v2writable: inject new Message-IDs on true duplicates

[public-inbox.git] / lib / PublicInbox / V2Writable.pm

diff --git a/lib/PublicInbox/V2Writable.pm b/lib/PublicInbox/V2Writable.pm
index 57cb7d38113de1495f0bcfbc1cfbf1545f480d7e..6d7382780b6607acae8818d2ec2d399f944707ec 100644 (file)
--- a/lib/PublicInbox/V2Writable.pm
+++ b/lib/PublicInbox/V2Writable.pm
@@ -11,8 +11,8 @@ use PublicInbox::SearchIdxSkeleton;
 use PublicInbox::MIME;
 use PublicInbox::Git;
 use PublicInbox::Import;
-use PublicInbox::MID qw(mid_clean mid_mime);
-use PublicInbox::ContentId qw(content_id);
+use PublicInbox::MID qw(mids);
+use PublicInbox::ContentId qw(content_id content_digest);
 use PublicInbox::Inbox;
 
 # an estimate of the post-packed size to the raw uncompressed size
@@ -62,21 +62,8 @@ sub add {
        # leaking FDs to it...
        $self->idx_init;
 
-       my $mid = mid_clean(mid_mime($mime));
-       my $num = $self->{skel}->{mm}->mid_insert($mid);
-       if (!defined($num)) { # mid is already known
-               $self->done; # ensure all subprocesses are done writing
-
-               my $existing = $self->lookup_content($mime);
-               warn "<$mid> resent\n" if $existing;
-               return if $existing; # easy, don't store duplicates
-
-               # reuse NNTP article number?
-               warn "<$mid> reused for mismatched content\n";
-               $self->idx_init;
-               $num = $self->{skel}->{mm}->num_for($mid);
-       }
-
+       my $num = num_for($self, $mime);
+       defined $num or return; # duplicate
        my $im = $self->importer;
        my $cmt = $im->add($mime);
        $cmt = $im->get_mark($cmt);
@@ -95,6 +82,70 @@ sub add {
        $mime;
 }
 
+sub num_for {
+       my ($self, $mime) = @_;
+       my $mids = mids($mime->header_obj);
+       if (@$mids) {
+               my $mid = $mids->[0];
+               my $num = $self->{skel}->{mm}->mid_insert($mid);
+               return $num if defined($num); # common case
+
+               # crap, Message-ID is already known, hope somebody just resent:
+               $self->done; # write barrier, clears $self->{skel}
+               foreach my $m (@$mids) {
+                       # read-only lookup now safe to do after above barrier
+                       my $existing = $self->lookup_content($mime, $m);
+                       if ($existing) {
+                               warn "<$m> resent\n";
+                               return; # easy, don't store duplicates
+                       }
+               }
+
+               # very unlikely:
+               warn "<$mid> reused for mismatched content\n";
+               $self->idx_init;
+
+               # try the rest of the mids
+               foreach my $i (1..$#$mids) {
+                       my $m = $mids->[$i];
+                       $num = $self->{skel}->{mm}->mid_insert($m);
+                       if (defined $num) {
+                               warn "alternative <$m> for <$mid> found\n";
+                               return $num;
+                       }
+               }
+       }
+       # none of the existing Message-IDs are good, generate a new one:
+       num_for_harder($self, $mime);
+}
+
+sub num_for_harder {
+       my ($self, $mime) = @_;
+
+       my $hdr = $mime->header_obj;
+       my $dig = content_digest($mime);
+       my $mid = $dig->clone->hexdigest . '@localhost';
+       my $num = $self->{skel}->{mm}->mid_insert($mid);
+       unless (defined $num) {
+               # it's hard to spoof the last Received: header
+               my @recvd = $hdr->header_raw('Received');
+               $dig->add("Received: $_") foreach (@recvd);
+               $mid = $dig->clone->hexdigest . '@localhost';
+               $num = $self->{skel}->{mm}->mid_insert($mid);
+
+               # fall back to a random Message-ID and give up determinism:
+               until (defined($num)) {
+                       $dig->add(rand);
+                       $mid = $dig->clone->hexdigest . '@localhost';
+                       warn "using random Message-ID <$mid> as fallback\n";
+                       $num = $self->{skel}->{mm}->mid_insert($mid);
+               }
+       }
+       my @cur = $hdr->header_raw('Message-Id');
+       $hdr->header_set('Message-Id', @cur, "<$mid>");
+       $num;
+}
+
 sub idx_part {
        my ($self, $part) = @_;
        $self->{idx_parts}->[$part];
@@ -268,13 +319,12 @@ sub import_init {
 }
 
 sub lookup_content {
-       my ($self, $mime) = @_;
+       my ($self, $mime, $mid) = @_;
        my $ibx = $self->{-inbox};
 
        my $srch = $ibx->search;
        my $cid = content_id($mime);
        my $found;
-       my $mid = mid_mime($mime);
        $srch->each_smsg_by_mid($mid, sub {
                my ($smsg) = @_;
                $smsg->load_expand;