Re: [WIP] searchidx: support incremental indexing on indexlevel=basic

[ebiederm@xmission.com (Eric W. Biederman)]

ebiederm@xmission.com (Eric W. Biederman) writes:

> ebiederm@xmission.com (Eric W. Biederman) writes:
>
>> Eric Wong <e@80x24.org> writes:
>>
>>> I wrote:
>>>> While testing this, it looks like I introduced a bug to
>>>> indexlevel=basic which broke incremental indexing when I made it
>>>> possible to upgrade to (medium|full).  Patch coming for that in
>>>> a bit...
>>>
>>> Eep, I think there's deeper problems with indexlevel=basic and
>>> incremental updates, since it's still doing lookups against
>>> Xapian for deletes...
>>>
>>> This is my work-in-progress to stop full-reindexing, at least.
>>
>> So I don't think your change is quite right.
>>
>> If the repo has only lived with indexlevel == 'basic' then last_commit
>> should always match the output of xdb->get_metadata('last_commit') as
>> it will always been undef or ''.
>>
>> In fact I don't see any code that is updating
>> $xdb->get_metadata('last_commit');
>>
>> Am I wrong or can we just always use mm->last_commit for this logic?
>
> Yes.  I was wrong.  I had overlooked the get_metadata($mkey) and
> set_metadata($mkey) calls.   From just below but those are all
> with $mkey == 'last_commit'  So 'last_commit' does get updated.
>
> I think we want something more like below.  Where _last_x_commit
> just computes the last_commit value to use, using both values of
> last_commit.
>
> I am not 100% about the loop.  Perhaps that check to see if either
> value of last_commit changes?
>
> I definitely don't think when we already have one set of logic
> for substituting in last_commit we should be adding in another.
> That gets confusing very fast.
>
Make that something like this where we remove the $mkey variable 
and all of it's special semantics with regards to reindexing entirely.

Eric


diff --git a/lib/PublicInbox/SearchIdx.pm b/lib/PublicInbox/SearchIdx.pm
index 198f39b96e6c..8b12da0436a4 100644
--- a/lib/PublicInbox/SearchIdx.pm
+++ b/lib/PublicInbox/SearchIdx.pm
@@ -669,6 +669,23 @@ sub need_update ($$$) {
 	($n eq '' || $n > 0);
 }
 
+sub _last_x_commit
+{
+	my ($self) = @_;
+        my $lm = $mm->last_commit || '';
+	my $lx = '';
+	if ($self->{indexlevel} ~= $xapianlevels) {
+		$lx = $self->{xdb}->get_metadata('last_commit') || '';
+        } else {
+		$lx = $lm;
+	}
+	# Use last_commit from msgmap if it is older or unset
+	if (!$lm || ($lx && $lx && is_ancestor($git, $lm, $lx))) {
+		$lx = $lm;
+	}
+	$lx;
+}
+
 # indexes all unindexed messages (v1 only)
 sub _index_sync {
 	my ($self, $opts) = @_;
@@ -682,19 +699,8 @@ sub _index_sync {
 	my $mm = _msgmap_init($self);
 	do {
 		$xlog = undef;
-		$mkey = 'last_commit';
-		$last_commit = $xdb->get_metadata('last_commit');
-		$lx = $last_commit;
-		if ($reindex) {
-			$lx = '';
-			$mkey = undef if $last_commit ne '';
-		}
-
-		# use last_commit from msgmap if it is older or unset
-		my $lm = $mm->last_commit || '';
-		if (!$lm || ($lm && $lx && is_ancestor($git, $lm, $lx))) {
-			$lx = $lm;
-		}
+		$last_commit = $self->_last_x_commit;
+		$lx = !$reindex ? $last_commit : '';
 
 		$self->{over}->rollback_lazy;
 		$self->{over}->disconnect;
@@ -708,7 +714,7 @@ sub _index_sync {
 		$xlog = _git_log($self, $range);
 
 		$xdb = $self->begin_txn_lazy;
-	} while ($xdb->get_metadata('last_commit') ne $last_commit);
+	} while ($self->_last_x_commit ne $last_commit);
 
 	my $dbh = $mm->{dbh} if $mm;
 	my $cb = sub {
@@ -722,10 +728,10 @@ sub _index_sync {
 			}
 			$dbh->commit;
 		}
-		if ($mkey && $newest && $self->{indexlevel} =~ $xapianlevels) {
-			my $cur = $xdb->get_metadata($mkey);
+		if ($newest && $self->{indexlevel} =~ $xapianlevels) {
+			my $cur = $xdb->get_metadata('last_commit');
 			if (need_update($self, $cur, $newest)) {
-				$xdb->set_metadata($mkey, $newest);
+				$xdb->set_metadata('last_commit', $newest);
 			}
 		}
 		$self->commit_txn_lazy;