lei_to_mail: start --augment, dedupe, bz2 and xz

--augment will match the mairix(1) option of the same
name to augment existing search results.  We'll need
to implement deduplication for a better user experience.

mutt ships with compressed mbox support for bz2 and xz,
at least, so we'll support those out-of-the-box.

4 files changed, 150 insertions, 47 deletions

diff --git a/lib/PublicInbox/LeiToMail.pm b/lib/PublicInbox/LeiToMail.pm
index ebb50c50..294291b2 100644
--- a/lib/PublicInbox/LeiToMail.pm
+++ b/lib/PublicInbox/LeiToMail.pm
@@ -8,10 +8,12 @@ use v5.10.1;
 use PublicInbox::Eml;
 use PublicInbox::Lock;
 use PublicInbox::ProcessPipe;
-use PublicInbox::Spawn qw(which spawn);
+use PublicInbox::SharedKV;
+use PublicInbox::Spawn qw(which spawn popen_rd);
+use PublicInbox::ContentHash qw(content_hash);
 use Symbol qw(gensym);
-use File::Temp ();
 use IO::Handle; # ->autoflush
+use Fcntl qw(SEEK_SET);
 
 my %kw2char = ( # Maildir characters
         draft => 'D',
@@ -150,51 +152,123 @@ sub reap_compress { # dwaitpid callback
         $lei->fail("@$cmd failed", $? >> 8);
 }
 
-sub compress_dst {
-        my ($out, $sfx, $lei) = @_;
-        my $cmd = [];
-        if ($sfx eq 'gz') {
-                $cmd->[0] = which($lei->{env}->{GZIP} // 'pigz') //
-                                which('gzip') //
-                        die "pigz or gzip missing for $sfx\n";
-                        # TODO: use IO::Compress::Gzip
-                push @$cmd, '-c'; # stdout
-                push @$cmd, '--rsyncable' if $lei->{opt}->{rsyncable};
-        } else {
-                die "TODO $sfx"
+# all of these support -c for stdout and -d for decompression,
+# mutt is commonly distributed with hooks for gz, bz2 and xz, at least
+# { foo => '' } means "--foo" is passed to the command-line,
+# otherwise { foo => '--bar' } passes "--bar"
+our %zsfx2cmd = (
+        gz => [ qw(GZIP pigz gzip), {
+                rsyncable => '', threads => '-p' } ],
+        bz2 => [ 'bzip2', {} ],
+        xz => [ 'xz', { threads => '-T' } ],
+        # XXX does anybody care for these?  I prefer zstd on entire FSes,
+        # so it's probably not necessary on a per-file basis
+        # zst => [ 'zstd', { -default => [ qw(-q) ], # it's noisy by default
+        #        rsyncable => '', threads => '-T' } ],
+        # zz => [ 'pigz', { -default => [ '--zlib' ],
+        #        rsyncable => '', threads => '-p' }],
+        # lzo => [ 'lzop', {} ],
+        # lzma => [ 'lzma', {} ],
+);
+
+sub zsfx2cmd ($$$) {
+        my ($zsfx, $decompress, $lei) = @_;
+        my $x = $zsfx2cmd{$zsfx} // die "no support for suffix=.$zsfx";
+        my @info = @$x;
+        my $cmd_opt = pop @info;
+        my @cmd = (undef, $decompress ? qw(-dc) : qw(-c));
+        for my $exe (@info) {
+                # I think respecting client's ENV{GZIP} is OK, not sure
+                # about ENV overrides for other, less-common compressors
+                if ($exe eq uc($exe)) {
+                        $exe = $lei->{env}->{$exe} or next;
+                }
+                $cmd[0] = which($exe) and last;
+        }
+        $cmd[0] // die join(' or ', @info)." missing for .$zsfx";
+        # push @cmd, @{$cmd_opt->{-default}} if $cmd_opt->{-default};
+        for my $bool (qw(rsyncable)) {
+                my $switch = $cmd_opt->{rsyncable} // next;
+                push @cmd, '--'.($switch || $bool);
+        }
+        for my $key (qw(threads)) { # support compression level?
+                my $switch = $cmd_opt->{$key} // next;
+                my $val = $lei->{opt}->{$key} // next;
+                push @cmd, $switch, $val;
         }
+        \@cmd;
+}
+
+sub compress_dst {
+        my ($out, $zsfx, $lei) = @_;
+        my $cmd = zsfx2cmd($zsfx, undef, $lei);
         pipe(my ($r, $w)) or die "pipe: $!";
         my $rdr = { 0 => $r, 1 => $out, 2 => $lei->{2} };
         my $pid = spawn($cmd, $lei->{env}, $rdr);
         $lei->{"pid.$pid"} = $cmd;
         my $pp = gensym;
         tie *$pp, 'PublicInbox::ProcessPipe', $pid, $w, \&reap_compress, $lei;
-        my $tmp = File::Temp->new("$sfx.lock-XXXXXX", TMPDIR => 1);
-        my $pipe_lk = ($lei->{opt}->{jobs} // 0) > 1 ? bless({
-                lock_path => $tmp->filename,
-                tmp => $tmp
-        }, 'PublicInbox::Lock') : undef;
+        my $pipe_lk = ($lei->{opt}->{jobs} // 0) > 1 ?
+                        PublicInbox::Lock->new_tmp($zsfx) : undef;
         ($pp, $pipe_lk);
 }
 
