[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / linux / rbtree_augmented.h

/*
  Red Black Trees
  (C) 1999  Andrea Arcangeli <andrea@suse.de>
  (C) 2002  David Woodhouse <dwmw2@infradead.org>
  (C) 2012  Michel Lespinasse <walken@google.com>

  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_augmented.h
*/

#ifndef _LINUX_RBTREE_AUGMENTED_H
#define _LINUX_RBTREE_AUGMENTED_H

#include <linux/compiler.h>
#include <linux/rbtree.h>

/*
 * Please note - only struct rb_augment_callbacks and the prototypes for
 * rb_insert_augmented() and rb_erase_augmented() are intended to be public.
 * The rest are implementation details you are not expected to depend on.
 *
 * See Documentation/rbtree.txt for documentation and samples.
 */

struct rb_augment_callbacks {
	void (*propagate)(struct rb_node *node, struct rb_node *stop);
	void (*copy)(struct rb_node *old, struct rb_node *new);
	void (*rotate)(struct rb_node *old, struct rb_node *new);
};

extern void __rb_insert_augmented(struct rb_node *node, struct rb_root *root,
	void (*augment_rotate)(struct rb_node *old, struct rb_node *new));
static inline void
rb_insert_augmented(struct rb_node *node, struct rb_root *root,
		    const struct rb_augment_callbacks *augment)
{
	__rb_insert_augmented(node, root, augment->rotate);
}

#define RB_DECLARE_CALLBACKS(rbstatic, rbname, rbstruct, rbfield,	\
			     rbtype, rbaugmented, rbcompute)		\
static inline void							\
rbname ## _propagate(struct rb_node *rb, struct rb_node *stop)		\
{									\
	while (rb != stop) {						\
		rbstruct *node = rb_entry(rb, rbstruct, rbfield);	\
		rbtype augmented = rbcompute(node);			\
		if (node->rbaugmented == augmented)			\
			break;						\
		node->rbaugmented = augmented;				\
		rb = rb_parent(&node->rbfield);				\
	}								\
}									\
static inline void							\
rbname ## _copy(struct rb_node *rb_old, struct rb_node *rb_new)		\
{									\
	rbstruct *old = rb_entry(rb_old, rbstruct, rbfield);		\
	rbstruct *new = rb_entry(rb_new, rbstruct, rbfield);		\
	new->rbaugmented = old->rbaugmented;				\
}									\
static void								\
rbname ## _rotate(struct rb_node *rb_old, struct rb_node *rb_new)	\
{									\
	rbstruct *old = rb_entry(rb_old, rbstruct, rbfield);		\
	rbstruct *new = rb_entry(rb_new, rbstruct, rbfield);		\
	new->rbaugmented = old->rbaugmented;				\
	old->rbaugmented = rbcompute(old);				\
}									\
rbstatic const struct rb_augment_callbacks rbname = {			\
	rbname ## _propagate, rbname ## _copy, rbname ## _rotate	\
};


#define	RB_RED		0
#define	RB_BLACK	1

#define __rb_parent(pc)    ((struct rb_node *)(pc & ~3))

#define __rb_color(pc)     ((pc) & 1)
#define __rb_is_black(pc)  __rb_color(pc)
#define __rb_is_red(pc)    (!__rb_color(pc))
#define rb_color(rb)       __rb_color((rb)->__rb_parent_color)
#define rb_is_red(rb)      __rb_is_red((rb)->__rb_parent_color)
#define rb_is_black(rb)    __rb_is_black((rb)->__rb_parent_color)

static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p)
{
	rb->__rb_parent_color = rb_color(rb) | (unsigned long)p;
}

static inline void rb_set_parent_color(struct rb_node *rb,
				       struct rb_node *p, int color)
{
	rb->__rb_parent_color = (unsigned long)p | color;
}

static inline void
__rb_change_child(struct rb_node *old, struct rb_node *new,
		  struct rb_node *parent, struct rb_root *root)
{
	if (parent) {
		if (parent->rb_left == old)
			parent->rb_left = new;
		else
			parent->rb_right = new;
	} else
		root->rb_node = new;
}

