[PATCH 7/9] extsearchidx: simplify reindex code paths

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

Since we're inside a Xapian transaction, calling ->index_raw
followed by ->shard_add_eidx_info calls on the same docid
doesn't seem to hurt indexing performance.  It definitely
reduces FS read traffic and IPC from git at the cost of some
more IPC between the parent and workers.  Nevertheless, the code
and FD reductions seem worth it.
---
 lib/PublicInbox/ExtSearchIdx.pm   | 58 ++++++++++++++++------------
 lib/PublicInbox/SearchIdx.pm      | 64 -------------------------------
 lib/PublicInbox/SearchIdxShard.pm | 17 ++------
 3 files changed, 37 insertions(+), 102 deletions(-)

diff --git a/lib/PublicInbox/ExtSearchIdx.pm b/lib/PublicInbox/ExtSearchIdx.pm
index 3b021a1b..d5295735 100644
--- a/lib/PublicInbox/ExtSearchIdx.pm
+++ b/lib/PublicInbox/ExtSearchIdx.pm
@@ -149,7 +149,7 @@ sub index_unseen ($) {
 	my $oid = $new_smsg->{blob};
 	my $ibx = delete $req->{ibx} or die 'BUG: {ibx} unset';
 	$self->{oidx}->add_xref3($docid, $req->{xnum}, $oid, $ibx->eidx_key);
-	$idx->index_raw(undef, $eml, $new_smsg, $ibx);
+	$idx->index_raw(undef, $eml, $new_smsg, $ibx->eidx_key);
 	check_batch_limit($req);
 }
 
@@ -395,23 +395,39 @@ DELETE FROM xref3 WHERE docid NOT IN (SELECT num FROM over)
 	done($self);
 }
 
