[PATCH 2/2] extindex: fix boost with partial runs

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

Boost relies on knowledge of all inboxes in a given config file
to work properly.  So while we support indexing a subset of
inboxes, we must still account for boost in inboxes we're not
indexing.  So split internal inbox groups into "known" and
"active", where previously we only cared for inboxes which were
being actively indexed.

Furthermore, boost checks need to be applied when a
message arrives in different inboxes across multiple
invocations.

Reported-by: Konstantin Ryabitsev <konstantin@linuxfoundation.org>
Link: https://public-inbox.org/meta/20210802204058.vscbxs5q7xyolyu2@nitro.local/
---
 lib/PublicInbox/ExtSearchIdx.pm | 112 +++++++++++++++++++++++---------
 script/public-inbox-extindex    |   2 +-
 t/extsearch.t                   |  12 ++++
 3 files changed, 96 insertions(+), 30 deletions(-)

diff --git a/lib/PublicInbox/ExtSearchIdx.pm b/lib/PublicInbox/ExtSearchIdx.pm
index 7b7dfb53..cf61237c 100644
--- a/lib/PublicInbox/ExtSearchIdx.pm
+++ b/lib/PublicInbox/ExtSearchIdx.pm
@@ -44,7 +44,8 @@ sub new {
 		topdir => $dir,
 		creat => $opt->{creat},
 		ibx_map => {}, # (newsgroup//inboxdir) => $ibx
-		ibx_cfg => [], # by config section order
+		ibx_active => [], # by config section order
+		ibx_known => [], # by config section order
 		indexlevel => $l,
 		transact_bytes => 0,
 		total_bytes => 0,
@@ -61,23 +62,41 @@ sub new {
 }
 
 sub attach_inbox {
-	my ($self, $ibx) = @_;
+	my ($self, $ibx, $types) = @_;
 	$self->{ibx_map}->{$ibx->eidx_key} //= do {
-		delete $self->{-ibx_ary}; # invalidate cache
-		push @{$self->{ibx_cfg}}, $ibx;
+		delete $self->{-ibx_ary_known}; # invalidate cache
+		delete $self->{-ibx_ary_active}; # invalidate cache
+		$types //= [ qw(active known) ];
+		for my $t (@$types) {
+			push @{$self->{"ibx_$t"}}, $ibx;
+		}
 		$ibx;
 	}
 }
 
 sub _ibx_attach { # each_inbox callback
-	my ($ibx, $self) = @_;
-	attach_inbox($self, $ibx);
+	my ($ibx, $self, $types) = @_;
+	attach_inbox($self, $ibx, $types);
 }
 
 sub attach_config {
-	my ($self, $cfg) = @_;
+	my ($self, $cfg, $ibxs) = @_;
 	$self->{cfg} = $cfg;
-	$cfg->each_inbox(\&_ibx_attach, $self);
+	my $types;
+	if ($ibxs) {
+		for my $ibx (@$ibxs) {
+			$self->{ibx_map}->{$ibx->eidx_key} //= do {
+				push @{$self->{ibx_active}}, $ibx;
+				push @{$self->{ibx_known}}, $ibx;
+			}
+		}
+		# invalidate cache
+		delete $self->{-ibx_ary_known};
+		delete $self->{-ibx_ary_active};
+		$types = [ 'known' ];
+	}
+	$types //= [ qw(known active) ];
+	$cfg->each_inbox(\&_ibx_attach, $self, $types);
 }
 
 sub check_batch_limit ($) {
@@ -90,6 +109,25 @@ sub check_batch_limit ($) {
 	${$req->{need_checkpoint}} = 1 if $n >= $self->{batch_bytes};
 }
 
