sandbox: AVL tree deletion bugfixes and testing

sandbox/base/main.c

@@ -3,13 +3,14 @@
 #include <stdlib.h>
 #include <inttypes.h>
 #include <time.h>
+#include <assert.h>
 #include <sys/mman.h>
 #include <socks/types.h>
 #include <socks/btree.h>
 #include <socks/memblock.h>
 #include <socks/vm.h>
 
-#define NR_BTREE_NODES 16383
+#define NR_BTREE_NODES 13
 
 /* we're working with 512MiB of simulated system RAM */
 #define MEMORY_SIZE_MB 512
@@ -166,10 +167,14 @@ void btree_print(btree_node_t *node, int depth)
  */
 static int btree_avl_validate(btree_node_t *x)
 {
+	if (!x) {
+		return 0;
+	}
+
 	if (!x->b_left && !x->b_right) {
 		return 1;
 	}
-	
+
 	int left = 0, right = 0;
 
 	if (x->b_left) {
@@ -200,7 +205,7 @@ static int btree_avl_validate(btree_node_t *x)
 	if (height != x->b_height) {
 		return -1;
 	}
-	
+
 	return height;
 }
 
@@ -210,38 +215,42 @@ static int btree_test(void)
 	btree_node_t *nodes = calloc(NR_BTREE_NODES, sizeof *nodes);
 
 	for (int i = 0; i < NR_BTREE_NODES; i++) {
-		nodes[i].b_key = (rand() % 512000) + 1;
+		nodes[i].b_key = (rand() % 128) + 1;
 		printf(" - node %d: %llu\n", i, nodes[i].b_key);
 	}
 
+	int validation_result = 0;
 	for (int i = 0; i < NR_BTREE_NODES; i++) {
 		printf("#######################\n");
 		printf("inserting node #%d: %llu\n", i, nodes[i].b_key);
 
 		btree_insert(&tree, &nodes[i]);
 		printf("#######################\n");
+
+		validation_result = btree_avl_validate(tree.b_root);
+		assert(validation_result >= 1);
 	}
 
 	btree_print(tree.b_root, 0);
 
 	int result = btree_avl_validate(tree.b_root);
-	printf("AVL validation result: %d (%s)\n", result, result != -1 ? "pass" : "fail");
-
-	#if 0
-	int to_delete[] = { 3, 1, 0 };
-	int nr_to_delete = sizeof to_delete / sizeof to_delete[0];
-
-	for (int i = 0; i < nr_to_delete; i++) {
-		int node_index = to_delete[i];
+	printf("AVL tree height: %d\n", result);
 
+	for (int i = 0; i < NR_BTREE_NODES; i++) {
 		printf("#######################\n");
-		printf("deleting node %llu\n", nodes[node_index].b_key);
+		printf("deleting node #%d: %llu\n", i, nodes[i].b_key);
 		printf("#######################\n");
 
-		btree_delete(&tree, &nodes[node_index]);
+		if (nodes[i].b_key == 89) {
+			printf("brk\n");
+		}
+
+		btree_delete(&tree, &nodes[i]);
 		btree_print(tree.b_root, 0);
+
+		validation_result = btree_avl_validate(tree.b_root);
+		assert(validation_result >= 0);
 	}
-	#endif
 
 	free(nodes);
 	return 0;