Add support for notifications

* Related to:
  - sysrepo/sysrepo-python#10
  - sysrepo/sysrepo-python#11

* Special recognition to @ishidawataru for providing the seed
  code for this new feature

Author: nicolasmorini

cffi/cdefs.h

@@ -407,6 +407,7 @@ typedef enum {
 #define LYD_OPT_DATA_NO_YANGLIB ...
 #define LYD_OPT_RPC ...
 #define LYD_OPT_RPCREPLY ...
+#define LYD_OPT_NOTIF ...
 #define LYD_OPT_EXPLICIT ...
 #define LYD_OPT_DESTRUCT ...
 #define LYD_OPT_NOSIBLINGS ...

libyang/__init__.py

@@ -4,7 +4,7 @@
 
 
 from .context import Context
-from .data import DContainer, DDiff, DLeaf, DLeafList, DList, DNode, DRpc
+from .data import DContainer, DDiff, DLeaf, DLeafList, DList, DNode, DNotif, DRpc
 from .diff import (
     BaseTypeAdded,
     BaseTypeRemoved,

libyang/context.py

@@ -193,7 +193,7 @@ def create_data_path(
 
         return DNode.new(self, dnode)
 
-    def parse_data_mem(
+    def parse_data_mem(  # pylint: disable=too-many-arguments
         self,
         d: Union[str, bytes],
         fmt: str,
@@ -204,6 +204,7 @@ def parse_data_mem(
         edit: bool = False,
         rpc: bool = False,
         rpcreply: bool = False,
+        notification: bool = False,
         strict: bool = False,
         trusted: bool = False,
         no_yanglib: bool = False,
@@ -220,6 +221,7 @@ def parse_data_mem(
             edit=edit,
             rpc=rpc,
             rpcreply=rpcreply,
+            notification=notification,
             strict=strict,
             trusted=trusted,
             no_yanglib=no_yanglib,
@@ -234,7 +236,7 @@ def parse_data_mem(
             if rpc_request is None:
                 raise ValueError("rpc_request node is required when rpcreply=True")
             args.append(rpc_request.cdata)
-        if rpc or rpcreply:
+        if rpc or rpcreply or notification:
             if data_tree is not None:
                 args.append(data_tree.cdata)
             else:

libyang/data.py

@@ -6,7 +6,17 @@
 
 from _libyang import ffi, lib
 from .keyed_list import KeyedList
-from .schema import Module, SContainer, SLeaf, SLeafList, SList, SNode, SRpc, Type
+from .schema import (
+    Module,
+    SContainer,
+    SLeaf,
+    SLeafList,
+    SList,
+    SNode,
+    SNotif,
+    SRpc,
+    Type,
+)
 from .util import LibyangError, c2str, deprecated, str2c
 
 
@@ -69,16 +79,20 @@ def parser_flags(
     edit: bool = False,
     rpc: bool = False,
     rpcreply: bool = False,
+    notification: bool = False,
     strict: bool = False,
     trusted: bool = False,
     no_yanglib: bool = False,
     destruct: bool = False,
     no_siblings: bool = False,
     explicit: bool = False,
 ) -> int:
-    if (data, config, get, getconfig, edit, rpc, rpcreply).count(True) > 1:
+    if (data, config, get, getconfig, edit, rpc, rpcreply, notification).count(
+        True
+    ) > 1:
         raise ValueError(
-            "Only one of data, config, get, getconfig, edit, rpc, rpcreply can be True"
+            "Only one of data, config, get, getconfig, edit, rpc, rpcreply, "
+            "notification can be True"
         )
     flags = 0
     if data:
@@ -95,6 +109,8 @@ def parser_flags(
         flags |= lib.LYD_OPT_RPC
     if rpcreply:
         flags |= lib.LYD_OPT_RPCREPLY
+    if notification:
+        flags |= lib.LYD_OPT_NOTIF
     if strict:
         flags |= lib.LYD_OPT_STRICT
     if trusted:
@@ -261,6 +277,7 @@ def validate(
         edit: bool = False,
         rpc: bool = False,
         rpcreply: bool = False,
+        notification: bool = False,
         no_yanglib: bool = False,
     ) -> None:
         if self.cdata.parent:
@@ -273,6 +290,7 @@ def validate(
             edit=edit,
             rpc=rpc,
             rpcreply=rpcreply,
+            notification=notification,
             no_yanglib=no_yanglib,
         )
         node_p = ffi.new("struct lyd_node **")
@@ -476,7 +494,9 @@ def _to_dict(node, parent_dic):
                 if name not in parent_dic:
                     parent_dic[name] = _init_yang_list(node.schema)
                 parent_dic[name].append(list_element)
-            elif node.schema.nodetype & (SNode.CONTAINER | SNode.RPC | SNode.ACTION):
+            elif node.schema.nodetype & (
+                SNode.CONTAINER | SNode.RPC | SNode.ACTION | SNode.NOTIF
+            ):
                 container = {}
                 child = node.child
                 while child:
@@ -666,6 +686,12 @@ class DLeafList(DLeaf):
     pass
 
