598 lines
19 KiB
C
598 lines
19 KiB
C
/*
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* Elastic Binary Trees - macros and structures for operations on 64bit nodes.
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* Version 6.0.6
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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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#ifndef _EB64TREE_H
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#define _EB64TREE_H
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#include "ebtree.h"
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/* Return the structure of type <type> whose member <member> points to <ptr> */
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#define eb64_entry(ptr, type, member) container_of(ptr, type, member)
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#define EB64_ROOT EB_ROOT
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#define EB64_TREE_HEAD EB_TREE_HEAD
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/* These types may sometimes already be defined */
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typedef unsigned long long u64;
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typedef signed long long s64;
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/* This structure carries a node, a leaf, and a key. It must start with the
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* eb_node so that it can be cast into an eb_node. We could also have put some
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* sort of transparent union here to reduce the indirection level, but the fact
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* is, the end user is not meant to manipulate internals, so this is pointless.
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* In case sizeof(void*)>=sizeof(u64), we know there will be some padding after
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* the key if it's unaligned. In this case we force the alignment on void* so
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* that we prefer to have the padding before for more efficient accesses.
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*/
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struct eb64_node {
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struct eb_node node; /* the tree node, must be at the beginning */
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MAYBE_ALIGN(sizeof(u64));
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ALWAYS_ALIGN(sizeof(void*));
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u64 key;
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} ALIGNED(sizeof(void*));
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/*
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* Exported functions and macros.
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* Many of them are always inlined because they are extremely small, and
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* are generally called at most once or twice in a program.
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*/
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/* Return leftmost node in the tree, or NULL if none */
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static inline struct eb64_node *eb64_first(struct eb_root *root)
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{
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return eb64_entry(eb_first(root), struct eb64_node, node);
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}
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/* Return rightmost node in the tree, or NULL if none */
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static inline struct eb64_node *eb64_last(struct eb_root *root)
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{
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return eb64_entry(eb_last(root), struct eb64_node, node);
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}
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/* Return next node in the tree, or NULL if none */
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static inline struct eb64_node *eb64_next(struct eb64_node *eb64)
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{
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return eb64_entry(eb_next(&eb64->node), struct eb64_node, node);
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}
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/* Return previous node in the tree, or NULL if none */
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static inline struct eb64_node *eb64_prev(struct eb64_node *eb64)
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{
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return eb64_entry(eb_prev(&eb64->node), struct eb64_node, node);
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}
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/* Return next leaf node within a duplicate sub-tree, or NULL if none. */
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static inline struct eb64_node *eb64_next_dup(struct eb64_node *eb64)
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{
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return eb64_entry(eb_next_dup(&eb64->node), struct eb64_node, node);
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}
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/* Return previous leaf node within a duplicate sub-tree, or NULL if none. */
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static inline struct eb64_node *eb64_prev_dup(struct eb64_node *eb64)
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{
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return eb64_entry(eb_prev_dup(&eb64->node), struct eb64_node, node);
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}
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/* Return next node in the tree, skipping duplicates, or NULL if none */
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static inline struct eb64_node *eb64_next_unique(struct eb64_node *eb64)
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{
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return eb64_entry(eb_next_unique(&eb64->node), struct eb64_node, node);
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}
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/* Return previous node in the tree, skipping duplicates, or NULL if none */
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static inline struct eb64_node *eb64_prev_unique(struct eb64_node *eb64)
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{
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return eb64_entry(eb_prev_unique(&eb64->node), struct eb64_node, node);
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}
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/* Delete node from the tree if it was linked in. Mark the node unused. Note
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* that this function relies on a non-inlined generic function: eb_delete.
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*/
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static inline void eb64_delete(struct eb64_node *eb64)
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{
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eb_delete(&eb64->node);
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}
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/*
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* The following functions are not inlined by default. They are declared
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* in eb64tree.c, which simply relies on their inline version.
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*/
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struct eb64_node *eb64_lookup(struct eb_root *root, u64 x);
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struct eb64_node *eb64i_lookup(struct eb_root *root, s64 x);
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struct eb64_node *eb64_lookup_le(struct eb_root *root, u64 x);
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struct eb64_node *eb64_lookup_ge(struct eb_root *root, u64 x);
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struct eb64_node *eb64_insert(struct eb_root *root, struct eb64_node *new);
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struct eb64_node *eb64i_insert(struct eb_root *root, struct eb64_node *new);
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/*
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* The following functions are less likely to be used directly, because their
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* code is larger. The non-inlined version is preferred.