-sub write_cb {
-        my ($cls, $dst, $lei) = @_;
-        if ($dst =~ s!\A(mbox(?:rd|cl|cl2|o))?:!!) {
-                my $m = "eml2$1";
-                my $eml2mbox = $cls->can($m) or die "$cls->$m missing";
-                my ($out, $pipe_lk);
-                open $out, '>>', $dst or die "open $dst: $!";
-                my $atomic = !!(($lei->{opt}->{jobs} // 0) > 1);
-                if ($dst =~ /\.(gz|bz2|xz)\z/) {
-                        ($out, $pipe_lk) = compress_dst($out, $1, $lei);
-                }
-                sub {
-                        my ($buf, $oid, $kw) = @_;
-                        $buf = $eml2mbox->(PublicInbox::Eml->new($buf), $kw);
+sub decompress_src ($$$) {
+        my ($in, $zsfx, $lei) = @_;
+        my $cmd = zsfx2cmd($zsfx, 1, $lei);
+        my $rdr = { 0 => $in, 2 => $lei->{2} };
+        popen_rd($cmd, $lei->{env}, $rdr);
+}
+
+sub dup_src ($) {
+        my ($in) = @_;
+        open my $dup, '+>>&', $in or die "dup: $!";
+        $dup;
+}
+
+# --augment existing output destination, without duplicating anything
+sub _augment { # MboxReader eml_cb
+        my ($eml, $lei) = @_;
+        $lei->{skv}->set_maybe(content_hash($eml), '');
+}
+
+sub _mbox_write_cb ($$$$) {
+        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 $atomic = !!(($lei->{opt}->{jobs} // 0) > 1);
+        $lei->{skv} = PublicInbox::SharedKV->new;
+        $lei->{skv}->dbh;
+        state $zsfx_allow = join('|', keys %zsfx2cmd);
+        my ($zsfx) = ($dst =~ /\.($zsfx_allow)\z/);
+        if ($lei->{opt}->{augment}) {
+                my $rd = $zsfx ? decompress_src($out, $zsfx, $lei) :
+                                dup_src($out);
+                PublicInbox::MboxReader->$mbox($rd, \&_augment, $lei);
+        } else {
+                truncate($out, 0) or die "truncate $dst: $!";
+        }
+        ($out, $pipe_lk) = compress_dst($out, $zsfx, $lei) if $zsfx;
+        sub {
+                my ($buf, $oid, $kw) = @_;
+                my $eml = PublicInbox::Eml->new($buf);
+                if ($lei->{skv}->set_maybe(content_hash($eml), '')) {
+                        $buf = $eml2mbox->($eml, $kw);
                         my $lock = $pipe_lk->lock_for_scope if $pipe_lk;
                         write_in_full($out, $buf, $atomic);
                 }
         }
 }
 
+sub write_cb { # returns a callback for git_to_mail
+        my ($cls, $dst, $lei) = @_;
+        if ($dst =~ s!\A(mbox(?:rd|cl|cl2|o))?:!!) {
+                _mbox_write_cb($cls, $1, $dst, $lei);
+        }
+}
+
 1;
diff --git a/lib/PublicInbox/Lock.pm b/lib/PublicInbox/Lock.pm
index 7fd17745..f6eaa5ce 100644
--- a/lib/PublicInbox/Lock.pm
+++ b/lib/PublicInbox/Lock.pm
@@ -8,6 +8,7 @@ use v5.10.1;
 use Fcntl qw(:flock :DEFAULT);
 use Carp qw(croak);
 use PublicInbox::OnDestroy;
+use File::Temp ();
 
 # we only acquire the flock if creating or reindexing;
 # PublicInbox::Import already has the lock on its own.
@@ -40,4 +41,10 @@ sub lock_for_scope {
         PublicInbox::OnDestroy->new(\&lock_release, $self);
 }
 
