db-ctl-base: Use partial map/set updates for last add/set commands.

Currently, command to add one item into a large set generates the
transaction with the full new content of that set plus 'wait'
operation for the full old content of that set.  So, if we're adding
one new load-balancer into a load-balancer group in OVN using
ovn-nbctl, transaction will include all the existing load-balancers
from that groups twice.

IDL supports partial updates for sets and maps.  The problem with that
is changes are not visible to the IDL user until the transaction
is committed.  That will cause problems for chained ctl commands.
However, we still can optimize the very last command in the list.
It makes sense to do, since it's a common case for manual invocations.

Updating the 'add' command as well as 'set' for a case where we're
actually adding one new element to the map.

One downside is that we can't check the set size without examining
it and checking for duplicates, so allowing the transaction to be
sent and constraints to be checked on the server side in that case.

Not touching 'remove' operation for now, since removals may have
different type, e.g. if elements from the map are removed by the key.
The function will likely need to be fully re-written to accommodate
all the corner cases.

Acked-by: Dumitru Ceara <dceara@redhat.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/tests/ovs-vsctl.at b/tests/ovs-vsctl.at
index abf4fb9cf..a92156f00 100644
--- a/tests/ovs-vsctl.at
+++ b/tests/ovs-vsctl.at
@@ -1071,9 +1071,13 @@ AT_CHECK([RUN_OVS_VSCTL([set controller br1 'connection-mode=xyz'])],
 AT_CHECK([RUN_OVS_VSCTL([set controller br1 connection-mode:x=y])],
   [1], [], [ovs-vsctl: cannot specify key to set for non-map column connection_mode
 ])
-AT_CHECK([RUN_OVS_VSCTL([add bridge br1 datapath_id x y])],
+AT_CHECK([RUN_OVS_VSCTL([add bridge br1 datapath_id x y -- show])],
   [1], [], [ovs-vsctl: "add" operation would put 2 values in column datapath_id of table Bridge but the maximum number is 1
 ])
+AT_CHECK([RUN_OVS_VSCTL([add bridge br1 datapath_id x y])], [1], [], [stderr])
+AT_CHECK([sed "/^.*|WARN|.*/d" < stderr], [0], [dnl
+ovs-vsctl: transaction error: {"details":"set must have 0 to 1 members but 2 are present","error":"syntax error","syntax":"[[\"set\",[\"x\",\"y\"]]]"}
+])
 AT_CHECK([RUN_OVS_VSCTL([remove netflow `cat netflow-uuid` targets '"1.2.3.4:567"'])],
   [1], [], [ovs-vsctl: "remove" operation would put 0 values in column targets of table NetFlow but the minimum number is 1
 ])