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*/
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/* Delete node from the tree if it was linked in. Mark the node unused. */
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static forceinline void __eb64_delete(struct eb64_node *eb64)
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{
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__eb_delete(&eb64->node);
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}
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/*
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* Find the first occurrence of a key in the tree <root>. If none can be
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* found, return NULL.
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*/
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static forceinline struct eb64_node *__eb64_lookup(struct eb_root *root, u64 x)
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{
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struct eb64_node *node;
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eb_troot_t *troot;
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u64 y;
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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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node = container_of(eb_untag(troot, EB_LEAF),
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struct eb64_node, node.branches);
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if (node->key == x)
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return node;
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else
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return NULL;
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}
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node = container_of(eb_untag(troot, EB_NODE),
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struct eb64_node, node.branches);
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y = node->key ^ x;
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if (!y) {
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/* Either we found the node which holds the key, or
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* we have a dup tree. In the later case, we have to
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* walk it down left to get the first entry.
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*/
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if (node->node.bit < 0) {
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troot = node->node.branches.b[EB_LEFT];
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while (eb_gettag(troot) != EB_LEAF)
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troot = (eb_untag(troot, EB_NODE))->b[EB_LEFT];
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node = container_of(eb_untag(troot, EB_LEAF),
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struct eb64_node, node.branches);
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}
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return node;
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}
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if ((y >> node->node.bit) >= EB_NODE_BRANCHES)
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return NULL; /* no more common bits */
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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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}
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/*
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* Find the first occurrence of a signed key in the tree <root>. If none can
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* be found, return NULL.
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*/
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static forceinline struct eb64_node *__eb64i_lookup(struct eb_root *root, s64 x)
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{
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struct eb64_node *node;
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eb_troot_t *troot;
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u64 key = x ^ (1ULL << 63);
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u64 y;
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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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node = container_of(eb_untag(troot, EB_LEAF),
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struct eb64_node, node.branches);
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if (node->key == (u64)x)
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return node;
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else
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return NULL;
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}
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node = container_of(eb_untag(troot, EB_NODE),
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struct eb64_node, node.branches);
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y = node->key ^ x;
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if (!y) {
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/* Either we found the node which holds the key, or
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* we have a dup tree. In the later case, we have to
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* walk it down left to get the first entry.
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*/
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if (node->node.bit < 0) {
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troot = node->node.branches.b[EB_LEFT];
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while (eb_gettag(troot) != EB_LEAF)
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troot = (eb_untag(troot, EB_NODE))->b[EB_LEFT];
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node = container_of(eb_untag(troot, EB_LEAF),
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struct eb64_node, node.branches);
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}
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return node;
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}
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if ((y >> node->node.bit) >= EB_NODE_BRANCHES)
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return NULL; /* no more common bits */
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troot = node->node.branches.b[(key >> node->node.bit) & EB_NODE_BRANCH_MASK];
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}
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}
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/* Insert eb64_node <new> into subtree starting at node root <root>.
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* Only new->key needs be set with the key. The eb64_node is returned.
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* If root->b[EB_RGHT]==1, the tree may only contain unique keys.
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*/
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static forceinline struct eb64_node *
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__eb64_insert(struct eb_root *root, struct eb64_node *new) {
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struct eb64_node *old;
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unsigned int side;
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eb_troot_t *troot;
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u64 newkey; /* caching the key saves approximately one cycle */
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eb_troot_t *root_right;
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int old_node_bit;
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side = EB_LEFT;
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troot = root->b[EB_LEFT];
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root_right = root->b[EB_RGHT];
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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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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 (unlikely(eb_gettag(troot) == EB_LEAF)) {
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eb_troot_t *new_left, *new_rght;
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eb_troot_t *new_leaf, *old_leaf;
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old = container_of(eb_untag(troot, EB_LEAF),
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struct eb64_node, node.branches);
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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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old_leaf = eb_dotag(&old->node.branches, EB_LEAF);
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new->node.node_p = old->node.leaf_p;
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/* Right here, we have 3 possibilities :
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- the tree does not contain the key, and we have
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new->key < old->key. We insert new above old, on
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the left ;
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- the tree does not contain the key, and we have
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new->key > old->key. We insert new above old, on
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the right ;
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- the tree does contain the key, which implies it
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is alone. We add the new key next to it as a
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first duplicate.
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The last two cases can easily be partially merged.
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*/
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if (new->key < old->key) {
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new->node.leaf_p = new_left;
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old->node.leaf_p = new_rght;
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new->node.branches.b[EB_LEFT] = new_leaf;
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new->node.branches.b[EB_RGHT] = old_leaf;
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} else {
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/* we may refuse to duplicate this key if the tree is
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* tagged as containing only unique keys.
