session: add subscription update option

Sysrepo allows to subscribe to configuration update before they are
applied to the datastore so it is possible to edit them.
Add the update flag to the subscribe_module_change and the
subscribe_module_change_unsafe functions.

Signed-off-by: Jeremie Leska <[email protected]>

Author: jeremie6wind

sysrepo/session.py

@@ -338,6 +338,7 @@ def subscribe_module_change(
         passive: bool = False,
         done_only: bool = False,
         enabled: bool = False,
+        update: bool = False,
         filter_origin: bool = False,
         private_data: Any = None,
         asyncio_register: bool = False,
@@ -372,6 +373,8 @@ def subscribe_module_change(
         :arg enabled:
             The subscriber wants to be notified about the current configuration
             at the moment of subscribing.
+        :arg update:
+            The subscriber wants to be called before the configuration is applied.
         :arg filter_origin:
             Filter events on the originator side to unburden the subscriber, but
             results in 0 value for filtered-out changes in the subscriber infos.
@@ -410,6 +413,7 @@ def subscribe_module_change(
             passive=passive,
             done_only=done_only,
             enabled=enabled,
+            update=update,
             filter_origin=filter_origin,
         )
 
@@ -464,6 +468,7 @@ def subscribe_module_change_unsafe(
         passive: bool = False,
         done_only: bool = False,
         enabled: bool = False,
+        update: bool = False,
         filter_origin: bool = False,
         private_data: Any = None,
         asyncio_register: bool = False,
@@ -499,6 +504,8 @@ def subscribe_module_change_unsafe(
         :arg enabled:
             The subscriber wants to be notified about the current configuration
             at the moment of subscribing.
+        :arg update:
+            The subscriber wants to be called before the configuration is applied.
         :arg filter_origin:
             Filter events on the originator side to unburden the subscriber, but
             results in 0 value for filtered-out changes in the subscriber infos.
@@ -531,6 +538,7 @@ def subscribe_module_change_unsafe(
             passive=passive,
             done_only=done_only,
             enabled=enabled,
+            update=update,
             filter_origin=filter_origin,
         )
         check_call(
@@ -1659,6 +1667,7 @@ def _subscribe_flags(
     enabled=False,
     oper_merge=False,
     filter_origin=False,
+    update=False,
 ):
     flags = 0
     if no_thread:
@@ -1669,6 +1678,8 @@ def _subscribe_flags(
         flags |= lib.SR_SUBSCR_DONE_ONLY
     if enabled:
         flags |= lib.SR_SUBSCR_ENABLED
+    if update:
+        flags |= lib.SR_SUBSCR_UPDATE
     if oper_merge:
         flags |= lib.SR_SUBSCR_OPER_MERGE
     if filter_origin: