[IMPORT] import ebtree v5.0 into directory ebtree/

We needed to upgrade ebtree to v5.0 to support string indexing,
and it was getting very painful to have it split across 2 dirs
and to have to patch it. Now we just have to copy the .c and .h
files to the right place.
diff --git a/ebtree/ebmbtree.h b/ebtree/ebmbtree.h
new file mode 100644
index 0000000..947dd5e
--- /dev/null
+++ b/ebtree/ebmbtree.h
@@ -0,0 +1,336 @@
+/*
+ * Elastic Binary Trees - macros and structures for Multi-Byte data nodes.
+ * Version 5.0
+ * (C) 2002-2009 - 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 <string.h>
+#include "ebtree.h"
+
+/* Return the structure of type <type> whose member <member> points to <ptr> */
+#define ebmb_entry(ptr, type, member) container_of(ptr, type, member)
+
+#define EBMB_ROOT	EB_ROOT
+#define EBMB_TREE_HEAD	EB_TREE_HEAD
+
+/* 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.
+ * The 'node.bit' value here works differently from scalar types, as it contains
+ * the number of identical bits between the two branches.
+ */
+struct ebmb_node {
+	struct eb_node node; /* the tree node, must be at the beginning */
+	unsigned char key[0]; /* the key, its size depends on the application */
+};
+
+/*
+ * 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 forceinline struct ebmb_node *ebmb_first(struct eb_root *root)
+{
+	return ebmb_entry(eb_first(root), struct ebmb_node, node);
+}
+
+/* Return rightmost node in the tree, or NULL if none */
+static forceinline struct ebmb_node *ebmb_last(struct eb_root *root)
+{
+	return ebmb_entry(eb_last(root), struct ebmb_node, node);
+}
+
+/* Return next node in the tree, or NULL if none */
+static forceinline struct ebmb_node *ebmb_next(struct ebmb_node *ebmb)
+{
+	return ebmb_entry(eb_next(&ebmb->node), struct ebmb_node, node);
+}
+
+/* Return previous node in the tree, or NULL if none */
+static forceinline struct ebmb_node *ebmb_prev(struct ebmb_node *ebmb)
+{
+	return ebmb_entry(eb_prev(&ebmb->node), struct ebmb_node, node);
+}
+
+/* Return next node in the tree, skipping duplicates, or NULL if none */
+static forceinline struct ebmb_node *ebmb_next_unique(struct ebmb_node *ebmb)
+{
+	return ebmb_entry(eb_next_unique(&ebmb->node), struct ebmb_node, node);
+}
+
+/* Return previous node in the tree, skipping duplicates, or NULL if none */
+static forceinline struct ebmb_node *ebmb_prev_unique(struct ebmb_node *ebmb)
+{
+	return ebmb_entry(eb_prev_unique(&ebmb->node), struct ebmb_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 forceinline void ebmb_delete(struct ebmb_node *ebmb)
+{
+	eb_delete(&ebmb->node);
+}
+
+/* The following functions are not inlined by default. They are declared
+ * in ebmbtree.c, which simply relies on their inline version.
+ */
+REGPRM3 struct ebmb_node *ebmb_lookup(struct eb_root *root, const void *x, unsigned int len);
+REGPRM3 struct ebmb_node *ebmb_insert(struct eb_root *root, struct ebmb_node *new, unsigned int len);
+
+/* 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 forceinline void __ebmb_delete(struct ebmb_node *ebmb)
+{
+	__eb_delete(&ebmb->node);
+}
+
+/* Find the first occurence of a key of <len> bytes in the tree <root>.
+ * If none can be found, return NULL.
+ */
+static forceinline struct ebmb_node *__ebmb_lookup(struct eb_root *root, const void *x, unsigned int len)
+{
+	struct ebmb_node *node;
+	eb_troot_t *troot;
+	unsigned int bit;
+
+	troot = root->b[EB_LEFT];
+	if (unlikely(troot == NULL))
+		return NULL;
+
+	bit = 0;
+	while (1) {
+		if ((eb_gettag(troot) == EB_LEAF)) {
+			node = container_of(eb_untag(troot, EB_LEAF),
+					    struct ebmb_node, node.branches);
+			if (memcmp(node->key, x, len) == 0)
+				return node;
+			else
+				return NULL;
+		}
+		node = container_of(eb_untag(troot, EB_NODE),
+				    struct ebmb_node, node.branches);
+
+		if (node->node.bit < 0) {
+			/* We have a dup tree now. Either it's for the same
+			 * value, and we walk down left, or it's a different
+			 * one and we don't have our key.
+			 */
+			if (memcmp(node->key, x, len) != 0)
+				return NULL;
+
+			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 ebmb_node, node.branches);
+			return node;
+		}
+
+		/* OK, normal data node, let's walk down */
+		bit = equal_bits(x, node->key, bit, node->node.bit);
+		if (bit < node->node.bit)
+			return NULL; /* no more common bits */
+
+		troot = node->node.branches.b[(((unsigned char*)x)[node->node.bit >> 3] >>
+					       (~node->node.bit & 7)) & 1];
+	}
+}
+
+/* Insert ebmb_node <new> into subtree starting at node root <root>.
+ * Only new->key needs be set with the key. The ebmb_node is returned.
+ * If root->b[EB_RGHT]==1, the tree may only contain unique keys. The
+ * len is specified in bytes.
+ */
+static forceinline struct ebmb_node *
+__ebmb_insert(struct eb_root *root, struct ebmb_node *new, unsigned int len)
+{
+	struct ebmb_node *old;
+	unsigned int side;
+	eb_troot_t *troot;
+	eb_troot_t *root_right = root;
+	int diff;
+	int bit;
+
+	side = EB_LEFT;
+	troot = root->b[EB_LEFT];
+	root_right = root->b[EB_RGHT];
+	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;
+	}
+
+	len <<= 3;
+
+	/* 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.
+	 */
+
+	bit = 0;
+	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 ebmb_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.
+			 */
+			bit = equal_bits(new->key, old->key, bit, len);
+			diff = cmp_bits(new->key, old->key, bit);
+
+			if (diff < 0) {
+				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 {
+				/* we may refuse to duplicate this key if the tree is
+				 * tagged as containing only unique keys.
+				 */
+				if (diff == 0 && eb_gettag(root_right))
+					return old;
+
+				/* 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 (diff == 0) {
+					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 ebmb_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. Note: we can compare more bits than
+		 * the current node's because as long as they are identical, we
+		 * know we descend along the correct side.
+		 */
+		if (old->node.bit < 0) {
+			/* we're above a duplicate tree, we must compare till the end */
+			bit = equal_bits(new->key, old->key, bit, len);
+			goto dup_tree;
+		}
+		else if (bit < old->node.bit) {
+			bit = equal_bits(new->key, old->key, bit, old->node.bit);
+		}
+
+		if (bit < old->node.bit) { /* we don't have all bits in common */
+			/* 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;
+
+		dup_tree:
+			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;
+
+			diff = cmp_bits(new->key, old->key, bit);
+			if (diff < 0) {
+				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 (diff > 0) {
+				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 ebmb_node, node);
+			}
+			break;
+		}
+
+		/* walk down */
+		root = &old->node.branches;
+		side = (new->key[old->node.bit >> 3] >> (~old->node.bit & 7)) & 1;
+		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.
+	 * This number of bits is already in <bit>.
+	 */
+	new->node.bit = bit;
+	root->b[side] = eb_dotag(&new->node.branches, EB_NODE);
+	return new;
+}
+