lei_to_mail: support for non-seekable outputs

Users may wish to pipe output to "git am", "spamc",
or similar, so we need to support those cases and
not bail out on lseek(2) or ftruncate(2) failures.

diff --git a/lib/PublicInbox/LeiToMail.pm b/lib/PublicInbox/LeiToMail.pm
index 1c0f3108f632ec551bf5e3aad95802c961a92df4..4476d84cb430430f767556aab827fa71e4f9f4d0 100644 (file)
--- a/lib/PublicInbox/LeiToMail.pm
+++ b/lib/PublicInbox/LeiToMail.pm
@@ -12,7 +12,7 @@ use PublicInbox::Spawn qw(which spawn popen_rd);
 use PublicInbox::LeiDedupe;
 use Symbol qw(gensym);
 use IO::Handle; # ->autoflush
-use Fcntl qw(SEEK_SET);
+use Fcntl qw(SEEK_SET SEEK_END);
 
 my %kw2char = ( # Maildir characters
        draft => 'D',
@@ -236,26 +236,34 @@ sub _mbox_write_cb ($$$$) {
        my ($cls, $mbox, $dst, $lei) = @_;
        my $m = "eml2$mbox";
        my $eml2mbox = $cls->can($m) or die "$cls->$m missing";
-       my ($out, $pipe_lk);
-       open $out, '+>>', $dst or die "open $dst: $!";
-       # Perl does SEEK_END even with O_APPEND :<
-       seek($out, 0, SEEK_SET) or die "seek $dst: $!";
+       my ($out, $pipe_lk, $seekable);
+       # XXX should we support /dev/stdout.gz ?
+       if ($dst eq '/dev/stdout') {
+               $out = $lei->{1};
+       } else { # TODO: mbox locking
+               open $out, '+>>', $dst or die "open $dst: $!";
+               # Perl does SEEK_END even with O_APPEND :<
+               $seekable = seek($out, 0, SEEK_SET);
+               die "seek $dst: $!\n" if !$seekable && !$!{ESPIPE};
+       }
        my $jobs = $lei->{opt}->{jobs} // 0;
        my $atomic = $jobs > 1;
        my $dedupe = $lei->{dedupe} = PublicInbox::LeiDedupe->new($lei);
        state $zsfx_allow = join('|', keys %zsfx2cmd);
        my ($zsfx) = ($dst =~ /\.($zsfx_allow)\z/);
        if ($lei->{opt}->{augment}) {
-               if (-s $out && $dedupe->prepare_dedupe) {
+               if ($seekable && -s $out && $dedupe->prepare_dedupe) {
                        my $rd = $zsfx ? decompress_src($out, $zsfx, $lei) :
                                        dup_src($out);
                        PublicInbox::MboxReader->$mbox($rd, \&_augment, $lei);
+               } elsif ($seekable && !$atomic) {
+                       seek($out, 0, SEEK_END) or die "seek: $!";
                }
                $dedupe->pause_dedupe if $jobs; # are we forking?
-       } else {
+       } elsif ($seekable) {
                truncate($out, 0) or die "truncate $dst: $!";
-               $dedupe->prepare_dedupe if !$jobs;
        }
+       $dedupe->prepare_dedupe if !$jobs;
        ($out, $pipe_lk) = compress_dst($out, $zsfx, $lei) if $zsfx;
        sub {
                my ($buf, $oid, $kw) = @_;

diff --git a/t/lei_to_mail.t b/t/lei_to_mail.t
index 5be4e285efc65ddce089fd3f1fc969f26297afa0..f3cc71adfeb35e7738e499f86b2a4ae199553480 100644 (file)
--- a/t/lei_to_mail.t
+++ b/t/lei_to_mail.t
@@ -6,6 +6,7 @@ use v5.10.1;
 use Test::More;
 use PublicInbox::TestCommon;
 use PublicInbox::Eml;
+use Fcntl qw(SEEK_SET);
 require_mods(qw(DBD::SQLite));
 use_ok 'PublicInbox::LeiToMail';
 my $from = "Content-Length: 10\nSubject: x\n\nFrom hell\n";
@@ -120,15 +121,41 @@ for my $zsfx (qw(gz bz2 xz)) { # XXX should we support zst, zz, lzo, lzma?
 }
 
 unlink $fn or BAIL_OUT $!;
+require PublicInbox::MboxReader;
 if ('default deduplication uses content_hash') {
        my $wcb = PublicInbox::LeiToMail->write_cb("mboxo:$fn", $lei);
        $wcb->(\(my $x = $buf), 'deadbeef', []) for (1..2);
        undef $wcb; # undef to commit changes
        my $cmp = '';
        open my $fh, '<', $fn or BAIL_OUT $!;
-       require PublicInbox::MboxReader;
        PublicInbox::MboxReader->mboxo($fh, sub { $cmp .= shift->as_string });
        is($cmp, $buf, 'only one message written');
 }
 
+{ # stdout support
+       open my $tmp, '+>', undef or BAIL_OUT $!;
+       local $lei->{1} = $tmp;
+       my $wcb = PublicInbox::LeiToMail->write_cb("mboxrd:/dev/stdout", $lei);
+       $wcb->(\(my $x = $buf), 'deadbeef', []);
+       undef $wcb; # commit
+       seek($tmp, 0, SEEK_SET) or BAIL_OUT $!;
+       my $cmp = '';
+       PublicInbox::MboxReader->mboxrd($tmp, sub { $cmp .= shift->as_string });
+       is($cmp, $buf, 'message written to stdout');
+}
+
+SKIP: { # FIFO support
+       use PublicInbox::Spawn qw(popen_rd which);
+       use POSIX qw(mkfifo);
+       my $fn = "$tmpdir/fifo";
+       mkfifo($fn, 0600) or skip("mkfifo not supported: $!", 1);
+       my $cat = popen_rd([which('cat'), $fn]);
+       my $wcb = PublicInbox::LeiToMail->write_cb("mboxo:$fn", $lei);
+       $wcb->(\(my $x = $buf), 'deadbeef', []);
+       undef $wcb; # commit
+       my $cmp = '';
+       PublicInbox::MboxReader->mboxo($cat, sub { $cmp .= shift->as_string });
+       is($cmp, $buf, 'message written to FIFO');
+}
+
 done_testing;