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*/
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if ((new->key == old->key) && eb_gettag(root_right))
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return old;
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/* new->key >= old->key, new goes the right */
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old->node.leaf_p = new_left;
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new->node.leaf_p = new_rght;
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new->node.branches.b[EB_LEFT] = old_leaf;
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new->node.branches.b[EB_RGHT] = new_leaf;
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if (new->key == old->key) {
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new->node.bit = -1;
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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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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 eb64_node, node.branches);
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old_node_bit = old->node.bit;
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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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eb_troot_t *new_left, *new_rght;
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eb_troot_t *new_leaf, *old_node;
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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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old_node = eb_dotag(&old->node.branches, EB_NODE);
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new->node.node_p = old->node.node_p;
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if (new->key < old->key) {
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new->node.leaf_p = new_left;
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old->node.node_p = new_rght;
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new->node.branches.b[EB_LEFT] = new_leaf;
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new->node.branches.b[EB_RGHT] = old_node;
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}
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else if (new->key > old->key) {
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old->node.node_p = new_left;
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new->node.leaf_p = new_rght;
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new->node.branches.b[EB_LEFT] = old_node;
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new->node.branches.b[EB_RGHT] = new_leaf;
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}
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else {
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struct eb_node *ret;
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ret = eb_insert_dup(&old->node, &new->node);
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return container_of(ret, struct eb64_node, node);
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}
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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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if (sizeof(long) >= 8) {
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side = newkey >> old_node_bit;
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} else {
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/* note: provides the best code on low-register count archs
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* such as i386.
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*/
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side = newkey;
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side >>= old_node_bit;
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if (old_node_bit >= 32) {
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side = newkey >> 32;
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side >>= old_node_bit & 0x1F;
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}
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}
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side &= EB_NODE_BRANCH_MASK;
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troot = root->b[side];
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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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/* 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 = fls64(new->key ^ old->key) - EB_NODE_BITS;
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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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/* Insert eb64_node <new> into subtree starting at node root <root>, using
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* signed keys. Only new->key needs be set with the key. The eb64_node
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* is returned. If root->b[EB_RGHT]==1, the tree may only contain unique keys.
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*/
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static forceinline struct eb64_node *
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__eb64i_insert(struct eb_root *root, struct eb64_node *new) {
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struct eb64_node *old;
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unsigned int side;
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eb_troot_t *troot;
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u64 newkey; /* caching the key saves approximately one cycle */
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eb_troot_t *root_right;
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int old_node_bit;
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side = EB_LEFT;
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troot = root->b[EB_LEFT];
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root_right = root->b[EB_RGHT];
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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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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 a high bit shift of the key being
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* inserted in order to have negative keys stored before positive
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* ones.
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*/
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newkey = new->key ^ (1ULL << 63);
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while (1) {
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if (unlikely(eb_gettag(troot) == EB_LEAF)) {
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eb_troot_t *new_left, *new_rght;
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eb_troot_t *new_leaf, *old_leaf;
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old = container_of(eb_untag(troot, EB_LEAF),
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struct eb64_node, node.branches);
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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);
|
|
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 ((s64)new->key < (s64)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 {
|
|
/* we may refuse to duplicate this key if the tree is
|
|
* tagged as containing only unique keys.
|
|
*/
|
|
if ((new->key == old->key) && 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 (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 eb64_node, node.branches);
|
|
old_node_bit = old->node.bit;
|
|
|
|
/* 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 */
|
|
(((new->key ^ 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 ((s64)new->key < (s64)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 ((s64)new->key > (s64)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 eb64_node, node);
|
|
}
|
|
break;
|
|
}
|
|
|
|
/* walk down */
|
|
root = &old->node.branches;
|
|
|
|
if (sizeof(long) >= 8) {
|
|
side = newkey >> old_node_bit;
|
|
} else {
|
|
/* note: provides the best code on low-register count archs
|
|
* such as i386.
|
|
*/
|
|
side = newkey;
|
|
side >>= old_node_bit;
|
|
if (old_node_bit >= 32) {
|
|
side = newkey >> 32;
|
|
side >>= old_node_bit & 0x1F;
|
|
}
|
|
}
|
|
side &= 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
|
|
new->node.bit = fls64(new->key ^ old->key) - EB_NODE_BITS;
|
|
root->b[side] = eb_dotag(&new->node.branches, EB_NODE);
|
|
|
|
return new;
|
|
}
|
|
|
|
#endif /* _EB64_TREE_H */
|