xcpdb: cleanup error handling and diagnosis

Running a full "public-inbox-index --reindex" in parallel
with "public-inbox-xcpdb" on the same inbox can still cause
problems, though.

diff --git a/lib/PublicInbox/Xapcmd.pm b/lib/PublicInbox/Xapcmd.pm
index 99f0e7c13d9e8d07927e7e56de3833699025abf4..697221d9a8e3c0f9b7cdcb0c135bf6e7cebd9e4f 100644 (file)
--- a/lib/PublicInbox/Xapcmd.pm
+++ b/lib/PublicInbox/Xapcmd.pm
@@ -163,13 +163,16 @@ sub run {
 }
 
 sub cpdb_retryable ($$) {
-       my ($src, $err) = @_;
-       if (ref($err) eq 'Search::Xapian::DatabaseModifiedError') {
-               warn "$err, reopening and retrying\n";
+       my ($src, $pfx) = @_;
+       if (ref($@) eq 'Search::Xapian::DatabaseModifiedError') {
+               warn "$pfx Xapian DB modified, reopening and retrying\n";
                $src->reopen;
                return 1;
        }
-       die $err if $err;
+       if ($@) {
+               warn "$pfx E: ", ref($@), "\n";
+               die;
+       }
        0;
 }
 
@@ -186,7 +189,8 @@ sub cpdb {
        my $creat = Search::Xapian::DB_CREATE();
        my $dst = Search::Xapian::WritableDatabase->new($tmp, $creat);
        my ($it, $end);
-       my ($pfx, $nr, $tot, $fmt); # progress output
+       my $pfx = '';
+       my ($nr, $tot, $fmt); # progress output
 
        do {
                eval {
@@ -196,15 +200,15 @@ sub cpdb {
 
                        $it = $src->postlist_begin('');
                        $end = $src->postlist_end('');
+                       $pfx = (split('/', $old))[-1].':';
                        if ($opt->{-progress}) {
                                $nr = 0;
-                               $pfx = (split('/', $old))[-1].':';
                                $tot = $src->get_doccount;
                                $fmt = "$pfx % ".length($tot)."u/$tot\n";
                                warn "$pfx copying $tot documents\n";
                        }
                };
-       } while (cpdb_retryable($src, $@));
+       } while (cpdb_retryable($src, $pfx));
 
        do {
                eval {
@@ -223,12 +227,13 @@ sub cpdb {
                        # the Perl APIs don't expose iterators for them
                        # (and public-inbox does not use those features)
                };
-       } while (cpdb_retryable($src, $@));
+       } while (cpdb_retryable($src, $pfx));
 
        warn(sprintf($fmt, $nr)) if $fmt;
        return unless $opt->{compact};
 
        $src = $dst = undef; # flushes and closes
+       $pfx = undef unless $fmt;
 
        warn "$pfx compacting...\n" if $pfx;
        # this is probably the best place to do xapian-compact