1/* A splay-tree datatype.
2   Copyright (C) 1998 Free Software Foundation, Inc.
3   Contributed by Mark Mitchell (mark@markmitchell.com).
4
5This file is part of GNU CC.
6
7GNU CC is free software; you can redistribute it and/or modify it
8under the terms of the GNU General Public License as published by
9the Free Software Foundation; either version 2, or (at your option)
10any later version.
11
12GNU CC is distributed in the hope that it will be useful, but
13WITHOUT ANY WARRANTY; without even the implied warranty of
14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15General Public License for more details.
16
17You should have received a copy of the GNU General Public License
18along with GNU CC; see the file COPYING.  If not, write to
19the Free Software Foundation, 59 Temple Place - Suite 330,
20Boston, MA 02111-1307, USA.  */
21
22/* For an easily readable description of splay-trees, see:
23
24     Lewis, Harry R. and Denenberg, Larry.  Data Structures and Their
25     Algorithms.  Harper-Collins, Inc.  1991.
26
27   The major feature of splay trees is that all basic tree operations
28   are amortized O(log n) time for a tree with n nodes.  */
29
30#ifndef _SPLAY_TREE_H
31#define _SPLAY_TREE_H
32
33#ifdef __cplusplus
34extern "C" {
35#endif /* __cplusplus */
36
37#include <ansidecl.h>
38
39/* Use typedefs for the key and data types to facilitate changing
40   these types, if necessary.  These types should be sufficiently wide
41   that any pointer or scalar can be cast to these types, and then
42   cast back, without loss of precision.  */
43typedef unsigned long int splay_tree_key;
44typedef unsigned long int splay_tree_value;
45
46/* Forward declaration for a node in the tree.  */
47typedef struct splay_tree_node *splay_tree_node;
48
49/* The type of a function which compares two splay-tree keys.  The
50   function should return values as for qsort.  */
51typedef int (*splay_tree_compare_fn) PARAMS((splay_tree_key, splay_tree_key));
52
53/* The type of a function used to deallocate any resources associated
54   with the key.  */
55typedef void (*splay_tree_delete_key_fn) PARAMS((splay_tree_key));
56
57/* The type of a function used to deallocate any resources associated
58   with the value.  */
59typedef void (*splay_tree_delete_value_fn) PARAMS((splay_tree_value));
60
61/* The type of a function used to iterate over the tree.  */
62typedef int (*splay_tree_foreach_fn) PARAMS((splay_tree_node, void*));
63
64/* The nodes in the splay tree.  */
65struct splay_tree_node
66{
67  /* The key.  */
68  splay_tree_key key;
69
70  /* The value.  */
71  splay_tree_value value;
72
73  /* The left and right children, respectively.  */
74  splay_tree_node left;
75  splay_tree_node right;
76};
77
78/* The splay tree itself.  */
79typedef struct splay_tree
80{
81  /* The root of the tree.  */
82  splay_tree_node root;
83
84  /* The comparision function.  */
85  splay_tree_compare_fn comp;
86
87  /* The deallocate-key function.  NULL if no cleanup is necessary.  */
88  splay_tree_delete_key_fn delete_key;
89
90  /* The deallocate-value function.  NULL if no cleanup is necessary.  */
91  splay_tree_delete_value_fn delete_value;
92} *splay_tree;
93
94extern splay_tree splay_tree_new        PARAMS((splay_tree_compare_fn,
95					        splay_tree_delete_key_fn,
96					        splay_tree_delete_value_fn));
97extern void splay_tree_delete           PARAMS((splay_tree));
98extern void splay_tree_insert           PARAMS((splay_tree,
99					        splay_tree_key,
100					        splay_tree_value));
101extern splay_tree_node splay_tree_lookup
102                                        PARAMS((splay_tree,
103					        splay_tree_key));
104extern int splay_tree_foreach           PARAMS((splay_tree,
105					        splay_tree_foreach_fn,
106					        void*));
107extern int splay_tree_compare_ints      PARAMS((splay_tree_key,
108						splay_tree_key));
109extern int splay_tree_compare_pointers  PARAMS((splay_tree_key,
110						splay_tree_key));
111
112#ifdef __cplusplus
113}
114#endif /* __cplusplus */
115
116#endif /* _SPLAY_TREE_H */
117