On 04/08/18 01:31, Rafael Antognolli wrote:
On Thu, Aug 02, 2018 at 10:39:20AM +0100, Lionel Landwerlin wrote:
Signed-off-by: Lionel Landwerlin <[email protected]>
---
src/util/rb_tree.h | 36 ++++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/src/util/rb_tree.h b/src/util/rb_tree.h
index c77e9255ea2..df1a4197b8a 100644
--- a/src/util/rb_tree.h
+++ b/src/util/rb_tree.h
@@ -243,6 +243,24 @@ struct rb_node *rb_node_prev(struct rb_node *node);
&node->field != NULL; \
node = rb_node_data(type, rb_node_next(&node->field), field))
+/** Iterate over the nodes in the tree, allowing the current node to be freed
+ *
+ * \param type The type of the containing data structure
+ *
+ * \param node The variable name for current node in the iteration;
+ * this will be declared as a pointer to \p type
+ *
+ * \param T The red-black tree
+ *
+ * \param field The rb_node field in containing data structure
+ */
+#define rb_tree_foreach_safe(type, node, T, field) \
+ for (type *node = rb_node_data(type, rb_tree_first(T), field), \
+ *_next = (&node->field != NULL) ? rb_node_data(type,
rb_node_next(&node->field), field) : node; \
+ &node->field != NULL; \
+ node = _next, \
+ _next = (&_next->field != NULL) ? rb_node_data(type,
rb_node_next(&_next->field), field) : _next)
+
This looks nice. I'm thinking if maybe a simple helper would make things
easier to read, like:
#define _next_if_available(node, type, field) \
(&node->field != NULL) ? rb_node_data(type, rb_node_next(&node->field),
field) : node
Wouldn't help to simplify things, but up to you in the end.
Yeah sounds nice, thanks!
/** Iterate over the nodes in the tree in reverse
*
* \param type The type of the containing data structure
@@ -259,6 +277,24 @@ struct rb_node *rb_node_prev(struct rb_node *node);
&node->field != NULL; \
node = rb_node_data(type, rb_node_prev(&node->field), field))
+/** Iterate over the nodes in the tree in reverse, allowing the current node to be freed
+ *
+ * \param type The type of the containing data structure
+ *
+ * \param node The variable name for current node in the iteration;
+ * this will be declared as a pointer to \p type
+ *
+ * \param T The red-black tree
+ *
+ * \param field The rb_node field in containing data structure
+ */
+#define rb_tree_foreach_rev_safe(type, node, T, field) \
+ for (type *node = rb_node_data(type, rb_tree_last(T), field), \
+ *_prev = rb_node_prev(&node->field) ? rb_node_data(type,
rb_node_prev(&node->field), field) : NULL; \
+ &node->field != NULL; \
+ node = _prev, \
+ _prev = (prev && rb_node_prev(&_prev->field)) ? rb_node_data(type,
rb_node_prev(&_prev->field), field) : NULL)
^^^^
I can't really find where this "prev" came from, but I also don't see
any warning when building it.
Also, same comment about the helper could apply here I guess, but this
"prev" is making things confusing to me.
Oops, indeed it's a bug. Didn't notice because I didn't use that macro...
+
/** Validate a red-black tree
*
* This function walks the tree and validates that this is a valid red-
--
2.18.0
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