lei_to_mail: improve comments and reduce LoC

We don't need to waste LoC on corner cases, single-use internal
subs, or restoring SIG{__WARN__} when a process exits.  All that
extra code contributes to memory use and startup time, especially
for users who can't use FD passing.

diff --git a/lib/PublicInbox/LeiToMail.pm b/lib/PublicInbox/LeiToMail.pm
index 2e736070ed7e23880dd7b2c38112e270174ce5f1..9411313bae891c29fa3eafae78567306fefd665a 100644 (file)
--- a/lib/PublicInbox/LeiToMail.pm
+++ b/lib/PublicInbox/LeiToMail.pm
@@ -138,18 +138,11 @@ sub eml2mboxcl2 {
 
 sub git_to_mail { # git->cat_async callback
        my ($bref, $oid, $type, $size, $arg) = @_;
-       if ($type ne 'blob') {
-               if ($type eq 'missing') {
-                       warn "missing $oid\n";
-               } else {
-                       warn "unexpected type=$type for $oid\n";
-               }
-       }
+       return warn("W: $oid is $type (!= blob)\n") if $type ne 'blob';
+       return warn("E: $oid is empty\n") unless $size;
        my ($write_cb, $smsg) = @$arg;
-       if ($smsg->{blob} ne $oid) {
-               die "BUG: expected=$smsg->{blob} got=$oid";
-       }
-       $write_cb->($bref, $smsg) if $size > 0;
+       die "BUG: expected=$smsg->{blob} got=$oid" if $smsg->{blob} ne $oid;
+       $write_cb->($bref, $smsg);
 }
 
 sub reap_compress { # dwaitpid callback
@@ -159,7 +152,7 @@ sub reap_compress { # dwaitpid callback
        $lei->fail("@$cmd failed", $? >> 8);
 }
 
-sub _post_augment_mbox { # open a compressor process
+sub _post_augment_mbox { # open a compressor process from top-level process
        my ($self, $lei) = @_;
        my $zsfx = $self->{zsfx} or return;
        my $cmd = PublicInbox::MboxReader::zsfx2cmd($zsfx, undef, $lei);
@@ -173,12 +166,6 @@ sub _post_augment_mbox { # open a compressor process
        $lei->{1} = $pp;
 }
 
-sub dup_src ($) {
-       my ($in) = @_;
-       open my $dup, '+>>&', $in or die "dup: $!";
-       $dup;
-}
-
 # --augment existing output destination, with deduplication
 sub _augment { # MboxReader eml_cb
        my ($eml, $lei) = @_;
@@ -309,7 +296,7 @@ sub _imap_write_cb ($$) {
        my $lse = $lei->{lse}; # may be undef
        sub { # for git_to_mail
                my ($bref, $smsg, $eml) = @_;
-               $mic // return $lei->fail; # dst may be undef-ed in last run
+               $mic // return $lei->fail; # mic may be undef-ed in last run
                if ($dedupe) {
                        $eml //= PublicInbox::Eml->new($$bref); # copy bref
                        return if $dedupe->is_dup($eml, $smsg->{blob});
@@ -488,9 +475,12 @@ sub _do_augment_mbox {
                truncate($out, 0) or die "truncate($dst): $!";
                return;
        }
-       my $zsfx = $self->{zsfx};
-       my $rd = $zsfx ? PublicInbox::MboxReader::zsfxcat($out, $zsfx, $lei)
-                       : dup_src($out);
+       my $rd;
+       if (my $zsfx = $self->{zsfx}) {
+               $rd = PublicInbox::MboxReader::zsfxcat($out, $zsfx, $lei);
+       } else {
+               open($rd, '+>>&', $out) or die "dup: $!";
+       }
        my $dedupe;
        if ($opt->{augment}) {
                $dedupe = $lei->{dedupe};
@@ -535,6 +525,7 @@ sub post_augment {
        $m->($self, $lei, @args);
 }
 
+# called by every single l2m worker process
 sub do_post_auth {
        my ($self) = @_;
        my $lei = $self->{lei};
@@ -542,7 +533,7 @@ sub do_post_auth {
        pkt_do($lei->{pkt_op_p}, 'incr_start_query') or
                die "incr_start_query: $!";
        my $aug;
-       if (lock_free($self)) {
+       if (lock_free($self)) { # all workers do_augment
                my $mod = $self->{-wq_nr_workers};
                my $shard = $self->{-wq_worker_nr};
                if (my $net = $lei->{net}) {
@@ -551,7 +542,7 @@ sub do_post_auth {
                        $self->{shard_info} = [ $mod, $shard ];
                }
                $aug = '+'; # incr_post_augment
-       } elsif ($self->{-wq_worker_nr} == 0) {
+       } elsif ($self->{-wq_worker_nr} == 0) { # 1st worker do_augment
                $aug = '.'; # do_post_augment
        }
        if ($aug) {
@@ -561,6 +552,7 @@ sub do_post_auth {
                pkt_do($lei->{pkt_op_p}, $aug) == 1 or
                                die "do_post_augment trigger: $!";
        }
+       # done augmenting, connect the compressor pipe for each worker
        if (my $zpipe = delete $lei->{zpipe}) {
                $lei->{1} = $zpipe->[1];
                close $zpipe->[0];
@@ -581,6 +573,7 @@ sub lock_free {
        $_[0]->{base_type} =~ /\A(?:maildir|imap|jmap)\z/ ? 1 : 0;
 }
 
+# wakes up the MUA when complete so it can refresh messages list
 sub poke_dst {
        my ($self) = @_;
        if ($self->{base_type} eq 'maildir') {
@@ -599,7 +592,6 @@ sub wq_atexit_child {
        my ($self) = @_;
        delete $self->{wcb};
        $self->{lei}->{ale}->git->async_wait_all;
-       $SIG{__WARN__} = 'DEFAULT';
 }
 
 # called in top-level lei-daemon when LeiAuth is done