extern void __rb_erase_color(struct rb_node *parent, struct rb_root *root,
	void (*augment_rotate)(struct rb_node *old, struct rb_node *new));

static __always_inline struct rb_node *
__rb_erase_augmented(struct rb_node *node, struct rb_root *root,
		     const struct rb_augment_callbacks *augment)
{
	struct rb_node *child = node->rb_right, *tmp = node->rb_left;
	struct rb_node *parent, *rebalance;
	unsigned long pc;

	if (!tmp) {
		/*
		 * Case 1: node to erase has no more than 1 child (easy!)
		 *
		 * Note that if there is one child it must be red due to 5)
		 * and node must be black due to 4). We adjust colors locally
		 * so as to bypass __rb_erase_color() later on.
		 */
		pc = node->__rb_parent_color;
		parent = __rb_parent(pc);
		__rb_change_child(node, child, parent, root);
		if (child) {
			child->__rb_parent_color = pc;
			rebalance = NULL;
		} else
			rebalance = __rb_is_black(pc) ? parent : NULL;
		tmp = parent;
	} else if (!child) {
		/* Still case 1, but this time the child is node->rb_left */
		tmp->__rb_parent_color = pc = node->__rb_parent_color;
		parent = __rb_parent(pc);
		__rb_change_child(node, tmp, parent, root);
		rebalance = NULL;
		tmp = parent;
	} else {
		struct rb_node *successor = child, *child2;
		tmp = child->rb_left;
		if (!tmp) {
			/*
			 * Case 2: node's successor is its right child
			 *
			 *    (n)          (s)
			 *    / \          / \
			 *  (x) (s)  ->  (x) (c)
			 *        \
			 *        (c)
			 */
			parent = successor;
			child2 = successor->rb_right;
			augment->copy(node, successor);
		} else {
			/*
			 * Case 3: node's successor is leftmost under
			 * node's right child subtree
			 *
			 *    (n)          (s)
			 *    / \          / \
			 *  (x) (y)  ->  (x) (y)
			 *      /            /
			 *    (p)          (p)
			 *    /            /
			 *  (s)          (c)
			 *    \
			 *    (c)
			 */
			do {
				parent = successor;
				successor = tmp;
				tmp = tmp->rb_left;
			} while (tmp);
			parent->rb_left = child2 = successor->rb_right;
			successor->rb_right = child;
			rb_set_parent(child, successor);
			augment->copy(node, successor);
			augment->propagate(parent, successor);
		}

		successor->rb_left = tmp = node->rb_left;
		rb_set_parent(tmp, successor);

		pc = node->__rb_parent_color;
		tmp = __rb_parent(pc);
		__rb_change_child(node, successor, tmp, root);
		if (child2) {
			successor->__rb_parent_color = pc;
			rb_set_parent_color(child2, parent, RB_BLACK);
			rebalance = NULL;
		} else {
			unsigned long pc2 = successor->__rb_parent_color;
			successor->__rb_parent_color = pc;
			rebalance = __rb_is_black(pc2) ? parent : NULL;
		}
		tmp = successor;
	}

	augment->propagate(tmp, NULL);
	return rebalance;
}

static __always_inline void
rb_erase_augmented(struct rb_node *node, struct rb_root *root,
		   const struct rb_augment_callbacks *augment)
{
	struct rb_node *rebalance = __rb_erase_augmented(node, root, augment);
	if (rebalance)
		__rb_erase_color(rebalance, root, augment->rotate);
}

