2017-11-05 12:31:29 +00:00
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/*
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* Elastic Binary Trees - exported functions for operations on 32bit nodes.
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* Version 6.0.6 with backports from v7-dev
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* (C) 2002-2011 - Willy Tarreau <w@1wt.eu>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation, version 2.1
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* exclusively.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/* Consult eb32sctree.h for more details about those functions */
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#include "eb32sctree.h"
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/* This function is used to build a tree of duplicates by adding a new node to
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* a subtree of at least 2 entries.
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*/
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2020-02-25 06:38:05 +00:00
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struct eb32sc_node *eb32sc_insert_dup(struct eb_node *sub, struct eb_node *new, unsigned long scope)
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2017-11-05 12:31:29 +00:00
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{
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2017-11-05 13:06:50 +00:00
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struct eb32sc_node *eb32;
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2017-11-05 12:31:29 +00:00
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struct eb_node *head = sub;
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eb_troot_t *new_left = eb_dotag(&new->branches, EB_LEFT);
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eb_troot_t *new_rght = eb_dotag(&new->branches, EB_RGHT);
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eb_troot_t *new_leaf = eb_dotag(&new->branches, EB_LEAF);
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/* first, identify the deepest hole on the right branch */
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while (eb_gettag(head->branches.b[EB_RGHT]) != EB_LEAF) {
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struct eb_node *last = head;
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2017-11-05 13:06:50 +00:00
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2017-11-05 12:31:29 +00:00
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head = container_of(eb_untag(head->branches.b[EB_RGHT], EB_NODE),
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struct eb_node, branches);
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2017-11-05 13:06:50 +00:00
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2017-11-13 15:16:09 +00:00
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if (unlikely(head->bit > last->bit + 1)) {
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/* there's a hole here, we must assign the top of the
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* following sub-tree to <sub> and mark all intermediate
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* nodes with the scope mask.
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*/
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do {
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eb32 = container_of(sub, struct eb32sc_node, node);
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if (!(eb32->node_s & scope))
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eb32->node_s |= scope;
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sub = container_of(eb_untag(sub->branches.b[EB_RGHT], EB_NODE),
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struct eb_node, branches);
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} while (sub != head);
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}
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2017-11-05 13:06:50 +00:00
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2017-11-13 15:16:09 +00:00
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eb32 = container_of(head, struct eb32sc_node, node);
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2017-11-15 18:38:29 +00:00
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if (!(eb32->node_s & scope))
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eb32->node_s |= scope;
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2017-11-05 12:31:29 +00:00
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}
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/* Here we have a leaf attached to (head)->b[EB_RGHT] */
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if (head->bit < -1) {
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/* A hole exists just before the leaf, we insert there */
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new->bit = -1;
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sub = container_of(eb_untag(head->branches.b[EB_RGHT], EB_LEAF),
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struct eb_node, branches);
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head->branches.b[EB_RGHT] = eb_dotag(&new->branches, EB_NODE);
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new->node_p = sub->leaf_p;
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new->leaf_p = new_rght;
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sub->leaf_p = new_left;
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new->branches.b[EB_LEFT] = eb_dotag(&sub->branches, EB_LEAF);
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new->branches.b[EB_RGHT] = new_leaf;
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2017-11-05 13:06:50 +00:00
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eb32 = container_of(new, struct eb32sc_node, node);
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eb32->node_s = container_of(sub, struct eb32sc_node, node)->leaf_s | scope;
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return eb32;
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2017-11-05 12:31:29 +00:00
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} else {
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int side;
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/* No hole was found before a leaf. We have to insert above
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* <sub>. Note that we cannot be certain that <sub> is attached
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* to the right of its parent, as this is only true if <sub>
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* is inside the dup tree, not at the head.
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*/
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new->bit = sub->bit - 1; /* install at the lowest level */
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side = eb_gettag(sub->node_p);
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head = container_of(eb_untag(sub->node_p, side), struct eb_node, branches);
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head->branches.b[side] = eb_dotag(&new->branches, EB_NODE);
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new->node_p = sub->node_p;
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new->leaf_p = new_rght;
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sub->node_p = new_left;
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new->branches.b[EB_LEFT] = eb_dotag(&sub->branches, EB_NODE);
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new->branches.b[EB_RGHT] = new_leaf;
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2017-11-05 13:06:50 +00:00
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eb32 = container_of(new, struct eb32sc_node, node);
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eb32->node_s = container_of(sub, struct eb32sc_node, node)->node_s | scope;
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return eb32;
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2017-11-05 12:31:29 +00:00
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}
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}
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/* Insert eb32sc_node <new> into subtree starting at node root <root>. Only
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* new->key needs be set with the key. The eb32sc_node is returned. This
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* implementation does NOT support unique trees.
