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| author | Stefan Roese <sr@denx.de> | 2008-10-21 11:43:08 +0200 | 
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| committer | Stefan Roese <sr@denx.de> | 2008-10-21 11:43:08 +0200 | 
| commit | f61f1e150c84f5b9347fca79a4bc5f2286c545d2 (patch) | |
| tree | ab90f076f18e56b2b3e8c9375b95917daa78c1d9 /include/linux/rbtree.h | |
| parent | ec081c2c190148b374e86a795fb6b1c49caeb549 (diff) | |
| parent | f82642e33899766892499b163e60560fbbf87773 (diff) | |
| download | olio-uboot-2014.01-f61f1e150c84f5b9347fca79a4bc5f2286c545d2.tar.xz olio-uboot-2014.01-f61f1e150c84f5b9347fca79a4bc5f2286c545d2.zip | |
Merge branch 'master' of /home/stefan/git/u-boot/u-boot
Diffstat (limited to 'include/linux/rbtree.h')
| -rw-r--r-- | include/linux/rbtree.h | 160 | 
1 files changed, 160 insertions, 0 deletions
| diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h new file mode 100644 index 000000000..6ff28e026 --- /dev/null +++ b/include/linux/rbtree.h @@ -0,0 +1,160 @@ +/* +  Red Black Trees +  (C) 1999  Andrea Arcangeli <andrea@suse.de> + +  This program is free software; you can redistribute it and/or modify +  it under the terms of the GNU General Public License as published by +  the Free Software Foundation; either version 2 of the License, or +  (at your option) any later version. + +  This program is distributed in the hope that it will be useful, +  but WITHOUT ANY WARRANTY; without even the implied warranty of +  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the +  GNU General Public License for more details. + +  You should have received a copy of the GNU General Public License +  along with this program; if not, write to the Free Software +  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA + +  linux/include/linux/rbtree.h + +  To use rbtrees you'll have to implement your own insert and search cores. +  This will avoid us to use callbacks and to drop drammatically performances. +  I know it's not the cleaner way,  but in C (not in C++) to get +  performances and genericity... + +  Some example of insert and search follows here. The search is a plain +  normal search over an ordered tree. The insert instead must be implemented +  int two steps: as first thing the code must insert the element in +  order as a red leaf in the tree, then the support library function +  rb_insert_color() must be called. Such function will do the +  not trivial work to rebalance the rbtree if necessary. + +----------------------------------------------------------------------- +static inline struct page * rb_search_page_cache(struct inode * inode, +						 unsigned long offset) +{ +	struct rb_node * n = inode->i_rb_page_cache.rb_node; +	struct page * page; + +	while (n) +	{ +		page = rb_entry(n, struct page, rb_page_cache); + +		if (offset < page->offset) +			n = n->rb_left; +		else if (offset > page->offset) +			n = n->rb_right; +		else +			return page; +	} +	return NULL; +} + +static inline struct page * __rb_insert_page_cache(struct inode * inode, +						   unsigned long offset, +						   struct rb_node * node) +{ +	struct rb_node ** p = &inode->i_rb_page_cache.rb_node; +	struct rb_node * parent = NULL; +	struct page * page; + +	while (*p) +	{ +		parent = *p; +		page = rb_entry(parent, struct page, rb_page_cache); + +		if (offset < page->offset) +			p = &(*p)->rb_left; +		else if (offset > page->offset) +			p = &(*p)->rb_right; +		else +			return page; +	} + +	rb_link_node(node, parent, p); + +	return NULL; +} + +static inline struct page * rb_insert_page_cache(struct inode * inode, +						 unsigned long offset, +						 struct rb_node * node) +{ +	struct page * ret; +	if ((ret = __rb_insert_page_cache(inode, offset, node))) +		goto out; +	rb_insert_color(node, &inode->i_rb_page_cache); + out: +	return ret; +} +----------------------------------------------------------------------- +*/ + +#ifndef	_LINUX_RBTREE_H +#define	_LINUX_RBTREE_H + +#include <linux/stddef.h> + +struct rb_node +{ +	unsigned long  rb_parent_color; +#define	RB_RED		0 +#define	RB_BLACK	1 +	struct rb_node *rb_right; +	struct rb_node *rb_left; +} __attribute__((aligned(sizeof(long)))); +    /* The alignment might seem pointless, but allegedly CRIS needs it */ + +struct rb_root +{ +	struct rb_node *rb_node; +}; + + +#define rb_parent(r)   ((struct rb_node *)((r)->rb_parent_color & ~3)) +#define rb_color(r)   ((r)->rb_parent_color & 1) +#define rb_is_red(r)   (!rb_color(r)) +#define rb_is_black(r) rb_color(r) +#define rb_set_red(r)  do { (r)->rb_parent_color &= ~1; } while (0) +#define rb_set_black(r)  do { (r)->rb_parent_color |= 1; } while (0) + +static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p) +{ +	rb->rb_parent_color = (rb->rb_parent_color & 3) | (unsigned long)p; +} +static inline void rb_set_color(struct rb_node *rb, int color) +{ +	rb->rb_parent_color = (rb->rb_parent_color & ~1) | color; +} + +#define RB_ROOT	(struct rb_root) { NULL, } +#define	rb_entry(ptr, type, member) container_of(ptr, type, member) + +#define RB_EMPTY_ROOT(root)	((root)->rb_node == NULL) +#define RB_EMPTY_NODE(node)	(rb_parent(node) == node) +#define RB_CLEAR_NODE(node)	(rb_set_parent(node, node)) + +extern void rb_insert_color(struct rb_node *, struct rb_root *); +extern void rb_erase(struct rb_node *, struct rb_root *); + +/* Find logical next and previous nodes in a tree */ +extern struct rb_node *rb_next(struct rb_node *); +extern struct rb_node *rb_prev(struct rb_node *); +extern struct rb_node *rb_first(struct rb_root *); +extern struct rb_node *rb_last(struct rb_root *); + +/* Fast replacement of a single node without remove/rebalance/add/rebalance */ +extern void rb_replace_node(struct rb_node *victim, struct rb_node *new, +			    struct rb_root *root); + +static inline void rb_link_node(struct rb_node * node, struct rb_node * parent, +				struct rb_node ** rb_link) +{ +	node->rb_parent_color = (unsigned long )parent; +	node->rb_left = node->rb_right = NULL; + +	*rb_link = node; +} + +#endif	/* _LINUX_RBTREE_H */ |