contrib/bind-9.2.4rc7/lib/isccc/include/isccc/symtab.h

   1 /*
   2  * Portions Copyright (C) 2004  Internet Systems Consortium, Inc. ("ISC")
   3  * Portions Copyright (C) 2001  Internet Software Consortium.
   4  * Portions Copyright (C) 2001  Nominum, Inc.
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
  11  * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  12  * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
  13  * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 /* $Id: symtab.h,v 1.2.2.1 2004/03/09 06:12:28 marka Exp $ */
  20
  21 #ifndef ISCCC_SYMTAB_H
  22 #define ISCCC_SYMTAB_H 1
  23
  24 /*****
  25  ***** Module Info
  26  *****/
  27
  28 /*
  29  * Symbol Table
  30  *
  31  * Provides a simple memory-based symbol table.
  32  *
  33  * Keys are C strings.  A type may be specified when looking up,
  34  * defining, or undefining.  A type value of 0 means "match any type";
  35  * any other value will only match the given type.
  36  *
  37  * It's possible that a client will attempt to define a <key, type,
  38  * value> tuple when a tuple with the given key and type already
  39  * exists in the table.  What to do in this case is specified by the
  40  * client.  Possible policies are:
  41  *
  42  *      isccc_symexists_reject  Disallow the define, returning ISC_R_EXISTS
  43  *      isccc_symexists_replace Replace the old value with the new.  The
  44  *                              undefine action (if provided) will be called
  45  *                              with the old <key, type, value> tuple.
  46  *      isccc_symexists_add     Add the new tuple, leaving the old tuple in
  47  *                              the table.  Subsequent lookups will retrieve
  48  *                              the most-recently-defined tuple.
  49  *
  50  * A lookup of a key using type 0 will return the most-recently
  51  * defined symbol with that key.  An undefine of a key using type 0
  52  * will undefine the most-recently defined symbol with that key.
  53  * Trying to define a key with type 0 is illegal.
  54  *
  55  * The symbol table library does not make a copy the key field, so the
  56  * caller must ensure that any key it passes to isccc_symtab_define()
  57  * will not change until it calls isccc_symtab_undefine() or
  58  * isccc_symtab_destroy().
  59  *
  60  * A user-specified action will be called (if provided) when a symbol
  61  * is undefined.  It can be used to free memory associated with keys
  62  * and/or values.
  63  */
  64
  65 /***
  66  *** Imports.
  67  ***/
  68
  69 #include <isc/lang.h>
  70 #include <isccc/types.h>
  71
  72 /***
  73  *** Symbol Tables.
  74  ***/
  75
  76 typedef union isccc_symvalue {
  77         void *                          as_pointer;
  78         int                             as_integer;
  79         unsigned int                    as_uinteger;
  80 } isccc_symvalue_t;
  81
  82 typedef void (*isccc_symtabundefaction_t)(char *key, unsigned int type,
  83                                         isccc_symvalue_t value, void *userarg);
  84
  85 typedef isc_boolean_t (*isccc_symtabforeachaction_t)(char *key,
  86                                                    unsigned int type,
  87                                                    isccc_symvalue_t value,
  88                                                    void *userarg);
  89
  90 typedef enum {
  91         isccc_symexists_reject = 0,
  92         isccc_symexists_replace = 1,
  93         isccc_symexists_add = 2
  94 } isccc_symexists_t;
  95
  96 ISC_LANG_BEGINDECLS
  97
  98 isc_result_t
  99 isccc_symtab_create(unsigned int size,
 100                   isccc_symtabundefaction_t undefine_action, void *undefine_arg,
 101                   isc_boolean_t case_sensitive, isccc_symtab_t **symtabp);
 102
 103 void
 104 isccc_symtab_destroy(isccc_symtab_t **symtabp);
 105
 106 isc_result_t
 107 isccc_symtab_lookup(isccc_symtab_t *symtab, const char *key, unsigned int type,
 108                   isccc_symvalue_t *value);
 109
 110 isc_result_t
 111 isccc_symtab_define(isccc_symtab_t *symtab, char *key, unsigned int type,
 112                   isccc_symvalue_t value, isccc_symexists_t exists_policy);
 113
 114 isc_result_t
 115 isccc_symtab_undefine(isccc_symtab_t *symtab, const char *key, unsigned int type);
 116
 117 void
 118 isccc_symtab_foreach(isccc_symtab_t *symtab, isccc_symtabforeachaction_t action,
 119                    void *arg);
 120
 121 ISC_LANG_ENDDECLS
 122
 123 #endif /* ISCCC_SYMTAB_H */