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-rw-r--r--src/eb64tree.c218
1 files changed, 218 insertions, 0 deletions
diff --git a/src/eb64tree.c b/src/eb64tree.c
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--- /dev/null
+++ b/src/eb64tree.c
@@ -0,0 +1,218 @@
+/*
+ * Elastic Binary Trees - exported functions for operations on 64bit nodes.
+ * Version 6.0.6
+ * (C) 2002-2011 - Willy Tarreau <w@1wt.eu>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, version 2.1
+ * exclusively.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/* Consult eb64tree.h for more details about those functions */
+
+#include <import/eb64tree.h>
+
+struct eb64_node *eb64_insert(struct eb_root *root, struct eb64_node *new)
+{
+ return __eb64_insert(root, new);
+}
+
+struct eb64_node *eb64i_insert(struct eb_root *root, struct eb64_node *new)
+{
+ return __eb64i_insert(root, new);
+}
+
+struct eb64_node *eb64_lookup(struct eb_root *root, u64 x)
+{
+ return __eb64_lookup(root, x);
+}
+
+struct eb64_node *eb64i_lookup(struct eb_root *root, s64 x)
+{
+ return __eb64i_lookup(root, x);
+}
+
+/*
+ * Find the last occurrence of the highest key in the tree <root>, which is
+ * equal to or less than <x>. NULL is returned is no key matches.
+ */
+struct eb64_node *eb64_lookup_le(struct eb_root *root, u64 x)
+{
+ struct eb64_node *node;
+ eb_troot_t *troot;
+
+ troot = root->b[EB_LEFT];
+ if (unlikely(troot == NULL))
+ return NULL;
+
+ while (1) {
+ if ((eb_gettag(troot) == EB_LEAF)) {
+ /* We reached a leaf, which means that the whole upper
+ * parts were common. We will return either the current
+ * node or its next one if the former is too small.
+ */
+ node = container_of(eb_untag(troot, EB_LEAF),
+ struct eb64_node, node.branches);
+ if (node->key <= x)
+ return node;
+ /* return prev */
+ troot = node->node.leaf_p;
+ break;
+ }
+ node = container_of(eb_untag(troot, EB_NODE),
+ struct eb64_node, node.branches);
+
+ if (node->node.bit < 0) {
+ /* We're at the top of a dup tree. Either we got a
+ * matching value and we return the rightmost node, or
+ * we don't and we skip the whole subtree to return the
+ * prev node before the subtree. Note that since we're
+ * at the top of the dup tree, we can simply return the
+ * prev node without first trying to escape from the
+ * tree.
+ */
+ if (node->key <= x) {
+ troot = node->node.branches.b[EB_RGHT];
+ while (eb_gettag(troot) != EB_LEAF)
+ troot = (eb_untag(troot, EB_NODE))->b[EB_RGHT];
+ return container_of(eb_untag(troot, EB_LEAF),
+ struct eb64_node, node.branches);
+ }
+ /* return prev */
+ troot = node->node.node_p;
+ break;
+ }
+
+ if (((x ^ node->key) >> node->node.bit) >= EB_NODE_BRANCHES) {
+ /* No more common bits at all. Either this node is too
+ * small and we need to get its highest value, or it is
+ * too large, and we need to get the prev value.
+ */
+ if ((node->key >> node->node.bit) < (x >> node->node.bit)) {
+ troot = node->node.branches.b[EB_RGHT];
+ return eb64_entry(eb_walk_down(troot, EB_RGHT), struct eb64_node, node);
+ }
+
+ /* Further values will be too high here, so return the prev
+ * unique node (if it exists).
+ */
+ troot = node->node.node_p;
+ break;
+ }
+ troot = node->node.branches.b[(x >> node->node.bit) & EB_NODE_BRANCH_MASK];
+ }
+
+ /* If we get here, it means we want to report previous node before the
+ * current one which is not above. <troot> is already initialised to
+ * the parent's branches.
