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-rw-r--r--lib/PublicInbox/LeiXSearch.pm660
1 files changed, 660 insertions, 0 deletions
diff --git a/lib/PublicInbox/LeiXSearch.pm b/lib/PublicInbox/LeiXSearch.pm
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+# Copyright (C) all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+
+# Combine any combination of PublicInbox::Search,
+# PublicInbox::ExtSearch, and PublicInbox::LeiSearch objects
+# into one Xapian DB
+package PublicInbox::LeiXSearch;
+use strict;
+use v5.10.1;
+use parent qw(PublicInbox::LeiSearch PublicInbox::IPC);
+use PublicInbox::DS qw(now);
+use File::Temp 0.19 (); # 0.19 for ->newdir
+use File::Spec ();
+use PublicInbox::Search qw(xap_terms);
+use PublicInbox::Spawn qw(popen_rd popen_wr which);
+use PublicInbox::MID qw(mids mid_escape);
+use PublicInbox::Smsg;
+use PublicInbox::Eml;
+use PublicInbox::LEI;
+use Fcntl qw(SEEK_SET F_SETFL O_APPEND O_RDWR);
+use PublicInbox::ContentHash qw(git_sha);
+use POSIX qw(strftime);
+use autodie qw(close open read seek truncate);
+use PublicInbox::Syscall qw($F_SETPIPE_SZ);
+use PublicInbox::OnDestroy;
+
+sub new {
+        my ($class) = @_;
+        PublicInbox::Search::load_xapian();
+        bless {
+                qp_flags => $PublicInbox::Search::QP_FLAGS |
+                                PublicInbox::Search::FLAG_PURE_NOT(),
+        }, $class
+}
+
+sub attach_external {
+        my ($self, $ibxish) = @_; # ibxish = ExtSearch or Inbox
+        my $desc = $ibxish->{inboxdir} // $ibxish->{topdir};
+        my $srch = $ibxish->search //
+                return warn("$desc not indexed for Xapian ($@ $!)\n");
+        my @shards = $srch->xdb_shards_flat or
+                return warn("$desc has no Xapian shards\n");
+
+        if (delete $self->{xdb}) { # XXX: do we need this?
+                # clobber existing {xdb} if amending
+                my $expect = delete $self->{nshard};
+                my $shards = delete $self->{shards_flat};
+                scalar(@$shards) == $expect or die
+                        "BUG: {nshard}$expect != shards=".scalar(@$shards);
+
+                my $prev = {};
+                for my $old_ibxish (@{$self->{shard2ibx}}) {
+                        next if $prev == $old_ibxish;
+                        $prev = $old_ibxish;
+                        my @shards = $old_ibxish->search->xdb_shards_flat;
+                        push @{$self->{shards_flat}}, @shards;
+                }
+                my $nr = scalar(@{$self->{shards_flat}});
+                $nr == $expect or die
+                        "BUG: reloaded $nr shards, expected $expect"
+        }
+        push @{$self->{shards_flat}}, @shards;
+        push(@{$self->{shard2ibx}}, $ibxish) for (@shards);
+}
+
+# returns a list of local inboxes (or count in scalar context)
+sub locals { @{$_[0]->{locals} // []} }
+
+sub remotes { @{$_[0]->{remotes} // []} }
+
+# called by PublicInbox::Search::xdb (usually via ->mset)
+sub xdb_shards_flat { @{$_[0]->{shards_flat} // []} }
+
+sub _mitem_kw { # retry_reopen callback
+        my ($srch, $smsg, $mitem, $flagged) = @_;
+        my $doc = $mitem->get_document;
+        my $kw = xap_terms('K', $doc);
+        $kw->{flagged} = 1 if $flagged;
+        my @L = xap_terms('L', $doc);
+        # we keep the empty {kw} array here to prevent expensive work in
