data tree FEATURE lyd_merge() implemented
diff --git a/src/tree_data.c b/src/tree_data.c
index 7ec7004..7dfae9e 100644
--- a/src/tree_data.c
+++ b/src/tree_data.c
@@ -740,6 +740,16 @@
return ret;
}
+/**
+ * @brief Update node value.
+ *
+ * @param[in] node Node to update.
+ * @param[in] value New value to set.
+ * @param[in] value_type Type of @p value for any node.
+ * @param[out] new_parent Set to @p node if the value was updated, otherwise set to NULL.
+ * @param[out] new_node Set to @p node if the value was updated, otherwise set to NULL.
+ * @return LY_ERR value.
+ */
static LY_ERR
lyd_new_path_update(struct lyd_node *node, const void *value, LYD_ANYDATA_VALUETYPE value_type,
struct lyd_node **new_parent, struct lyd_node **new_node)
@@ -2190,6 +2200,148 @@
return NULL;
}
+/**
+ * @brief Merge a source sibling into target siblings.
+ *
+ * @param[in,out] first_trg First target sibling, is updated if top-level.
+ * @param[in] parent_trg Target parent.
+ * @param[in,out] sibling_src Source sibling to merge, set to NULL if spent.
+ * @param[in] options Merge options.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lyd_merge_sibling_r(struct lyd_node **first_trg, struct lyd_node *parent_trg, const struct lyd_node **sibling_src_p,
+ int options)
+{
+ LY_ERR ret;
+ const struct lyd_node *child_src, *tmp, *sibling_src;
+ struct lyd_node *match_trg, *dup_src, *next, *elem;
+ struct lysc_type *type;
+ LYD_ANYDATA_VALUETYPE tmp_val_type;
+ union lyd_any_value tmp_val;
+
+ sibling_src = *sibling_src_p;
+ if (sibling_src->schema->nodetype & (LYS_LIST | LYS_LEAFLIST)) {
+ /* try to find the exact instance */
+ ret = lyd_find_sibling_first(*first_trg, sibling_src, &match_trg);
+ } else {
+ /* try to simply find the node, there cannot be more instances */
+ ret = lyd_find_sibling_val(*first_trg, sibling_src->schema, NULL, 0, &match_trg);
+ }
+
+ if (!ret) {
+ /* node found, make sure even value matches for all node types */
+ if ((match_trg->schema->nodetype == LYS_LEAF) && lyd_compare(sibling_src, match_trg, LYD_COMPARE_DEFAULTS)) {
+ /* since they are different, they cannot both be default */
+ assert(!(sibling_src->flags & LYD_DEFAULT) || !(match_trg->flags & LYD_DEFAULT));
+
+ /* update value (or only LYD_DEFAULT flag) only if no flag set or the source node is not default */
+ if (!(options & LYD_MERGE_EXPLICIT) || !(sibling_src->flags & LYD_DEFAULT)) {
+ type = ((struct lysc_node_leaf *)match_trg->schema)->type;
+ type->plugin->free(LYD_NODE_CTX(match_trg), &((struct lyd_node_term *)match_trg)->value);
+ LY_CHECK_RET(type->plugin->duplicate(LYD_NODE_CTX(match_trg), &((struct lyd_node_term *)sibling_src)->value,
+ &((struct lyd_node_term *)match_trg)->value));
+
+ /* copy flags and add LYD_NEW */
+ match_trg->flags = sibling_src->flags | LYD_NEW;
+ }
+ } else if ((match_trg->schema->nodetype & LYS_ANYDATA) && lyd_compare(sibling_src, match_trg, 0)) {
+ if (options & LYD_MERGE_DESTRUCT) {
+ dup_src = (struct lyd_node *)sibling_src;
+ lyd_unlink_tree(dup_src);
+ /* spend it */
+ *sibling_src_p = NULL;
+ } else {
+ dup_src = lyd_dup(sibling_src, NULL, 0);
+ LY_CHECK_RET(!dup_src, LY_EMEM);
+ }
+ /* just switch values */
+ tmp_val_type = ((struct lyd_node_any *)match_trg)->value_type;
+ tmp_val = ((struct lyd_node_any *)match_trg)->value;
+ ((struct lyd_node_any *)match_trg)->value_type = ((struct lyd_node_any *)sibling_src)->value_type;
+ ((struct lyd_node_any *)match_trg)->value = ((struct lyd_node_any *)sibling_src)->value;
+ ((struct lyd_node_any *)sibling_src)->value_type = tmp_val_type;
+ ((struct lyd_node_any *)sibling_src)->value = tmp_val;
+
+ /* copy flags and add LYD_NEW */
+ match_trg->flags = sibling_src->flags | LYD_NEW;
+
+ /* dup_src is not needed, actually */
+ lyd_free_tree(dup_src);
+ } else {
+ /* check descendants, recursively */
+ LY_LIST_FOR_SAFE(lyd_node_children(sibling_src), tmp, child_src) {
+ if ((child_src->schema->nodetype == LYS_LEAF) && (child_src->schema->flags & LYS_KEY)) {
+ /* skip keys */
+ continue;
