1/* A splay-tree datatype.
2   Copyright 1998, 1999, 2000, 2002 Free Software Foundation, Inc.
3   Contributed by Mark Mitchell (mark@markmitchell.com).
4
5This file is part of GCC.
6
7GCC 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
12GCC 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 GCC; see the file COPYING.  If not, write to
19the Free Software Foundation, 51 Franklin Street - Fifth Floor,
20Boston, MA 02110-1301, 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#ifndef GTY
40#define GTY(X)
41#endif
42
43/* Use typedefs for the key and data types to facilitate changing
44   these types, if necessary.  These types should be sufficiently wide
45   that any pointer or scalar can be cast to these types, and then
46   cast back, without loss of precision.  */
47typedef unsigned long int splay_tree_key;
48typedef unsigned long int splay_tree_value;
49
50/* Forward declaration for a node in the tree.  */
51typedef struct splay_tree_node_s *splay_tree_node;
52
53/* The type of a function which compares two splay-tree keys.  The
54   function should return values as for qsort.  */
55typedef int (*splay_tree_compare_fn) (splay_tree_key, splay_tree_key);
56
57/* The type of a function used to deallocate any resources associated
58   with the key.  */
59typedef void (*splay_tree_delete_key_fn) (splay_tree_key);
60
61/* The type of a function used to deallocate any resources associated
62   with the value.  */
63typedef void (*splay_tree_delete_value_fn) (splay_tree_value);
64
65/* The type of a function used to iterate over the tree.  */
66typedef int (*splay_tree_foreach_fn) (splay_tree_node, void*);
67
68/* The type of a function used to allocate memory for tree root and
69   node structures.  The first argument is the number of bytes needed;
70   the second is a data pointer the splay tree functions pass through
71   to the allocator.  This function must never return zero.  */
72typedef void *(*splay_tree_allocate_fn) (int, void *);
73
74/* The type of a function used to free memory allocated using the
75   corresponding splay_tree_allocate_fn.  The first argument is the
76   memory to be freed; the latter is a data pointer the splay tree
77   functions pass through to the freer.  */
78typedef void (*splay_tree_deallocate_fn) (void *, void *);
79
80/* The nodes in the splay tree.  */
81struct splay_tree_node_s GTY(())
82{
83  /* The key.  */
84  splay_tree_key GTY ((use_param1)) key;
85
86  /* The value.  */
87  splay_tree_value GTY ((use_param2)) value;
88
89  /* The left and right children, respectively.  */
90  splay_tree_node GTY ((use_params)) left;
91  splay_tree_node GTY ((use_params)) right;
92};
93
94/* The splay tree itself.  */
95struct splay_tree_s GTY(())
96{
97  /* The root of the tree.  */
98  splay_tree_node GTY ((use_params)) root;
99
100  /* The comparision function.  */
101  splay_tree_compare_fn comp;
102
103  /* The deallocate-key function.  NULL if no cleanup is necessary.  */
104  splay_tree_delete_key_fn delete_key;
105
106  /* The deallocate-value function.  NULL if no cleanup is necessary.  */
107  splay_tree_delete_value_fn delete_value;
108
109  /* Allocate/free functions, and a data pointer to pass to them.  */
110  splay_tree_allocate_fn allocate;
111  splay_tree_deallocate_fn deallocate;
112  void * GTY((skip)) allocate_data;
113
114};
115typedef struct splay_tree_s *splay_tree;
116
117extern splay_tree splay_tree_new        (splay_tree_compare_fn,
118                                         splay_tree_delete_key_fn,
119                                         splay_tree_delete_value_fn);
120extern splay_tree splay_tree_new_with_allocator (splay_tree_compare_fn,
121                                                 splay_tree_delete_key_fn,
122					        splay_tree_delete_value_fn,
123                                                 splay_tree_allocate_fn,
124                                                 splay_tree_deallocate_fn,
125                                                 void *);
126extern void splay_tree_delete           (splay_tree);
127extern splay_tree_node splay_tree_insert (splay_tree,
128                                          splay_tree_key,
129                                          splay_tree_value);
130extern void splay_tree_remove	(splay_tree, splay_tree_key);
131extern splay_tree_node splay_tree_lookup (splay_tree, splay_tree_key);
132extern splay_tree_node splay_tree_predecessor (splay_tree, splay_tree_key);
133extern splay_tree_node splay_tree_successor (splay_tree, splay_tree_key);
134extern splay_tree_node splay_tree_max (splay_tree);
135extern splay_tree_node splay_tree_min (splay_tree);
136extern int splay_tree_foreach (splay_tree, splay_tree_foreach_fn, void*);
137extern int splay_tree_compare_ints (splay_tree_key, splay_tree_key);
138extern int splay_tree_compare_pointers (splay_tree_key,	splay_tree_key);
139
140#ifdef __cplusplus
141}
142#endif /* __cplusplus */
143
144#endif /* _SPLAY_TREE_H */
145