source: arduino-1-6-7/trunk/fuentes/arduino-ide-amd64/hardware/tools/avr/include/libiberty/hashtab.h @ 4837

Last change on this file since 4837 was 4837, checked in by daduve, 2 years ago

Adding new version

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1/* An expandable hash tables datatype. 
2   Copyright (C) 1999-2015 Free Software Foundation, Inc.
3   Contributed by Vladimir Makarov (vmakarov@cygnus.com).
4
5This program is free software; you can redistribute it and/or modify
6it under the terms of the GNU General Public License as published by
7the Free Software Foundation; either version 2 of the License, or
8(at your option) any later version.
9
10This program is distributed in the hope that it will be useful,
11but WITHOUT ANY WARRANTY; without even the implied warranty of
12MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13GNU General Public License for more details.
14
15You should have received a copy of the GNU General Public License
16along with this program; if not, write to the Free Software
17Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */
18
19/* This package implements basic hash table functionality.  It is possible
20   to search for an entry, create an entry and destroy an entry.
21
22   Elements in the table are generic pointers.
23
24   The size of the table is not fixed; if the occupancy of the table
25   grows too high the hash table will be expanded.
26
27   The abstract data implementation is based on generalized Algorithm D
28   from Knuth's book "The art of computer programming".  Hash table is
29   expanded by creation of new hash table and transferring elements from
30   the old table to the new table.  */
31
32#ifndef __HASHTAB_H__
33#define __HASHTAB_H__
34
35#ifdef __cplusplus
36extern "C" {
37#endif /* __cplusplus */
38
39#include "ansidecl.h"
40
41/* The type for a hash code.  */
42typedef unsigned int hashval_t;
43
44/* Callback function pointer types.  */
45
46/* Calculate hash of a table entry.  */
47typedef hashval_t (*htab_hash) (const void *);
48
49/* Compare a table entry with a possible entry.  The entry already in
50   the table always comes first, so the second element can be of a
51   different type (but in this case htab_find and htab_find_slot
52   cannot be used; instead the variants that accept a hash value
53   must be used).  */
54typedef int (*htab_eq) (const void *, const void *);
55
56/* Cleanup function called whenever a live element is removed from
57   the hash table.  */
58typedef void (*htab_del) (void *);
59 
60/* Function called by htab_traverse for each live element.  The first
61   arg is the slot of the element (which can be passed to htab_clear_slot
62   if desired), the second arg is the auxiliary pointer handed to
63   htab_traverse.  Return 1 to continue scan, 0 to stop.  */
64typedef int (*htab_trav) (void **, void *);
65
66/* Memory-allocation function, with the same functionality as calloc().
67   Iff it returns NULL, the hash table implementation will pass an error
68   code back to the user, so if your code doesn't handle errors,
69   best if you use xcalloc instead.  */
70typedef void *(*htab_alloc) (size_t, size_t);
71
72/* We also need a free() routine.  */
73typedef void (*htab_free) (void *);
74
75/* Memory allocation and deallocation; variants which take an extra
76   argument.  */
77typedef void *(*htab_alloc_with_arg) (void *, size_t, size_t);
78typedef void (*htab_free_with_arg) (void *, void *);
79
80/* This macro defines reserved value for empty table entry.  */
81
82#define HTAB_EMPTY_ENTRY    ((PTR) 0)
83
84/* This macro defines reserved value for table entry which contained
85   a deleted element. */
86
87#define HTAB_DELETED_ENTRY  ((PTR) 1)
88
89/* Hash tables are of the following type.  The structure
90   (implementation) of this type is not needed for using the hash
91   tables.  All work with hash table should be executed only through
92   functions mentioned below.  The size of this structure is subject to
93   change.  */
94
95struct htab {
96  /* Pointer to hash function.  */
97  htab_hash hash_f;