+ }
+
+ LY_CHECK_RET(lyd_merge_sibling_r(lyd_node_children_p(match_trg), match_trg, &child_src, options));
+ }
+ }
+ } else {
+ /* node not found, merge it */
+ if (options & LYD_MERGE_DESTRUCT) {
+ dup_src = (struct lyd_node *)sibling_src;
+ lyd_unlink_tree(dup_src);
+ /* spend it */
+ *sibling_src_p = NULL;
+ } else {
+ dup_src = lyd_dup(sibling_src, NULL, LYD_DUP_RECURSIVE | LYD_DUP_WITH_FLAGS);
+ LY_CHECK_RET(!dup_src, LY_EMEM);
+ }
+
+ /* set LYD_NEW for all the new nodes, required for validation */
+ LYD_TREE_DFS_BEGIN(dup_src, next, elem) {
+ elem->flags |= LYD_NEW;
+ LYD_TREE_DFS_END(dup_src, next, elem);
+ }
+
+ lyd_insert_node(parent_trg, first_trg, dup_src);
+ }
+
+ return LY_SUCCESS;
+}
+
+API LY_ERR
+lyd_merge(struct lyd_node **target, const struct lyd_node *source, int options)
+{
+ const struct lyd_node *sibling_src, *tmp;
+ int first;
+
+ LY_CHECK_ARG_RET(NULL, target, LY_EINVAL);
+
+ if (!source) {
+ /* nothing to merge */
+ return LY_SUCCESS;
+ }
+
+ if (lysc_data_parent((*target)->schema) || lysc_data_parent(source->schema)) {
+ LOGERR(LYD_NODE_CTX(source), LY_EINVAL, "Invalid arguments - can merge only 2 top-level subtrees (%s()).", __func__);
+ return LY_EINVAL;
+ }
+
+ LY_LIST_FOR_SAFE(source, tmp, sibling_src) {
+ first = sibling_src == source ? 1 : 0;
+ LY_CHECK_RET(lyd_merge_sibling_r(target, NULL, &sibling_src, options));
+ if (first && !sibling_src) {
+ /* source was spent (unlinked), move to the next node */
+ source = tmp;
+ }
+
+ if (options & LYD_MERGE_NOSIBLINGS) {
+ break;
+ }
+ }
+
+ if (options & LYD_MERGE_DESTRUCT) {
+ /* free any leftover source data that were not merged */
+ lyd_free_siblings((struct lyd_node *)source);
+ }
+
+ return LY_SUCCESS;
+}
+
static LY_ERR
lyd_path_str_enlarge(char **buffer, size_t *buflen, size_t reqlen, int is_static)
{
diff --git a/src/tree_data.h b/src/tree_data.h
index 8e021d6..1c4e9c0 100644
--- a/src/tree_data.h
+++ b/src/tree_data.h
@@ -1043,11 +1043,44 @@
struct lyd_node *lyd_dup(const struct lyd_node *node, struct lyd_node_inner *parent, int options);
/**
- * @brief Resolve instance-identifier defined by lyd_value_path structure.
+ * @defgroup mergeoptions Data merge options.
+ * @ingroup datatree
*
- * @param[in] path Path structure specifying the instance-identifier target.
+ * Various options to change lyd_merge() behavior.
+ *
+ * Default behavior:
+ * - source data tree is not modified in any way,
+ * - source data tree is merged with any succeeding siblings,
+ * - any default nodes from source replace explicit nodes in the target.
+ * @{
+ */
+
+#define LYD_MERGE_DESTRUCT 0x01 /**< Spend source data tree in the function, it cannot be used afterwards! */
+#define LYD_MERGE_NOSIBLINGS 0x02 /**< Merge only the single source data tree, no siblings. */
+#define LYD_MERGE_EXPLICIT 0x04 /**< Default nodes in the source tree are ignored if there are explicit nodes
+ in the target tree. */
+
+/** @} mergeoptions */
+
+/**
+ * @brief Merge the source data tree into the target data tree. Merge may not be complete until validation
+ * is called on the resulting data tree (data from more cases may be present, default and non-default values).
+ *
+ * @param[in,out] target Target data tree to merge into, must be a top-level tree.
+ * @param[in] source Source data tree to merge, must be a top-level tree.
+ * @param[in] options Bitmask of option flags, see @ref mergeoptions.
+ * @return LY_SUCCESS on success,
+ * @return LY_ERR value on error.
+ */
+LY_ERR lyd_merge(struct lyd_node **target, const struct lyd_node *source, int options);
+
+/**
+ * @brief Find the target in data of a compiled ly_path structure (instance-identifier).
+ *
+ * @param[in] path Compiled path structure.
* @param[in] tree Data tree to be searched.
- * @return Target node of the instance-identifier present in the given data @p tree.
+ * @return Found target node,
+ * @return NULL if not found.
*/
const struct lyd_node_term *lyd_target(const struct ly_path *path, const struct lyd_node *tree);