user/dev discussion of public-inbox itself
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From: Eric Wong <e@80x24.org>
To: meta@public-inbox.org
Subject: [PATCH 12/36] lei_to_mail: support for non-seekable outputs
Date: Thu, 31 Dec 2020 13:51:30 +0000	[thread overview]
Message-ID: <20201231135154.6070-13-e@80x24.org> (raw)
In-Reply-To: <20201231135154.6070-1-e@80x24.org>

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.
---
 lib/PublicInbox/LeiToMail.pm | 24 ++++++++++++++++--------
 t/lei_to_mail.t              | 29 ++++++++++++++++++++++++++++-
 2 files changed, 44 insertions(+), 9 deletions(-)

diff --git a/lib/PublicInbox/LeiToMail.pm b/lib/PublicInbox/LeiToMail.pm
index 1c0f3108..4476d84c 100644
--- 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 5be4e285..f3cc71ad 100644
--- 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;

  parent reply	other threads:[~2020-12-31 13:51 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-31 13:51 [PATCH 00/36] another round of lei stuff Eric Wong
2020-12-31 13:51 ` [PATCH 01/36] import: respect init.defaultBranch Eric Wong
2020-12-31 13:51 ` [PATCH 02/36] lei_store: use per-machine refname as git HEAD Eric Wong
2020-12-31 13:51 ` [PATCH 03/36] revert "lei_store: use per-machine refname as git HEAD" Eric Wong
2020-12-31 13:51 ` [PATCH 04/36] lei_to_mail: initial implementation for writing mbox formats Eric Wong
2020-12-31 13:51 ` [PATCH 05/36] sharedkv: fork()-friendly key-value store Eric Wong
2020-12-31 13:51 ` [PATCH 06/36] sharedkv: split out index_values Eric Wong
2020-12-31 13:51 ` [PATCH 07/36] lei_to_mail: start atomic and compressed mbox writing Eric Wong
2020-12-31 13:51 ` [PATCH 08/36] mboxreader: new class for reading various mbox formats Eric Wong
2020-12-31 13:51 ` [PATCH 09/36] lei_to_mail: start --augment, dedupe, bz2 and xz Eric Wong
2020-12-31 13:51 ` [PATCH 10/36] lei: implement various deduplication strategies Eric Wong
2020-12-31 13:51 ` [PATCH 11/36] lei_to_mail: lazy-require LeiDedupe Eric Wong
2020-12-31 13:51 ` Eric Wong [this message]
2020-12-31 13:51 ` [PATCH 13/36] lei_to_mail: support Maildir, fix+test --augment Eric Wong
2020-12-31 13:51 ` [PATCH 14/36] ipc: generic IPC dispatch based on Storable Eric Wong
2020-12-31 13:51 ` [PATCH 15/36] ipc: support Sereal Eric Wong
2020-12-31 13:51 ` [PATCH 16/36] lei_store: add ->set_eml, ->add_eml can return smsg Eric Wong
2020-12-31 13:51 ` [PATCH 17/36] lei: rename "extinbox" => "external" Eric Wong
2020-12-31 13:51 ` [PATCH 18/36] mid: use defined-or with `push' for uniqueness check Eric Wong
2020-12-31 13:51 ` [PATCH 19/36] mid: hoist out mids_in sub Eric Wong
2020-12-31 13:51 ` [PATCH 20/36] lei_store: handle messages without Message-ID at all Eric Wong
2020-12-31 13:51 ` [PATCH 21/36] ipc: use shutdown(2), base atfork* callback Eric Wong
2020-12-31 13:51 ` [PATCH 22/36] lei_to_mail: unlink mboxes if not augmenting Eric Wong
2020-12-31 13:51 ` [PATCH 23/36] lei: add --mfolder as an --output alias Eric Wong
2020-12-31 13:51 ` [PATCH 24/36] spawn: move run_die here from PublicInbox::Import Eric Wong
2020-12-31 13:51 ` [PATCH 25/36] init: remove embedded UnlinkMe package Eric Wong
2020-12-31 13:51 ` [PATCH 26/36] t/run: avoid uninitialized var on incomplete test Eric Wong
2020-12-31 13:51 ` [PATCH 27/36] gcf2client: reap process on DESTROY Eric Wong
2020-12-31 13:51 ` [PATCH 28/36] lei_to_mail: open FIFOs O_WRONLY so we block Eric Wong
2020-12-31 13:51 ` [PATCH 29/36] searchidxshard: call DS->Reset at worker start Eric Wong
2020-12-31 13:51 ` [PATCH 30/36] t/ipc.t: test for references via `die' Eric Wong
2020-12-31 13:51 ` [PATCH 31/36] use PublicInbox::DS for dwaitpid Eric Wong
2020-12-31 13:51 ` [PATCH 32/36] syscall: SFD_NONBLOCK can be a constant, again Eric Wong
2020-12-31 13:51 ` [PATCH 33/36] lei: avoid Spawn package when starting daemon Eric Wong
2020-12-31 13:51 ` [PATCH 34/36] avoid calling waitpid from children in DESTROY Eric Wong
2020-12-31 13:51 ` [PATCH 35/36] ds: clobber $in_loop first at reset Eric Wong
2020-12-31 13:51 ` [PATCH 36/36] on_destroy: support PID owner guard Eric Wong

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