 
+# -------------------------------------------------------------------------------------
+@DNode.register(SNode.NOTIF)
+class DNotif(DContainer):
+    pass
+
+
 # -------------------------------------------------------------------------------------
 def dict_to_dnode(
     dic: Dict[str, Any],
@@ -678,6 +704,7 @@ def dict_to_dnode(
     edit: bool = False,
     rpc: bool = False,
     rpcreply: bool = False,
+    notification: bool = False,
     strict: bool = False,
     no_yanglib: bool = False,
     validate: bool = True,
@@ -709,6 +736,8 @@ def dict_to_dnode(
         Data represents RPC or action input parameters.
     :arg rpcreply:
         Data represents RPC or action output parameters.
+    :arg notification:
+        Data represents notification parameters.
     :arg strict:
         Instead of ignoring (with a warning message) data without schema definition,
         raise an error.
@@ -874,6 +903,10 @@ def _to_dnode(_dic, _schema, _parent=ffi.NULL, in_rpc_output=False):
                     n = _create_container(_parent, module, name, in_rpc_output)
                     _to_dnode(v, s, n, in_rpc_output)
 
+            elif isinstance(s, SNotif):
+                n = _create_container(_parent, module, name, in_rpc_output)
+                _to_dnode(value, s, n, in_rpc_output)
+
     result = None
 
     try:
@@ -900,6 +933,7 @@ def _to_dnode(_dic, _schema, _parent=ffi.NULL, in_rpc_output=False):
                     edit=edit,
                     rpc=rpc,
                     rpcreply=rpcreply,
+                    notification=notification,
                     no_yanglib=no_yanglib,
                 )
     except:

libyang/diff.py

@@ -4,7 +4,7 @@
 from typing import Any, Callable, Iterator, Optional
 
 from .context import Context
-from .schema import SContainer, SLeaf, SLeafList, SList, SNode, SRpc, SRpcInOut
+from .schema import SContainer, SLeaf, SLeafList, SList, SNode, SNotif, SRpc, SRpcInOut
 
 
 # -------------------------------------------------------------------------------------
@@ -40,7 +40,7 @@ def flatten(node, dic):
         if exclude_node_cb(node):
             return
         dic[node.schema_path()] = node
-        if isinstance(node, (SContainer, SList, SRpc, SRpcInOut)):
+        if isinstance(node, (SContainer, SList, SNotif, SRpc, SRpcInOut)):
             for child in node:
                 flatten(child, dic)
 

libyang/schema.py

@@ -136,6 +136,7 @@ def parse_data_dict(
         edit: bool = False,
         rpc: bool = False,
         rpcreply: bool = False,
+        notification: bool = False,
         strict: bool = False,
         no_yanglib: bool = False,
         validate: bool = True,
@@ -163,6 +164,8 @@ def parse_data_dict(
             Data represents RPC or action input parameters.
         :arg rpcreply:
             Data represents RPC or action output parameters.
+        :arg notification:
+            Data represents a NETCONF notification.
         :arg strict:
             Instead of ignoring (with a warning message) data without schema definition,
             raise an error.
@@ -185,6 +188,7 @@ def parse_data_dict(
             edit=edit,
             rpc=rpc,
             rpcreply=rpcreply,
+            notification=notification,
             strict=strict,
             no_yanglib=no_yanglib,
             validate=validate,
@@ -731,6 +735,7 @@ class SNode:
     ACTION = lib.LYS_ACTION
     INPUT = lib.LYS_INPUT
     OUTPUT = lib.LYS_OUTPUT
+    NOTIF = lib.LYS_NOTIF
     KEYWORDS = {
         CONTAINER: "container",
         LEAF: "leaf",
@@ -740,6 +745,7 @@ class SNode:
         ACTION: "action",
         INPUT: "input",
         OUTPUT: "output",
+        NOTIF: "notification",
     }
 