+        # ->xsmsg_vmd, _unbless_smsg will clobber it iff it's empty
+        $smsg->{kw} = [ sort keys %$kw ];
+        $smsg->{L} = \@L if scalar(@L);
+}
+
+sub mitem_kw ($$$;$) {
+        my ($srch, $smsg, $mitem, $flagged) = @_;
+        $srch->retry_reopen(\&_mitem_kw, $smsg, $mitem, $flagged);
+}
+
+# like over->get_art
+sub smsg_for {
+        my ($self, $mitem) = @_;
+        # cf. https://trac.xapian.org/wiki/FAQ/MultiDatabaseDocumentID
+        my $nshard = $self->{nshard};
+        my $docid = $mitem->get_docid;
+        my $shard = ($docid - 1) % $nshard;
+        my $num = int(($docid - 1) / $nshard) + 1;
+        my $ibx = $self->{shard2ibx}->[$shard];
+        my $smsg = $ibx->over->get_art($num);
+        return if $smsg->{bytes} == 0; # external message
+        if ($ibx->can('msg_keywords')) {
+                mitem_kw($self, $smsg, $mitem);
+        }
+        $smsg;
+}
+
+sub over {}
+
+sub _check_mset_limit ($$$) {
+        my ($lei, $desc, $mset) = @_;
+        return if defined($lei->{opt}->{limit}); # user requested limit
+        my $est = $mset->get_matches_estimated;
+        my $tot = $lei->{mset_opt}->{total};
+        $est > $tot and $lei->qerr(<<"");
+# $desc estimated matches ($est) exceeds default --limit=$tot
+
+}
+
+sub _mset_more ($$) {
+        my ($mset, $mo) = @_;
+        my $size = $mset->size;
+        $size >= $mo->{limit} && (($mo->{offset} += $size) < $mo->{total});
+}
+
+# $startq will see `q' in do_post_augment -> start_mua if spawning MUA.
+# Otherwise $startq will EOF when do_augment is done augmenting and allow
+# query_combined_mset and query_thread_mset to proceed.
+sub wait_startq ($) {
+        my ($lei) = @_;
+        read(delete($lei->{startq}) // return, my $buf, 1) or return; # EOF
+        die "BUG: wrote `$buf' to au_done" if $buf ne 'q';
+        $lei->{opt}->{quiet} = 1;
+        delete $lei->{opt}->{verbose};
+        delete $lei->{-progress};
+}
+
+sub mset_progress {
+        my $lei = shift;
+        return if $lei->{early_mua} || !$lei->{-progress};
+        if ($lei->{pkt_op_p}) {
+                $lei->{pkt_op_p}->pkt_do('mset_progress', @_);
+        } else { # single lei-daemon consumer
+                my ($desc, $mset_size, $mset_total_est) = @_;
+                $lei->{-mset_total} += $mset_size if $mset_total_est ne '?';
+                $lei->qerr("# $desc $mset_size/$mset_total_est");
+        }
+}
+
+sub query_one_mset { # for --threads and l2m w/o sort
+        my ($self, $ibxish) = @_;
+        my $lei = $self->{lei};
+        my ($srch, $over) = ($ibxish->search, $ibxish->over);
+        my $dir = $ibxish->{inboxdir} // $ibxish->{topdir};
+        return warn("$dir not indexed by Xapian\n") unless ($srch && $over);
+        bless $srch, 'PublicInbox::LeiSearch'; # for ->qparse_new
+        my $mo = { %{$lei->{mset_opt}} }; # copy
+        local $0 = "$0 1 $mo->{qstr}";
+        my $mset;
+        my $each_smsg = $lei->{ovv}->ovv_each_smsg_cb($lei);
+        my $can_kw = !!$ibxish->can('msg_keywords');
+        my $threads = $lei->{opt}->{threads} // 0;
+        my $fl = $threads > 1 ? 1 : undef;
+        my $mid = $lei->{opt}->{'thread-id'};
+        $mo->{threadid} = $over->mid2tid($mid) if defined $mid;
+        my $lss = $lei->{lss};
+        my $maxk = "external.$dir.maxuid"; # max of previous, so our min
