[PATCH 09/27] import: (v2) delete writes the blob into history in subdir

["Eric Wong (Contractor, The Linux Foundation)" <e@80x24.org>]

This makes it easier to audit deletes with "git log -p" and
prevents an unstable specification of "content_id" from being
stored in history.

This should be cost-free if done in the same partition (and even
cheaper than before as it introduces no new blobs).  It does
have a higher cost across partitions, but is probably irrelevant
given the typical ham:spam ratio.
---
 lib/PublicInbox/Import.pm     | 15 ++++++++++-----
 lib/PublicInbox/V2Writable.pm |  4 +++-
 t/v2writable.t                |  9 +++++++++
 3 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/lib/PublicInbox/Import.pm b/lib/PublicInbox/Import.pm
index e20c6e0..94a49fe 100644
--- a/lib/PublicInbox/Import.pm
+++ b/lib/PublicInbox/Import.pm
@@ -11,7 +11,6 @@ use Fcntl qw(:flock :DEFAULT);
 use PublicInbox::Spawn qw(spawn);
 use PublicInbox::MID qw(mid_mime mid2path);
 use PublicInbox::Address;
-use PublicInbox::ContentId qw(content_id);
 use PublicInbox::MsgTime qw(msg_timestamp);
 
 sub new {
@@ -163,7 +162,6 @@ sub get_mark {
 # ('MISMATCH', Email::MIME) on mismatch
 # (:MARK, Email::MIME) on success
 #
-# For v2 inboxes, the content_id is returned instead of the msg
 # v2 callers should check with Xapian before calling this as
 # it is not idempotent.
 sub remove {
@@ -179,10 +177,17 @@ sub remove {
 		($err, $cur) = check_remove_v1($r, $w, $tip, $path, $mime);
 		return ($err, $cur) if $err;
 	} else {
-		$cur = content_id($mime);
-		my $len = length($cur);
+		my $sref;
+		if (ref($mime) eq 'SCALAR') { # optimization used by V2Writable
+			$sref = $mime;
+		} else { # XXX should not be necessary:
+			my $str = $mime->as_string;
+			$sref = \$str;
+		}
+		my $len = length($$sref);
 		$blob = $self->{mark}++;
-		print $w "blob\nmark :$blob\ndata $len\n$cur\n" or wfail;
+		print $w "blob\nmark :$blob\ndata $len\n",
+			$$sref, "\n" or wfail;
 	}
 
 	my $ref = $self->{ref};
diff --git a/lib/PublicInbox/V2Writable.pm b/lib/PublicInbox/V2Writable.pm
index 656f069..fd9bf61 100644
--- a/lib/PublicInbox/V2Writable.pm
+++ b/lib/PublicInbox/V2Writable.pm
@@ -220,6 +220,7 @@ sub remove {
 				warn "broken smsg for $mid\n";
 				return 1; # continue
 			}
+			my $orig = $$msg;
 			my $cur = PublicInbox::MIME->new($msg);
 			if (content_id($cur) eq $cid) {
 				$mm->num_delete($smsg->num);
@@ -227,7 +228,8 @@ sub remove {
 				# no bugs in our deduplication code:
 				$removed = $smsg;
 				$removed->{mime} = $cur;
-				$im->remove($cur, $cmt_msg);
+				$im->remove(\$orig, $cmt_msg);
+				$orig = undef;
 				$removed->num; # memoize this for callers
 
 				my $oid = $smsg->{blob};
diff --git a/t/v2writable.t b/t/v2writable.t
index 6e37b72..a5c982e 100644
--- a/t/v2writable.t
+++ b/t/v2writable.t
@@ -191,6 +191,7 @@ EOF
 {
 	local $ENV{NPROC} = 2;
 	my @before = $git0->qx(qw(log --pretty=oneline));
+	my $before = $git0->qx(qw(log --pretty=raw --raw -r --no-abbrev));
 	$im = PublicInbox::V2Writable->new($ibx, 1);
 	is($im->{partitions}, 1, 'detected single partition from previous');
 	my $smsg = $im->remove($mime, 'test removal');
@@ -207,6 +208,14 @@ EOF
 	my @found = ();
 	$srch->each_smsg_by_mid($smsg->mid, sub { push @found, @_; 1 });
 	is(scalar(@found), 0, 'no longer found in Xapian skeleton');
+
+	my $after = $git0->qx(qw(log -1 --pretty=raw --raw -r --no-abbrev));
+	if ($after =~ m!( [a-f0-9]+ )A\td$!) {
+		my $oid = $1;
+		ok(index($before, $oid) > 0, 'no new blob introduced');
+	} else {
+		fail('failed to extract blob from log output');
+	}
 }
 
 done_testing();
-- 
EW