     def __init__(self, context: "libyang.Context", cdata):
@@ -1055,6 +1061,16 @@ def children(self, types: Optional[Tuple[int, ...]] = None) -> Iterator[SNode]:
         return iter_children(self.context, self.cdata, types=types)
 
 
+# -------------------------------------------------------------------------------------
+@SNode.register(SNode.NOTIF)
+class SNotif(SNode):
+    def __iter__(self) -> Iterator[SNode]:
+        return self.children()
+
+    def children(self, types: Optional[Tuple[int, ...]] = None) -> Iterator[SNode]:
+        return iter_children(self.context, self.cdata, types=types)
+
+
 # -------------------------------------------------------------------------------------
 def iter_children(
     context: "libyang.Context",
@@ -1071,6 +1087,7 @@ def iter_children(
             lib.LYS_RPC,
             lib.LYS_LEAF,
             lib.LYS_LEAFLIST,
+            lib.LYS_NOTIF,
         )
 
     def _skip(node) -> bool:

tests/test_data.py

@@ -7,7 +7,7 @@
 from unittest.mock import patch
 
 from _libyang import lib
-from libyang import Context, DContainer, DDiff, DNode, DRpc, LibyangError
+from libyang import Context, DContainer, DDiff, DNode, DNotif, DRpc, LibyangError
 
 
 YANG_DIR = os.path.join(os.path.dirname(__file__), "yang")
@@ -490,6 +490,28 @@ def test_data_to_dict_action(self):
             },
         )
 
+    DICT_NOTIF = {
+        "alarm-triggered": {"description": "An error occurred", "severity": 3}
+    }
+
+    JSON_NOTIF = """{
+  "yolo-system:alarm-triggered": {
+    "description": "An error occurred",
+    "severity": 3
+  }
+}
+"""
+
+    def test_notification_from_dict_module(self):
+        module = self.ctx.get_module("yolo-system")
+        dnotif = module.parse_data_dict(self.DICT_NOTIF, strict=True, notification=True)
+        self.assertIsInstance(dnotif, DNotif)
+        try:
+            j = dnotif.print_mem("json", pretty=True)
+        finally:
+            dnotif.free()
+        self.assertEqual(json.loads(j), json.loads(self.JSON_NOTIF))
+
     XML_DIFF_STATE1 = """<state xmlns="urn:yang:yolo:system">
   <hostname>foo</hostname>
   <speed>1234</speed>

tests/test_diff.py

@@ -65,6 +65,9 @@ class DiffTest(unittest.TestCase):
             (StatusRemoved, "/yolo-system:conf/yolo-system:obsolete-leaf"),
             (StatusRemoved, "/yolo-system:state/yolo-system:deprecated-leaf"),
             (StatusRemoved, "/yolo-system:state/yolo-system:obsolete-leaf"),
+            (SNodeAdded, "/yolo-system:alarm-triggered"),
+            (SNodeAdded, "/yolo-system:alarm-triggered/yolo-system:severity"),
+            (SNodeAdded, "/yolo-system:alarm-triggered/yolo-system:description"),
         )
     )
 

tests/test_schema.py

@@ -52,7 +52,7 @@ def test_mod_filepath(self):
 
     def test_mod_iter(self):
         children = list(iter(self.module))
-        self.assertEqual(len(children), 4)
+        self.assertEqual(len(children), 5)
 
     def test_mod_children_rpcs(self):
         rpcs = list(self.module.children(types=(SNode.RPC,)))

tests/yang/yolo/yolo-system.yang

@@ -157,4 +157,15 @@ module yolo-system {
       }
     }
   }
+
+  notification alarm-triggered {
+    description
+      "Notification about a new alarm.";
+    leaf description {
+      type string;
+    }
+    leaf severity {
+      type uint32;
+    }
+  }
 }