+        my $min = $lss ? ($lss->{-cfg}->{$maxk} // 0) : 0;
+        ref($min) and return warn("$maxk=$min has multiple values\n");
+        ($min =~ /[^0-9]/) and return warn("$maxk=$min not numeric\n");
+        my $first_ids;
+        do {
+                $mset = eval { $srch->mset($mo->{qstr}, $mo) };
+                return $lei->child_error(22 << 8, "E: $@") if $@; # 22 from curl
+                mset_progress($lei, $dir, $mo->{offset} + $mset->size,
+                                $mset->get_matches_estimated);
+                wait_startq($lei); # wait for keyword updates
+                my $ids = $srch->mset_to_artnums($mset, $mo);
+                my $i = 0;
+                if ($threads) {
+                        # copy $ids if $lss since over->expand_thread
+                        # shifts @{$ctx->{ids}}
+                        $first_ids = [ @$ids ] if $lss;
+                        my $ctx = { ids => $ids, min => $min };
+                        my %n2item = map { $ids->[$i++] => $_ } $mset->items;
+                        while ($over->expand_thread($ctx)) { # fills {xids}
+                                for my $n (@{delete $ctx->{xids}}) {
+                                        my $smsg = $over->get_art($n) or next;
+                                        my $mi = delete $n2item{$n};
+                                        next if $smsg->{bytes} == 0;
+                                        if ($mi && $can_kw) {
+                                                mitem_kw($srch, $smsg, $mi, $fl)
+                                        } elsif ($mi && $fl) {
+                                                # call ->xsmsg_vmd, later
+                                                $smsg->{lei_q_tt_flagged} = 1;
+                                        }
+                                        $each_smsg->($smsg, $mi);
+                                }
+                        }
+                } else {
+                        $first_ids = $ids;
+                        my @items = $mset->items; # parallel with @$ids
+                        for my $n (@$ids) {
+                                my $mitem = $items[$i++];
+                                next if $n <= $min;
+                                my $smsg = $over->get_art($n) or next;
+                                next if $smsg->{bytes} == 0;
+                                mitem_kw($srch, $smsg, $mitem, $fl) if $can_kw;
+                                $each_smsg->($smsg, $mitem);
+                        }
+                }
+        } while (_mset_more($mset, $mo));
+        _check_mset_limit($lei, $dir, $mset);
+        if ($lss && scalar(@$first_ids)) {
+                my $max = $first_ids->[0];
+                $lss->cfg_set($maxk, $max);
+                undef $lss;
+        }
+        undef $each_smsg; # may commit
+        $lei->{ovv}->ovv_atexit_child($lei);
+}
+
+sub query_combined_mset { # non-parallel for non-"--threads" users
+        my ($self) = @_;
+        my $lei = $self->{lei};
+        my $mo = { %{$lei->{mset_opt}} };
+        local $0 = "$0 C $mo->{qstr}";
+        my $mset;
+        for my $loc (locals($self)) {
+                attach_external($self, $loc);
+        }
+        my $each_smsg = $lei->{ovv}->ovv_each_smsg_cb($lei);
+        do {
