diff --git a/cffi/cdefs.h b/cffi/cdefs.h index aa75004..e7dc978 100644 --- a/cffi/cdefs.h +++ b/cffi/cdefs.h @@ -861,6 +861,8 @@ const struct lysc_node* lys_find_child(const struct lysc_node *, const struct ly const struct lysc_node* lysc_node_child(const struct lysc_node *); const struct lysc_node_action* lysc_node_actions(const struct lysc_node *); const struct lysc_node_notif* lysc_node_notifs(const struct lysc_node *); +LY_ERR lysc_node_lref_targets(const struct lysc_node *, struct ly_set **); +LY_ERR lysc_node_lref_backlinks(const struct ly_ctx *, const struct lysc_node *, ly_bool, struct ly_set **); typedef enum { LYD_PATH_STD, diff --git a/libyang/context.py b/libyang/context.py index fb4a330..f91d1e3 100644 --- a/libyang/context.py +++ b/libyang/context.py @@ -4,7 +4,7 @@ # SPDX-License-Identifier: MIT import os -from typing import IO, Any, Callable, Iterator, Optional, Tuple, Union +from typing import IO, Any, Callable, Iterator, Optional, Tuple, Union, List from _libyang import ffi, lib from .data import ( @@ -646,6 +646,104 @@ def parse_data_file( json_null=json_null, ) + def find_leafref_path_target_paths(self, leafref_path: str) -> List[str]: + """ + Fetch all leafref targets of the specified path + + This is an enhanced version of lysc_node_lref_target() which will return + a set of leafref target paths retrieved from the specified schema path. + While lysc_node_lref_target() will only work on nodetype of LYS_LEAF and + LYS_LEAFLIST this function will also evaluate other datatypes that may + contain leafrefs such as LYS_UNION. This does not, however, search for + children with leafref targets. + + :arg self + This instance on context + :arg leafref_path: + Path to node to search for leafref targets + :returns List of target paths that the leafrefs of the specified node + point to. + """ + if self.cdata is None: + raise RuntimeError("context already destroyed") + if leafref_path is None: + raise RuntimeError("leafref_path must be defined") + + out = [] + + node = lib.lys_find_path(self.cdata, ffi.NULL, str2c(leafref_path), 0) + if node == ffi.NULL: + raise self.error("leafref_path not found") + + node_set = ffi.new("struct ly_set **") + if (lib.lysc_node_lref_targets(node, node_set) != lib.LY_SUCCESS or + node_set[0] == ffi.NULL or node_set[0].count == 0): + raise self.error("leafref_path does not contain any leafref targets") + + node_set = node_set[0] + for i in range(node_set.count): + path = lib.lysc_path(node_set.snodes[i], lib.LYSC_PATH_DATA, ffi.NULL, 0); + out.append(c2str(path)) + lib.free(path) + + lib.ly_set_free(node_set, ffi.NULL) + + return out + + + def find_backlinks_paths(self, match_path: str = None, match_ancestors: bool = False) -> List[str]: + """ + Search entire schema for nodes that contain leafrefs and return as a + list of schema node paths. + + Perform a complete scan of the schema tree looking for nodes that + contain leafref entries. When a node contains a leafref entry, and + match_path is specified, determine if reference points to match_path, + if so add the node's path to returned list. If no match_path is + specified, the node containing the leafref is always added to the + returned set. When match_ancestors is true, will evaluate if match_path + is self or an ansestor of self. + + This does not return the leafref targets, but the actual node that + contains a leafref. + + :arg self + This instance on context + :arg match_path: + Target path to use for matching + :arg match_ancestors: + Whether match_path is a base ancestor or an exact node + :returns List of paths. Exception of match_path is not found or if no + backlinks are found. + """ + if self.cdata is None: + raise RuntimeError("context already destroyed") + out = [] + + match_node = ffi.NULL + if match_path is not None and match_path == "/" or match_path == "": + match_path = None + + if match_path: + match_node = lib.lys_find_path(self.cdata, ffi.NULL, str2c(match_path), 0) + if match_node == ffi.NULL: + raise self.error("match_path not found") + + node_set = ffi.new("struct ly_set **") + if (lib.lysc_node_lref_backlinks(self.cdata, match_node, match_ancestors, node_set) + != lib.LY_SUCCESS or node_set[0] == ffi.NULL or node_set[0].count == 0): + raise self.error("backlinks not