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*/
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2020-02-25 06:38:05 +00:00
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struct eb32sc_node *eb32sc_insert(struct eb_root *root, struct eb32sc_node *new, unsigned long scope)
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2017-11-05 12:31:29 +00:00
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{
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struct eb32sc_node *old;
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unsigned int side;
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eb_troot_t *troot, **up_ptr;
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u32 newkey; /* caching the key saves approximately one cycle */
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eb_troot_t *new_left, *new_rght;
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eb_troot_t *new_leaf;
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int old_node_bit;
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2017-11-05 13:06:50 +00:00
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unsigned long old_scope;
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2017-11-05 12:31:29 +00:00
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side = EB_LEFT;
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troot = root->b[EB_LEFT];
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if (unlikely(troot == NULL)) {
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/* Tree is empty, insert the leaf part below the left branch */
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root->b[EB_LEFT] = eb_dotag(&new->node.branches, EB_LEAF);
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new->node.leaf_p = eb_dotag(root, EB_LEFT);
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new->node.node_p = NULL; /* node part unused */
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2017-11-05 13:06:50 +00:00
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new->node_s = scope;
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new->leaf_s = scope;
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2017-11-05 12:31:29 +00:00
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return new;
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}
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/* The tree descent is fairly easy :
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* - first, check if we have reached a leaf node
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* - second, check if we have gone too far
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* - third, reiterate
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* Everywhere, we use <new> for the node node we are inserting, <root>
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* for the node we attach it to, and <old> for the node we are
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* displacing below <new>. <troot> will always point to the future node
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* (tagged with its type). <side> carries the side the node <new> is
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* attached to below its parent, which is also where previous node
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* was attached. <newkey> carries the key being inserted.
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*/
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newkey = new->key;
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while (1) {
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if (eb_gettag(troot) == EB_LEAF) {
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/* insert above a leaf */
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old = container_of(eb_untag(troot, EB_LEAF),
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struct eb32sc_node, node.branches);
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new->node.node_p = old->node.leaf_p;
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up_ptr = &old->node.leaf_p;
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2017-11-05 13:06:50 +00:00
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old_scope = old->leaf_s;
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2017-11-05 12:31:29 +00:00
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break;
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}
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/* OK we're walking down this link */
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old = container_of(eb_untag(troot, EB_NODE),
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struct eb32sc_node, node.branches);
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old_node_bit = old->node.bit;
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2017-11-15 18:38:29 +00:00
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/* our new node will be found through this one, we must mark it */
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if ((old->node_s | scope) != old->node_s)
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old->node_s |= scope;
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2017-11-05 12:31:29 +00:00
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/* Stop going down when we don't have common bits anymore. We
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* also stop in front of a duplicates tree because it means we
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* have to insert above.
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*/
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if ((old_node_bit < 0) || /* we're above a duplicate tree, stop here */
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(((new->key ^ old->key) >> old_node_bit) >= EB_NODE_BRANCHES)) {
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/* The tree did not contain the key, so we insert <new> before the node
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* <old>, and set ->bit to designate the lowest bit position in <new>
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* which applies to ->branches.b[].
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*/
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new->node.node_p = old->node.node_p;
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up_ptr = &old->node.node_p;
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2017-11-05 13:06:50 +00:00
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old_scope = old->node_s;
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2017-11-05 12:31:29 +00:00
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break;
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}
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/* walk down */
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root = &old->node.branches;
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side = (newkey >> old_node_bit) & EB_NODE_BRANCH_MASK;
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troot = root->b[side];
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}
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new_left = eb_dotag(&new->node.branches, EB_LEFT);
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new_rght = eb_dotag(&new->node.branches, EB_RGHT);
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new_leaf = eb_dotag(&new->node.branches, EB_LEAF);
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/* We need the common higher bits between new->key and old->key.
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* What differences are there between new->key and the node here ?