+                $mset = eval { $self->mset($mo->{qstr}, $mo) };
+                return $lei->child_error(22 << 8, "E: $@") if $@; # 22 from curl
+                mset_progress($lei, 'xsearch', $mo->{offset} + $mset->size,
+                                $mset->get_matches_estimated);
+                wait_startq($lei); # wait for keyword updates
+                for my $mitem ($mset->items) {
+                        my $smsg = smsg_for($self, $mitem) or next;
+                        $each_smsg->($smsg, $mitem);
+                }
+        } while (_mset_more($mset, $mo));
+        _check_mset_limit($lei, 'xsearch', $mset);
+        undef $each_smsg; # may commit
+        $lei->{ovv}->ovv_atexit_child($lei);
+}
+
+sub _smsg_fill ($$) {
+        my ($smsg, $eml) = @_;
+        $smsg->populate($eml);
+        $smsg->parse_references($eml, mids($eml));
+        $smsg->{$_} //= '' for qw(from to cc ds subject references mid);
+        delete @$smsg{qw(From Subject -ds -ts)};
+}
+
+sub each_remote_eml { # callback for MboxReader->mboxrd
+        my ($eml, $self, $lei, $each_smsg) = @_;
+        my $xoids = $lei->{ale}->xoids_for($eml, 1);
+        my $smsg = bless {}, 'PublicInbox::Smsg';
+        if ($self->{import_sto} && !$xoids) {
+                my ($res, $kw) = $self->{import_sto}->wq_do('add_eml', $eml);
+                if (ref($res) eq ref($smsg)) { # totally new message
+                        $smsg = $res;
+                        $self->{-sto_imported} = 1;
+                }
+                $smsg->{kw} = $kw; # short-circuit xsmsg_vmd
+        }
+        $smsg->{blob} //= $xoids ? (keys(%$xoids))[0]
+                                : $lei->git_oid($eml)->hexdigest;
+        _smsg_fill($smsg, $eml);
+        wait_startq($lei);
+        my $nr = ++$lei->{-nr_remote_eml}; # needed for lss->cfg_set
+        if ($lei->{-progress}) {
+                my $now = now();
+                my $next = $lei->{-next_progress} //= ($now + 1);
+                if ($now > $next) {
+                        $lei->{-next_progress} = $now + 1;
+                        mset_progress($lei, $lei->{-current_url}, $nr, '?');
+                }
+        }
+        $each_smsg->($smsg, undef, $eml);
+}
+
+sub fudge_qstr_time ($$$) {
+        my ($lei, $uri, $qstr) = @_;
+        return ($qstr, undef) unless $lei->{lss};
+        my $cfg = $lei->{lss}->{-cfg} // die 'BUG: no lss->{-cfg}';
+        my $cfg_key = "external.$uri.lastresult";
+        my $lr = $cfg->{$cfg_key} or return ($qstr, $cfg_key);
+        if ($lr !~ /\A\-?[0-9]+\z/) {
+                $lei->child_error(0,
+                        "$cfg->{-f}: $cfg_key=$lr not an integer, ignoring");
+                return ($qstr, $cfg_key);
+        }
+        my $rft = $lei->{opt}->{'remote-fudge-time'};
+        if ($rft && $rft !~ /\A-?[0-9]+\z/) {
+                my @t = $lei->{lss}->git->date_parse($rft);
+                my $diff = time - $t[0];
+                $lei->qerr("# $rft => $diff seconds");
+                $rft = $diff;
+        }
+        $lr -= ($rft || (48 * 60 * 60));
+        require PublicInbox::Admin;
+        $lei->qerr("# $uri limiting to ".
+                PublicInbox::Admin::fmt_localtime($lr).' and newer');
+        # this should really be rt: (received-time), but no stable
+        # public-inbox releases support it, yet.
