[MINOR] merge ebtree version 3.0
Version 3.0 of ebtree has been merged in but is not used yet.
diff --git a/include/common/ebpttree.h b/include/common/ebpttree.h
new file mode 100644
index 0000000..4908f81
--- /dev/null
+++ b/include/common/ebpttree.h
@@ -0,0 +1,317 @@
+/*
+ * Elastic Binary Trees - macros and structures for operations on pointer nodes.
+ * (C) 2002-2007 - Willy Tarreau <w@1wt.eu>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "ebtree.h"
+
+
+/* Return the structure of type <type> whose member <member> points to <ptr> */
+#define ebpt_entry(ptr, type, member) container_of(ptr, type, member)
+
+#define EBPT_ROOT EB_ROOT
+#define EBPT_TREE_HEAD EB_TREE_HEAD
+
+/* on *almost* all platforms, a pointer can be cast into a size_t which is unsigned */
+#ifndef PTR_INT_TYPE
+#define PTR_INT_TYPE size_t
+#endif
+
+typedef PTR_INT_TYPE ptr_t;
+
+/* This structure carries a node, a leaf, and a key. It must start with the
+ * eb_node so that it can be cast into an eb_node. We could also have put some
+ * sort of transparent union here to reduce the indirection level, but the fact
+ * is, the end user is not meant to manipulate internals, so this is pointless.
+ */
+struct ebpt_node {
+ struct eb_node node; /* the tree node, must be at the beginning */
+ void *key;
+};
+
+/*
+ * Exported functions and macros.
+ * Many of them are always inlined because they are extremely small, and
+ * are generally called at most once or twice in a program.
+ */
+
+/* Return leftmost node in the tree, or NULL if none */
+static inline struct ebpt_node *ebpt_first(struct eb_root *root)
+{
+ return ebpt_entry(eb_first(root), struct ebpt_node, node);
+}
+
+/* Return rightmost node in the tree, or NULL if none */
+static inline struct ebpt_node *ebpt_last(struct eb_root *root)
+{
+ return ebpt_entry(eb_last(root), struct ebpt_node, node);
+}
+
+/* Return next node in the tree, or NULL if none */
+static inline struct ebpt_node *ebpt_next(struct ebpt_node *ebpt)
+{
+ return ebpt_entry(eb_next(&ebpt->node), struct ebpt_node, node);
+}
+
+/* Return previous node in the tree, or NULL if none */
+static inline struct ebpt_node *ebpt_prev(struct ebpt_node *ebpt)
+{
+ return ebpt_entry(eb_prev(&ebpt->node), struct ebpt_node, node);
+}
+
+/* Return next node in the tree, skipping duplicates, or NULL if none */
+static inline struct ebpt_node *ebpt_next_unique(struct ebpt_node *ebpt)
+{
+ return ebpt_entry(eb_next_unique(&ebpt->node), struct ebpt_node, node);
+}
+
+/* Return previous node in the tree, skipping duplicates, or NULL if none */
+static inline struct ebpt_node *ebpt_prev_unique(struct ebpt_node *ebpt)
+{
+ return ebpt_entry(eb_prev_unique(&ebpt->node), struct ebpt_node, node);
+}
+
+/* Delete node from the tree if it was linked in. Mark the node unused. Note
+ * that this function relies on a non-inlined generic function: eb_delete.
+ */
+static inline void ebpt_delete(struct ebpt_node *ebpt)
+{
+ eb_delete(&ebpt->node);
+}
+
+/*
+ * The following functions are not inlined by default. They are declared
+ * in ebpttree.c, which simply relies on their inline version.
+ */
+REGPRM2 struct ebpt_node *ebpt_lookup(struct eb_root *root, void *x);
+REGPRM2 struct ebpt_node *ebpt_insert(struct eb_root *root, struct ebpt_node *new);
+
+/*
+ * The following functions are less likely to be used directly, because their
+ * code is larger. The non-inlined version is preferred.