#endif	/* _LINUX_RBTREE_AUGMENTED_H */
Commit	Line	Data
9c079add ML	1	/*
	2	Red Black Trees
	3	(C) 1999 Andrea Arcangeli <andrea@suse.de>
	4	(C) 2002 David Woodhouse <dwmw2@infradead.org>
	5	(C) 2012 Michel Lespinasse <walken@google.com>
	6
	7	This program is free software; you can redistribute it and/or modify
	8	it under the terms of the GNU General Public License as published by
	9	the Free Software Foundation; either version 2 of the License, or
	10	(at your option) any later version.
	11
	12	This program is distributed in the hope that it will be useful,
	13	but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	GNU General Public License for more details.
	16
	17	You should have received a copy of the GNU General Public License
	18	along with this program; if not, write to the Free Software
	19	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	20
	21	linux/include/linux/rbtree_augmented.h
	22	*/
	23
	24	#ifndef _LINUX_RBTREE_AUGMENTED_H
	25	#define _LINUX_RBTREE_AUGMENTED_H
	26
29fc7c5a	27	#include <linux/compiler.h>
9c079add ML	28	#include <linux/rbtree.h>
	29
	30	/*
	31	* Please note - only struct rb_augment_callbacks and the prototypes for
	32	* rb_insert_augmented() and rb_erase_augmented() are intended to be public.
	33	* The rest are implementation details you are not expected to depend on.
	34	*
	35	* See Documentation/rbtree.txt for documentation and samples.
	36	*/
	37
	38	struct rb_augment_callbacks {
	39	void (propagate)(struct rb_node node, struct rb_node *stop);
	40	void (copy)(struct rb_node old, struct rb_node *new);
	41	void (rotate)(struct rb_node old, struct rb_node *new);
	42	};
	43
	44	extern void __rb_insert_augmented(struct rb_node node, struct rb_root root,
	45	void (augment_rotate)(struct rb_node old, struct rb_node *new));
	46	static inline void
	47	rb_insert_augmented(struct rb_node node, struct rb_root root,
	48	const struct rb_augment_callbacks *augment)
	49	{
	50	__rb_insert_augmented(node, root, augment->rotate);
	51	}
	52
	53	#define RB_DECLARE_CALLBACKS(rbstatic, rbname, rbstruct, rbfield, \
	54	rbtype, rbaugmented, rbcompute) \
	55	static inline void \
	56	rbname ## _propagate(struct rb_node rb, struct rb_node stop) \
	57	{ \
	58	while (rb != stop) { \
	59	rbstruct *node = rb_entry(rb, rbstruct, rbfield); \
	60	rbtype augmented = rbcompute(node); \
	61	if (node->rbaugmented == augmented) \
	62	break; \
	63	node->rbaugmented = augmented; \
	64	rb = rb_parent(&node->rbfield); \
	65	} \
	66	} \
	67	static inline void \
	68	rbname ## _copy(struct rb_node rb_old, struct rb_node rb_new) \
	69	{ \
	70	rbstruct *old = rb_entry(rb_old, rbstruct, rbfield); \
	71	rbstruct *new = rb_entry(rb_new, rbstruct, rbfield); \
	72	new->rbaugmented = old->rbaugmented; \
	73	} \
	74	static void \
	75	rbname ## _rotate(struct rb_node rb_old, struct rb_node rb_new) \
	76	{ \
	77	rbstruct *old = rb_entry(rb_old, rbstruct, rbfield); \
	78	rbstruct *new = rb_entry(rb_new, rbstruct, rbfield); \
	79	new->rbaugmented = old->rbaugmented; \
	80	old->rbaugmented = rbcompute(old); \
	81	} \
	82	rbstatic const struct rb_augment_callbacks rbname = { \
	83	rbname ## _propagate, rbname ## _copy, rbname ## _rotate \
	84	};
	85
	86
	87	#define RB_RED 0
	88	#define RB_BLACK 1
	89
	90	#define __rb_parent(pc) ((struct rb_node *)(pc & ~3))
	91
92	#define __rb_color(pc) ((pc) & 1)
93	#define __rb_is_black(pc) __rb_color(pc)
94	#define __rb_is_red(pc) (!__rb_color(pc))
95	#define rb_color(rb) __rb_color((rb)->__rb_parent_color)
96	#define rb_is_red(rb) __rb_is_red((rb)->__rb_parent_color)
97	#define rb_is_black(rb) __rb_is_black((rb)->__rb_parent_color)
98
99	static inline void rb_set_parent(struct rb_node rb, struct rb_node p)
100	{
