1 files changed, 62 insertions, 0 deletions
diff --git a/src/diff.h b/src/diff.h
new file mode 100644
index 0000000..dab1614
--- /dev/null
+++ b/src/diff.h
@@ -0,0 +1,62 @@
+/**
+ * @file diff.h
+ * @author Michal Vasko <mvasko@cesnet.cz>
+ * @brief internal diff header
+ *
+ * Copyright (c) 2020 CESNET, z.s.p.o.
+ *
+ * This source code is licensed under BSD 3-Clause License (the "License").
+ * You may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://opensource.org/licenses/BSD-3-Clause
+ */
+
+#ifndef LY_DIFF_H_
+#define LY_DIFF_H_
+
+#include <stdint.h>
+
+#include "log.h"
+
+struct lyd_node;
+
+/**
+ * @brief Internal structure for storing current (virtual) user-ordered instances order.
+ */
+struct lyd_diff_userord {
+    const struct lysc_node *schema; /**< User-ordered list/leaf-list schema node. */
+    uint64_t pos;                   /**< Current position in the second tree. */
+    const struct lyd_node **inst;   /**< Sized array of current instance order. */
+};
+
+/**
+ * @brief Diff operations.
+ */
+enum lyd_diff_op {
+    LYD_DIFF_OP_CREATE,    /**< Subtree created. */
+    LYD_DIFF_OP_DELETE,    /**< Subtree deleted. */
+    LYD_DIFF_OP_REPLACE,   /**< Node value changed or (leaf-)list instance moved. */
+    LYD_DIFF_OP_NONE       /**< No change of an existing inner node or default flag change of a term node. */
+};
+
+/**
+ * @brief Add a new change into diff.
+ *
+ * @param[in] node Node (subtree) to add into diff.
+ * @param[in] op Operation to set.
+ * @param[in] orig_default Original default metadata to set.
+ * @param[in] orig_value Original value metadata to set.
+ * @param[in] key Key metadata to set.
+ * @param[in] value Value metadata to set.
+ * @param[in] position Position metadata to set.
+ * @param[in] orig_key Original key metadata to set.
+ * @param[in] orig_position Original position metadata to set.
+ * @param[in,out] diff Diff to append to.
+ * @return LY_ERR value.
+ */
+LIBYANG_API_DECL LY_ERR lyd_diff_add(const struct lyd_node *node, enum lyd_diff_op op, const char *orig_default, const char *orig_value,
+        const char *key, const char *value, const char *position, const char *orig_key, const char *orig_position,
+        struct lyd_node **diff);
+
+#endif /* LY_DIFF_H_ */