RB-Tree implementation in Target Utils

include/target-utils/rbt/rbt.h

@@ -0,0 +1,204 @@
+/*
+ * Copyright(c) 2024 Intel Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include <stdint.h>
+#include <stdbool.h>
+
+#define BLACK 0
+#define RED   1
+
+typedef enum bf_rbt_sts_t {
+  BF_RBT_OK,
+  BF_RBT_ERR,
+  BF_RBT_NO_KEY,
+  BF_RBT_KEY_EXISTS
+} bf_rbt_sts_t;
+
+enum rbt_node_direction {
+	BF_RBT_LEFT_NODE,
+	BF_RBT_RIGHT_NODE,
+	BF_RBT_ROOT_NODE
+};
+
+typedef struct bf_rbt_node_t {
+	uint32_t priority;
+	bool color;
+	struct bf_rbt_node_t *left, *right, *parent;
+	void *data;
+} bf_rbt_node_t;
+
+/*!
+ * Create a tree node for the priority
+ *
+ * @param priority parsed from match spec
+ * @param root parent node of new node to be created
+ * @return pointer to newly created node
+ */
+bf_rbt_node_t *bf_create_rbt_node(uint32_t priority, bf_rbt_node_t *root);
+
+/*!
+ * Perform a right rotation of node
+ *
+ * @param node around which rotation happens
+ * @param rbt_head head ptr of rb-tree
+ * @return pointer to node after rotation
+ */
+bf_rbt_node_t *bf_right_rotate_rbt_node(bf_rbt_node_t *node, bf_rbt_node_t **rbt_head);
+
+/*!
+ * Perform a left rotation of node
+ *
+ * @param node around which rotation happens
+ * @param rbt_head head ptr of rb-tree
+ * @return pointer to node after rotation
+ */
+bf_rbt_node_t *bf_left_rotate_rbt_node(bf_rbt_node_t *node, bf_rbt_node_t **rbt_head);
+
+/*!
+ * Call left/right rotate APIs based on parent-child node direction
+ *
+ * @param parent node based on which direction of rotation is evaluated
+ * @param rbt_head head ptr of rb-tree
+ * @param key priority of child node
+ * @return pointer to node after rotation
+ */
+bf_rbt_node_t *bf_perform_rotation(bf_rbt_node_t *parent, bf_rbt_node_t **rbt_head, uint32_t key);
+
+/*!
+ * Fix RBT node colors as part of balancing tree
+ *
+ * @param parent node based on which direction of rotation is evaluated
+ * @param key priority of child node
+ * @param key priority of child node
+ * @return void
+ */
+void bf_color_fix_rbt_nodes(bf_rbt_node_t *parent, bf_rbt_node_t **rbt_head, uint32_t key);
+
+/*!
+ * Retrieve color of neighbor node
+ *
+ * @param root node for which it is necessary to determine its neighboring node color.
+ * @return color of neighbor node RED/BLACK
+ */
+bool bf_get_rbt_neigh_color(bf_rbt_node_t *root);
+
+/*!
+ * Retrieve neighbor node for given node
+ *
+ * @param root node for which it is necessary to determine its neighboring node.
+ * @return pointer to neighbor node
+ */
+bf_rbt_node_t *bf_get_neighbor_rbt_node(bf_rbt_node_t *root);
+
+/*!
+ * Retrieve direction of given node
+ *
+ * @param root child node for which it is necessary to determine its direction.
+ * @return direction left/right child
+ */
+int bf_get_rbt_node_direction(bf_rbt_node_t *root);
+
+/*!
+ * Retrieve inorder successor node for given node
+ *
+ * @param root node for which it is necessary to determine its successor node.
+ * @return pointer to successor node
+ */
+bf_rbt_node_t *bf_get_successor_rbt_node(bf_rbt_node_t *root);
+
+/*!
+ * Retrieve inorder predecessor node for given node
+ *
+ * @param root node for which it is necessary to determine its predecessor node.
+ * @return pointer to predecessor node
+ */
+bf_rbt_node_t *bf_get_predecessor_rbt_node(bf_rbt_node_t *root);
+
+/*!
+ * Insert a tree node into RBT with given priority
+ *
+ * @param key priority to be inserted into RBT
+ * @param root parent node of new node to be created
+ * @return pointer to newly created node
+ */
+bf_rbt_node_t *bf_insert_rbt_entry(bf_rbt_node_t *root, uint32_t key, bf_rbt_node_t **rbt_head);
+
+/*!
+ * Rtrieve node which is just lesser than or equal to given priority
+ *
+ * @param priority for which lower bound has to be found
+ * @param rbt_head head ptr of rb-tree
+ * @return pointer to lower bound node
+ */
+bf_rbt_node_t *bf_get_lower_bound(uint32_t priority, bf_rbt_node_t *rbt_head);
+
+/*!
+ * Retrieve node which is just greater than or equal to given priority
+ *
+ * @param priority for which upper bound has to be found
+ * @param rbt_head head ptr of rb-tree
+ * @return pointer to upper bound node
+ */
+bf_rbt_node_t *bf_get_upper_bound(uint32_t priority, bf_rbt_node_t *rbt_head);
+
+/*!
+ * Retrieve node with highest priority in rb-tree
+ *
+ * @param rbt_head head ptr of rb-tree
+ * @return pointer to highest priority node
+ */
+bf_rbt_node_t *bf_get_highest_priority_node(bf_rbt_node_t *rbt_head);
+
+/*!
+ * Retrieve node with lowest priority in rb-tree
+ *
+ * @param rbt_head head ptr of rb-tree
+ * @return pointer to lowest priority node
+ */
+bf_rbt_node_t *bf_get_lowest_priority_node(bf_rbt_node_t *rbt_head);
+
+/*!
+ * Perform BST node deletion for given key and update color information
+ *
+ * @param key priority to be deleted from RBT
+ * @param color address where color needs to be updated
+ * @return node which has to be deleted
+ */
+bf_rbt_node_t *bf_bst_node_deletion(uint32_t key, bf_rbt_node_t *rbt_head, int *color);
+
+/*!
+ * Remove a tree node from RBT with given priority
+ *
+ * @param key priority of node to be deleted from RBT
+ * @return status of API call
+ */
+int bf_remove_rbt_entry(uint32_t key, bf_rbt_node_t **rbt_head);
+
+/*!
+ * Balance RBT after insertion of new node
+ *
+ * @param root parent of the node which got inserted
+ * @param key priority of inserted node
+ * @return void
+ */
+void bf_balance_rbt_post_insertion(bf_rbt_node_t *root, bf_rbt_node_t **rbt_head, uint32_t key);
+
+/*!
+ * Balance RBT after deletion of a node
+ *
+ * @param node node to be deleted from RBT
+ * @return void
+ */
+void bf_balance_rbt_post_deletion(bf_rbt_node_t *node, bf_rbt_node_t **rbt_head);

src/CMakeLists.txt

@@ -7,5 +7,6 @@ add_library(target_sysutil_o OBJECT
   fbitset/fbitset.c
   id/id.c
   map/map.c
+  rbt/rbt.c
   power2_allocator/power2_allocator.c
 )