found") + + node_set = node_set[0] + for i in range(node_set.count): + path = lib.lysc_path(node_set.snodes[i], lib.LYSC_PATH_DATA, ffi.NULL, 0); + out.append(c2str(path)) + lib.free(path) + + lib.ly_set_free(node_set, ffi.NULL) + + return out + def __iter__(self) -> Iterator[Module]: """ Return an iterator that yields all implemented modules from the context diff --git a/tests/test_schema.py b/tests/test_schema.py index a310aad..4aae73a 100644 --- a/tests/test_schema.py +++ b/tests/test_schema.py @@ -801,6 +801,64 @@ def test_leaf_list_parsed(self): self.assertFalse(pnode.ordered()) +# ------------------------------------------------------------------------------------- +class BacklinksTest(unittest.TestCase): + def setUp(self): + self.ctx = Context(YANG_DIR) + self.ctx.load_module("yolo-leafref-search") + self.ctx.load_module("yolo-leafref-search-extmod") + def tearDown(self): + self.ctx.destroy() + self.ctx = None + def test_backlinks_all_nodes(self): + expected = [ + "/yolo-leafref-search-extmod:my_extref_list/my_extref", + "/yolo-leafref-search:refstr", + "/yolo-leafref-search:refnum", + "/yolo-leafref-search-extmod:my_extref_list/my_extref_union" + ] + refs = self.ctx.find_backlinks_paths() + expected.sort() + refs.sort() + self.assertEqual(expected, refs) + def test_backlinks_one(self): + expected = [ + "/yolo-leafref-search-extmod:my_extref_list/my_extref", + "/yolo-leafref-search:refstr", + "/yolo-leafref-search-extmod:my_extref_list/my_extref_union" + ] + refs = self.ctx.find_backlinks_paths( + match_path="/yolo-leafref-search:my_list/my_leaf_string" + ) + expected.sort() + refs.sort() + self.assertEqual(expected, refs) + def test_backlinks_children(self): + expected = [ + "/yolo-leafref-search-extmod:my_extref_list/my_extref", + "/yolo-leafref-search:refstr", + "/yolo-leafref-search:refnum", + "/yolo-leafref-search-extmod:my_extref_list/my_extref_union" + ] + refs = self.ctx.find_backlinks_paths( + match_path="/yolo-leafref-search:my_list", + match_ancestors=True + ) + expected.sort() + refs.sort() + self.assertEqual(expected, refs) + def test_backlinks_leafref_target_paths(self): + expected = [ + "/yolo-leafref-search:my_list/my_leaf_string" + ] + refs = self.ctx.find_leafref_path_target_paths( + "/yolo-leafref-search-extmod:my_extref_list/my_extref" + ) + expected.sort() + refs.sort() + self.assertEqual(expected, refs) + + # ------------------------------------------------------------------------------------- class ChoiceTest(unittest.TestCase): def setUp(self): diff --git a/tests/yang/yolo/yolo-leafref-search-extmod.yang b/tests/yang/yolo/yolo-leafref-search-extmod.yang new file mode 100644 index 0000000..046ceec --- /dev/null +++ b/tests/yang/yolo/yolo-leafref-search-extmod.yang @@ -0,0 +1,39 @@ +module yolo-leafref-search-extmod { + yang-version 1.1; + namespace "urn:yang:yolo:leafref-search-extmod"; + prefix leafref-search-extmod; + + import wtf-types { prefix types; } + + import yolo-leafref-search { + prefix leafref-search; + } + + revision 2025-02-11 { + description + "Initial version."; + } + + list my_extref_list { + key my_leaf_string; + leaf my_leaf_string { + type string; + } + leaf my_extref { + type leafref { + path "/leafref-search:my_list/leafref-search:my_leaf_string"; + } + } + leaf my_extref_union { + type union { + type leafref { + path "/leafref-search:my_list/leafref-search:my_leaf_string"; + } + type leafref { + path "/leafref-search:my_list/leafref-search:my_leaf_number"; + } + type types:number; + } + } + } +} diff --git a/tests/yang/yolo/yolo-leafref-search.yang b/tests/yang/yolo/yolo-leafref-search.yang new file mode 100644 index 0000000..5f4af48 --- /dev/null +++ b/tests/yang/yolo/yolo-leafref-search.yang @@ -0,0 +1,36 @@ +module yolo-leafref-search { + yang-version 1.1; + namespace "urn:yang:yolo:leafref-search"; + prefix leafref-search; + + import wtf-types { prefix types; } + + revision 2025-02-11 { + description + "Initial version."; + } + + list my_list { + key my_leaf_string; + leaf my_leaf_string { + type string; + } + leaf my_leaf_number { + description + "A number."; + type types:number; + } + } + + leaf refstr { + type leafref { + path "../my_list/my_leaf_string"; + } + } + + leaf refnum { + type leafref { + path "../my_list/my_leaf_number"; + } + } +}