[PATCH 2/5] lei q: reduce lei/store work for kw changes to stored mail

[Eric Wong <e@80x24.org>]

We can tweak lse->kw_changed to return docids and reduce IPC
traffic and reduce work the lei/store worker needs to do.
---
 lib/PublicInbox/LeiSearch.pm | 9 +++++----
 lib/PublicInbox/LeiStore.pm  | 8 ++++----
 lib/PublicInbox/LeiToMail.pm | 6 +++---
 3 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/lib/PublicInbox/LeiSearch.pm b/lib/PublicInbox/LeiSearch.pm
index 07d570ec..69ba8303 100644
--- a/lib/PublicInbox/LeiSearch.pm
+++ b/lib/PublicInbox/LeiSearch.pm
@@ -100,10 +100,11 @@ sub xoids_for {
 
 # returns true if $eml is indexed by lei/store and keywords don't match
 sub kw_changed {
-	my ($self, $eml, $new_kw_sorted) = @_;
-	my $xoids = xoids_for($self, $eml, 1) // return;
-	my ($num) = values %$xoids;
-	my @cur_kw = msg_keywords($self, $num);
+	my ($self, $eml, $new_kw_sorted, $docids) = @_;
+	my $xoids = xoids_for($self, $eml) // return;
+	$docids //= [];
+	@$docids = sort { $a <=> $b } values %$xoids;
+	my @cur_kw = msg_keywords($self, $docids->[0]);
 	join("\0", @$new_kw_sorted) eq join("\0", @cur_kw) ? 0 : 1;
 }
 
diff --git a/lib/PublicInbox/LeiStore.pm b/lib/PublicInbox/LeiStore.pm
index b76af4d3..48ab1d76 100644
--- a/lib/PublicInbox/LeiStore.pm
+++ b/lib/PublicInbox/LeiStore.pm
@@ -131,13 +131,13 @@ sub _docids_for ($$) {
 }
 
 sub set_eml_vmd {
-	my ($self, $eml, $vmd) = @_;
+	my ($self, $eml, $vmd, $docids) = @_;
 	my $eidx = eidx_init($self);
-	my @docids = _docids_for($self, $eml);
-	for my $docid (@docids) {
+	$docids //= [ _docids_for($self, $eml) ];
+	for my $docid (@$docids) {
 		$eidx->idx_shard($docid)->ipc_do('set_vmd', $docid, $vmd);
 	}
-	\@docids;
+	$docids;
 }
 
 sub add_eml_vmd {
diff --git a/lib/PublicInbox/LeiToMail.pm b/lib/PublicInbox/LeiToMail.pm
index da633da4..0364d8ef 100644
--- a/lib/PublicInbox/LeiToMail.pm
+++ b/lib/PublicInbox/LeiToMail.pm
@@ -228,10 +228,10 @@ sub _mbox_write_cb ($$) {
 sub update_kw_maybe ($$$$) {
 	my ($lei, $lse, $eml, $kw) = @_;
 	return unless $lse;
-	my $lse_oids = $lse->kw_changed($eml, $kw);
+	my $c = $lse->kw_changed($eml, $kw, my $docids = []);
 	my $vmd = { kw => $kw };
-	if ($lse_oids) { # already in lei/store
-		$lei->{sto}->ipc_do('set_eml', $eml, $vmd);
+	if (scalar @$docids) { # already in lei/store
+		$lei->{sto}->ipc_do('set_eml_vmd', undef, $vmd, $docids) if $c;
 	} elsif (my $xoids = $lei->{ale}->xoids_for($eml)) {
 		# it's in an external, only set kw, here
 		$lei->{sto}->ipc_do('set_xvmd', $xoids, $eml, $vmd);