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-rw-r--r--tests/rbtree.c177
1 files changed, 177 insertions, 0 deletions
diff --git a/tests/rbtree.c b/tests/rbtree.c
new file mode 100644
index 0000000..1c5ab4d
--- /dev/null
+++ b/tests/rbtree.c
@@ -0,0 +1,177 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * rbtree.c
+ *
+ * Copyright (C) 2020 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "config.h"
+
+#include <stdlib.h>
+#include <assert.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "rbtree.h"
+
+static int key_compare(const void *a, const void *b)
+{
+ return *((sqfs_s32 *)a) - *((sqfs_s32 *)b);
+}
+
+static size_t count_nodes_dfs(rbtree_node_t *n)
+{
+ return 1 + (n->left == NULL ? 0 : count_nodes_dfs(n->left))
+ + (n->right == NULL ? 0 : count_nodes_dfs(n->right));
+}
+
+static size_t min_depth(rbtree_node_t *n)
+{
+ size_t lhs, rhs;
+
+ if (n == NULL)
+ return 0;
+
+ lhs = min_depth(n->left) + 1;
+ rhs = min_depth(n->right) + 1;
+
+ return lhs < rhs ? lhs : rhs;
+}
+
+static size_t max_depth(rbtree_node_t *n)
+{
+ size_t lhs, rhs;
+
+ if (n == NULL)
+ return 0;
+
+ lhs = min_depth(n->left) + 1;
+ rhs = min_depth(n->right) + 1;
+
+ return lhs > rhs ? lhs : rhs;
+}
+
+static size_t get_ref_black_depth(rbtree_t *rb)
+{
+ rbtree_node_t *n;
+ size_t count = 0;
+
+ for (n = rb->root; n != NULL; n = n->left) {
+ if (!n->is_red)
+ count += 1;
+ }
+
+ return count;
+}
+
+static void check_binary_tree_dfs(rbtree_node_t *n)
+{
+ const void *key = rbtree_node_key(n);
+ const void *cmp;
+
+ if (n->left != NULL) {
+ cmp = rbtree_node_key(n->left);
+ assert(key_compare(cmp, key) < 0);
+
+ check_binary_tree_dfs(n->left);
+ }
+
+ if (n->right != NULL) {
+ cmp = rbtree_node_key(n->right);
+ assert(key_compare(cmp, key) > 0);
+
+ check_binary_tree_dfs(n->right);
+ }
+}
+
+static void check_colors_dfs(rbtree_node_t *n)
+{
+ if (n->is_red) {
+ assert(n->left == NULL || !n->left->is_red);
+ assert(n->right == NULL || !n->right->is_red);
+ }
+
+ if (n->left != NULL)
+ check_colors_dfs(n->left);
+
+ if (n->right != NULL)
+ check_colors_dfs(n->right);
+}
+
+static void check_black_depth_dfs(rbtree_node_t *n, size_t ref,
+ size_t counter)
+{
+ if (!n->is_red)
+ counter += 1;
+
+ if (n->left == NULL || n->right == NULL)
+ assert(counter == ref);
+
+ if (n->left != NULL)
+ check_black_depth_dfs(n->left, ref, counter);
+
+ if (n->right != NULL)
+ check_black_depth_dfs(n->right, ref, counter);
+}
+
+int main(void)
+{
+ size_t count, blkdepth, mind, maxd;
+ sqfs_s32 key, key2;
+ rbtree_node_t *n;
+ sqfs_u64 value;
+ rbtree_t rb;
+
+ assert(rbtree_init(&rb, sizeof(sqfs_s32),
+ sizeof(sqfs_u64), key_compare) == 0);
+
+ count = 0;
+
+ for (key = -1000; key < 1000; ++key) {
+ /* lookup of current key must fail prior to insert */
+ assert(rbtree_lookup(&rb, &key) == NULL);
+
+ /* previous key/value pairs must still be there */
+ for (key2 = -1000; key2 < key; ++key2) {
+ n = rbtree_lookup(&rb, &key2);
+ assert(n != NULL);
+ value = *((sqfs_u64 *)rbtree_node_value(n));
+ assert((sqfs_u64)(key2 + 10000) == value);
+ }
+
+ /* insert key value pair */
+ value = key + 10000;
+ assert(rbtree_insert(&rb, &key, &value) == 0);
+ count += 1;
+
+ /* check if the tree has the right number of nodes */
+ assert(count_nodes_dfs(rb.root) == count);
+
+ /* check if it is still a binary tree */
+ check_binary_tree_dfs(rb.root);
+
+ /* root node must be black. Every red node
+ must have black children. */
+ assert(!rb.root->is_red);
+ check_colors_dfs(rb.root);
+
+ /* every path from the root to a leave must have
+ the same number of black nodes. */
+ blkdepth = get_ref_black_depth(&rb);
+ check_black_depth_dfs(rb.root, blkdepth, 0);
+
+ /* longest root to leaf path must be at most
+ twice as long as the shortest. */
+ mind = min_depth(rb.root);
+ maxd = max_depth(rb.root);
+ assert(maxd <= mind * 2);
+
+ /* lookup of current key must work after insert */
+ n = rbtree_lookup(&rb, &key);
+ assert(n != NULL);
+ value = *((sqfs_u64 *)rbtree_node_value(n));
+ assert((sqfs_u64)(key + 10000) == value);
+ }
+
+ rbtree_cleanup(&rb);
+ return EXIT_SUCCESS;
+}