1/* A splay-tree datatype.
2   Copyright (C) 1998-2022 Free Software Foundation, Inc.
3   Contributed by Mark Mitchell (mark@markmitchell.com).
4
5   This file is part of GCC.
6
7   GCC is free software; you can redistribute it and/or modify it
8   under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 2, or (at your option)
10   any later version.
11
12   GCC is distributed in the hope that it will be useful, but
13   WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15   General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with GCC; see the file COPYING.  If not, write to
19   the Free Software Foundation, 51 Franklin Street - Fifth Floor,
20   Boston, 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#ifdef HAVE_STDINT_H
40#include <stdint.h>
41#endif
42#ifdef HAVE_INTTYPES_H
43#include <inttypes.h>
44#endif
45
46/* Use typedefs for the key and data types to facilitate changing
47   these types, if necessary.  These types should be sufficiently wide
48   that any pointer or scalar can be cast to these types, and then
49   cast back, without loss of precision.  */
50typedef uintptr_t splay_tree_key;
51typedef uintptr_t splay_tree_value;
52
53/* Forward declaration for a node in the tree.  */
54typedef struct splay_tree_node_s *splay_tree_node;
55
56/* The type of a function which compares two splay-tree keys.  The
57   function should return values as for qsort.  */
58typedef int (*splay_tree_compare_fn) (splay_tree_key, splay_tree_key);
59
60/* The type of a function used to deallocate any resources associated
61   with the key.  If you provide this function, the splay tree
62   will take the ownership of the memory of the splay_tree_key arg
63   of splay_tree_insert.  This function is called to release the keys
64   present in the tree when calling splay_tree_delete or splay_tree_remove.
65   If splay_tree_insert is called with a key equal to a key already
66   present in the tree, the old key and old value will be released.  */
67typedef void (*splay_tree_delete_key_fn) (splay_tree_key);
68
69/* The type of a function used to deallocate any resources associated
70   with the value.  If you provide this function, the memory of the
71   splay_tree_value arg of splay_tree_insert is managed similarly to
72   the splay_tree_key memory: see splay_tree_delete_key_fn.  */
73typedef void (*splay_tree_delete_value_fn) (splay_tree_value);
74
75/* The type of a function used to iterate over the tree.  */
76typedef int (*splay_tree_foreach_fn) (splay_tree_node, void*);
77
78/* The type of a function used to allocate memory for tree root and
79   node structures.  The first argument is the number of bytes needed;
80   the second is a data pointer the splay tree functions pass through
81   to the allocator.  This function must never return zero.  */
82typedef void *(*splay_tree_allocate_fn) (int, void *);
83
84/* The type of a function used to free memory allocated using the
85   corresponding splay_tree_allocate_fn.  The first argument is the
86   memory to be freed; the latter is a data pointer the splay tree
87   functions pass through to the freer.  */
88typedef void (*splay_tree_deallocate_fn) (void *, void *);
89
90/* The nodes in the splay tree.  */
91struct splay_tree_node_s {
92  /* The key.  */
93  splay_tree_key key;
94
95  /* The value.  */
96  splay_tree_value value;
97
98  /* The left and right children, respectively.  */
99  splay_tree_node left;
100  splay_tree_node right;
101};
102
103/* The splay tree itself.  */
104struct splay_tree_s {
105  /* The root of the tree.  */
106  splay_tree_node root;
107
108  /* The comparision function.  */
109  splay_tree_compare_fn comp;
110
111  /* The deallocate-key function.  NULL if no cleanup is necessary.  */
112  splay_tree_delete_key_fn delete_key;
113
114  /* The deallocate-value function.  NULL if no cleanup is necessary.  */
115  splay_tree_delete_value_fn delete_value;
116
117  /* Node allocate function.  Takes allocate_data as a parameter. */
118  splay_tree_allocate_fn allocate;
119
120  /* Free function for nodes and trees.  Takes allocate_data as a parameter.  */
121  splay_tree_deallocate_fn deallocate;
122
123  /* Parameter for allocate/free functions.  */
124  void *allocate_data;
125};
126
127typedef struct splay_tree_s *splay_tree;
128
129extern splay_tree splay_tree_new (splay_tree_compare_fn,
130				  splay_tree_delete_key_fn,
131				  splay_tree_delete_value_fn);
132extern splay_tree splay_tree_new_with_allocator (splay_tree_compare_fn,
133						 splay_tree_delete_key_fn,
134						 splay_tree_delete_value_fn,
135						 splay_tree_allocate_fn,
136						 splay_tree_deallocate_fn,
137						 void *);
138extern splay_tree splay_tree_new_typed_alloc (splay_tree_compare_fn,
139					      splay_tree_delete_key_fn,
140					      splay_tree_delete_value_fn,
141					      splay_tree_allocate_fn,
142					      splay_tree_allocate_fn,
143					      splay_tree_deallocate_fn,
144					      void *);
145extern void splay_tree_delete (splay_tree);
146extern splay_tree_node splay_tree_insert (splay_tree,
147					  splay_tree_key,
148					  splay_tree_value);
149extern void splay_tree_remove	(splay_tree, splay_tree_key);
150extern splay_tree_node splay_tree_lookup (splay_tree, splay_tree_key);
151extern splay_tree_node splay_tree_predecessor (splay_tree, splay_tree_key);
152extern splay_tree_node splay_tree_successor (splay_tree, splay_tree_key);
153extern splay_tree_node splay_tree_max (splay_tree);
154extern splay_tree_node splay_tree_min (splay_tree);
155extern int splay_tree_foreach (splay_tree, splay_tree_foreach_fn, void*);
156extern int splay_tree_compare_ints (splay_tree_key, splay_tree_key);
157extern int splay_tree_compare_pointers (splay_tree_key, splay_tree_key);
158extern int splay_tree_compare_strings (splay_tree_key, splay_tree_key);
159extern void splay_tree_delete_pointers (splay_tree_value);
160
161#ifdef __cplusplus
162}
163#endif /* __cplusplus */
164
165#endif /* _SPLAY_TREE_H */
166