haproxy/src/eb64tree.c
Willy Tarreau 8d2b777fe3 REORG: ebtree: move the include files from ebtree to include/import/
This is where other imported components are located. All files which
used to directly include ebtree were touched to update their include
path so that "import/" is now prefixed before the ebtree-related files.

The ebtree.h file was slightly adjusted to read compiler.h from the
common/ subdirectory (this is the only change).

A build issue was encountered when eb32sctree.h is loaded before
eb32tree.h because only the former checks for the latter before
defining type u32. This was addressed by adding the reverse ifdef
in eb32tree.h.

No further cleanup was done yet in order to keep changes minimal.
2020-06-11 09:31:11 +02:00

219 lines
6.9 KiB
C

/*
* 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;
}