/*
Libraries for fields, doubly-linked lists and red-black trees.
Copyright (C) 2001 James S. Plank

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library 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
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

---------------------------------------------------------------------------
Please see http://www.cs.utk.edu/~plank/plank/classes/cs360/360/notes/Libfdr/
for instruction on how to use this library.

Jim Plank
plank@cs.utk.edu
http://www.cs.utk.edu/~plank

Associate Professor
Department of Computer Science
University of Tennessee
203 Claxton Complex
1122 Volunteer Blvd.
Knoxville, TN 37996-3450

     865-974-4397
Fax: 865-974-4404
 */
#ifndef	_JRB_H_
#define	_JRB_H_

/* Main jrb_node.  You only ever use the fields
   flink
   blink
   k.key or k.ikey
   v.val
*/


typedef struct jrb_node {
  unsigned char red;
  unsigned char internal;
  unsigned char left;
  unsigned char roothead;  /* (bit 1 is root, bit 2 is head) */
  struct jrb_node *flink;
  struct jrb_node *blink;
  struct jrb_node *parent;
  void *key;
  void *val;
} *JRB;


extern JRB make_jrb(void);   /* Creates a new rb-tree */


/* Creates a node with key key and val val and inserts it into the tree.
   jrb_insert uses strcmp() as comparison funcion.  jrb_inserti uses <>=,
   jrb_insertg uses func() */

extern JRB jrb_insert_gen(JRB tree, void *key, void *val,
    int (*func)(const void *, const void *));

/* returns an external node in t whose value is equal k. Returns NULL if
   there is no such node in the tree */

extern JRB jrb_find_gen(JRB root, const void *,
    int (*func)(const void *, const void *));

/* returns an external node in t whose value is equal
  k or whose value is the smallest value greater than k. Sets found to
  1 if the key was found, and 0 otherwise.  */

extern JRB jrb_find_gte_gen(JRB root, const void *key, 
    int (*func)(const void *, const void *), int *found);


/* Creates a node with key key and val val and inserts it into the 
   tree before/after node nd.  Does not check to ensure that you are 
   keeping the correct order */

extern void jrb_delete_node(JRB node);  /* Deletes and frees a node (but 
                                              not the key or val) */
extern void jrb_free_tree(JRB root);  /* Deletes and frees an entire tree */

extern void *jrb_val(JRB node);  /* Returns node->v.val -- this is to shut
                                       lint up */

extern int jrb_nblack(JRB n); /* returns # of black nodes in path from
                                    n to the root */
int jrb_plength(JRB n);       /* returns the # of nodes in path from
				    n to the root */
 
#define jrb_first(n) ((n)->flink)
#define jrb_last(n) ((n)->blink)
#define jrb_next(n) ((n)->flink)
#define jrb_prev(n) ((n)->blink)
#define jrb_empty(t) ((t)->flink == (t))
#ifndef jrb_nil
#define jrb_nil(t) (t)
#endif
 
#define jrb_traverse(ptr, lst) \
  for(ptr = jrb_first(lst); ptr != jrb_nil(lst); ptr = jrb_next(ptr))
 
#define jrb_rtraverse(ptr, lst) \
  for(ptr = jrb_last(lst); ptr != jrb_nil(lst); ptr = jrb_prev(ptr))
 
#endif