+ */
+
+/* Delete node from the tree if it was linked in. Mark the node unused. */
+static inline void __ebpt_delete(struct ebpt_node *ebpt)
+{
+ __eb_delete(&ebpt->node);
+}
+
+/*
+ * Find the first occurence of a key in the tree <root>. If none can be
+ * found, return NULL.
+ */
+static inline struct ebpt_node *__ebpt_lookup(struct eb_root *root, void *x)
+{
+ struct ebpt_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)) {
+ node = container_of(eb_untag(troot, EB_LEAF),
+ struct ebpt_node, node.branches);
+ if (node->key == x)
+ return node;
+ else
+ return NULL;
+ }
+ node = container_of(eb_untag(troot, EB_NODE),
+ struct ebpt_node, node.branches);
+
+ if (x == node->key) {
+ /* Either we found the node which holds the key, or
+ * we have a dup tree. In the later case, we have to
+ * walk it down left to get the first entry.
+ */
+ if (node->node.bit < 0) {
+ troot = node->node.branches.b[EB_LEFT];
+ while (eb_gettag(troot) != EB_LEAF)
+ troot = (eb_untag(troot, EB_NODE))->b[EB_LEFT];
+ node = container_of(eb_untag(troot, EB_LEAF),
+ struct ebpt_node, node.branches);
+ }
+ return node;
+ }
+
+ troot = node->node.branches.b[((ptr_t)x >> node->node.bit) & EB_NODE_BRANCH_MASK];
+ }
+}
+
+/* Insert ebpt_node <new> into subtree starting at node root <root>.
+ * Only new->key needs be set with the key. The ebpt_node is returned.
+ */
+static inline struct ebpt_node *
+__ebpt_insert(struct eb_root *root, struct ebpt_node *new) {
+ struct ebpt_node *old;
+ unsigned int side;
+ eb_troot_t *troot;
+ void *newkey; /* caching the key saves approximately one cycle */
+
+ side = EB_LEFT;
+ troot = root->b[EB_LEFT];
+ if (unlikely(troot == NULL)) {
+ /* Tree is empty, insert the leaf part below the left branch */
+ root->b[EB_LEFT] = eb_dotag(&new->node.branches, EB_LEAF);
+ new->node.leaf_p = eb_dotag(root, EB_LEFT);
+ new->node.node_p = NULL; /* node part unused */
+ return new;
+ }
+
+ /* The tree descent is fairly easy :
+ * - first, check if we have reached a leaf node
+ * - second, check if we have gone too far
+ * - third, reiterate
+ * Everywhere, we use <new> for the node node we are inserting, <root>
+ * for the node we attach it to, and <old> for the node we are
+ * displacing below <new>. <troot> will always point to the future node
+ * (tagged with its type). <side> carries the side the node <new> is
+ * attached to below its parent, which is also where previous node
+ * was attached. <newkey> carries the key being inserted.
+ */
+ newkey = new->key;
+
+ while (1) {
+ if (unlikely(eb_gettag(troot) == EB_LEAF)) {
+ eb_troot_t *new_left, *new_rght;
+ eb_troot_t *new_leaf, *old_leaf;
+
+ old = container_of(eb_untag(troot, EB_LEAF),
+ struct ebpt_node, node.branches);
+
+ new_left = eb_dotag(&new->node.branches, EB_LEFT);
+ new_rght = eb_dotag(&new->node.branches, EB_RGHT);
+ new_leaf = eb_dotag(&new->node.branches, EB_LEAF);
+ old_leaf = eb_dotag(&old->node.branches, EB_LEAF);
+
+ new->node.node_p = old->node.leaf_p;
+
+ /* Right here, we have 3 possibilities :
+ - the tree does not contain the key, and we have
+ new->key < old->key. We insert new above old, on
+ the left ;
+
+ - the tree does not contain the key, and we have
+ new->key > old->key. We insert new above old, on
+ the right ;
+
+ - the tree does contain the key, which implies it
+ is alone. We add the new key next to it as a
+ first duplicate.
+
+ The last two cases can easily be partially merged.
