[WIP 11/17] import: APIs to support v2 use

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

Wrap "get-mark" and "checkpoint" commands for git-fast-import
while documenting/cementing parts of the API.
---
 lib/PublicInbox/Import.pm | 28 ++++++++++++++++++++++------
 t/import.t                |  4 +++-
 2 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/lib/PublicInbox/Import.pm b/lib/PublicInbox/Import.pm
index b8e9dd0..811e355 100644
--- a/lib/PublicInbox/Import.pm
+++ b/lib/PublicInbox/Import.pm
@@ -138,9 +138,27 @@ sub check_remove_v1 {
 	(undef, $cur);
 }
 
+# used for v2 (maybe)
+sub checkpoint {
+	my ($self) = @_;
+	return unless $self->{pid};
+	print { $self->{out} } "checkpoint\n" or wfail;
+	undef;
+}
+
+# used for v2
+sub get_mark {
+	my ($self, $mark) = @_;
+	die "not active\n" unless $self->{pid};
+	my ($r, $w) = $self->gfi_start;
+	print $w "get-mark $mark\n" or wfail;
+	defined(my $oid = <$r>) or die "get-mark failed, need git 2.6.0+\n";
+	$oid;
+}
+
 # returns undef on non-existent
-# ('MISMATCH', msg) on mismatch
-# (:MARK, msg) on success
+# ('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
@@ -189,6 +207,7 @@ sub remove {
 }
 
 # returns undef on duplicate
+# returns the :MARK of the most recent commit
 sub add {
 	my ($self, $mime, $check_cb) = @_; # mime = Email::MIME
 
@@ -234,10 +253,7 @@ sub add {
 
 	# v2: we need this for Xapian
 	if ($self->{want_object_id}) {
-		print $w "get-mark :$blob\n" or wfail;
-		defined(my $object_id = <$r>) or
-				die "get-mark failed, need git 2.6.0+\n";
-		chomp($self->{last_object_id} = $object_id);
+		chomp($self->{last_object_id} = $self->get_mark(":$blob"));
 	}
 
 	my $ref = $self->{ref};
diff --git a/t/import.t b/t/import.t
index 92c82b9..ca59772 100644
--- a/t/import.t
+++ b/t/import.t
@@ -87,6 +87,8 @@ isnt($msg->header('Subject'), $mime->header('Subject'), 'subject mismatch');
 $mime->header_set('Message-Id', '<failcheck@example.com>');
 is($im->add($mime, sub { undef }), undef, 'check callback fails');
 is($im->remove($mime), undef, 'message not added, so not removed');
-
+is(undef, $im->checkpoint, 'checkpoint works before ->done');
 $im->done;
+is(undef, $im->checkpoint, 'checkpoint works after ->done');
+$im->checkpoint;
 done_testing();
-- 
EW