+sub new_tmp {
+        my ($cls, $ident) = @_;
+        my $tmp = File::Temp->new("$ident.lock-XXXXXX", TMPDIR => 1);
+        bless { lock_path => $tmp->filename, tmp => $tmp }, $cls;
+}
+
 1;
diff --git a/lib/PublicInbox/MboxReader.pm b/lib/PublicInbox/MboxReader.pm
index e1944aaf..ac0c0f52 100644
--- a/lib/PublicInbox/MboxReader.pm
+++ b/lib/PublicInbox/MboxReader.pm
@@ -5,6 +5,7 @@
 package PublicInbox::MboxReader;
 use strict;
 use v5.10.1;
+use PublicInbox::DS (); # localize $in_loop for error detection :<
 use Data::Dumper;
 $Data::Dumper::Useqq = 1; # should've been the default, for bad data
 
@@ -13,6 +14,7 @@ my $from_strict =
 
 sub _mbox_from {
         my ($mbfh, $from_re, $eml_cb, @arg) = @_;
+        local $PublicInbox::DS::in_loop; # disable dwaitpid
         my $buf = '';
         my @raw;
         while (defined(my $r = read($mbfh, $buf, 65536, length($buf)))) {
@@ -73,6 +75,7 @@ sub _extract_hdr {
 
 sub _mbox_cl ($$$;@) {
         my ($mbfh, $uxs_from, $eml_cb, @arg) = @_;
+        local $PublicInbox::DS::in_loop; # disable dwaitpid
         my $buf = '';
         while (defined(my $r = read($mbfh, $buf, 65536, length($buf)))) {
                 if ($r == 0) { # detect "curl --fail"
diff --git a/t/lei_to_mail.t b/t/lei_to_mail.t
index 231cf543..e4551e69 100644
--- a/t/lei_to_mail.t
+++ b/t/lei_to_mail.t
@@ -92,21 +92,40 @@ my $orig = do {
         is($raw, do { local $/; <$fh> }, 'jobs > 1');
         $raw;
 };
-SKIP: {
-        use PublicInbox::Spawn qw(which);
-        my $gzip = which('gzip') or skip 'gzip not found', 1;
-        my $wcb = PublicInbox::LeiToMail->write_cb("mboxcl2:$fn.gz", $lei);
-        $wcb->(\(my $dup = $buf), 'deadbeef', [ qw(seen) ]);
-        undef $wcb;
-        my $uncompressed = xqx([$gzip, '-dc', "$fn.gz"]);
-        is($uncompressed, $orig, 'gzip works');
+for my $zsfx (qw(gz bz2 xz)) { # XXX should we support zst, zz, lzo, lzma?
+        my $zsfx2cmd = PublicInbox::LeiToMail->can('zsfx2cmd');
+        SKIP: {
+                my $cmd = eval { $zsfx2cmd->($zsfx, 0, $lei) };
+                skip $@, 3 if $@;
+                my $dc_cmd = eval { $zsfx2cmd->($zsfx, 1, $lei) };
+                ok($dc_cmd, "decompressor for .$zsfx");
+                my $f = "$fn.$zsfx";
+                my $dst = "mboxcl2:$f";
+                my $wcb = PublicInbox::LeiToMail->write_cb($dst, $lei);
+                $wcb->(\(my $dup = $buf), 'deadbeef', [ qw(seen) ]);
+                undef $wcb;
+                my $uncompressed = xqx([@$dc_cmd, $f]);
+                is($uncompressed, $orig, "$zsfx works unlocked");
 
-        local $lei->{opt} = { jobs => 2 };
-        unlink "$fn.gz" or die "unlink $!";
-        $wcb = PublicInbox::LeiToMail->write_cb("mboxcl2:$fn.gz", $lei);
-        $wcb->(\(my $dupe = $buf), 'deadbeef', [ qw(seen) ]);
-        undef $wcb;
-        is(xqx([$gzip, '-dc', "$fn.gz"]), $orig);
+                local $lei->{opt} = { jobs => 2 }; # for atomic writes
+                unlink $f or BAIL_OUT "unlink $!";
+                $wcb = PublicInbox::LeiToMail->write_cb($dst, $lei);
+                $wcb->(\($dup = $buf), 'deadbeef', [ qw(seen) ]);
+                undef $wcb;
+                is(xqx([@$dc_cmd, $f]), $orig, "$zsfx matches with lock");
+        }
+}
+
+unlink $fn or BAIL_OUT $!;
+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');
 }
 
 done_testing;