+ */
+
+ if (new->key < old->key) {
+ new->node.leaf_p = new_left;
+ old->node.leaf_p = new_rght;
+ new->node.branches.b[EB_LEFT] = new_leaf;
+ new->node.branches.b[EB_RGHT] = old_leaf;
+ } else {
+ /* new->key >= old->key, new goes the right */
+ old->node.leaf_p = new_left;
+ new->node.leaf_p = new_rght;
+ new->node.branches.b[EB_LEFT] = old_leaf;
+ new->node.branches.b[EB_RGHT] = new_leaf;
+
+ if (new->key == old->key) {
+ new->node.bit = -1;
+ root->b[side] = eb_dotag(&new->node.branches, EB_NODE);
+ return new;
+ }
+ }
+ break;
+ }
+
+ /* OK we're walking down this link */
+ old = container_of(eb_untag(troot, EB_NODE),
+ struct ebpt_node, node.branches);
+
+ /* Stop going down when we don't have common bits anymore. We
+ * also stop in front of a duplicates tree because it means we
+ * have to insert above.
+ */
+
+ if ((old->node.bit < 0) || /* we're above a duplicate tree, stop here */
+ ((((ptr_t)new->key ^ (ptr_t)old->key) >> old->node.bit) >= EB_NODE_BRANCHES)) {
+ /* The tree did not contain the key, so we insert <new> before the node
+ * <old>, and set ->bit to designate the lowest bit position in <new>
+ * which applies to ->branches.b[].
+ */
+ eb_troot_t *new_left, *new_rght;
+ eb_troot_t *new_leaf, *old_node;
+
+ new_left = eb_dotag(&new->node.branches, EB_LEFT);
+ new_rght = eb_dotag(&new->node.branches, EB_RGHT);
+ new_leaf = eb_dotag(&new->node.branches, EB_LEAF);
+ old_node = eb_dotag(&old->node.branches, EB_NODE);
+
+ new->node.node_p = old->node.node_p;
+
+ if (new->key < old->key) {
+ new->node.leaf_p = new_left;
+ old->node.node_p = new_rght;
+ new->node.branches.b[EB_LEFT] = new_leaf;
+ new->node.branches.b[EB_RGHT] = old_node;
+ }
+ else if (new->key > old->key) {
+ old->node.node_p = new_left;
+ new->node.leaf_p = new_rght;
+ new->node.branches.b[EB_LEFT] = old_node;
+ new->node.branches.b[EB_RGHT] = new_leaf;
+ }
+ else {
+ struct eb_node *ret;
+ ret = eb_insert_dup(&old->node, &new->node);
+ return container_of(ret, struct ebpt_node, node);
+ }
+ break;
+ }
+
+ /* walk down */
+ root = &old->node.branches;
+ side = ((ptr_t)newkey >> old->node.bit) & EB_NODE_BRANCH_MASK;
+ troot = root->b[side];
+ }
+
+ /* Ok, now we are inserting <new> between <root> and <old>. <old>'s
+ * parent is already set to <new>, and the <root>'s branch is still in
+ * <side>. Update the root's leaf till we have it. Note that we can also
+ * find the side by checking the side of new->node.node_p.
+ */
+
+ /* We need the common higher bits between new->key and old->key.
+ * What differences are there between new->key and the node here ?
+ * NOTE that bit(new) is always < bit(root) because highest
+ * bit of new->key and old->key are identical here (otherwise they
+ * would sit on different branches).
+ */
+ // note that if EB_NODE_BITS > 1, we should check that it's still >= 0
+
+ /* let the compiler choose the best branch based on the pointer size */
+ if (sizeof(ptr_t) == 4)
+ new->node.bit = flsnz((ptr_t)new->key ^ (ptr_t)old->key) - EB_NODE_BITS;
+ else
+ new->node.bit = fls64((ptr_t)new->key ^ (ptr_t)old->key) - EB_NODE_BITS;
+ root->b[side] = eb_dotag(&new->node.branches, EB_NODE);
+
+ return new;
+}
+