+sub _ibx_for ($$$) {
+	my ($self, $sync, $smsg) = @_;
+	my $ibx_id = delete($smsg->{ibx_id}) // die '{ibx_id} unset';
+	my $pos = $sync->{id2pos}->{$ibx_id} // die "$ibx_id no pos";
+	$self->{ibx_list}->[$pos] // die "BUG: ibx for $smsg->{blob} not mapped"
+}
+
 sub _reindex_finalize ($$$) {
 	my ($req, $smsg, $eml) = @_;
 	my $sync = $req->{sync};
 	my $self = $sync->{self};
-	my $by_chash = $req->{by_chash};
+	my $by_chash = delete $req->{by_chash} or die 'BUG: no {by_chash}';
 	my $nr = scalar(keys(%$by_chash)) or die 'BUG: no content hashes';
 	my $orig_smsg = $req->{orig_smsg} // die 'BUG: no {orig_smsg}';
 	my $docid = $smsg->{num} = $orig_smsg->{num};
 	$self->{oidx}->add_overview($eml, $smsg); # may rethread
 	check_batch_limit({ %$sync, new_smsg => $smsg });
-	if ($nr == 1) { # likely, all good
-		$self->idx_shard($docid)->shard_reindex_docid($docid);
-		return;
+	my $chash0 = $smsg->{chash} // die "BUG: $smsg->{blob} no {chash}";
+	my $stable = delete($by_chash->{$chash0}) //
+				die "BUG: $smsg->{blob} chash missing";
+	my $idx = $self->idx_shard($docid);
+	my $top_smsg = pop @$stable;
+	$top_smsg == $smsg or die 'BUG: top_smsg != smsg';
+	my $ibx = _ibx_for($self, $sync, $smsg);
+	$idx->index_raw(undef, $eml, $smsg, $ibx->eidx_key);
+	for my $x (reverse @$stable) {
+		$ibx = _ibx_for($self, $sync, $x);
+		my $hdr = delete $x->{hdr} // die 'BUG: no {hdr}';
+		$idx->shard_add_eidx_info($docid, $ibx->eidx_key, $hdr);
 	}
+	return if $nr == 1; # likely, all good
+
 	warn "W: #$docid split into $nr due to deduplication change\n";
-	my $chash0 = $smsg->{chash} // die "BUG: $smsg->{blob} no {chash}";
-	delete($by_chash->{$chash0}) // die "BUG: $smsg->{blob} chash missing";
 	my @todo;
 	for my $ary (values %$by_chash) {
 		for my $x (reverse @$ary) {
@@ -419,21 +435,16 @@ sub _reindex_finalize ($$$) {
 			my $n = $self->{oidx}->remove_xref3($docid, $x->{blob});
 			die "BUG: $x->{blob} invalidated #$docid" if $n == 0;
 		}
-		my $x = $ary->[-1] // die "BUG: #$docid {by_chash} empty";
+		my $x = pop(@$ary) // die "BUG: #$docid {by_chash} empty";
 		$x->{num} = delete($x->{xnum}) // die '{xnum} unset';
-		my $ibx_id = delete($x->{ibx_id}) // die '{ibx_id} unset';
-		my $pos = $sync->{id2pos}->{$ibx_id} // die "$ibx_id no pos";
-		my $ibx = $self->{ibx_list}->[$pos] //
-			die "BUG: ibx for $x->{blob} not mapped";
+		$ibx = _ibx_for($self, $sync, $x);
 		my $e = $ibx->over->get_art($x->{num});
 		$e->{blob} eq $x->{blob} or die <<EOF;
 $x->{blob} != $e->{blob} (${\$ibx->eidx_key}:$e->{num});
 EOF
 		push @todo, $ibx, $e;
 	}
-	$self->{oidx}->commit_lazy; # ensure shard workers can see xref removals
-	$self->{oidx}->begin_lazy;
-	$self->idx_shard($docid)->shard_reindex_docid($docid);
+	undef $by_chash;
 	while (my ($ibx, $e) = splice(@todo, 0, 2)) {
 		reindex_unseen($self, $sync, $ibx, $e);
 	}
@@ -444,14 +455,14 @@ sub _reindex_oid { # git->cat_async callback
 	my $sync = $req->{sync};
 	my $self = $sync->{self};
 	my $orig_smsg = $req->{orig_smsg} // die 'BUG: no {orig_smsg}';
-	my $expect_oid = $req->{xr3}->[$req->{ix}]->[2];
+	my $expect_oid = $req->{xr3r}->[$req->{ix}]->[2];
 	my $docid = $orig_smsg->{num};
 	if (is_bad_blob($oid, $type, $size, $expect_oid)) {
 		my $remain = $self->{oidx}->remove_xref3($docid, $expect_oid);
 		if ($remain == 0) {
 			warn "W: #$docid gone or corrupted\n";
 			$self->idx_shard($docid)->shard_remove($docid);
-		} elsif (my $next_oid = $req->{xr3}->[++$req->{ix}]->[2]) {
+		} elsif (my $next_oid = $req->{xr3r}->[++$req->{ix}]->[2]) {
 			$self->git->cat_async($next_oid, \&_reindex_oid, $req);
 		} else {
 			warn "BUG: #$docid gone (UNEXPECTED)\n";
@@ -468,10 +479,11 @@ sub _reindex_oid { # git->cat_async callback
 				cotime => $orig_smsg->{ts} });
 	my $chash = content_hash($eml);
 	$re_smsg->{chash} = $chash;
-	$re_smsg->{xnum} = $req->{xr3}->[$req->{ix}]->[1];
-	$re_smsg->{ibx_id} = $req->{xr3}->[$req->{ix}]->[0];
+	$re_smsg->{xnum} = $req->{xr3r}->[$req->{ix}]->[1];
+	$re_smsg->{ibx_id} = $req->{xr3r}->[$req->{ix}]->[0];
+	$re_smsg->{hdr} = $eml->header_obj;
 	push @{$req->{by_chash}->{$chash}}, $re_smsg;
-	if (my $next_oid = $req->{xr3}->[++$req->{ix}]->[2]) {
+	if (my $next_oid = $req->{xr3r}->[++$req->{ix}]->[2]) {
 		$self->git->cat_async($next_oid, \&_reindex_oid, $req);
 	} else { # last $re_smsg is the highest priority xref3
 		local $self->{current_info} = "$ci #$docid";
@@ -492,7 +504,7 @@ BUG? #$docid $smsg->{blob} is not referenced by inboxes during reindex
 		return;
 	}
 
