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, write to the Free 17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 18 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 35 struct 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. */ 45 extern void insque (void *__elem, void *__prev) __THROW; 46 47 /* Unlink ELEM from the doubly-linked list that it is in. */ 48 extern void remque (void *__elem) __THROW; 49 #endif 50 51 52 /* For use with hsearch(3). */ 53 #ifndef __COMPAR_FN_T 54 # define __COMPAR_FN_T 55 typedef int (*__compar_fn_t) (__const void *, __const void *); 56 57 # ifdef __USE_GNU 58 typedef __compar_fn_t comparison_fn_t; 59 # endif 60 #endif 61 62 /* Action which shall be performed in the call the hsearch. */ 63 typedef enum 64 { 65 FIND, 66 ENTER 67 } 68 ACTION; 69 70 typedef struct entry 71 { 72 char *key; 73 void *data; 74 } 75 ENTRY; 76 77 /* Opaque type for internal use. */ 78 struct _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 signle 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. */ 88 extern ENTRY *hsearch (ENTRY __item, ACTION __action) __THROW; 89 90 /* Create a new hashing table which will at most contain NEL elements. */ 91 extern int hcreate (size_t __nel) __THROW; 92 93 /* Destroy current internal hashing table. */ 94 extern void hdestroy (void) __THROW; 95 96 #ifdef __USE_GNU 97 /* Data type for reentrant functions. */ 98 struct 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. */ 107 extern int hsearch_r (ENTRY __item, ACTION __action, ENTRY **__retval, 108 struct hsearch_data *__htab) __THROW; 109 extern int hcreate_r (size_t __nel, struct hsearch_data *__htab) __THROW; 110 extern void hdestroy_r (struct hsearch_data *__htab) __THROW; 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 */ 119 typedef enum 120 { 121 preorder, 122 postorder, 123 endorder, 124 leaf 125 } 126 VISIT; 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. */ 130 extern void *tsearch (__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. */ 135 extern void *tfind (__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. */ 139 extern void *tdelete (__const void *__restrict __key, 140 void **__restrict __rootp, 141 __compar_fn_t __compar); 142 143 #ifndef __ACTION_FN_T 144 # define __ACTION_FN_T 145 typedef void (*__action_fn_t) (__const void *__nodep, 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. */ 151 extern void twalk (__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. */ 156 typedef void (*__free_fn_t) (void *__nodep); 157 158 /* Destroy the whole tree, call FREEFCT for each node or leaf. */ 159 extern void tdestroy (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). */ 165 extern void *lfind (__const void *__key, __const void *__base, 166 size_t *__nmemb, size_t __size, __compar_fn_t __compar); 167 168 /* Perform linear search for KEY by comparing by COMPAR function in 169 array [BASE,BASE+NMEMB*SIZE) and insert entry if not found. */ 170 extern void *lsearch (__const void *__key, void *__base, 171 size_t *__nmemb, size_t __size, __compar_fn_t __compar); 172 173 __END_DECLS 174 175 #endif /* search.h */ 176
