[PATCH 3/4] lei: avoid extra fork for v2 outputs

[Eric Wong]

We've always forced LeiToMail to only have one process for v2
outputs anyways since v2 has its own sharding and IPC.  Thus we
can use the single LeiToMail process directly to avoid extra IPC
overhead.
---
 lib/PublicInbox/LeiConvert.pm |  7 ++-----
 lib/PublicInbox/LeiToMail.pm  | 19 +++++++++----------
 lib/PublicInbox/LeiXSearch.pm |  6 +-----
 lib/PublicInbox/V2Writable.pm |  2 --
 4 files changed, 12 insertions(+), 22 deletions(-)

diff --git a/lib/PublicInbox/LeiConvert.pm b/lib/PublicInbox/LeiConvert.pm
index 4a1f8323..9d2479b0 100644
--- a/lib/PublicInbox/LeiConvert.pm
+++ b/lib/PublicInbox/LeiConvert.pm
@@ -35,12 +35,9 @@ sub process_inputs { # via wq_do
        my $lei = $self->{lei};
        delete $lei->{1};
        my $l2m = delete $lei->{l2m};
-       my $nr_w = delete($l2m->{-nr_write}) // 0;
        delete $self->{wcb}; # commit
-       if (my $v2w = delete $lei->{v2w}) {
-               $nr_w = $v2w->wq_do('done'); # may die
-               $v2w->wq_close;
-       }
+       if (my $v2w = delete $lei->{v2w}) { $v2w->done } # may die
+       my $nr_w = delete($l2m->{-nr_write}) // 0;
        my $d = (delete($l2m->{-nr_seen}) // 0) - $nr_w;
        $d = $d ? " ($d duplicates)" : '';
        $lei->qerr("# converted $nr_w messages$d");
diff --git a/lib/PublicInbox/LeiToMail.pm b/lib/PublicInbox/LeiToMail.pm
index 2d9b7061..0d62888d 100644
--- a/lib/PublicInbox/LeiToMail.pm
+++ b/lib/PublicInbox/LeiToMail.pm
@@ -369,12 +369,14 @@ sub _v2_write_cb ($$) {
        my ($self, $lei) = @_;
        my $dedupe = $lei->{dedupe};
        $dedupe->prepare_dedupe if $dedupe;
+       # only call in worker
+       $PublicInbox::Import::DROP_UNIQUE_UNSUB = $lei->{-drop_unique_unsub};
        sub { # for git_to_mail
                my ($bref, $smsg, $eml) = @_;
                $eml //= PublicInbox::Eml->new($bref);
                ++$self->{-nr_seen};
                return if $dedupe && $dedupe->is_dup($eml, $smsg);
-               $lei->{v2w}->wq_do('add', $eml); # V2Writable->add
+               $lei->{v2w}->add($eml) and ++$self->{-nr_write};
        }
 }
 
@@ -647,11 +649,6 @@ sub _do_augment_mbox {
        $dedupe->pause_dedupe if $dedupe;
 }
 
-sub v2w_done_wait { # awaitpid cb
-       my ($pid, $v2w, $lei) = @_;
-       $lei->child_error($?, "error for $v2w->{ibx}->{inboxdir}") if $?;
-}
-
 sub _pre_augment_v2 {
        my ($self, $lei) = @_;
        my $dir = $self->{dst};
@@ -677,11 +674,9 @@ sub _pre_augment_v2 {
                $lei->x_it(shift);
                die "E: can't write v2 inbox with broken config\n";
        });
+       $lei->{-drop_unique_unsub} = $PublicInbox::Import::DROP_UNIQUE_UNSUB;
        $ibx->init_inbox if @creat;
-       my $v2w = $ibx->importer;
-       $v2w->wq_workers_start("lei/v2w $dir", 1, $lei->oldset, {lei => $lei},
-                               \&v2w_done_wait, $lei);
-       $lei->{v2w} = $v2w;
+       $lei->{v2w} = $ibx->importer;
        return if !$lei->{opt}->{shared};
        my $d = "$lei->{ale}->{git}->{git_dir}/objects";
        open my $fh, '+>>', my $f = "$dir/git/0.git/objects/info/alternates";
@@ -806,6 +801,10 @@ sub wq_atexit_child {
        my $lei = $self->{lei};
        $lei->{ale}->git->async_wait_all;
        my ($nr_w, $nr_s) = delete(@$self{qw(-nr_write -nr_seen)});
+       if (my $v2w = delete $lei->{v2w}) {
+               eval { $v2w->done };
+               $lei->child_error($?, "E: $@ ($v2w->{ibx}->{inboxdir})") if $@;
+       }
        delete $self->{wcb};
        (($nr_w //= 0) + ($nr_s //= 0)) or return;
        return if $lei->{early_mua} || !$lei->{-progress} || !$lei->{pkt_op_p};
diff --git a/lib/PublicInbox/LeiXSearch.pm b/lib/PublicInbox/LeiXSearch.pm
index 7eda6f9e..5e36c11a 100644
--- a/lib/PublicInbox/LeiXSearch.pm
+++ b/lib/PublicInbox/LeiXSearch.pm
@@ -391,11 +391,6 @@ sub query_done { # EOF callback for main daemon
        ($lei->{opt}->{'mail-sync'} && !$lei->{sto}) and
                warn "BUG: {sto} missing with --mail-sync";
        $lei->sto_done_request;
-       my $nr_w = delete($lei->{-nr_write}) // 0;
-       if (my $v2w = delete $lei->{v2w}) {
-               $nr_w = $v2w->wq_do('done'); # may die
-               $v2w->wq_close;
-       }
        $lei->{ovv}->ovv_end($lei);
        if ($l2m) { # close() calls LeiToMail reap_compress
                if (my $out = delete $lei->{old_1}) {
@@ -413,6 +408,7 @@ Error closing $lei->{ovv}->{dst}: \$!=$! \$?=$?
                        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 = $lei->{-mset_total} // 0;
diff --git a/lib/PublicInbox/V2Writable.pm b/lib/PublicInbox/V2Writable.pm
index 231ed516..fb259396 100644
--- a/lib/PublicInbox/V2Writable.pm
+++ b/lib/PublicInbox/V2Writable.pm
@@ -135,7 +135,6 @@ sub add {
        if (do_idx($self, $mime, $smsg)) {
                $self->checkpoint;
        }
-       ++$self->{-nr_add}; # for lei convert
        $cmt;
 }
 
@@ -611,7 +610,6 @@ sub done {
        $self->lock_release(!!$nbytes) if $shards;
        $self->git->cleanup;
        die $err if $err;
-       delete $self->{-nr_add}; # for lei-convert
 }
 
 sub importer {