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* NOTE that bit(new) is always < bit(root) because highest
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* bit of new->key and old->key are identical here (otherwise they
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* would sit on different branches).
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*/
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// note that if EB_NODE_BITS > 1, we should check that it's still >= 0
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new->node.bit = flsnz(new->key ^ old->key) - EB_NODE_BITS;
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2017-11-05 13:06:50 +00:00
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new->leaf_s = scope;
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new->node_s = old_scope | scope;
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2017-11-05 12:31:29 +00:00
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if (new->key == old->key) {
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new->node.bit = -1; /* mark as new dup tree, just in case */
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if (eb_gettag(troot) != EB_LEAF) {
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/* there was already a dup tree below */
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return eb32sc_insert_dup(&old->node, &new->node, scope);
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}
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/* otherwise fall through */
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}
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if (new->key >= old->key) {
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new->node.branches.b[EB_LEFT] = troot;
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new->node.branches.b[EB_RGHT] = new_leaf;
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new->node.leaf_p = new_rght;
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*up_ptr = new_left;
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}
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else {
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new->node.branches.b[EB_LEFT] = new_leaf;
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new->node.branches.b[EB_RGHT] = troot;
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new->node.leaf_p = new_left;
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*up_ptr = new_rght;
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}
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/* Ok, now we are inserting <new> between <root> and <old>. <old>'s
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* parent is already set to <new>, and the <root>'s branch is still in
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* <side>. Update the root's leaf till we have it. Note that we can also
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* find the side by checking the side of new->node.node_p.
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*/
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root->b[side] = eb_dotag(&new->node.branches, EB_NODE);
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return new;
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}
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/*
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* Find the first occurrence of the lowest key in the tree <root>, which is
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* equal to or greater than <x>. NULL is returned is no key matches.
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*/
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2020-02-25 06:38:05 +00:00
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struct eb32sc_node *eb32sc_lookup_ge(struct eb_root *root, u32 x, unsigned long scope)
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2017-11-05 12:31:29 +00:00
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{
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struct eb32sc_node *node;
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eb_troot_t *troot;
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troot = root->b[EB_LEFT];
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if (unlikely(troot == NULL))
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return NULL;
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while (1) {
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if ((eb_gettag(troot) == EB_LEAF)) {
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/* We reached a leaf, which means that the whole upper
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* parts were common. We will return either the current
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* node or its next one if the former is too small.
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*/
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node = container_of(eb_untag(troot, EB_LEAF),
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struct eb32sc_node, node.branches);
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2017-11-05 13:33:01 +00:00
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if ((node->leaf_s & scope) && node->key >= x)
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2017-11-05 12:31:29 +00:00
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return node;
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/* return next */
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troot = node->node.leaf_p;
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break;
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}
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node = container_of(eb_untag(troot, EB_NODE),
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struct eb32sc_node, node.branches);
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if (node->node.bit < 0) {
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/* We're at the top of a dup tree. Either we got a
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* matching value and we return the leftmost node, or
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* we don't and we skip the whole subtree to return the
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* next node after the subtree. Note that since we're
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* at the top of the dup tree, we can simply return the
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* next node without first trying to escape from the
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* tree.
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*/
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2017-11-05 13:33:01 +00:00
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if ((node->node_s & scope) && node->key >= x)
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troot = eb_dotag(&node->node.branches, EB_LEFT);
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else
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troot = node->node.node_p;
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2017-11-05 12:31:29 +00:00
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break;
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}
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if (((x ^ node->key) >> node->node.bit) >= EB_NODE_BRANCHES) {
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/* No more common bits at all. Either this node is too
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* large and we need to get its lowest value, or it is too
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* small, and we need to get the next value.
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*/
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2017-11-05 13:33:01 +00:00
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if ((node->node_s & scope) && (node->key >> node->node.bit) > (x >> node->node.bit))
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troot = eb_dotag(&node->node.branches, EB_LEFT);
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else
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troot = node->node.node_p;
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2017-11-05 12:31:29 +00:00
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break;
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}
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troot = node->node.branches.b[(x >> node->node.bit) & EB_NODE_BRANCH_MASK];
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}
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/* If we get here, it means we want to report next node after the
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* current one which is not below. <troot> is already initialised
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* to the parent's branches.