98
99  /* Pointer to comparison function.  */
100  htab_eq eq_f;
101
102  /* Pointer to cleanup function.  */
103  htab_del del_f;
104
105  /* Table itself.  */
106  void **entries;
107
108  /* Current size (in entries) of the hash table.  */
109  size_t size;
110
111  /* Current number of elements including also deleted elements.  */
112  size_t n_elements;
113
114  /* Current number of deleted elements in the table.  */
115  size_t n_deleted;
116
117  /* The following member is used for debugging. Its value is number
118     of all calls of `htab_find_slot' for the hash table. */
119  unsigned int searches;
120
121  /* The following member is used for debugging.  Its value is number
122     of collisions fixed for time of work with the hash table. */
123  unsigned int collisions;
124
125  /* Pointers to allocate/free functions.  */
126  htab_alloc alloc_f;
127  htab_free free_f;
128
129  /* Alternate allocate/free functions, which take an extra argument.  */
130  void *alloc_arg;
131  htab_alloc_with_arg alloc_with_arg_f;
132  htab_free_with_arg free_with_arg_f;
133
134  /* Current size (in entries) of the hash table, as an index into the
135     table of primes.  */
136  unsigned int size_prime_index;
137};
138
139typedef struct htab *htab_t;
140
141/* An enum saying whether we insert into the hash table or not.  */
142enum insert_option {NO_INSERT, INSERT};
143
144/* The prototypes of the package functions. */
145
146extern htab_t   htab_create_alloc  (size_t, htab_hash,
147                                    htab_eq, htab_del,
148                                    htab_alloc, htab_free);
149
150extern htab_t   htab_create_alloc_ex (size_t, htab_hash,
151                                      htab_eq, htab_del,
152                                      void *, htab_alloc_with_arg,
153                                      htab_free_with_arg);
154
155extern htab_t  htab_create_typed_alloc (size_t, htab_hash, htab_eq, htab_del,
156                                        htab_alloc, htab_alloc, htab_free);
157
158/* Backward-compatibility functions.  */
159extern htab_t htab_create (size_t, htab_hash, htab_eq, htab_del);
160extern htab_t htab_try_create (size_t, htab_hash, htab_eq, htab_del);
161
162extern void     htab_set_functions_ex (htab_t, htab_hash,
163                                       htab_eq, htab_del,
164                                       void *, htab_alloc_with_arg,
165                                       htab_free_with_arg);
166
167extern void     htab_delete (htab_t);
168extern void     htab_empty (htab_t);
169
170extern void *   htab_find (htab_t, const void *);
171extern void **  htab_find_slot (htab_t, const void *, enum insert_option);
172extern void *   htab_find_with_hash (htab_t, const void *, hashval_t);
173extern void **  htab_find_slot_with_hash (htab_t, const void *,
174                                          hashval_t, enum insert_option);
175extern void     htab_clear_slot (htab_t, void **);
176extern void     htab_remove_elt (htab_t, void *);
177extern void     htab_remove_elt_with_hash (htab_t, void *, hashval_t);
178
179extern void     htab_traverse (htab_t, htab_trav, void *);
180extern void     htab_traverse_noresize (htab_t, htab_trav, void *);
181
182extern size_t   htab_size (htab_t);
183extern size_t   htab_elements (htab_t);
184extern double   htab_collisions (htab_t);
185
186/* A hash function for pointers.  */
187extern htab_hash htab_hash_pointer;
188
189/* An equality function for pointers.  */
190extern htab_eq htab_eq_pointer;
191
192/* A hash function for null-terminated strings.  */
193extern hashval_t htab_hash_string (const void *);
194
195/* An iterative hash function for arbitrary data.  */
196extern hashval_t iterative_hash (const void *, size_t, hashval_t);
197/* Shorthand for hashing something with an intrinsic size.  */
198#define iterative_hash_object(OB,INIT) iterative_hash (&OB, sizeof (OB), INIT)
199
200#ifdef __cplusplus
201}
202#endif /* __cplusplus */
203
204#endif /* __HASHTAB_H */
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