+sub apply_boost ($$) {
+	my ($req, $smsg) = @_;
+	my $id2pos = $req->{id2pos}; # index in ibx_sorted
+	my $xr3 = $req->{self}->{oidx}->get_xref3($smsg->{num}, 1);
+	@$xr3 = sort {
+		$id2pos->{$a->[0]} <=> $id2pos->{$b->[0]}
+				||
+		$a->[1] <=> $b->[1] # break ties with {xnum}
+	} @$xr3;
+	my $top_blob = unpack('H*', $xr3->[0]->[2]);
+	my $new_smsg = $req->{new_smsg};
+	return if $top_blob ne $new_smsg->{blob}; # loser
+
+	# replace the old smsg with the more boosted one
+	$new_smsg->{num} = $smsg->{num};
+	$new_smsg->populate($req->{eml}, $req);
+	$req->{self}->{oidx}->add_overview($req->{eml}, $new_smsg);
+}
+
 sub do_xpost ($$) {
 	my ($req, $smsg) = @_;
 	my $self = $req->{self};
@@ -103,6 +141,7 @@ sub do_xpost ($$) {
 		my $xnum = $req->{xnum};
 		$self->{oidx}->add_xref3($docid, $xnum, $oid, $eidx_key);
 		$idx->ipc_do('add_eidx_info', $docid, $eidx_key, $eml);
+		apply_boost($req, $smsg) if $req->{boost_in_use};
 	} else { # 'd'
 		my $rm_eidx_info;
 		my $nr = $self->{oidx}->remove_xref3($docid, $oid, $eidx_key,
@@ -389,7 +428,8 @@ sub _ibx_for ($$$) {
 	my ($self, $sync, $smsg) = @_;
 	my $ibx_id = delete($smsg->{ibx_id}) // die '{ibx_id} unset';
 	my $pos = $sync->{id2pos}->{$ibx_id} // die "$ibx_id no pos";
-	$self->{-ibx_ary}->[$pos] // die "BUG: ibx for $smsg->{blob} not mapped"
+	$self->{-ibx_ary_known}->[$pos] //
+		die "BUG: ibx for $smsg->{blob} not mapped"
 }
 
 sub _fd_constrained ($) {
@@ -403,7 +443,8 @@ sub _fd_constrained ($) {
 			chomp($soft = `sh -c 'ulimit -n'`);
 		}
 		if (defined($soft)) {
-			my $want = scalar(@{$self->{-ibx_ary}}) + 64; # estimate
+			# $want is an estimate
+			my $want = scalar(@{$self->{ibx_active}}) + 64;
 			my $ret = $want > $soft;
 			if ($ret) {
 				warn <<EOF;
@@ -622,17 +663,25 @@ EOF
 	undef;
 }
 
-sub ibx_sorted ($) {
-	my ($self) = @_;
-	$self->{-ibx_ary} //= do {
+sub ibx_sorted ($$) {
+	my ($self, $type) = @_;
+	$self->{"-ibx_ary_$type"} //= do {
 		# highest boost first, stable for config-ordering tiebreaker
 		use sort 'stable';
 		[ sort {
 			($b->{boost} // 0) <=> ($a->{boost} // 0)
-		  } @{$self->{ibx_cfg}} ];
+		  } @{$self->{'ibx_'.$type} // die "BUG: $type unknown"} ];
 	}
 }
 
+sub prep_id2pos ($) {
+	my ($self) = @_;
+	my %id2pos;
+	my $pos = 0;
+	$id2pos{$_->{-ibx_id}} = $pos++ for (@{ibx_sorted($self, 'known')});
+	\%id2pos;
+}
+
 sub eidxq_process ($$) { # for reindexing
 	my ($self, $sync) = @_;
 
@@ -647,12 +696,7 @@ sub eidxq_process ($$) { # for reindexing
 		my $max = $dbh->selectrow_array('SELECT MAX(docid) FROM eidxq');
 		$pr->("Xapian indexing $min..$max (total=$tot)\n");
 	}
-	$sync->{id2pos} //= do {
-		my %id2pos;
-		my $pos = 0;
-		$id2pos{$_->{-ibx_id}} = $pos++ for (@{ibx_sorted($self)});
-		\%id2pos;
-	};
+	$sync->{id2pos} //= prep_id2pos($self);
 	my ($del, $iter);
 restart:
 	$del = $dbh->prepare('DELETE FROM eidxq WHERE docid = ?');
@@ -841,7 +885,7 @@ sub eidx_reindex {
 		warn "E: aborting --reindex\n";
 		return;
 	}
-	for my $ibx (@{ibx_sorted($self)}) {
+	for my $ibx (@{ibx_sorted($self, 'active')}) {
 		_reindex_inbox($self, $sync, $ibx);
 		last if $sync->{quit};
 	}
@@ -987,9 +1031,15 @@ sub eidx_sync { # main entry point
 	local $SIG{QUIT} = $quit;
 	local $SIG{INT} = $quit;
 	local $SIG{TERM} = $quit;
-	for my $ibx (@{ibx_sorted($self)}) {
+	for my $ibx (@{ibx_sorted($self, 'known')}) {
 		$ibx->{-ibx_id} //= $self->{oidx}->ibx_id($ibx->eidx_key);
 	}
+
+	if (scalar(grep { defined($_->{boost}) } @{$self->{ibx_known}})) {
+		$sync->{id2pos} //= prep_id2pos($self);
+		$sync->{boost_in_use} = 1;
+	}
+
 	if (my $msgids = delete($opt->{dedupe})) {
 		local $sync->{checkpoint_unlocks} = 1;
 		eidx_dedupe($self, $sync, $msgids);
@@ -1001,7 +1051,7 @@ sub eidx_sync { # main entry point
 
