File: /Users/paulross/dev/linux/linux-3.13/include/linux/rbtree.h

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       1: /*
       2:   Red Black Trees
       3:   (C) 1999  Andrea Arcangeli <andrea@suse.de>
       4:   
       5:   This program is free software; you can redistribute it and/or modify
       6:   it under the terms of the GNU General Public License as published by
       7:   the Free Software Foundation; either version 2 of the License, or
       8:   (at your option) any later version.
       9: 
      10:   This program is distributed in the hope that it will be useful,
      11:   but WITHOUT ANY WARRANTY; without even the implied warranty of
      12:   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      13:   GNU General Public License for more details.
      14: 
      15:   You should have received a copy of the GNU General Public License
      16:   along with this program; if not, write to the Free Software
      17:   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
      18: 
      19:   linux/include/linux/rbtree.h
      20: 
      21:   To use rbtrees you'll have to implement your own insert and search cores.
      22:   This will avoid us to use callbacks and to drop drammatically performances.
      23:   I know it's not the cleaner way,  but in C (not in C++) to get
      24:   performances and genericity...
      25: 
      26:   See Documentation/rbtree.txt for documentation and samples.
      27: */
      28: 
      29: #ifndef    _LINUX_RBTREE_H
      30: #define    _LINUX_RBTREE_H
      31: 
      32: #include <linux/kernel.h>
      33: #include <linux/stddef.h>
      34: 
      35: struct rb_node {
      36:     unsigned long  __rb_parent_color;
      37:     struct rb_node *rb_right;
      38:     struct rb_node *rb_left;
      39: } __attribute__((aligned(sizeof(long))));
      40:     /* The alignment might seem pointless, but allegedly CRIS needs it */
      41: 
      42: struct rb_root {
      43:     struct rb_node *rb_node;
      44: };
      45: 
      46: 
      47: #define rb_parent(r)   ((struct rb_node *)((r)->__rb_parent_color & ~3))
      48: 
      49: #define RB_ROOT    (struct rb_root) { NULL, }
      50: #define    rb_entry(ptr, type, member) container_of(ptr, type, member)
      51: 
      52: #define RB_EMPTY_ROOT(root)  ((root)->rb_node == NULL)
      53: 
      54: /* 'empty' nodes are nodes that are known not to be inserted in an rbree */
      55: #define RB_EMPTY_NODE(node)  \
      56:     ((node)->__rb_parent_color == (unsigned long)(node))
      57: #define RB_CLEAR_NODE(node)  \
      58:     ((node)->__rb_parent_color = (unsigned long)(node))
      59: 
      60: 
      61: extern void rb_insert_color(struct rb_node *, struct rb_root *);
      62: extern void rb_erase(struct rb_node *, struct rb_root *);
      63: 
      64: 
      65: /* Find logical next and previous nodes in a tree */
      66: extern struct rb_node *rb_next(const struct rb_node *);
      67: extern struct rb_node *rb_prev(const struct rb_node *);
      68: extern struct rb_node *rb_first(const struct rb_root *);
      69: extern struct rb_node *rb_last(const struct rb_root *);
      70: 
      71: /* Postorder iteration - always visit the parent after its children */
      72: extern struct rb_node *rb_first_postorder(const struct rb_root *);
      73: extern struct rb_node *rb_next_postorder(const struct rb_node *);
      74: 
      75: /* Fast replacement of a single node without remove/rebalance/add/rebalance */
      76: extern void rb_replace_node(struct rb_node *victim, struct rb_node *new, 
      77:                 struct rb_root *root);
      78: 
      79: static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,
      80:                 struct rb_node ** rb_link)
      81: {
      82:     node->__rb_parent_color = (unsigned long)parent;
      83:     node->rb_left = node->rb_right = NULL;
      84: 
      85:     *rb_link = node;
      86: }
      87: 
      88: #define rb_entry_safe(ptr, type, member) \
      89:     ({ typeof(ptr) ____ptr = (ptr); \
      90:        ____ptr ? rb_entry(____ptr, type, member) : NULL; \
      91:     })
      92: 
      93: /**
      94:  * rbtree_postorder_for_each_entry_safe - iterate over rb_root in post order of
      95:  * given type safe against removal of rb_node entry
      96:  *
      97:  * @pos:    the 'type *' to use as a loop cursor.
      98:  * @n:        another 'type *' to use as temporary storage
      99:  * @root:    'rb_root *' of the rbtree.
     100:  * @field:    the name of the rb_node field within 'type'.
     101:  */
     102: #define rbtree_postorder_for_each_entry_safe(pos, n, root, field) \
     103:     for (pos = rb_entry_safe(rb_first_postorder(root), typeof(*pos), field); \
     104:          pos && ({ n = rb_entry_safe(rb_next_postorder(&pos->field), \
     105:             typeof(*pos), field); 1; }); \
     106:          pos = n)
     107: 
     108: #endif    /* _LINUX_RBTREE_H */
     109: