/*

  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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  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 dramatically 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

  in two steps: First, the code must insert the element in order as a red leaf

  in the tree, and 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 <stdlib.h>

#include <stdint.h>

#include "compiler.h"

#if __GNUC_PREREQ (4, 6)

#pragma GCC diagnostic push

#pragma GCC diagnostic ignored "-Wunused-function"

#endif

struct rb_node

{

  uintptr_t  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 ext2fs_rb_parent(r)   ((struct rb_node *)((r)->rb_parent_color & ~3))

#define ext2fs_rb_color(r)   ((r)->rb_parent_color & 1)

#define ext2fs_rb_is_red(r)   (!ext2fs_rb_color(r))

#define ext2fs_rb_is_black(r) ext2fs_rb_color(r)

#define ext2fs_rb_set_red(r)  do { (r)->rb_parent_color &= ~1; } while (0)

#define ext2fs_rb_set_black(r)  do { (r)->rb_parent_color |= 1; } while (0)

static inline void ext2fs_rb_set_parent(struct rb_node *rb, struct rb_node *p)

{

  rb->rb_parent_color = (rb->rb_parent_color & 3) | (uintptr_t)p;

}

Unexecuted instantiation: blkmap64_rb.c:ext2fs_rb_set_parent

Unexecuted instantiation: rbtree.c:ext2fs_rb_set_parent

static inline void ext2fs_rb_set_color(struct rb_node *rb, int color)

{

  rb->rb_parent_color = (rb->rb_parent_color & ~1) | color;

}

Unexecuted instantiation: blkmap64_rb.c:ext2fs_rb_set_color

Unexecuted instantiation: rbtree.c:ext2fs_rb_set_color

#define RB_ROOT (struct rb_root) { NULL, }

#define ext2fs_rb_entry(ptr, type, member) container_of(ptr, type, member)

static inline int ext2fs_rb_empty_root(struct rb_root *root)

{

  return root->rb_node == NULL;

}

Unexecuted instantiation: blkmap64_rb.c:ext2fs_rb_empty_root

Unexecuted instantiation: rbtree.c:ext2fs_rb_empty_root

static inline int ext2fs_rb_empty_node(struct rb_node *node)

{

  return ext2fs_rb_parent(node) == node;

}

Unexecuted instantiation: blkmap64_rb.c:ext2fs_rb_empty_node

Unexecuted instantiation: rbtree.c:ext2fs_rb_empty_node

static inline void ext2fs_rb_clear_node(struct rb_node *node)

{

  ext2fs_rb_set_parent(node, node);

}

Unexecuted instantiation: blkmap64_rb.c:ext2fs_rb_clear_node

Unexecuted instantiation: rbtree.c:ext2fs_rb_clear_node

extern void ext2fs_rb_insert_color(struct rb_node *, struct rb_root *);

extern void ext2fs_rb_erase(struct rb_node *, struct rb_root *);

/* Find logical next and previous nodes in a tree */

extern struct rb_node *ext2fs_rb_next(struct rb_node *);

extern struct rb_node *ext2fs_rb_prev(struct rb_node *);

extern struct rb_node *ext2fs_rb_first(const struct rb_root *);

extern struct rb_node *ext2fs_rb_last(const struct rb_root *);

/* Fast replacement of a single node without remove/rebalance/add/rebalance */

extern void ext2fs_rb_replace_node(struct rb_node *victim, struct rb_node *new_,

         struct rb_root *root);

static inline void ext2fs_rb_link_node(struct rb_node * node,

             struct rb_node * parent,

             struct rb_node ** rb_link)

{

  node->rb_parent_color = (uintptr_t)parent;

  node->rb_left = node->rb_right = NULL;

  *rb_link = node;

}

Unexecuted instantiation: blkmap64_rb.c:ext2fs_rb_link_node

Unexecuted instantiation: rbtree.c:ext2fs_rb_link_node

#if __GNUC_PREREQ (4, 6)

#pragma GCC diagnostic pop

#endif

#endif  /* _LINUX_RBTREE_H */