+        my $dt = 'dt:'.strftime('%Y%m%d%H%M%S', gmtime($lr)).'..';
+        if ($qstr =~ /\S/) {
+                substr($qstr, 0, 0, '(');
+                $qstr .= ') AND ';
+        }
+        ($qstr .= $dt, $cfg_key);
+}
+
+sub query_remote_mboxrd {
+        my ($self, $uris) = @_;
+        local $SIG{TERM} = sub { exit(0) }; # for DESTROY (File::Temp, $reap)
+        my $lei = $self->{lei};
+        my $opt = $lei->{opt};
+        my $qstr = $lei->{mset_opt}->{qstr};
+        local $0 = "$0 R $qstr";
+        my @qform = (x => 'm');
+        push(@qform, t => 1) if $opt->{threads};
+        open my $cerr, '+>', undef;
+        my $rdr = { 2 => $cerr };
+        my @lbf_tee;
+        if ($opt->{verbose}) {
+                # spawn a line-buffered tee(1) script, otherwise curl
+                # will write 1 character at-a-time and parallel outputs
+                # mmmaaayyy llloookkk llliiikkkeee ttthhhiiisss
+                # (n.b. POSIX tee(1) cannot do any buffering)
+                my $o = { 1 => $cerr, 2 => $lei->{2} };
+                delete $rdr->{2};
+                @lbf_tee = ([ $^X, qw(-w -p -e), <<'' ], undef, $o);
+BEGIN { $| = 1; use IO::Handle; STDERR->autoflush(1); }
+print STDERR $_;
+
+        }
+        my $curl = PublicInbox::LeiCurl->new($lei, $self->{curl}) or return;
+        push @$curl, '-s', '-d', '';
+        my $each_smsg = $lei->{ovv}->ovv_each_smsg_cb($lei);
+        $self->{import_sto} = $lei->{sto} if $lei->{opt}->{'import-remote'};
+        if (defined(my $mid = $opt->{'thread-id'})) {
+                $mid = mid_escape($mid);
+                for my $uri (@$uris) {
+                        $uri->path($uri->path.$mid.'/');
+                }
+        }
+        for my $uri (@$uris) {
+                $lei->{-current_url} = $uri->as_string;
+                my $start = time;
+                my ($q, $key) = fudge_qstr_time($lei, $uri, $qstr);
+                $uri->query_form(@qform, q => $q);
+                my $cmd = $curl->for_uri($lei, $uri);
+                $lei->qerr("# $cmd");
+                $rdr->{2} //= popen_wr(@lbf_tee) if @lbf_tee;
+                my $fh = popen_rd($cmd, undef, $rdr);
+                $fh = IO::Uncompress::Gunzip->new($fh,
+                                        MultiStream => 1, AutoClose => 1);
+                eval {
+                        PublicInbox::MboxReader->mboxrd($fh, \&each_remote_eml,
+                                                $self, $lei, $each_smsg);
+                };
+                my ($exc, $code) = ($@, $?);
+                $lei->sto_barrier_request if delete($self->{-sto_imported});
+                die "E: $exc" if $exc && !$code;
+                my $nr = delete $lei->{-nr_remote_eml} // 0;
+                if (!$code) { # don't update if no results, maybe MTA is down
+                        $lei->{lss}->cfg_set($key, $start) if $key && $nr;
+                        mset_progress($lei, $lei->{-current_url}, $nr, $nr);
+                        next;
+                }
+                delete($rdr->{2})->close if @lbf_tee;
+                seek($cerr, 0, SEEK_SET);
+                read($cerr, my $err, -s $cerr);
+                truncate($cerr, 0);
+                next if (($code >> 8) == 22 && $err =~ /\b404\b/);
+                $uri->query_form(q => $qstr);
+                $lei->child_error($code, "E: <$uri> `$cmd` failed");
+        }
+        undef $each_smsg;
+        $lei->{ovv}->ovv_atexit_child($lei);
+}
+
+sub git { $_[0]->{git} // die 'BUG: git uninitialized' }
+
+sub xsearch_done_wait { # awaitpid cb
+        my ($pid, $wq, $lei) = @_;
+        return if !$?;
+        my $s = $? & 127;
+        return $lei->child_error($?) if $s == 13 || $s == 15;
+        $lei->child_error($?, 'non-fatal error from '.ref($wq)." \$?=$?");
+}
+
+sub query_done { # EOF callback for main daemon
+        my ($lei) = @_;
+        my $l2m = delete $lei->{l2m};
+        delete $lei->{lxs};
+        ($lei->{opt}->{'mail-sync'} && !$lei->{sto}) and
+                warn "BUG: {sto} missing with --mail-sync";
+        $lei->sto_barrier_request;
+        $lei->{ovv}->ovv_end($lei);
+        if ($l2m) { # close() calls LeiToMail reap_compress
+                $l2m->finish_output($lei);
+                if ($l2m->lock_free) {
+                        $l2m->poke_dst;
+                        $lei->poke_mua;
+                } else { # mbox users
+                        delete $l2m->{mbl}; # drop dotlock
+                }
+        }
+        my $nr_w = delete($lei->{-nr_write}) // 0;
+        my $nr_dup = (delete($lei->{-nr_seen}) // 0) - $nr_w;
+        if ($lei->{-progress}) {
+                my $tot = $lei->{-mset_total} // 0;
+                my $x = "$tot matches";
+                $x .= ", $nr_dup duplicates" if $nr_dup;
+                if ($l2m) {
+                        my $m = "# $nr_w written to " .
