zone-tree: treat NULL tree as empty

src/knot/zone/zone-tree.c

@@ -51,12 +51,12 @@ knot_zone_tree_t* knot_zone_tree_create()
 
 /*----------------------------------------------------------------------------*/
 
-size_t knot_zone_tree_weight(knot_zone_tree_t* tree)
+size_t knot_zone_tree_weight(const knot_zone_tree_t* tree)
 {
 	return hattrie_weight(tree);
 }
 
-int knot_zone_tree_is_empty(knot_zone_tree_t *tree)
+int knot_zone_tree_is_empty(const knot_zone_tree_t *tree)
 {
 	return knot_zone_tree_weight(tree) == 0;
 }
@@ -65,6 +65,10 @@ int knot_zone_tree_is_empty(knot_zone_tree_t *tree)
 
 int knot_zone_tree_insert(knot_zone_tree_t *tree, knot_node_t *node)
 {
+	if (tree == NULL) {
+		return KNOT_EINVAL;
+	}
+
 	assert(tree && node && node->owner);
 	uint8_t lf[KNOT_DNAME_MAXLEN];
 	knot_dname_lf(lf, node->owner, NULL);
@@ -78,7 +82,7 @@ int knot_zone_tree_insert(knot_zone_tree_t *tree, knot_node_t *node)
 int knot_zone_tree_find(knot_zone_tree_t *tree, const knot_dname_t *owner,
                           const knot_node_t **found)
 {
-	if (tree == NULL || owner == NULL || found == NULL) {
+	if (owner == NULL || found == NULL) {
 		return KNOT_EINVAL;
 	}
 
@@ -90,10 +94,14 @@ int knot_zone_tree_find(knot_zone_tree_t *tree, const knot_dname_t *owner,
 int knot_zone_tree_get(knot_zone_tree_t *tree, const knot_dname_t *owner,
                          knot_node_t **found)
 {
-	if (tree == NULL || owner == NULL) {
+	if (owner == NULL) {
 		return KNOT_EINVAL;
 	}
 
+	if (knot_zone_tree_is_empty(tree)) {
+		return KNOT_ENONODE;
+	}
+
 	uint8_t lf[KNOT_DNAME_MAXLEN];
 	knot_dname_lf(lf, owner, NULL);
 
@@ -114,7 +122,7 @@ int knot_zone_tree_find_less_or_equal(knot_zone_tree_t *tree,
                                         const knot_node_t **found,
                                         const knot_node_t **previous)
 {
-	if (tree == NULL || owner == NULL || found == NULL || previous == NULL) {
+	if (owner == NULL || found == NULL || previous == NULL) {
 		return KNOT_EINVAL;
 	}
 
@@ -134,11 +142,14 @@ int knot_zone_tree_get_less_or_equal(knot_zone_tree_t *tree,
                                        knot_node_t **found,
                                        knot_node_t **previous)
 {
-	if (tree == NULL || owner == NULL || found == NULL
-	    || previous == NULL) {
+	if (owner == NULL || found == NULL || previous == NULL) {
 		return KNOT_EINVAL;
 	}
 
+	if (knot_zone_tree_is_empty(tree)) {
+		return KNOT_ENONODE;
+	}
+
 	uint8_t lf[KNOT_DNAME_MAXLEN];
 	knot_dname_lf(lf, owner, NULL);
 
@@ -197,10 +208,14 @@ int knot_zone_tree_remove(knot_zone_tree_t *tree,
                             const knot_dname_t *owner,
                           knot_node_t **removed)
 {
-	if (tree == NULL || owner == NULL) {
+	if (owner == NULL) {
 		return KNOT_EINVAL;
 	}
 
+	if (knot_zone_tree_is_empty(tree)) {
+		return KNOT_ENONODE;
+	}
+
 	uint8_t lf[KNOT_DNAME_MAXLEN];
 	knot_dname_lf(lf, owner, NULL);
 
@@ -222,10 +237,14 @@ int knot_zone_tree_apply_inorder(knot_zone_tree_t *tree,
                                  knot_zone_tree_apply_cb_t function,
                                  void *data)
 {
-	if (tree == NULL || function == NULL) {
+	if (function == NULL) {
 		return KNOT_EINVAL;
 	}
 
