external/ibm-public/postfix/dist/src/util/dict_ht.c

   1 /*      $NetBSD$        */
   2
   3 /*++
   4 /* NAME
   5 /*      dict_ht 3
   6 /* SUMMARY
   7 /*      dictionary manager interface to hash tables
   8 /* SYNOPSIS
   9 /*      #include <dict_ht.h>
  10 /*
  11 /*      DICT    *dict_ht_open(name, table, remove)
  12 /*      const char *name;
  13 /*      HTABLE  *table;
  14 /*      void    (*remove)(char *value)
  15 /* DESCRIPTION
  16 /*      dict_ht_open() makes specified hash table accessible via the
  17 /*      generic dictionary operations documented in dict_open(3).
  18 /*      \fIremove\fR specifies an optional callback function
  19 /*      that is called by the hash table manager when the hash table is
  20 /*      removed from the dictionary manager's care. The hash table is not
  21 /*      destroyed when \fIremove\fR is a null pointer.
  22 /* SEE ALSO
  23 /*      dict(3) generic dictionary manager
  24 /* LICENSE
  25 /* .ad
  26 /* .fi
  27 /*      The Secure Mailer license must be distributed with this software.
  28 /* AUTHOR(S)
  29 /*      Wietse Venema
  30 /*      IBM T.J. Watson Research
  31 /*      P.O. Box 704
  32 /*      Yorktown Heights, NY 10598, USA
  33 /*--*/
  34
  35 /* System library. */
  36
  37 #include "sys_defs.h"
  38
  39 /* Utility library. */
  40
  41 #include "mymalloc.h"
  42 #include "htable.h"
  43 #include "dict.h"
  44 #include "dict_ht.h"
  45
  46 /* Application-specific. */
  47
  48 typedef struct {
  49     DICT    dict;                       /* generic members */
  50     HTABLE *table;                      /* hash table */
  51     void    (*remove) (char *);         /* callback */
  52 } DICT_HT;
  53
  54 /* dict_ht_lookup - find hash-table entry */
  55
  56 static const char *dict_ht_lookup(DICT *dict, const char *name)
  57 {
  58     DICT_HT *dict_ht = (DICT_HT *) dict;
  59
  60     dict_errno = 0;
  61
  62     return (htable_find(dict_ht->table, name));
  63 }
  64
  65 /* dict_ht_update - add or update hash-table entry */
  66
  67 static void dict_ht_update(DICT *dict, const char *name, const char *value)
  68 {
  69     DICT_HT *dict_ht = (DICT_HT *) dict;
  70     HTABLE_INFO *ht;
  71
  72     if ((ht = htable_locate(dict_ht->table, name)) != 0) {
  73         myfree(ht->value);
  74     } else {
  75         ht = htable_enter(dict_ht->table, name, (char *) 0);
  76     }
  77     ht->value = mystrdup(value);
  78 }
  79
  80 /* dict_ht_close - disassociate from hash table */
  81
  82 static void dict_ht_close(DICT *dict)
  83 {
  84     DICT_HT *dict_ht = (DICT_HT *) dict;
  85
  86     if (dict_ht->remove)
  87         htable_free(dict_ht->table, dict_ht->remove);
  88     dict_free(dict);
  89 }
  90
  91 /* dict_ht_open - create association with hash table */
  92
  93 DICT   *dict_ht_open(const char *name, HTABLE *table, void (*remove) (char *))
  94 {
  95     DICT_HT *dict_ht;
  96
  97     dict_ht = (DICT_HT *) dict_alloc(DICT_TYPE_HT, name, sizeof(*dict_ht));
  98     dict_ht->dict.lookup = dict_ht_lookup;
  99     dict_ht->dict.update = dict_ht_update;
 100     dict_ht->dict.close = dict_ht_close;
 101     dict_ht->table = table;
 102     dict_ht->remove = remove;
 103     return (&dict_ht->dict);
 104 }