transport: don't flush when disconnecting stateless-rpc helper

Since ba227857d2 (Reduce the number of connects when fetching, 2008-02-04), when we disconnect a git transport, we send a final flush packet. This cleanly tells the other side that we're done, and avoids the other side complaining "the remote end hung up unexpectedly" (though we'd only see that for transports that pass along the server stderr, like ssh or local-host). But when we've initiated a v2 stateless-connect session over a transport helper, there's no point in sending this flush packet. Each operation we've performed is self-contained, and the other side is fine with us hanging up between operations. But much worse, by sending the flush packet we may cause the helper to issue an entirely new request _just_ to send the flush packet. So we can incur an extra network request just to say "by the way, we have nothing more to send". Let's drop this extra flush packet. As the test shows, this reduces the number of POSTs required for a v2 ls-remote over http from 2 to 1. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jeff King committed Jan 8, 2020 at 02:10 UTC 4d8cab95ccdac8a0859ba0a6c044bd024f8d8a5f

2 files changed +13 -1

t/t5702-protocol-v2.sh

+12

@@ -652,6 +652,18 @@ test_expect_success 'fetch from namespaced repo respects namespaces' '

652 test_cmp expect actual

653 '

654

655 +test_expect_success 'ls-remote with v2 http sends only one POST' '

656 + test_when_finished "rm -f log" &&

657 +

658 + git ls-remote "$HTTPD_DOCUMENT_ROOT_PATH/http_parent" >expect &&

659 + GIT_TRACE_CURL="$(pwd)/log" git -c protocol.version=2 \

660 + ls-remote "$HTTPD_URL/smart/http_parent" >actual &&

661 + test_cmp expect actual &&

662 +

663 + grep "Send header: POST" log >posts &&

664 + test_line_count = 1 posts

665 +'

666 +

667 test_expect_success 'push with http:// and a config of v2 does not request v2' '

668 test_when_finished "rm -f log" &&

669 # Till v2 for push is designed, make sure that if a client has

transport.c

+1 -1

@@ -730,7 +730,7 @@ static int disconnect_git(struct transport *transport)

730 {

731 struct git_transport_data *data = transport->data;

732 if (data->conn) {

733 - if (data->got_remote_heads)

733 + if (data->got_remote_heads && !transport->stateless_rpc)

734 packet_flush(data->fd[1]);

735 close(data->fd[0]);

736 close(data->fd[1]);