}
}
- /*
- * Note the node that points to the level of the node that is being
- * deleted. If the deleted node is the top level, parent will be set
- * to NULL.
- */
- parent = get_upper_node(node);
+ for (;;) {
+ /*
+ * Note the node that points to the level of the node
+ * that is being deleted. If the deleted node is the
+ * top level, parent will be set to NULL.
+ */
+ parent = get_upper_node(node);
- /*
- * This node now has no down pointer (either because it didn't
- * have one to start, or because it was recursively removed).
- * So now the node needs to be removed from this level.
- */
- dns_rbt_deletefromlevel(node, parent == NULL ? &rbt->root :
+ /*
+ * This node now has no down pointer (either because it didn't
+ * have one to start, or because it was recursively removed).
+ * So now the node needs to be removed from this level.
+ */
+ dns_rbt_deletefromlevel(node, parent == NULL ? &rbt->root :
&DOWN(parent));
- if (DATA(node) != NULL && rbt->data_deleter != NULL)
- rbt->data_deleter(DATA(node), rbt->deleter_arg);
+ if (DATA(node) != NULL && rbt->data_deleter != NULL)
+ rbt->data_deleter(DATA(node), rbt->deleter_arg);
- unhash_node(rbt, node);
+ unhash_node(rbt, node);
#if DNS_RBT_USEMAGIC
- node->magic = 0;
+ node->magic = 0;
#endif
- dns_rbtnode_refdestroy(node);
- isc_mem_put(rbt->mctx, node, NODE_SIZE(node));
- rbt->nodecount--;
+ dns_rbtnode_refdestroy(node);
+ isc_mem_put(rbt->mctx, node, NODE_SIZE(node));
+ rbt->nodecount--;
- /*
- * There are now two special cases that can exist that would
- * not have existed if the tree had been created using only
- * the names that now exist in it. (This is all related to
- * join_nodes() as described in this function's introductory comment.)
- * Both cases exist when the deleted node's parent (the node
- * that pointed to the deleted node's level) is not null but
- * it has no data: parent != NULL && DATA(parent) == NULL.
- *
- * The first case is that the deleted node was the last on its level:
- * DOWN(parent) == NULL. This case can only exist if the parent was
- * previously deleted -- and so now, apparently, the parent should go
- * away. That can't be done though because there might be external
- * references to it, such as through a nodechain.
- *
- * The other case also involves a parent with no data, but with the
- * deleted node being the next-to-last node instead of the last:
- * LEFT(DOWN(parent)) == NULL && RIGHT(DOWN(parent)) == NULL.
- * Presumably now the remaining node on the level should be joined
- * with the parent, but it's already been described why that can't be
- * done.
- */
+ /*
+ * There are now two special cases that can exist that
+ * would not have existed if the tree had been created
+ * using only the names that now exist in it. (This is
+ * all related to join_nodes() as described in this
+ * function's introductory comment.) Both cases exist
+ * when the deleted node's parent (the node that pointed
+ * to the deleted node's level) is not null but it has
+ * no data: parent != NULL && DATA(parent) == NULL.
+ *
+ * The first case is that the deleted node was the last
+ * on its level: DOWN(parent) == NULL. This case can
+ * only exist if the parent was previously deleted --
+ * and so now, apparently, the parent should go away.
+ * That can't be done though because there might be
+ * external references to it, such as through a
+ * nodechain. XXXMUKS: We don't care about this.
+ *
+ * The other case also involves a parent with no data,
+ * but with the deleted node being the next-to-last node
+ * instead of the last: LEFT(DOWN(parent)) == NULL &&
+ * RIGHT(DOWN(parent)) == NULL. Presumably now the
+ * remaining node on the level should be joined with the
+ * parent, but it's already been described why that
+ * can't be done.
+ */
+
+ /*
+ * Is this the root?.
+ */
+ if (parent == NULL)
+ break;
+
+ /*
+ * If the node deletion did not cause the subtree to disappear
+ * completely, return early.
+ */
+ if (DOWN(parent) != NULL)
+ break;
+
+ /*
+ * If the upper node is not empty, it cannot be deleted.
+ */
+ if (DATA(parent) != NULL)
+ break;
+
+ /*
+ * If upper node is the root node (.), don't attempt to
+ * delete it. The root node must always exist.
+ */
+ if (parent == rbt->root)
+ break;
+
+ /*
+ * Ascend up the tree and delete the upper node.
+ */
+ node = parent;
+ }
/*
* This function never fails.
#define NEGATIVE(header) \
(((header)->attributes & RDATASET_ATTR_NEGATIVE) != 0)
-#define DEFAULT_NODE_LOCK_COUNT 7 /*%< Should be prime. */
+#define DEFAULT_NODE_LOCK_COUNT 523 /*%< Should be prime. */
/*%
* Number of buckets for cache DB entries (locks, LRU lists, TTL heaps).
INSIST(!ISC_LINK_LINKED(node, deadlink));
+ if (isc_log_wouldlog(dns_lctx, ISC_LOG_DEBUG(1))) {
+ char printname[DNS_NAME_FORMATSIZE];
+ isc_log_write(dns_lctx,
+ DNS_LOGCATEGORY_DATABASE,
+ DNS_LOGMODULE_CACHE,
+ ISC_LOG_DEBUG(1),
+ "delete_node(): %p %s (bucket %d)",
+ node,
+ dns_rbt_formatnodename(node,
+ printname, sizeof(printname)),
+ node->locknum);
+ }
+
switch (node->nsec) {
case DNS_RBT_NSEC_NORMAL:
#ifdef BIND9
deadlink);
}
} else {
- if (isc_log_wouldlog(dns_lctx, ISC_LOG_DEBUG(1))) {
- char printname[DNS_NAME_FORMATSIZE];
-
- isc_log_write(dns_lctx,
- DNS_LOGCATEGORY_DATABASE,
- DNS_LOGMODULE_CACHE,
- ISC_LOG_DEBUG(1),
- "decrement_reference: "
- "delete from rbt: %p %s",
- node,
- dns_rbt_formatnodename(node,
- printname,
- sizeof(printname)));
- }
-
delete_node(rbtdb, node);
}
} else {
projects / thirdparty / bind9.git / commitdiff