+                                "$lei->{ovv}->{dst} ($x)";
+                        $nr_w ? $lei->qfin($m) : $lei->qerr($m);
+                } else {
+                        $lei->qerr("# $x");
+                }
+        }
+        $lei->start_mua if $l2m && !$l2m->lock_free;
+        $lei->dclose;
+}
+
+sub post_augment_done { # via on_destroy in top-level lei-daemon
+        my ($lei) = @_;
+        my $err = delete $lei->{post_augment_err};
+        if ($err) {
+                if (my $lxs = delete $lei->{lxs}) {
+                        $lxs->wq_kill(-POSIX::SIGTERM());
+                        $lxs->wq_close;
+                }
+                $lei->fail("$err");
+        }
+        if (!$err && delete $lei->{early_mua}) { # non-augment case
+                eval { $lei->start_mua }; # may trigger wait_startq
+                $lei->fail($@) if $@;
+        }
+        close(delete $lei->{au_done}); # trigger wait_startq if start_mua didn't
+}
+
+sub do_post_augment {
+        my ($lei) = @_;
+        my $l2m = $lei->{l2m} or return; # client disconnected
+        $l2m->post_augment($lei, on_destroy(\&post_augment_done, $lei));
+}
+
+sub incr_post_augment { # called whenever an l2m shard finishes augment
+        my ($lei) = @_;
+        my $l2m = $lei->{l2m} or return; # client disconnected
+        return if ++$lei->{nr_post_augment} != $l2m->{-wq_nr_workers};
+        do_post_augment($lei);
+}
+
+my $MAX_PER_HOST = 4;
+
+sub concurrency {
+        my ($self, $opt) = @_;
+        my $nl = $opt->{threads} ? locals($self) : 1;
+        my $nr = remotes($self);
+        $nr = $MAX_PER_HOST if $nr > $MAX_PER_HOST;
+        $nl + $nr;
+}
+
+sub start_query ($$) { # always runs in main (lei-daemon) process
+        my ($self, $lei) = @_;
+        local $PublicInbox::LEI::current_lei = $lei;
+        if ($lei->{opt}->{threads} ||
+                        defined($lei->{opt}->{'thread-id'}) ||
+                        ($lei->{l2m} && !$lei->{opt}->{'sort'})) {
+                for my $ibxish (locals($self)) {
+                        $self->wq_io_do('query_one_mset', [], $ibxish);
+                }
+        } elsif (locals($self)) {
+                $self->wq_io_do('query_combined_mset', []);
+        }
+        my $i = 0;
+        my $q = [];
+        for my $uri (remotes($self)) {
+                push @{$q->[$i++ % $MAX_PER_HOST]}, $uri;
+        }
+        for my $uris (@$q) {
+                $self->wq_io_do('query_remote_mboxrd', [], $uris);
+        }
+        if ($self->{-do_lcat}) {
+                $self->wq_io_do('lcat_dump', []);
+        }
+        $self->wq_close; # lei_xsearch workers stop when done
+}
+
+sub incr_start_query { # called whenever an l2m shard starts do_post_auth
+        my ($lei, $self) = @_;
+        my $l2m = $lei->{l2m};
+        return if ++$self->{nr_start_query} != $l2m->{-wq_nr_workers};
+        start_query($self, $lei);
+}
+
+sub ipc_atfork_child {
+        my ($self) = @_;
+        $self->{lei}->_lei_atfork_child;
+        $self->SUPER::ipc_atfork_child;
+}
+
+sub do_query {
+        my ($self, $lei) = @_;
+        my $l2m = $lei->{l2m};
+        my $qstr = \($lei->{mset_opt}->{qstr});