-	# we sort {xr3} in the reverse order of {ibx_list} so we can
+	# we sort {xr3r} in the reverse order of {ibx_list} so we can
 	# hit the common case in _reindex_finalize without rereading
 	# from git (or holding multiple messages in memory).
 	my $id2pos = $sync->{id2pos}; # index in {ibx_list}
@@ -502,15 +514,13 @@ BUG? #$docid $smsg->{blob} is not referenced by inboxes during reindex
 		$b->[1] <=> $a->[1] # break ties with {xnum}
 	} @$xr3;
 	@$xr3 = map { [ $_->[0], $_->[1], unpack('H*', $_->[2]) ] } @$xr3;
-	my $req = { orig_smsg => $smsg, sync => $sync, xr3 => $xr3, ix => 0 };
+	my $req = { orig_smsg => $smsg, sync => $sync, xr3r => $xr3, ix => 0 };
 	$self->git->cat_async($xr3->[$req->{ix}]->[2], \&_reindex_oid, $req);
 }
 
 sub eidxq_process ($$) { # for reindexing
 	my ($self, $sync) = @_;
 
-	$self->{oidx}->commit_lazy; # ensure shard workers can see it
-	$self->{oidx}->begin_lazy;
 	my $dbh = $self->{oidx}->dbh;
 	my $tot = $dbh->selectrow_array('SELECT COUNT(*) FROM eidxq') or return;
 	${$sync->{nr}} = 0;
diff --git a/lib/PublicInbox/SearchIdx.pm b/lib/PublicInbox/SearchIdx.pm
index cd8f4dd7..c6d2a0e8 100644
--- a/lib/PublicInbox/SearchIdx.pm
+++ b/lib/PublicInbox/SearchIdx.pm
@@ -1008,68 +1008,4 @@ SELECT COUNT(*) FROM over WHERE num = ?
 	}
 }
 
