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 7 License as published by the Free Software Foundation; either 8 version 2.1 of the 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; if not, see 17 <http://www.gnu.org/licenses/>. */ 18 19 #ifndef _SEARCH_H 20 #define _SEARCH_H 1 21 22 #include <features.h> 23 24 #define __need_size_t 25 #include <stddef.h> 26 27 __BEGIN_DECLS 28 29 #if defined __USE_SVID || defined __USE_XOPEN_EXTENDED 30 /* Prototype structure for a linked-list data structure. 31 This is the type used by the `insque' and `remque' functions. */ 32 33 # ifdef __USE_GNU 34 struct qelem 35 { 36 struct qelem *q_forw; 37 struct qelem *q_back; 38 char q_data[1]; 39 }; 40 # endif 41 42 43 /* Insert ELEM into a doubly-linked list, after PREV. */ 44 extern void insque (void *__elem, void *__prev) __THROW; 45 46 /* Unlink ELEM from the doubly-linked list that it is in. */ 47 extern void remque (void *__elem) __THROW; 48 #endif 49 50 51 /* For use with hsearch(3). */ 52 #ifndef __COMPAR_FN_T 53 # define __COMPAR_FN_T 54 typedef int (*__compar_fn_t) (const void *, const void *); 55 56 # ifdef __USE_GNU 57 typedef __compar_fn_t comparison_fn_t; 58 # endif 59 #endif 60 61 /* Action which shall be performed in the call the hsearch. */ 62 typedef enum 63 { 64 FIND, 65 ENTER 66 } 67 ACTION; 68 69 typedef struct entry 70 { 71 char *key; 72 void *data; 73 } 74 ENTRY; 75 76 /* Opaque type for internal use. */ 77 struct _ENTRY; 78 79 /* Family of hash table handling functions. The functions also 80 have reentrant counterparts ending with _r. The non-reentrant 81 functions all work on a signle internal hashing table. */ 82 83 /* Search for entry matching ITEM.key in internal hash table. If 84 ACTION is `FIND' return found entry or signal error by returning 85 NULL. If ACTION is `ENTER' replace existing data (if any) with 86 ITEM.data. */ 87 extern ENTRY *hsearch (ENTRY __item, ACTION __action) __THROW; 88 89 /* Create a new hashing table which will at most contain NEL elements. */ 90 extern int hcreate (size_t __nel) __THROW; 91 92 /* Destroy current internal hashing table. */ 93 extern void hdestroy (void) __THROW; 94 95 #ifdef __USE_GNU 96 /* Data type for reentrant functions. */ 97 struct hsearch_data 98 { 99 struct _ENTRY *table; 100 unsigned int size; 101 unsigned int filled; 102 }; 103 104 /* Reentrant versions which can handle multiple hashing tables at the 105 same time. */ 106 extern int hsearch_r (ENTRY __item, ACTION __action, ENTRY **__retval, 107 struct hsearch_data *__htab) __THROW; 108 libc_hidden_proto(hsearch_r) 109 extern int hcreate_r (size_t __nel, struct hsearch_data *__htab) __THROW; 110 libc_hidden_proto(hcreate_r) 111 extern void hdestroy_r (struct hsearch_data *__htab) __THROW; 112 libc_hidden_proto(hdestroy_r) 113 #endif 114 115 116 /* The tsearch routines are very interesting. They make many 117 assumptions about the compiler. It assumes that the first field 118 in node must be the "key" field, which points to the datum. 119 Everything depends on that. */ 120 /* For tsearch */ 121 typedef enum 122 { 123 preorder, 124 postorder, 125 endorder, 126 leaf 127 } 128 VISIT; 129 130 /* Search for an entry matching the given KEY in the tree pointed to 131 by *ROOTP and insert a new element if not found. */ 132 extern void *tsearch (const void *__key, void **__rootp, 133 __compar_fn_t __compar); 134 libc_hidden_proto(tsearch) 135 136 /* Search for an entry matching the given KEY in the tree pointed to 137 by *ROOTP. If no matching entry is available return NULL. */ 138 extern void *tfind (const void *__key, void *const *__rootp, 139 __compar_fn_t __compar); 140 libc_hidden_proto(tfind) 141 142 /* Remove the element matching KEY from the tree pointed to by *ROOTP. */ 143 extern void *tdelete (const void *__restrict __key, 144 void **__restrict __rootp, 145 __compar_fn_t __compar); 146 147 #ifndef __ACTION_FN_T 148 # define __ACTION_FN_T 149 typedef void (*__action_fn_t) (const void *__nodep, VISIT __value, 150 int __level); 151 #endif 152 153 /* Walk through the whole tree and call the ACTION callback for every node 154 or leaf. */ 155 extern void twalk (const void *__root, __action_fn_t __action); 156 157 #ifdef __USE_GNU 158 /* Callback type for function to free a tree node. If the keys are atomic 159 data this function should do nothing. */ 160 typedef void (*__free_fn_t) (void *__nodep); 161 162 /* Destroy the whole tree, call FREEFCT for each node or leaf. */ 163 extern void tdestroy (void *__root, __free_fn_t __freefct); 164 libc_hidden_proto(tdestroy) 165 #endif 166 167 168 /* Perform linear search for KEY by comparing by COMPAR in an array 169 [BASE,BASE+NMEMB*SIZE). */ 170 extern void *lfind (const void *__key, const void *__base, 171 size_t *__nmemb, size_t __size, __compar_fn_t __compar); 172 libc_hidden_proto(lfind) 173 174 /* Perform linear search for KEY by comparing by COMPAR function in 175 array [BASE,BASE+NMEMB*SIZE) and insert entry if not found. */ 176 extern void *lsearch (const void *__key, void *__base, 177 size_t *__nmemb, size_t __size, __compar_fn_t __compar); 178 179 __END_DECLS 180 181 #endif /* search.h */ 182