the mailbox"
@@ -320,7 +320,7 @@ sub cmd_uid_fetch ($$$;@) {
        if ($range =~ /\A([0-9]+):([0-9]+)\z/s) {
                ($beg, $end) = ($1, $2);
        } elsif ($range =~ /\A([0-9]+):\*\z/s) {
-               ($beg, $end) =  ($1, $ibx->mm->num_highwater // 0);
+               ($beg, $end) =  ($1, $ibx->mm->max // 0);
        } elsif ($range =~ /\A[0-9]+\z/) {
                my $smsg = $ibx->over->get_art($range) or return "$tag OK\r\n";
                push @$msgs, $smsg;
@@ -365,7 +365,7 @@ sub cmd_uid_search ($$$;) {
        } elsif ($arg eq 'UID' && scalar(@rest) == 1) {
                if ($rest[0] =~ /\A([0-9]+):([0-9]+|\*)\z/s) {
                        my ($beg, $end) = ($1, $2);
-                       $end = ($ibx->mm->minmax)[1] if $end eq '*';
+                       $end = $ibx->mm->max if $end eq '*';
                        $self->msg_more('* SEARCH');
                        long_response($self, \&uid_search_uid_range,
                                        $tag, $ibx, \$beg, $end);

diff --git a/lib/PublicInbox/Msgmap.pm b/lib/PublicInbox/Msgmap.pm
index a2ffe7203e74c026af8675fea0922c026740f7f7..d115cbce352cd3551b406d5b5c9d90782e9feab1 100644 (file)
--- a/lib/PublicInbox/Msgmap.pm
+++ b/lib/PublicInbox/Msgmap.pm
@@ -55,8 +55,7 @@ sub new_file {
                $dbh->begin_work;
                $self->created_at(time) unless $self->created_at;
 
-               my (undef, $max) = $self->minmax();
-               $max ||= 0;
+               my $max = $self->max // 0;
                $self->num_highwater($max);
                $dbh->commit;
        }
@@ -159,17 +158,20 @@ sub num_for {
        $sth->fetchrow_array;
 }
 
+sub max {
+       my $sth = $_[0]->{dbh}->prepare_cached('SELECT MAX(num) FROM msgmap',
+                                               undef, 1);
+       $sth->execute;
+       $sth->fetchrow_array;
+}
+
 sub minmax {
-       my ($self) = @_;
-       my $dbh = $self->{dbh};
        # breaking MIN and MAX into separate queries speeds up from 250ms
        # to around 700us with 2.7million messages.
-       my $sth = $dbh->prepare_cached('SELECT MIN(num) FROM msgmap', undef, 1);
-       $sth->execute;
-       my $min = $sth->fetchrow_array;
-       $sth = $dbh->prepare_cached('SELECT MAX(num) FROM msgmap', undef, 1);
+       my $sth = $_[0]->{dbh}->prepare_cached('SELECT MIN(num) FROM msgmap',
+                                               undef, 1);
        $sth->execute;
-       ($min, $sth->fetchrow_array);
+       ($sth->fetchrow_array, max($_[0]));
 }
 
 sub mid_delete {