searchmsg: add git object ID to doc_data

Doing git tree lookups based on the SHA-1 of the Message-ID
is expensive as trees get larger, instead, use the SHA-1
object ID directly.  This drastically reduces the amount
of time spent in the "git cat-file --batch" process for
fetching the /$INBOX/all.mbox.gz endpoint on the ~800MB
git@vger.kernel.org mirror

This retains backwards compatibility and allows existing
indices to be transparently upgraded without performance
degradation.

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/PublicInbox/Mbox.pm b/lib/PublicInbox/Mbox.pm
index d2c09544..1e3de5b0 100644
--- a/lib/PublicInbox/Mbox.pm
+++ b/lib/PublicInbox/Mbox.pm
@@ -129,7 +129,7 @@ sub getline {
         my $gz = $self->{gz};
         do {
                 while (defined(my $smsg = shift @{$self->{msgs}})) {
-                        my $msg = eval { $ibx->msg_by_mid($smsg->mid) } or next;
+                        my $msg = eval { $ibx->msg_by_smsg($smsg) } or next;
                         $msg = Email::Simple->new($msg);
                         $gz->write(PublicInbox::Mbox::msg_str($ctx, $msg));
                         my $bref = $self->{buf};