1/* Declarations for System V style searching functions.
2   Copyright (C) 1995-1999, 2000 Free Software Foundation, Inc.
3   This file is part of the GNU C Library.
4
5   The GNU C Library is free software; you can redistribute it and/or
6   modify it under the terms of the GNU Lesser General Public License as
7   published by the Free Software Foundation; either version 2.1 of the
8   License, or (at your option) any later version.
9
10   The GNU C Library 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 GNU
13   Lesser General Public License for more details.
14
15   You should have received a copy of the GNU Lesser General Public
16   License along with the GNU C Library; see the file COPYING.LIB.  If not,
17   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18   Boston, MA 02111-1307, USA.  */
19
20#ifndef _SEARCH_H
21#define	_SEARCH_H 1
22
23#include <features.h>
24
25#define __need_size_t
26#include <stddef.h>
27
28__BEGIN_DECLS
29
30#if defined __USE_SVID || defined __USE_XOPEN_EXTENDED
31/* Prototype structure for a linked-list data structure.
32   This is the type used by the `insque' and `remque' functions.  */
33
34# ifdef __USE_GNU
35struct qelem
36  {
37    struct qelem *q_forw;
38    struct qelem *q_back;
39    char q_data[1];
40  };
41# endif
42
43
44/* Insert ELEM into a doubly-linked list, after PREV.  */
45extern void insque __P ((void *__elem, void *__prev));
46
47/* Unlink ELEM from the doubly-linked list that it is in.  */
48extern void remque __P ((void *__elem));
49#endif
50
51
52/* For use with hsearch(3).  */
53#ifndef __COMPAR_FN_T
54# define __COMPAR_FN_T
55typedef int (*__compar_fn_t) __PMT ((__const __ptr_t, __const __ptr_t));
56
57# ifdef	__USE_GNU
58typedef __compar_fn_t comparison_fn_t;
59# endif
60#endif
61
62/* Action which shall be performed in the call the hsearch.  */
63typedef enum
64  {
65    FIND,
66    ENTER
67  }
68ACTION;
69
70typedef struct entry
71  {
72    char *key;
73    void *data;
74  }
75ENTRY;
76
77/* Opaque type for internal use.  */
78struct _ENTRY;
79
80/* Family of hash table handling functions.  The functions also
81   have reentrant counterparts ending with _r.  The non-reentrant
82   functions all work on a single internal hashing table.  */
83
84/* Search for entry matching ITEM.key in internal hash table.  If
85   ACTION is `FIND' return found entry or signal error by returning
86   NULL.  If ACTION is `ENTER' replace existing data (if any) with
87   ITEM.data.  */
88extern ENTRY *hsearch __P ((ENTRY __item, ACTION __action));
89
90/* Create a new hashing table which will at most contain NEL elements.  */
91extern int hcreate __P ((size_t __nel));
92
93/* Destroy current internal hashing table.  */
94extern void hdestroy __P ((void));
95
96#ifdef __USE_GNU
97/* Data type for reentrant functions.  */
98struct hsearch_data
99  {
100    struct _ENTRY *table;
101    unsigned int size;
102    unsigned int filled;
103  };
104
105/* Reentrant versions which can handle multiple hashing tables at the
106   same time.  */
107extern int hsearch_r __P ((ENTRY __item, ACTION __action, ENTRY **__retval,
108			   struct hsearch_data *__htab));
109extern int hcreate_r __P ((size_t __nel, struct hsearch_data *__htab));
110extern void hdestroy_r __P ((struct hsearch_data *__htab));
111#endif
112
113
114/* The tsearch routines are very interesting. They make many
115   assumptions about the compiler.  It assumes that the first field
116   in node must be the "key" field, which points to the datum.
117   Everything depends on that.  */
118/* For tsearch */
119typedef enum
120{
121  preorder,
122  postorder,
123  endorder,
124  leaf
125}
126VISIT;
127
128/* Search for an entry matching the given KEY in the tree pointed to
129   by *ROOTP and insert a new element if not found.  */
130extern void *tsearch __PMT ((__const void *__key, void **__rootp,
131			     __compar_fn_t __compar));
132
133/* Search for an entry matching the given KEY in the tree pointed to
134   by *ROOTP.  If no matching entry is available return NULL.  */
135extern void *tfind __PMT ((__const void *__key, void *__const *__rootp,
136			   __compar_fn_t __compar));
137
138/* Remove the element matching KEY from the tree pointed to by *ROOTP.  */
139extern void *tdelete __PMT ((__const void *__key, void **__rootp,
140			     __compar_fn_t __compar));
141
142#ifndef __ACTION_FN_T
143# define __ACTION_FN_T
144typedef void (*__action_fn_t) __PMT ((__const void *__nodep,
145				      VISIT __value,
146				      int __level));
147#endif
148
149/* Walk through the whole tree and call the ACTION callback for every node
150   or leaf.  */
151extern void twalk __PMT ((__const void *__root, __action_fn_t __action));
152
153#ifdef __USE_GNU
154/* Callback type for function to free a tree node.  If the keys are atomic
155   data this function should do nothing.  */
156typedef void (*__free_fn_t) __PMT ((void *__nodep));
157
158/* Destroy the whole tree, call FREEFCT for each node or leaf.  */
159extern void tdestroy __PMT ((void *__root, __free_fn_t __freefct));
160#endif
161
162
163/* Perform linear search for KEY by comparing by COMPAR in an array
164   [BASE,BASE+NMEMB*SIZE).  */
165extern void *lfind __PMT ((__const void *__key, __const void *__base,
166			   size_t *__nmemb, size_t __size,
167			   __compar_fn_t __compar));
168
169/* Perform linear search for KEY by comparing by COMPAR function in
170   array [BASE,BASE+NMEMB*SIZE) and insert entry if not found.  */
171extern void *lsearch __PMT ((__const void *__key, void *__base,
172			     size_t *__nmemb, size_t __size,
173			     __compar_fn_t __compar));
174
175__END_DECLS
176
177#endif /* search.h */
178