misc/search.h

   1 /* Declarations for System V style searching functions.
   2    Copyright (C) 1995, 1996, 1997, 1998 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 Library General Public License as
   7    published by the Free Software Foundation; either version 2 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    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library 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 #define __need_NULL
  27 #include <stddef.h>
  28
  29 __BEGIN_DECLS
  30
  31 #if defined __USE_SVID || defined __USE_XOPEN_EXTENDED
  32 /* Prototype structure for a linked-list data structure.
  33    This is the type used by the `insque' and `remque' functions.  */
  34
  35 struct qelem
  36   {
  37     struct qelem *q_forw;
  38     struct qelem *q_back;
  39     char q_data[1];
  40   };
  41
  42
  43 /* Insert ELEM into a doubly-linked list, after PREV.  */
  44 extern void insque __P ((void *__elem, void *__prev));
  45
  46 /* Unlink ELEM from the doubly-linked list that it is in.  */
  47 extern void remque __P ((void *__elem));
  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) __PMT ((__const __ptr_t, __const __ptr_t));
  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     char *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 __P ((ENTRY __item, ACTION __action));
  88
  89 /* Create a new hashing table which will at most contain NEL elements.  */
  90 extern int hcreate __P ((size_t __nel));
  91
  92 /* Destroy current internal hashing table.  */
  93 extern void __hdestroy __P ((void));
  94 extern void hdestroy __P ((void));
  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 __P ((ENTRY __item, ACTION __action, ENTRY **__retval,
 108                            struct hsearch_data *__htab));
 109 extern int hcreate_r __P ((size_t __nel, struct hsearch_data *htab));
 110 extern 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 */
 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 __PMT ((__const void *__key, void **__rootp,
 131                                __compar_fn_t compar));
 132 extern void *tsearch __PMT ((__const void *__key, void **__rootp,
 133                              __compar_fn_t compar));
 134
 135 /* Search for an entry matching the given KEY in the tree pointed to
 136    by *ROOTP.  If no matching entry is available return NULL.  */
 137 extern void *__tfind __PMT ((__const void *__key, void *__const *__rootp,
 138                              __compar_fn_t compar));
 139 extern void *tfind __PMT ((__const void *__key, void *__const *__rootp,
 140                            __compar_fn_t compar));
 141
 142 /* Remove the element matching KEY from the tree pointed to by *ROOTP.  */
 143 extern void *__tdelete __PMT ((__const void *__key, void **__rootp,
 144                                __compar_fn_t compar));
 145 extern void *tdelete __PMT ((__const void *__key, void **__rootp,
 146                              __compar_fn_t compar));
 147
 148 #ifndef __ACTION_FN_T
 149 # define __ACTION_FN_T
 150 typedef void (*__action_fn_t) __PMT ((__const void *__nodep,
 151                                       VISIT __value,
 152                                       int __level));
 153 #endif
 154
 155 /* Walk through the whole tree and call the ACTION callback for every node
 156    or leaf.  */
 157 extern void __twalk __PMT ((__const void *__root, __action_fn_t action));
 158 extern void twalk __PMT ((__const void *__root, __action_fn_t action));
 159
 160 #ifdef __USE_GNU
 161 /* Callback type for function to free a tree node.  If the keys are atomic
 162    data this function should do nothing.  */
 163 typedef void (*__free_fn_t) __PMT ((void *__nodep));
 164
 165 /* Destroy the whole tree, call FREEFCT for each node or leaf.  */
 166 extern void __tdestroy __PMT ((void *__root, __free_fn_t freefct));
 167 extern void tdestroy __PMT ((void *__root, __free_fn_t freefct));
 168 #endif
 169
 170
 171 /* Perform linear search for KEY by comparing by COMPAR in an array
 172    [BASE,BASE+NMEMB*SIZE).  */
 173 extern void *lfind __PMT ((__const void *__key, __const void *__base,
 174                            size_t *__nmemb, size_t __size,
 175                            __compar_fn_t __compar));
 176
 177 /* Perform linear search for KEY by comparing by COMPAR function in
 178    array [BASE,BASE+NMEMB*SIZE) and insert entry if not found.  */
 179 extern void *lsearch __PMT ((__const void *__key, void *__base,
 180                              size_t *__nmemb, size_t __size,
 181                              __compar_fn_t __compar));
 182
 183 __END_DECLS
 184
 185 #endif /* search.h */