[PATCH 2/4] *index: avoid per-epoch --batch-check processes

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

Since all.git (v2) and ALL.git (extindex) encompass every single
epoch or indexed inbox; and we is_ancestor() only uses
hexadecimal OIDs, there is no good reason to to use $unit->{git}
for an epoch-local $git->check avoids redundant long-lived
processes.

This prevents dozens/hundreds of --batch-check processes from
being left running after indexing and can improve locality
if size checks are being done (since that uses --batch-check,
too).

Theoretically an several epochs may have conflicting OIDs, but
we're screwed in those cases, anyways, so we might as well
detect it earlier (though I'm not sure what the behavior would
be :x).
---
 lib/PublicInbox/ExtSearchIdx.pm | 2 +-
 lib/PublicInbox/V2Writable.pm   | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/PublicInbox/ExtSearchIdx.pm b/lib/PublicInbox/ExtSearchIdx.pm
index 14ffdadb..2d230dc1 100644
--- a/lib/PublicInbox/ExtSearchIdx.pm
+++ b/lib/PublicInbox/ExtSearchIdx.pm
@@ -361,7 +361,7 @@ sub update_last_commit { # overrides V2Writable
 		die "Unsupported inbox version: $v";
 	}
 	my $last = $self->{oidx}->eidx_meta($meta_key);
-	if (defined $last && is_ancestor($unit->{git}, $last, $latest_cmt)) {
+	if (defined $last && is_ancestor($self->git, $last, $latest_cmt)) {
 		my @cmd = (qw(rev-list --count), "$last..$latest_cmt");
 		chomp(my $n = $unit->{git}->qx(@cmd));
 		return if $n ne '' && $n == 0;
diff --git a/lib/PublicInbox/V2Writable.pm b/lib/PublicInbox/V2Writable.pm
index 87b76501..cf44c95b 100644
--- a/lib/PublicInbox/V2Writable.pm
+++ b/lib/PublicInbox/V2Writable.pm
@@ -966,7 +966,7 @@ sub update_last_commit {
 	my $latest_cmt = $stk ? $stk->{latest_cmt} : ${$sync->{latest_cmt}};
 	defined($latest_cmt) or return;
 	my $last = last_epoch_commit($self, $unit->{epoch});
-	if (defined $last && is_ancestor($unit->{git}, $last, $latest_cmt)) {
+	if (defined $last && is_ancestor($self->git, $last, $latest_cmt)) {
 		my @cmd = (qw(rev-list --count), "$last..$latest_cmt");
 		chomp(my $n = $unit->{git}->qx(@cmd));
 		return if $n ne '' && $n == 0;
@@ -1003,7 +1003,7 @@ sub log_range ($$$) {
 	my $range = "$cur..$tip";
 	$pr->("$i.git checking contiguity... ") if $pr;
 	my $git = $unit->{git};
-	if (is_ancestor($git, $cur, $tip)) { # common case
+	if (is_ancestor($sync->{self}->git, $cur, $tip)) { # common case
 		$pr->("OK\n") if $pr;
 		my $n = $git->qx(qw(rev-list --count), $range);
 		chomp($n);