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*/
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2017-11-13 18:17:54 +00:00
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return eb32sc_next_with_parent(troot, scope);
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2017-11-05 12:31:29 +00:00
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}
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2017-11-05 20:23:21 +00:00
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/*
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* Find the first occurrence of the lowest key in the tree <root> which is
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* equal to or greater than <x>, matching scope <scope>. If not found, it loops
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* back to the beginning of the tree. NULL is returned is no key matches.
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*/
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2020-02-25 06:38:05 +00:00
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struct eb32sc_node *eb32sc_lookup_ge_or_first(struct eb_root *root, u32 x, unsigned long scope)
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2017-11-05 20:23:21 +00:00
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{
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|
struct eb32sc_node *eb32;
|
|
|
|
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.
|
|
|
|
*/
|
|
|
|
eb32 = container_of(eb_untag(troot, EB_LEAF),
|
|
|
|
struct eb32sc_node, node.branches);
|
|
|
|
if ((eb32->leaf_s & scope) && eb32->key >= x)
|
|
|
|
return eb32;
|
|
|
|
/* return next */
|
|
|
|
troot = eb32->node.leaf_p;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
eb32 = container_of(eb_untag(troot, EB_NODE),
|
|
|
|
struct eb32sc_node, node.branches);
|
|
|
|
|
|
|
|
if (eb32->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 ((eb32->node_s & scope) && eb32->key >= x)
|
|
|
|
troot = eb_dotag(&eb32->node.branches, EB_LEFT);
|
|
|
|
else
|
|
|
|
troot = eb32->node.node_p;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (((x ^ eb32->key) >> eb32->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 ((eb32->node_s & scope) && (eb32->key >> eb32->node.bit) > (x >> eb32->node.bit))
|
|
|
|
troot = eb_dotag(&eb32->node.branches, EB_LEFT);
|
|
|
|
else
|
|
|
|
troot = eb32->node.node_p;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
troot = eb32->node.branches.b[(x >> eb32->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.
|
|
|
|
*/
|
2017-11-13 18:17:54 +00:00
|
|
|
eb32 = eb32sc_next_with_parent(troot, scope);
|
2017-11-05 20:23:21 +00:00
|
|
|
if (!eb32)
|
|
|
|
eb32 = eb32sc_walk_down_left(root->b[EB_LEFT], scope);
|
|
|
|
|
|
|
|
return eb32;
|
|
|
|
}
|
|
|
|
|
2017-11-05 12:31:29 +00:00
|
|
|
/* Removes a leaf node from the tree if it was still in it. Marks the node
|
|
|
|
* as unlinked.
|
|
|
|
*/
|
|
|
|
void eb32sc_delete(struct eb32sc_node *eb32)
|
|
|
|
{
|
|
|
|
struct eb_node *node = &eb32->node;
|
|
|
|
unsigned int pside, gpside, sibtype;
|
|
|
|
struct eb_node *parent;
|
|
|
|
struct eb_root *gparent;
|
2017-11-13 15:16:09 +00:00
|
|
|
unsigned long scope;
|
2017-11-05 12:31:29 +00:00
|
|
|
|
|
|
|
if (!node->leaf_p)
|
|
|
|
return;
|
|
|
|
|
|
|
|
/* we need the parent, our side, and the grand parent */
|
|
|
|
pside = eb_gettag(node->leaf_p);
|
|
|
|
parent = eb_root_to_node(eb_untag(node->leaf_p, pside));
|
|
|
|
|
|
|
|
/* We likely have to release the parent link, unless it's the root,
|
|
|
|
* in which case we only set our branch to NULL. Note that we can
|
|
|
|
* only be attached to the root by its left branch.
|
|
|
|
*/
|
|
|
|
|
|
|
|
if (eb_clrtag(parent->branches.b[EB_RGHT]) == NULL) {
|
|
|
|
/* we're just below the root, it's trivial. */
|
|
|
|
parent->branches.b[EB_LEFT] = NULL;
|
|
|
|
goto delete_unlink;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* To release our parent, we have to identify our sibling, and reparent
|
|
|
|
* it directly to/from the grand parent. Note that the sibling can
|
|
|
|
* either be a link or a leaf.
