More glib like interface for ZixTree.

Move ZixTree debug stuff to tree_debug.h.
Support reverse iteration over ZixTree.


git-svn-id: http://svn.drobilla.net/zix/trunk@40 df6676b4-ccc9-40e5-b5d6-7c4628a128e3

1 files changed, 154 insertions, 0 deletions

diff --git a/src/tree_debug.h b/src/tree_debug.h
new file mode 100644
index 0000000..c2af4bf
--- /dev/null
+++ b/src/tree_debug.h
@@ -0,0 +1,154 @@
+/*
+  Copyright 2011 David Robillard <http://drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#ifndef ZIX_TREE_DEBUG_H
+#define ZIX_TREE_DEBUG_H
+
+#ifdef ZIX_TREE_DUMP
+static void
+zix_tree_print(ZixTreeNode* node, int level)
+{
+	if (node) {
+		if (!node->parent) {
+			printf("{{{\n");
+		}
+		zix_tree_print(node->right, level + 1);
+		for (int i = 0; i < level; i++) {
+			printf("  ");
+		}
+		printf("%ld.%d\n", (intptr_t)node->data, node->balance);
+		zix_tree_print(node->left, level + 1);
+		if (!node->parent) {
+			printf("}}}\n");
+		}
+	}
+}
+#endif
+
+#ifdef ZIX_TREE_HYPER_VERIFY
+static size_t
+height(ZixTreeNode* n)
+{
+	if (!n) {
+		return 0;
+	} else {
+		return 1 + MAX(height(n->left), height(n->right));
+	}
+}
+#endif
+
+#if defined(ZIX_TREE_VERIFY) || !defined(NDEBUG)
+static bool
+verify_balance(ZixTreeNode* n)
+{
+	if (!n) {
+		return true;
+	}
+
+	if (n->balance < -2 || n->balance > 2) {
+		fprintf(stderr, "Balance out of range : %ld (balance %d)\n",
+		        (intptr_t)n->data, n->balance);
+		return false;
+	}
+
+	if (n->balance < 0 && !n->left) {
+		fprintf(stderr, "Bad balance : %ld (balance %d) has no left child\n",
+		        (intptr_t)n->data, n->balance);
+		return false;
+	}
+
+	if (n->balance > 0 && !n->right) {
+		fprintf(stderr, "Bad balance : %ld (balance %d) has no right child\n",
+		        (intptr_t)n->data, n->balance);
+		return false;
+	}
+
+	if (n->balance != 0 && !n->left && !n->right) {
+		fprintf(stderr, "Bad balance : %ld (balance %d) has no children\n",
+		        (intptr_t)n->data, n->balance);
+		return false;
+	}
+
+#ifdef ZIX_TREE_HYPER_VERIFY
+	const intptr_t left_height  = (intptr_t)height(n->left);
+	const intptr_t right_height = (intptr_t)height(n->right);
+	if (n->balance != right_height - left_height) {
+		fprintf(stderr, "Bad balance at %ld: h_r (%zu) - l_h (%zu) != %d\n",
+		        (intptr_t)n->data, right_height, left_height, n->balance);
+		assert(false);
+		return false;
+	}
+#endif
+
+	return true;
+}
+#endif
+
+#ifdef ZIX_TREE_VERIFY
+static bool
+verify(ZixTree* t, ZixTreeNode* n)
+{
+	if (!n) {
+		return true;
+	}
+
+	if (n->parent) {
+		if ((n->parent->left != n) && (n->parent->right != n)) {
+			fprintf(stderr, "Corrupt child/parent pointers\n");
+			return false;
+		}
+	}
+
+	if (n->left) {
+		if (t->cmp(n->left->data, n->data, t->cmp_data) > 0) {
+			fprintf(stderr, "Bad order: %zu with left child\n",
+			        (intptr_t)n->data);
+			fprintf(stderr, "%p ? %p\n", (void*)n, (void*)n->left);
+			fprintf(stderr, "%" PRIdPTR " ? %" PRIdPTR "\n", (intptr_t)n->data,
+			        (intptr_t)n->left->data);
+			return false;
+		}
+		if (!verify(t, n->left)) {
+			return false;
+		}
+	}
+
+	if (n->right) {
+		if (t->cmp(n->right->data, n->data, t->cmp_data) < 0) {
+			fprintf(stderr, "Bad order: %zu with right child\n",
+			        (intptr_t)n->data);
+			return false;
+		}
+		if (!verify(t, n->right)) {
+			return false;
+		}
+	}
+
+	if (!verify_balance(n)) {
+		return false;
+	}
+
+	if (n->balance <= -2 || n->balance >= 2) {
+		fprintf(stderr, "Imbalance: %p (balance %d)\n",
+		        (void*)n, n->balance);
+		return false;
+	}
+
+	return true;
+}
+#endif
+
+#endif  // ZIX_TREE_DEBUG_H