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, 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#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) PARAMS((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) PARAMS((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) PARAMS((splay_tree_value));
64
65/* The type of a function used to iterate over the tree.  */
66typedef int (*splay_tree_foreach_fn) PARAMS((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 PTR (*splay_tree_allocate_fn) PARAMS((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) PARAMS((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  PTR GTY((skip)) allocate_data;
113
114};
115typedef struct splay_tree_s *splay_tree;
116
117extern splay_tree splay_tree_new        PARAMS((splay_tree_compare_fn,
118					        splay_tree_delete_key_fn,
119					        splay_tree_delete_value_fn));
120extern splay_tree splay_tree_new_with_allocator
121                                        PARAMS((splay_tree_compare_fn,
122					        splay_tree_delete_key_fn,
123					        splay_tree_delete_value_fn,
124                                                splay_tree_allocate_fn,
125                                                splay_tree_deallocate_fn,
126                                                void *));
127extern void splay_tree_delete           PARAMS((splay_tree));
128extern splay_tree_node splay_tree_insert
129		                        PARAMS((splay_tree,
130					        splay_tree_key,
131					        splay_tree_value));
132extern void splay_tree_remove		PARAMS((splay_tree,
133						splay_tree_key));
134extern splay_tree_node splay_tree_lookup
135                                        PARAMS((splay_tree,
136					        splay_tree_key));
137extern splay_tree_node splay_tree_predecessor
138                                        PARAMS((splay_tree,
139						splay_tree_key));
140extern splay_tree_node splay_tree_successor
141                                        PARAMS((splay_tree,
142						splay_tree_key));
143extern splay_tree_node splay_tree_max
144                                        PARAMS((splay_tree));
145extern splay_tree_node splay_tree_min
146                                        PARAMS((splay_tree));
147extern int splay_tree_foreach           PARAMS((splay_tree,
148					        splay_tree_foreach_fn,
149					        void*));
150extern int splay_tree_compare_ints      PARAMS((splay_tree_key,
151						splay_tree_key));
152extern int splay_tree_compare_pointers  PARAMS((splay_tree_key,
153						splay_tree_key));
154
155#ifdef __cplusplus
156}
157#endif /* __cplusplus */
158
159#endif /* _SPLAY_TREE_H */
160