-sub reindex_xap { # git->cat_async callback
-	my ($bref, $oid, $type, $size, $ary) = @_;
-	my ($ibx_id, $oidhex, $req, $more) = @$ary;
-	my $self = $req->{self} // die 'BUG: {self} missing';
-	my $eidx = $self->{eidx} // die 'BUG: {eidx} missing';
-	my $eidx_key = $self->{-eidx_key_for}->{$ibx_id} //
-			die "BUG: bad ibx_id=$ibx_id ($oid)";
-
-	my $docid = $req->{docid};
-	local $eidx->{current_info} = "#$docid $oid";
-	return if is_bad_blob($oid, $type, $size, $oidhex);
-	if (my $doc = $req->{doc}) { # modify existing doc
-		$req->{tg_isset} //= do { # for existing documents in {xdb}
-			term_generator($self)->set_document($doc);
-			1;
-		};
-		$doc->add_boolean_term('O'.$eidx_key);
-		index_list_id($self, $doc, PublicInbox::Eml->new($bref));
-	} else { # first time seeing this doc
-		my $smsg = $self->{eidx}->over->get_art($docid) //
-			die "BUG: #$docid ($oid) not in over";
-		$smsg->{bytes} = $size + crlf_adjust($$bref);
-		$smsg->{eidx_key} = $eidx_key;
-		my $eml = PublicInbox::Eml->new($bref);
-		$req->{doc} = eml2doc($self, $eml, $smsg);
-		$req->{tg_isset} = 1; # eml2doc calls $tg->set_document
-	}
-	return if $more;
-	my $doc = delete($req->{doc}) or return; # all bad blobs!
-	$eidx->{transact_bytes} += $size;
-	$self->{xdb}->replace_document($req->{docid}, $doc);
-}
-
-sub reindex_docid {
-	my ($self, $docid) = @_;
-	my $eidx = $self->{eidx} // die 'BUG: {eidx} missing';
-	my $eidx_key_for = $self->{-eidx_key_for} //= do {
-		my %eidx_key_for = map {
-			$_->[0] => $_->[1];
-		} @{$eidx->over->dbh->selectall_arrayref(<<'')};
-SELECT ibx_id,eidx_key FROM inboxes
-
-		\%eidx_key_for;
-	};
-
-	begin_txn_lazy($self);
-	my $doc = eval { $self->{xdb}->get_document($docid) };
-	my $req = { doc => $doc, self => $self, docid => $docid };
-	my $sth = $eidx->over->dbh->prepare_cached(<<'', undef, 1);
-SELECT ibx_id,oidbin FROM xref3 WHERE docid = ? ORDER BY ibx_id ASC
-
-	$sth->execute($docid);
-	my $rows = $sth->fetchall_arrayref;
-	while (my $row = shift(@$rows)) {
-		my ($ibx_id, $oidbin) = @$row;
-		my $oidhex = unpack('H*', $oidbin);
-		$eidx->git->cat_async($oidhex, \&reindex_xap,
-				[ $ibx_id, $oidhex, $req, scalar(@$rows) ]);
-	}
-	if ($eidx->{transact_bytes} >= $eidx->{batch_bytes}) {
-		commit_txn_lazy($self);
-	}
-}
-
 1;
diff --git a/lib/PublicInbox/SearchIdxShard.pm b/lib/PublicInbox/SearchIdxShard.pm
index b6eef6bd..ee00858b 100644
--- a/lib/PublicInbox/SearchIdxShard.pm
+++ b/lib/PublicInbox/SearchIdxShard.pm
@@ -94,8 +94,6 @@ sub shard_worker_loop ($$$$$) {
 			my $over_fn = $1;
 			$over_fn =~ tr/\0/\n/;
 			$self->over_check(PublicInbox::Over->new($over_fn));
-		} elsif ($line =~ /\AE ([0-9]+)\n/) {
-			$self->reindex_docid($1 + 0);
 		} else {
 			chomp $line;
 			my $eidx_key;
@@ -124,9 +122,9 @@ sub shard_worker_loop ($$$$$) {
 }
 
 sub index_raw {
-	my ($self, $msgref, $eml, $smsg, $ibx) = @_;
+	my ($self, $msgref, $eml, $smsg, $eidx_key) = @_;
 	if (my $w = $self->{w}) {
-		my @ekey = $ibx ? ('X='.$ibx->eidx_key."\0") : ();
+		my @ekey = defined($eidx_key) ? ("X=$eidx_key\0") : ();
 		$msgref //= \($eml->as_string);
 		$smsg->{raw_bytes} //= length($$msgref);
 		# mid must be last, it can contain spaces (but not LF)
@@ -140,7 +138,7 @@ sub index_raw {
 			$eml = PublicInbox::Eml->new($msgref);
 		}
 		$self->begin_txn_lazy;
-		$smsg->{eidx_key} = $ibx->eidx_key if $ibx;
+		$smsg->{eidx_key} = $eidx_key if defined $eidx_key;
 		$self->add_message($eml, $smsg);
 	}
 }
@@ -225,13 +223,4 @@ sub shard_over_check {
 	}
 }
 
-sub shard_reindex_docid {
-	my ($self, $docid) = @_;
-	if (my $w = $self->{w}) {
-		print $w "E $docid\n" or die "failed to write to shard: $!";
-	} else {
-		$self->reindex_docid($docid);
-	}
-}
-
 1;