+ */
+ while (eb_gettag(troot) == EB_LEFT) {
+ /* Walking up from left branch. We must ensure that we never
+ * walk beyond root.
+ */
+ if (unlikely(eb_clrtag((eb_untag(troot, EB_LEFT))->b[EB_RGHT]) == NULL))
+ return NULL;
+ troot = (eb_root_to_node(eb_untag(troot, EB_LEFT)))->node_p;
+ }
+ /* Note that <troot> cannot be NULL at this stage */
+ troot = (eb_untag(troot, EB_RGHT))->b[EB_LEFT];
+ node = eb64_entry(eb_walk_down(troot, EB_RGHT), struct eb64_node, node);
+ return node;
+}
+
+/*
+ * Find the first occurrence of the lowest key in the tree <root>, which is
+ * equal to or greater than <x>. NULL is returned is no key matches.
+ */
+struct eb64_node *eb64_lookup_ge(struct eb_root *root, u64 x)
+{
+ struct eb64_node *node;
+ eb_troot_t *troot;
+
+ troot = root->b[EB_LEFT];
+ if (unlikely(troot == NULL))
+ return NULL;
+
+ while (1) {
+ if ((eb_gettag(troot) == EB_LEAF)) {
+ /* We reached a leaf, which means that the whole upper
+ * parts were common. We will return either the current
+ * node or its next one if the former is too small.
+ */
+ node = container_of(eb_untag(troot, EB_LEAF),
+ struct eb64_node, node.branches);
+ if (node->key >= x)
+ return node;
+ /* return next */
+ troot = node->node.leaf_p;
+ break;
+ }
+ node = container_of(eb_untag(troot, EB_NODE),
+ struct eb64_node, node.branches);
+
+ if (node->node.bit < 0) {
+ /* We're at the top of a dup tree. Either we got a
+ * matching value and we return the leftmost node, or
+ * we don't and we skip the whole subtree to return the
+ * next node after the subtree. Note that since we're
+ * at the top of the dup tree, we can simply return the
+ * next node without first trying to escape from the
+ * tree.
+ */
+ if (node->key >= x) {
+ troot = node->node.branches.b[EB_LEFT];
+ while (eb_gettag(troot) != EB_LEAF)
+ troot = (eb_untag(troot, EB_NODE))->b[EB_LEFT];
+ return container_of(eb_untag(troot, EB_LEAF),
+ struct eb64_node, node.branches);
+ }
+ /* return next */
+ troot = node->node.node_p;
+ break;
+ }
+
+ if (((x ^ node->key) >> node->node.bit) >= EB_NODE_BRANCHES) {
+ /* No more common bits at all. Either this node is too
+ * large and we need to get its lowest value, or it is too
+ * small, and we need to get the next value.
+ */
+ if ((node->key >> node->node.bit) > (x >> node->node.bit)) {
+ troot = node->node.branches.b[EB_LEFT];
+ return eb64_entry(eb_walk_down(troot, EB_LEFT), struct eb64_node, node);
+ }
+
+ /* Further values will be too low here, so return the next
+ * unique node (if it exists).
+ */
+ troot = node->node.node_p;
+ break;
+ }
+ troot = node->node.branches.b[(x >> node->node.bit) & EB_NODE_BRANCH_MASK];
+ }
+
+ /* If we get here, it means we want to report next node after the
+ * current one which is not below. <troot> is already initialised
+ * to the parent's branches.
+ */
+ while (eb_gettag(troot) != EB_LEFT)
+ /* Walking up from right branch, so we cannot be below root */
+ troot = (eb_root_to_node(eb_untag(troot, EB_RGHT)))->node_p;
+
+ /* Note that <troot> cannot be NULL at this stage */
+ troot = (eb_untag(troot, EB_LEFT))->b[EB_RGHT];
+ if (eb_clrtag(troot) == NULL)
+ return NULL;
+
+ node = eb64_entry(eb_walk_down(troot, EB_LEFT), struct eb64_node, node);
+ return node;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-12 11:16:51 +0000