+	if (knot_zone_tree_is_empty(tree)) {
+		return KNOT_EOK;
+	}
+
 	int result = KNOT_EOK;
 
 	hattrie_iter_t *i = hattrie_iter_begin(tree, 1);
@@ -247,10 +266,14 @@ int knot_zone_tree_apply(knot_zone_tree_t *tree,
                          knot_zone_tree_apply_cb_t function,
                          void *data)
 {
-	if (tree == NULL || function == NULL) {
+	if (function == NULL) {
 		return KNOT_EINVAL;
 	}
 
+	if (knot_zone_tree_is_empty(tree)) {
+		return KNOT_EOK;
+	}
+
 	return hattrie_apply_rev(tree, (int (*)(value_t*,void*))function, data);
 }
 
@@ -259,11 +282,15 @@ int knot_zone_tree_apply(knot_zone_tree_t *tree,
 int knot_zone_tree_shallow_copy(knot_zone_tree_t *from,
                                   knot_zone_tree_t **to)
 {
-	if (to == NULL || from == NULL) {
+	if (to == NULL) {
 		return KNOT_EINVAL;
 	}
 
-	*to = hattrie_dup(from, knot_zone_node_copy);
+	if (from != NULL) {
+		*to = hattrie_dup(from, knot_zone_node_copy);
+	} else {
+		*to = NULL;
+	}
 
 	return KNOT_EOK;
 }
@@ -273,11 +300,15 @@ int knot_zone_tree_shallow_copy(knot_zone_tree_t *from,
 int knot_zone_tree_deep_copy(knot_zone_tree_t *from,
                              knot_zone_tree_t **to)
 {
-	if (to == NULL || from == NULL) {
+	if (to == NULL) {
 		return KNOT_EINVAL;
 	}
 
-	*to = hattrie_dup(from, knot_zone_node_deep_copy);
+	if (from != NULL) {
+		*to = hattrie_dup(from, knot_zone_node_deep_copy);
+	} else {
+		*to = NULL;
+	}
 
 	return KNOT_EOK;
 }
@@ -313,31 +344,3 @@ void knot_zone_tree_deep_free(knot_zone_tree_t **tree)
 	knot_zone_tree_apply(*tree, knot_zone_tree_free_node, NULL);
 	knot_zone_tree_free(tree);
 }
-
-/*----------------------------------------------------------------------------*/
-
-void hattrie_insert_dname(hattrie_t *tr, knot_dname_t *dname)
-{
-	uint8_t lf[KNOT_DNAME_MAXLEN];
-	knot_dname_lf(lf, dname, NULL);
-	*hattrie_get(tr, (char*)lf+1, *lf) = dname;
-}
-
-/*----------------------------------------------------------------------------*/
-
-knot_dname_t *hattrie_get_dname(hattrie_t *tr, knot_dname_t *dname)
-{
-	if (tr == NULL || dname == NULL) {
-		return NULL;
-	}
-
-	uint8_t lf[KNOT_DNAME_MAXLEN];
-	knot_dname_lf(lf, dname, NULL);
-
-	value_t *val = hattrie_tryget(tr, (char*)lf+1, *lf);
-	if (val == NULL) {
-		return NULL;
-	} else {
-		return (knot_dname_t *)(*val);
-	}
-}

src/knot/zone/zone-tree.h

@@ -54,7 +54,7 @@ knot_zone_tree_t* knot_zone_tree_create();
  * \param tree Zone tree.
  * \return number of nodes in tree.
  */
-size_t knot_zone_tree_weight(knot_zone_tree_t* tree);
+size_t knot_zone_tree_weight(const knot_zone_tree_t* tree);
 
 /*!
  * \brief Checks if the zone tree is empty.
@@ -63,7 +63,7 @@ size_t knot_zone_tree_weight(knot_zone_tree_t* tree);
  *
  * \return Nonzero if the zone tree is empty.
  */
-int knot_zone_tree_is_empty(knot_zone_tree_t *tree);
+int knot_zone_tree_is_empty(const knot_zone_tree_t *tree);
 
 /*!
  * \brief Inserts the given node into the zone tree.
@@ -242,9 +242,6 @@ void knot_zone_tree_free(knot_zone_tree_t **tree);
  */
 void knot_zone_tree_deep_free(knot_zone_tree_t **tree);
 
-void hattrie_insert_dname(hattrie_t *tr, knot_dname_t *dname);
-knot_dname_t *hattrie_get_dname(hattrie_t *tr, knot_dname_t *dname);
-
 /*----------------------------------------------------------------------------*/
 
 #endif // _KNOT_ZONE_TREE_H_