OpenCores
URL https://opencores.org/ocsvn/or1k/or1k/trunk

Subversion Repositories or1k

[/] [or1k/] [trunk/] [insight/] [include/] [hashtab.h] - Blame information for rev 1765

Details | Compare with Previous | View Log

Line No. Rev Author Line
1 578 markom
/* An expandable hash tables datatype.
2
   Copyright (C) 1999, 2000 Free Software Foundation, Inc.
3
   Contributed by Vladimir Makarov (vmakarov@cygnus.com).
4
 
5
This program is free software; you can redistribute it and/or modify
6
it under the terms of the GNU General Public License as published by
7
the Free Software Foundation; either version 2 of the License, or
8
(at your option) any later version.
9
 
10
This program is distributed in the hope that it will be useful,
11
but WITHOUT ANY WARRANTY; without even the implied warranty of
12
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13
GNU General Public License for more details.
14
 
15
You should have received a copy of the GNU General Public License
16
along with this program; if not, write to the Free Software
17
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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
36
extern "C" {
37
#endif /* __cplusplus */
38
 
39
#include <ansidecl.h>
40
 
41
/* The type for a hash code.  */
42
typedef unsigned int hashval_t;
43
 
44
/* Callback function pointer types.  */
45
 
46
/* Calculate hash of a table entry.  */
47
typedef hashval_t (*htab_hash) PARAMS ((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).  */
54
typedef int (*htab_eq) PARAMS ((const void *, const void *));
55
 
56
/* Cleanup function called whenever a live element is removed from
57
   the hash table.  */
58
typedef void (*htab_del) PARAMS ((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.  */
64
typedef int (*htab_trav) PARAMS ((void **, void *));
65
 
66
/* Hash tables are of the following type.  The structure
67
   (implementation) of this type is not needed for using the hash
68
   tables.  All work with hash table should be executed only through
69
   functions mentioned below. */
70
 
71
struct htab
72
{
73
  /* Pointer to hash function.  */
74
  htab_hash hash_f;
75
 
76
  /* Pointer to comparison function.  */
77
  htab_eq eq_f;
78
 
79
  /* Pointer to cleanup function.  */
80
  htab_del del_f;
81
 
82
  /* Table itself.  */
83
  PTR *entries;
84
 
85
  /* Current size (in entries) of the hash table */
86
  size_t size;
87
 
88
  /* Current number of elements including also deleted elements */
89
  size_t n_elements;
90
 
91
  /* Current number of deleted elements in the table */
92
  size_t n_deleted;
93
 
94
  /* The following member is used for debugging. Its value is number
95
     of all calls of `htab_find_slot' for the hash table. */
96
  unsigned int searches;
97
 
98
  /* The following member is used for debugging.  Its value is number
99
     of collisions fixed for time of work with the hash table. */
100
  unsigned int collisions;
101
 
102
  /* This is non-zero if we are allowed to return NULL for function calls
103
     that allocate memory.  */
104
  int return_allocation_failure;
105
};
106
 
107
typedef struct htab *htab_t;
108
 
109
/* An enum saying whether we insert into the hash table or not.  */
110
enum insert_option {NO_INSERT, INSERT};
111
 
112
/* The prototypes of the package functions. */
113
 
114
extern htab_t   htab_create     PARAMS ((size_t, htab_hash,
115
                                         htab_eq, htab_del));
116
 
117
/* This function is like htab_create, but may return NULL if memory
118
   allocation fails, and also signals that htab_find_slot_with_hash and
119
   htab_find_slot are allowed to return NULL when inserting.  */
120
extern htab_t   htab_try_create PARAMS ((size_t, htab_hash,
121
                                         htab_eq, htab_del));
122
extern void     htab_delete     PARAMS ((htab_t));
123
extern void     htab_empty      PARAMS ((htab_t));
124
 
125
extern PTR      htab_find       PARAMS ((htab_t, const void *));
126
extern PTR     *htab_find_slot  PARAMS ((htab_t, const void *,
127
                                         enum insert_option));
128
extern PTR      htab_find_with_hash       PARAMS ((htab_t, const void *,
129
                                                   hashval_t));
130
extern PTR     *htab_find_slot_with_hash  PARAMS ((htab_t, const void *,
131
                                                   hashval_t,
132
                                                   enum insert_option));
133
extern void     htab_clear_slot PARAMS ((htab_t, void **));
134
extern void     htab_remove_elt PARAMS ((htab_t, void *));
135
 
136
extern void     htab_traverse   PARAMS ((htab_t, htab_trav, void *));
137
 
138
extern size_t   htab_size       PARAMS ((htab_t));
139
extern size_t   htab_elements   PARAMS ((htab_t));
140
extern double   htab_collisions PARAMS ((htab_t));
141
 
142
/* A hash function for pointers.  */
143
extern htab_hash htab_hash_pointer;
144
 
145
/* An equality function for pointers.  */
146
extern htab_eq htab_eq_pointer;
147
 
148
#ifdef __cplusplus
149
}
150
#endif /* __cplusplus */
151
 
152
#endif /* __HASHTAB_H */

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.