support setting No_COW on Perl <5.22

[public-inbox.git] / lib / PublicInbox / Over.pm

diff --git a/lib/PublicInbox/Over.pm b/lib/PublicInbox/Over.pm
index e32104f0cf81754bf8ed1d6e8012eb13420f506c..2b314882bc4d9546ab567d523c8c9878d89b6d7b 100644 (file)
--- a/lib/PublicInbox/Over.pm
+++ b/lib/PublicInbox/Over.pm
@@ -15,18 +15,37 @@ use constant DEFAULT_LIMIT => 1000;
 
 sub dbh_new {
        my ($self, $rw) = @_;
-       my $f = $self->{filename};
-       if ($rw && !-f $f) { # SQLite defaults mode to 0644, we want 0666
-               open my $fh, '+>>', $f or die "failed to open $f: $!";
+       my $f = delete $self->{filename};
+       if (!-f $f) { # SQLite defaults mode to 0644, we want 0666
+               if ($rw) {
+                       require PublicInbox::Spawn;
+                       open my $fh, '+>>', $f or die "failed to open $f: $!";
+                       PublicInbox::Spawn::nodatacow_fd(fileno($fh));
+                       my $j = "$f-journal";
+                       open $fh, '+>>', $j or die "failed to open $j: $!";
+                       PublicInbox::Spawn::nodatacow_fd(fileno($fh));
+               } else {
+                       $self->{filename} = $f; # die on stat() below:
+               }
        }
-       my $dbh = DBI->connect("dbi:SQLite:dbname=$f",'','', {
-               AutoCommit => 1,
-               RaiseError => 1,
-               PrintError => 0,
-               ReadOnly => !$rw,
-               sqlite_use_immediate_transaction => 1,
-       });
-       $dbh->{sqlite_unicode} = 1;
+       my (@st, $st, $dbh);
+       my $tries = 0;
+       do {
+               @st = stat($f) or die "failed to stat $f: $!";
+               $st = pack('dd', $st[0], $st[1]); # 0: dev, 1: inode
+               $dbh = DBI->connect("dbi:SQLite:dbname=$f",'','', {
+                       AutoCommit => 1,
+                       RaiseError => 1,
+                       PrintError => 0,
+                       ReadOnly => !$rw,
+                       sqlite_use_immediate_transaction => 1,
+               });
+               $self->{st} = $st;
+               @st = stat($f) or die "failed to stat $f: $!";
+               $st = pack('dd', $st[0], $st[1]);
+       } while ($st ne $self->{st} && $tries++ < 3);
+       warn "W: $f: .st_dev, .st_ino unstable\n" if $st ne $self->{st};
+       $dbh->do('PRAGMA synchronous = OFF') if ($rw // 0) > 1;
        $dbh;
 }
 
@@ -35,9 +54,14 @@ sub new {
        bless { filename => $f }, $class;
 }
 
-sub disconnect { $_[0]->{dbh} = undef }
+sub disconnect {
+       my ($self) = @_;
+       if (my $dbh = delete $self->{dbh}) {
+               $self->{filename} = $dbh->sqlite_db_filename;
+       }
+}
 
-sub connect { $_[0]->{dbh} ||= $_[0]->dbh_new }
+sub connect { $_[0]->{dbh} //= $_[0]->dbh_new }
 
 sub load_from_row ($;$) {
        my ($smsg, $cull) = @_;
@@ -238,25 +262,30 @@ SELECT MAX(num) FROM over WHERE num > 0
        $sth->fetchrow_array // 0;
 }
 
-sub imap_status {
+sub imap_exists {
        my ($self, $uid_base, $uid_end) = @_;
-       my $dbh = $self->connect;
-       my $sth = $dbh->prepare_cached(<<'', undef, 1);
+       my $sth = $self->connect->prepare_cached(<<'', undef, 1);
 SELECT COUNT(num) FROM over WHERE num > ? AND num <= ?
 
        $sth->execute($uid_base, $uid_end);
-       my $exists = $sth->fetchrow_array;
-
-       $sth = $dbh->prepare_cached(<<'', undef, 1);
-SELECT MAX(num) + 1 FROM over WHERE num <= ?
-
-       $sth->execute($uid_end);
-       my $uidnext = $sth->fetchrow_array;
-
-       $sth = $dbh->prepare_cached(<<'', undef, 1);
-SELECT MAX(num) FROM over WHERE num > 0
+       $sth->fetchrow_array;
+}
 
-       ($exists, $uidnext, $sth->fetchrow_array // 0);
+sub check_inodes {
+       my ($self) = @_;
+       my $dbh = $self->{dbh} or return;
+       my $f = $dbh->sqlite_db_filename;
+       if (my @st = stat($f)) { # did st_dev, st_ino change?
+               my $st = pack('dd', $st[0], $st[1]);
+
+               # don't actually reopen, just let {dbh} be recreated later
+               if ($st ne ($self->{st} // $st)) {
+                       delete($self->{dbh});
+                       $self->{filename} = $f;
+               }
+       } else {
+               warn "W: stat $f: $!\n";
+       }
 }
 
 1;