3908836aa7
As proposed by Peter Zijlstra, this makes it easier to define the augmented rbtree callbacks. Signed-off-by: Michel Lespinasse <walken@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
133 lines
4.7 KiB
C
133 lines
4.7 KiB
C
/*
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Red Black Trees
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(C) 1999 Andrea Arcangeli <andrea@suse.de>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program 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
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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linux/include/linux/rbtree.h
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To use rbtrees you'll have to implement your own insert and search cores.
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This will avoid us to use callbacks and to drop drammatically performances.
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I know it's not the cleaner way, but in C (not in C++) to get
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performances and genericity...
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See Documentation/rbtree.txt for documentation and samples.
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*/
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#ifndef _LINUX_RBTREE_H
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#define _LINUX_RBTREE_H
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#include <linux/kernel.h>
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#include <linux/stddef.h>
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struct rb_node {
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unsigned long __rb_parent_color;
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struct rb_node *rb_right;
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struct rb_node *rb_left;
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} __attribute__((aligned(sizeof(long))));
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/* The alignment might seem pointless, but allegedly CRIS needs it */
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struct rb_root {
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struct rb_node *rb_node;
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};
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#define rb_parent(r) ((struct rb_node *)((r)->__rb_parent_color & ~3))
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#define RB_ROOT (struct rb_root) { NULL, }
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#define rb_entry(ptr, type, member) container_of(ptr, type, member)
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#define RB_EMPTY_ROOT(root) ((root)->rb_node == NULL)
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/* 'empty' nodes are nodes that are known not to be inserted in an rbree */
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#define RB_EMPTY_NODE(node) \
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((node)->__rb_parent_color == (unsigned long)(node))
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#define RB_CLEAR_NODE(node) \
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((node)->__rb_parent_color = (unsigned long)(node))
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extern void rb_insert_color(struct rb_node *, struct rb_root *);
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extern void rb_erase(struct rb_node *, struct rb_root *);
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struct rb_augment_callbacks {
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void (*propagate)(struct rb_node *node, struct rb_node *stop);
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void (*copy)(struct rb_node *old, struct rb_node *new);
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void (*rotate)(struct rb_node *old, struct rb_node *new);
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};
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extern void __rb_insert_augmented(struct rb_node *node, struct rb_root *root,
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void (*augment_rotate)(struct rb_node *old, struct rb_node *new));
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extern void rb_erase_augmented(struct rb_node *node, struct rb_root *root,
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const struct rb_augment_callbacks *augment);
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static inline void
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rb_insert_augmented(struct rb_node *node, struct rb_root *root,
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const struct rb_augment_callbacks *augment)
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{
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__rb_insert_augmented(node, root, augment->rotate);
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}
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#define RB_DECLARE_CALLBACKS(rbstatic, rbname, rbstruct, rbfield, \
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rbtype, rbaugmented, rbcompute) \
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static void rbname ## _propagate(struct rb_node *rb, struct rb_node *stop) \
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{ \
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while (rb != stop) { \
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rbstruct *node = rb_entry(rb, rbstruct, rbfield); \
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rbtype augmented = rbcompute(node); \
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if (node->rbaugmented == augmented) \
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break; \
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node->rbaugmented = augmented; \
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rb = rb_parent(&node->rbfield); \
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} \
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} \
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static void rbname ## _copy(struct rb_node *rb_old, struct rb_node *rb_new) \
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{ \
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rbstruct *old = rb_entry(rb_old, rbstruct, rbfield); \
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rbstruct *new = rb_entry(rb_new, rbstruct, rbfield); \
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new->rbaugmented = old->rbaugmented; \
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} \
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static void rbname ## _rotate(struct rb_node *rb_old, struct rb_node *rb_new) \
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{ \
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rbstruct *old = rb_entry(rb_old, rbstruct, rbfield); \
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rbstruct *new = rb_entry(rb_new, rbstruct, rbfield); \
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new->rbaugmented = old->rbaugmented; \
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old->rbaugmented = rbcompute(old); \
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} \
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rbstatic const struct rb_augment_callbacks rbname = { \
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rbname ## _propagate, rbname ## _copy, rbname ## _rotate \
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};
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/* Find logical next and previous nodes in a tree */
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extern struct rb_node *rb_next(const struct rb_node *);
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extern struct rb_node *rb_prev(const struct rb_node *);
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extern struct rb_node *rb_first(const struct rb_root *);
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extern struct rb_node *rb_last(const struct rb_root *);
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/* Fast replacement of a single node without remove/rebalance/add/rebalance */
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extern void rb_replace_node(struct rb_node *victim, struct rb_node *new,
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struct rb_root *root);
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static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,
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struct rb_node ** rb_link)
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{
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node->__rb_parent_color = (unsigned long)parent;
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node->rb_left = node->rb_right = NULL;
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*rb_link = node;
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}
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#endif /* _LINUX_RBTREE_H */
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