+        chomp $$qstr;
+        $$qstr =~ s/[ \n\t]+/ /sg; # make URLs and $0 less ugly
+        my $ops = {
+                sigpipe_handler => [ $lei ],
+                fail_handler => [ $lei ],
+                do_post_augment => [ \&do_post_augment, $lei ],
+                incr_post_augment => [ \&incr_post_augment, $lei ],
+                '' => [ \&query_done, $lei ],
+                mset_progress => [ \&mset_progress, $lei ],
+                incr => [ $lei ],
+                x_it => [ $lei ],
+                child_error => [ $lei ],
+                incr_start_query => [ \&incr_start_query, $lei, $self ],
+        };
+        $lei->{auth}->op_merge($ops, $l2m, $lei) if $l2m && $lei->{auth};
+        my $end = $lei->pkt_op_pair;
+        $lei->{1}->autoflush(1);
+        $lei->start_pager if delete $lei->{need_pager};
+        $lei->{ovv}->ovv_begin($lei);
+        die 'BUG: xdb|over open' if $lei->{lse}->{xdb} || $lei->{lse}->{over};
+        if ($l2m) {
+                $l2m->pre_augment($lei);
+                if ($lei->{opt}->{augment} && delete $lei->{early_mua}) {
+                        $lei->start_mua;
+                }
+                if ($l2m->{-wq_nr_workers} > 1 &&
+                                $l2m->{base_type} =~ /\A(?:maildir|mbox)\z/) {
+                        # setup two barriers to coordinate ->has_entries
+                        # between l2m workers
+                        pipe(my ($a_r, $a_w)) or die "pipe: $!";
+                        fcntl($a_r, $F_SETPIPE_SZ, 4096) if $F_SETPIPE_SZ;
+                        pipe(my ($b_r, $b_w)) or die "pipe: $!";
+                        fcntl($b_r, $F_SETPIPE_SZ, 4096) if $F_SETPIPE_SZ;
+                        $l2m->{au_peers} = [ $a_r, $a_w, $b_r, $b_w ];
+                }
+                $l2m->wq_workers_start('lei2mail', undef,
+                                        $lei->oldset, { lei => $lei },
+                                        \&xsearch_done_wait, $lei);
+                pipe($lei->{startq}, $lei->{au_done}) or die "pipe: $!";
+                fcntl($lei->{startq}, $F_SETPIPE_SZ, 4096) if $F_SETPIPE_SZ;
+                delete $l2m->{au_peers};
+                close(delete $l2m->{-wq_s2}); # share wq_s1 with lei_xsearch
+        }
+        $self->wq_workers_start('lei_xsearch', undef,
+                                $lei->oldset, { lei => $lei },
+                                \&xsearch_done_wait, $lei);
+        my $op_c = delete $lei->{pkt_op_c};
+        delete $lei->{pkt_op_p};
+        @$end = ();
+        $self->{-do_lcat} = !!(delete $lei->{lcat_todo});
+        if ($l2m) {
+                $l2m->net_merge_all_done($lei) unless $lei->{auth};
+        } else {
+                start_query($self, $lei);
+        }
+        $lei->event_step_init; # wait for shutdowns
+        $lei->wait_wq_events($op_c, $ops);
+}
+
+sub add_uri {
+        my ($self, $uri) = @_;
+        if (my $curl = $self->{curl} //= which('curl') // 0) {
+                require PublicInbox::MboxReader;
+                require IO::Uncompress::Gunzip;
+                require PublicInbox::LeiCurl;
+                push @{$self->{remotes}}, $uri;