101	rb->__rb_parent_color = rb_color(rb) \| (unsigned long)p;
102	}
103
104	static inline void rb_set_parent_color(struct rb_node *rb,
105	struct rb_node *p, int color)
106	{
107	rb->__rb_parent_color = (unsigned long)p \| color;
108	}
109
110	static inline void
111	__rb_change_child(struct rb_node old, struct rb_node new,
112	struct rb_node parent, struct rb_root root)
113	{
114	if (parent) {
115	if (parent->rb_left == old)
116	parent->rb_left = new;
117	else
118	parent->rb_right = new;
119	} else
120	root->rb_node = new;
121	}
122
123	extern void __rb_erase_color(struct rb_node parent, struct rb_root root,
124	void (augment_rotate)(struct rb_node old, struct rb_node *new));
125
3cb7a563 ML	126	static __always_inline struct rb_node *
	127	__rb_erase_augmented(struct rb_node node, struct rb_root root,
	128	const struct rb_augment_callbacks *augment)
9c079add ML	129	{
	130	struct rb_node child = node->rb_right, tmp = node->rb_left;
	131	struct rb_node parent, rebalance;
	132	unsigned long pc;
	133
	134	if (!tmp) {
	135	/*
	136	* Case 1: node to erase has no more than 1 child (easy!)
	137	*
	138	* Note that if there is one child it must be red due to 5)
	139	* and node must be black due to 4). We adjust colors locally
	140	* so as to bypass __rb_erase_color() later on.
	141	*/
	142	pc = node->__rb_parent_color;
	143	parent = __rb_parent(pc);
	144	__rb_change_child(node, child, parent, root);
	145	if (child) {
	146	child->__rb_parent_color = pc;
	147	rebalance = NULL;
	148	} else
	149	rebalance = __rb_is_black(pc) ? parent : NULL;
	150	tmp = parent;
	151	} else if (!child) {
	152	/* Still case 1, but this time the child is node->rb_left */
	153	tmp->__rb_parent_color = pc = node->__rb_parent_color;
	154	parent = __rb_parent(pc);
	155	__rb_change_child(node, tmp, parent, root);
	156	rebalance = NULL;
	157	tmp = parent;
	158	} else {
	159	struct rb_node successor = child, child2;
	160	tmp = child->rb_left;
	161	if (!tmp) {
	162	/*
	163	* Case 2: node's successor is its right child
	164	*
	165	* (n) (s)
	166	* / \ / \
	167	* (x) (s) -> (x) (c)
	168	* \
	169	* (c)
	170	*/
	171	parent = successor;
	172	child2 = successor->rb_right;
	173	augment->copy(node, successor);
	174	} else {
	175	/*
	176	* Case 3: node's successor is leftmost under
	177	* node's right child subtree
	178	*
	179	* (n) (s)
	180	* / \ / \
	181	* (x) (y) -> (x) (y)
	182	* / /
	183	* (p) (p)
	184	* / /
	185	* (s) (c)
	186	* \
	187	* (c)
	188	*/
	189	do {
	190	parent = successor;
	191	successor = tmp;
	192	tmp = tmp->rb_left;
193	} while (tmp);
194	parent->rb_left = child2 = successor->rb_right;
195	successor->rb_right = child;
196	rb_set_parent(child, successor);
197	augment->copy(node, successor);
198	augment->propagate(parent, successor);
199	}
200
201	successor->rb_left = tmp = node->rb_left;
202	rb_set_parent(tmp, successor);
203
204	pc = node->__rb_parent_color;
205	tmp = __rb_parent(pc);
206	__rb_change_child(node, successor, tmp, root);
207	if (child2) {
208	successor->__rb_parent_color = pc;
209	rb_set_parent_color(child2, parent, RB_BLACK);
210	rebalance = NULL;
211	} else {
212	unsigned long pc2 = successor->__rb_parent_color;
213	successor->__rb_parent_color = pc;
214	rebalance = __rb_is_black(pc2) ? parent : NULL;
215	}
216	tmp = successor;
217	}
218
219	augment->propagate(tmp, NULL);
3cb7a563 ML	220	return rebalance;
	221	}
	222
	223	static __always_inline void
	224	rb_erase_augmented(struct rb_node node, struct rb_root root,
	225	const struct rb_augment_callbacks *augment)
	226	{
	227	struct rb_node *rebalance = __rb_erase_augmented(node, root, augment);
9c079add ML	228	if (rebalance)
	229	__rb_erase_color(rebalance, root, augment->rotate);
	230	}
	231
	232	#endif /* _LINUX_RBTREE_AUGMENTED_H */