From ebb59815035b42c276a89a585e16e69f51dbdb98 Mon Sep 17 00:00:00 2001 From: "Eric Wong (Contractor, The Linux Foundation)" Date: Tue, 27 Feb 2018 20:25:23 +0000 Subject: [PATCH] searchidx: do not modify Xapian DB while iterating Iterating through a list of documents while modifying them does not seem to be supported in Xapian and it can trigger DatabaseCorruptError exceptions. This only worked with past datasets out of dumb luck. With the work-in-progress "v2" public-inbox layout, this problem might become more visible as the "thread skeleton" is partitioned out to a separate, smaller Xapian database. I've reproduced the problem on both Debian 8.x and 9.x with Xapian 1.2.19 (chert backend) and 1.4.3 (glass backend) respectively. --- lib/PublicInbox/SearchIdx.pm | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/lib/PublicInbox/SearchIdx.pm b/lib/PublicInbox/SearchIdx.pm index 66faed31..5559b39d 100644 --- a/lib/PublicInbox/SearchIdx.pm +++ b/lib/PublicInbox/SearchIdx.pm @@ -696,15 +696,22 @@ sub create_ghost { sub merge_threads { my ($self, $winner_tid, $loser_tid) = @_; return if $winner_tid == $loser_tid; - my ($head, $tail) = $self->find_doc_ids('G' . $loser_tid); my $db = $self->{xdb}; - for (; $head != $tail; $head->inc) { - my $docid = $head->get_docid; - my $doc = $db->get_document($docid); - $doc->remove_term('G' . $loser_tid); - $doc->add_term('G' . $winner_tid); - $db->replace_document($docid, $doc); + my $batch_size = 1000; # don't let @ids grow too large to avoid OOM + while (1) { + my ($head, $tail) = $self->find_doc_ids('G' . $loser_tid); + return if $head == $tail; + my @ids; + for (; $head != $tail && @ids < $batch_size; $head->inc) { + push @ids, $head->get_docid; + } + foreach my $docid (@ids) { + my $doc = $db->get_document($docid); + $doc->remove_term('G' . $loser_tid); + $doc->add_term('G' . $winner_tid); + $db->replace_document($docid, $doc); + } } } -- 2.44.0