|
|
|
|
*/
|
|
|
|
|
|
|
|
gpside = eb_gettag(parent->node_p);
|
|
|
|
gparent = eb_untag(parent->node_p, gpside);
|
|
|
|
|
|
|
|
gparent->b[gpside] = parent->branches.b[!pside];
|
|
|
|
sibtype = eb_gettag(gparent->b[gpside]);
|
|
|
|
|
|
|
|
if (sibtype == EB_LEAF) {
|
|
|
|
eb_root_to_node(eb_untag(gparent->b[gpside], EB_LEAF))->leaf_p =
|
|
|
|
eb_dotag(gparent, gpside);
|
|
|
|
} else {
|
|
|
|
eb_root_to_node(eb_untag(gparent->b[gpside], EB_NODE))->node_p =
|
|
|
|
eb_dotag(gparent, gpside);
|
|
|
|
}
|
|
|
|
/* Mark the parent unused. Note that we do not check if the parent is
|
|
|
|
* our own node, but that's not a problem because if it is, it will be
|
|
|
|
* marked unused at the same time, which we'll use below to know we can
|
|
|
|
* safely remove it.
|
|
|
|
*/
|
|
|
|
parent->node_p = NULL;
|
|
|
|
|
|
|
|
/* The parent node has been detached, and is currently unused. It may
|
|
|
|
* belong to another node, so we cannot remove it that way. Also, our
|
|
|
|
* own node part might still be used. so we can use this spare node
|
|
|
|
* to replace ours if needed.
|
|
|
|
*/
|
|
|
|
|
|
|
|
/* If our link part is unused, we can safely exit now */
|
|
|
|
if (!node->node_p)
|
|
|
|
goto delete_unlink;
|
|
|
|
|
|
|
|
/* From now on, <node> and <parent> are necessarily different, and the
|
|
|
|
* <node>'s node part is in use. By definition, <parent> is at least
|
2017-11-05 17:06:22 +00:00
|
|
|
* below <node>, so keeping its key for the bit string is OK. However
|
|
|
|
* its scope must be enlarged to cover the new branch it absorbs.
|
2017-11-05 12:31:29 +00:00
|
|
|
*/
|
|
|
|
|
|
|
|
parent->node_p = node->node_p;
|
|
|
|
parent->branches = node->branches;
|
|
|
|
parent->bit = node->bit;
|
|
|
|
|
|
|
|
/* We must now update the new node's parent... */
|
|
|
|
gpside = eb_gettag(parent->node_p);
|
|
|
|
gparent = eb_untag(parent->node_p, gpside);
|
|
|
|
gparent->b[gpside] = eb_dotag(&parent->branches, EB_NODE);
|
|
|
|
|
|
|
|
/* ... and its branches */
|
2017-11-13 15:16:09 +00:00
|
|
|
scope = 0;
|
2017-11-05 12:31:29 +00:00
|
|
|
for (pside = 0; pside <= 1; pside++) {
|
|
|
|
if (eb_gettag(parent->branches.b[pside]) == EB_NODE) {
|
|
|
|
eb_root_to_node(eb_untag(parent->branches.b[pside], EB_NODE))->node_p =
|
|
|
|
eb_dotag(&parent->branches, pside);
|
2017-11-13 15:16:09 +00:00
|
|
|
scope |= container_of(eb_untag(parent->branches.b[pside], EB_NODE), struct eb32sc_node, node.branches)->node_s;
|
2017-11-05 12:31:29 +00:00
|
|
|
} else {
|
|
|
|
eb_root_to_node(eb_untag(parent->branches.b[pside], EB_LEAF))->leaf_p =
|
|
|
|
eb_dotag(&parent->branches, pside);
|
2017-11-13 15:16:09 +00:00
|
|
|
scope |= container_of(eb_untag(parent->branches.b[pside], EB_LEAF), struct eb32sc_node, node.branches)->leaf_s;
|
2017-11-05 12:31:29 +00:00
|
|
|
}
|
|
|
|
}
|
2017-11-13 15:16:09 +00:00
|
|
|
container_of(parent, struct eb32sc_node, node)->node_s = scope;
|
|
|
|
|
2017-11-05 12:31:29 +00:00
|
|
|
delete_unlink:
|
|
|
|
/* Now the node has been completely unlinked */
|
|
|
|
node->leaf_p = NULL;
|
|
|
|
return; /* tree is not empty yet */
|
|
|
|
}
|