context: adds find_xpath_atoms function

This patch is adding find_xpath_atoms on context level to allow users to
get all nodes needed for xpath evaluation

Signed-off-by: Stefan Gula <[email protected]>

Author: steweg

cffi/cdefs.h

@@ -215,6 +215,7 @@ struct lys_module* ly_ctx_get_module_latest(const struct ly_ctx *, const char *)
 LY_ERR ly_ctx_compile(struct ly_ctx *);
 
 LY_ERR lys_find_xpath(const struct ly_ctx *, const struct lysc_node *, const char *, uint32_t, struct ly_set **);
+LY_ERR lys_find_xpath_atoms(const struct ly_ctx *, const struct lysc_node *, const char *, uint32_t, struct ly_set **);
 void ly_set_free(struct ly_set *, void(*)(void *obj));
 
 struct ly_set {

libyang/context.py

@@ -401,6 +401,38 @@ def find_path(
         finally:
             lib.ly_set_free(node_set, ffi.NULL)
 
+    def find_xpath_atoms(
+        self,
+        path: str,
+        output: bool = False,
+        root_node: Optional["libyang.SNode"] = None,
+    ) -> Iterator[SNode]:
+        if self.cdata is None:
+            raise RuntimeError("context already destroyed")
+
+        if root_node is not None:
+            ctx_node = root_node.cdata
+        else:
+            ctx_node = ffi.NULL
+
+        flags = lib.LYS_FIND_XP_OUTPUT if output else 0
+
+        node_set = ffi.new("struct ly_set **")
+        if (
+            lib.lys_find_xpath_atoms(self.cdata, ctx_node, str2c(path), flags, node_set)
+            != lib.LY_SUCCESS
+        ):
+            raise self.error("cannot find path")
+
+        node_set = node_set[0]
+        if node_set.count == 0:
+            raise self.error("cannot find path")
+        try:
+            for i in range(node_set.count):
+                yield SNode.new(self, node_set.snodes[i])
+        finally:
+            lib.ly_set_free(node_set, ffi.NULL)
+
     def find_jsonpath(
         self,
         path: str,

tests/test_context.py

@@ -4,7 +4,7 @@
 import os
 import unittest
 
-from libyang import Context, LibyangError, Module, SLeaf, SLeafList
+from libyang import Context, LibyangError, Module, SContainer, SLeaf, SLeafList
 from libyang.util import c2str
 
 
@@ -95,6 +95,22 @@ def test_ctx_find_path(self):
             node2 = next(ctx.find_path("../number", root_node=node))
             self.assertIsInstance(node2, SLeafList)
 
+    def test_ctx_find_xpath_atoms(self):
+        with Context(YANG_DIR) as ctx:
+            ctx.load_module("yolo-system")
+            node_iter = ctx.find_xpath_atoms("/yolo-system:conf/offline")
+            node = next(node_iter)
+            self.assertIsInstance(node, SContainer)
+            node = next(node_iter)
+            self.assertIsInstance(node, SLeaf)
+            node_iter = ctx.find_xpath_atoms("../number", root_node=node)
+            node = next(node_iter)
+            self.assertIsInstance(node, SLeaf)
+            node = next(node_iter)
+            self.assertIsInstance(node, SContainer)
+            node = next(node_iter)
+            self.assertIsInstance(node, SLeafList)
+
     def test_ctx_iter_modules(self):
         with Context(YANG_DIR) as ctx:
             ctx.load_module("yolo-system")