 	# don't use $_ here, it'll get clobbered by reindex_checkpoint
 	if ($opt->{scan} // 1) {
-		for my $ibx (@{ibx_sorted($self)}) {
+		for my $ibx (@{ibx_sorted($self, 'active')}) {
 			last if $sync->{quit};
 			sync_inbox($self, $sync, $ibx);
 		}
@@ -1143,7 +1193,7 @@ sub idx_init { # similar to V2Writable
 		}
 		undef $dh;
 	}
-	for my $ibx (@{ibx_sorted($self)}) {
+	for my $ibx (@{ibx_sorted($self, 'active')}) {
 		# create symlinks for multi-pack-index
 		$git_midx += symlink_packs($ibx, $pd);
 		# add new lines to our alternates file
@@ -1208,8 +1258,10 @@ sub eidx_reload { # -extindex --watch SIGHUP handler
 		my $pr = $self->{-watch_sync}->{-opt}->{-progress};
 		$pr->('reloading ...') if $pr;
 		delete $self->{-resync_queue};
-		delete $self->{-ibx_ary};
-		$self->{ibx_cfg} = [];
+		delete $self->{-ibx_ary_known};
+		delete $self->{-ibx_ary_active};
+		$self->{ibx_known} = [];
+		$self->{ibx_active} = [];
 		%{$self->{ibx_map}} = ();
 		delete $self->{-watch_sync}->{id2pos};
 		my $cfg = PublicInbox::Config->new;
@@ -1223,7 +1275,7 @@ sub eidx_reload { # -extindex --watch SIGHUP handler
 
 sub eidx_resync_start ($) { # -extindex --watch SIGUSR1 handler
 	my ($self) = @_;
-	$self->{-resync_queue} //= [ @{ibx_sorted($self)} ];
+	$self->{-resync_queue} //= [ @{ibx_sorted($self, 'active')} ];
 	PublicInbox::DS::requeue($self); # trigger our ->event_step
 }
 
@@ -1254,9 +1306,11 @@ sub eidx_watch { # public-inbox-extindex --watch main loop
 	require PublicInbox::Sigfd;
 	my $idler = PublicInbox::InboxIdle->new($self->{cfg});
 	if (!$self->{cfg}) {
-		$idler->watch_inbox($_) for (@{ibx_sorted($self)});
+		$idler->watch_inbox($_) for (@{ibx_sorted($self, 'active')});
+	}
+	for my $ibx (@{ibx_sorted($self, 'active')}) {
+		$ibx->subscribe_unlock(__PACKAGE__, $self)
 	}
-	$_->subscribe_unlock(__PACKAGE__, $self) for (@{ibx_sorted($self)});
 	my $pr = $opt->{-progress};
 	$pr->("performing initial scan ...\n") if $pr;
 	my $sync = eidx_sync($self, $opt); # initial sync
diff --git a/script/public-inbox-extindex b/script/public-inbox-extindex
index addd5ac6..327980d2 100755
--- a/script/public-inbox-extindex
+++ b/script/public-inbox-extindex
@@ -76,7 +76,7 @@ if ($opt->{gc}) {
 	if ($opt->{all}) {
 		$eidx->attach_config($cfg);
 	} else {
-		$eidx->attach_inbox($_) for @ibxs;
+		$eidx->attach_config($cfg, \@ibxs);
 	}
 	if ($opt->{watch}) {
 		$cfg = undef; # save memory only after SIGHUP
diff --git a/t/extsearch.t b/t/extsearch.t
index d933b948..b03adc17 100644
--- a/t/extsearch.t
+++ b/t/extsearch.t
@@ -86,6 +86,18 @@ if ('with boost') {
 	like($v2[0], qr/\Av2\.example.*?\b\Q$smsg->{blob}\E\b/,
 			'smsg->{blob} respects boost after reindex');
 
+	# high boost added later
+	my $b2 = "$home/extindex-bb";
+	ok(run_script([qw(-extindex), $b2, "$home/v1test"]),
+		'extindex with low boost inbox only');
+	ok(run_script([qw(-extindex), $b2, "$home/v2test"]),
+		'extindex with high boost inbox only');
+	$es = PublicInbox::ExtSearch->new($b2);
+	$smsg = $es->over->get_art(1);
+	$xref3 = $es->over->get_xref3($smsg->{num});
+	like($v2[0], qr/\Av2\.example.*?\b\Q$smsg->{blob}\E\b/,
+		'smsg->{blob} respected boost across 2 index runs');
+
 	xsys([qw(git config --unset publicinbox.v1test.boost)],
 		{ GIT_CONFIG => $cfg_path });
 	xsys([qw(git config --unset publicinbox.v2test.boost)],