+                $uri;
+        } else {
+                warn "curl missing, ignoring $uri\n";
+                undef;
+        }
+}
+
+# returns URI or PublicInbox::Inbox-like object
+sub prepare_external {
+        my ($self, $loc, $boost) = @_; # n.b. already ordered by boost
+        if (ref $loc) { # already a URI, or PublicInbox::Inbox-like object
+                return add_uri($self, $loc) if $loc->can('scheme');
+                # fall-through on Inbox-like objects
+        } elsif ($loc =~ m!\Ahttps?://!) {
+                require URI;
+                return add_uri($self, URI->new($loc));
+        } elsif (-f "$loc/ei.lock" && -d "$loc/ALL.git/objects") {
+                require PublicInbox::ExtSearch;
+                die "`\\n' not allowed in `$loc'\n" if index($loc, "\n") >= 0;
+                $loc = PublicInbox::ExtSearch->new($loc);
+        } elsif ((-f "$loc/inbox.lock" && -d "$loc/all.git/objects") ||
+                        (-d "$loc/public-inbox" && -d "$loc/objects")) {
+                die "`\\n' not allowed in `$loc'\n" if index($loc, "\n") >= 0;
+                require PublicInbox::Inbox; # v2, v1
+                $loc = bless { inboxdir => $loc }, 'PublicInbox::Inbox';
+        } elsif (!-e $loc) {
+                warn "W: $loc gone, perhaps run: lei forget-external $loc\n";
+                return undef;
+        } else {
+                warn "W: $loc ignored, unable to determine external type\n";
+                return undef;
+        }
+        push @{$self->{locals}}, $loc;
+        $loc;
+}
+
+sub _lcat_i { # LeiMailSync->each_src iterator callback
+        my ($oidbin, $id, $each_smsg) = @_;
+        $each_smsg->({blob => unpack('H*', $oidbin), pct => 100});
+}
+
+sub _lcat2smsg { # git->cat_async callback
+        my ($bref, $oid, $type, $size, $smsg) = @_;
+        if ($bref) {
+                my $eml = PublicInbox::Eml->new($bref);
+                my $json_dump = delete $smsg->{-json_dump};
+                bless $smsg, 'PublicInbox::Smsg';
+                _smsg_fill($smsg, $eml);
+                $json_dump->($smsg, undef, $eml);
+        }
+}
+
+sub lcat_dump { # via wq_io_do
+        my ($self) = @_;
+        my $lei = $self->{lei};
+        my $each_smsg = $lei->{ovv}->ovv_each_smsg_cb($lei);
+        my $git = $lei->{ale}->git;
+        if (!$lei->{l2m}) {
+                my $json_dump = $each_smsg;
+                $each_smsg = sub {
+                        my ($smsg) = @_;
+                        $smsg->{-json_dump} = $json_dump;
+                        $git->cat_async($smsg->{blob}, \&_lcat2smsg, $smsg);
+                };
+        }
+        my $lms;
+        for my $ent (@{$lei->{lcat_todo}}) {
+                if (ref $ent eq 'HASH') { # { fid => $fid ,.. }
+                        $lms //= $lei->{lse}->lms;
+                        $lms->each_src($ent, \&_lcat_i, $each_smsg);
+                } else { # oidhex
+                        $each_smsg->({ blob => $ent, pct => 100 });
+                }
+        }
+        $git->async_wait_all;
+        undef $each_smsg; # may commit
+        $lei->{ovv}->ovv_atexit_child($lei);
+}
+
+1;