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/*++
/* NAME
/* nvtable 3
/* SUMMARY
/* attribute list manager
/* SYNOPSIS
/* #include <nvtable.h>
/*
/* typedef struct {
/* .in +4
/* char *key;
/* char *value;
/* /* private fields... */
/* .in -4
/* } NVTABLE_INFO;
/*
/* NVTABLE *nvtable_create(size)
/* int size;
/*
/* NVTABLE_INFO *nvtable_update(table, key, value)
/* NVTABLE *table;
/* const char *key;
/* const char *value;
/*
/* char *nvtable_find(table, key)
/* NVTABLE *table;
/* const char *key;
/*
/* NVTABLE_INFO *nvtable_locate(table, key)
/* NVTABLE *table;
/* const char *key;
/*
/* void nvtable_delete(table, key)
/* NVTABLE *table;
/* const char *key;
/*
/* void nvtable_free(table)
/* NVTABLE *table;
/*
/* void nvtable_walk(table, action, ptr)
/* NVTABLE *table;
/* void (*action)(NVTABLE_INFO *, char *ptr);
/* char *ptr;
/*
/* NVTABLE_INFO **nvtable_list(table)
/* NVTABLE *table;
/* DESCRIPTION
/* This module maintains one or more attribute lists. It provides a
/* more convenient interface than hash tables, although it uses the
/* same underlying implementation. Each attribute list entry consists
/* of a unique string-valued lookup key and a string value.
/*
/* nvtable_create() creates a table of the specified size and returns a
/* pointer to the result.
/*
/* nvtable_update() stores or updates a (key, value) pair in the specified
/* table and returns a pointer to the resulting entry. The key and the
/* value are copied.
/*
/* nvtable_find() returns the value that was stored under the given key,
/* or a null pointer if it was not found. In order to distinguish
/* a null value from a non-existent value, use nvtable_locate().
/*
/* nvtable_locate() returns a pointer to the entry that was stored
/* for the given key, or a null pointer if it was not found.
/*
/* nvtable_delete() removes one entry that was stored under the given key.
/*
/* nvtable_free() destroys a hash table, including contents.
/*
/* nvtable_walk() invokes the action function for each table entry, with
/* a pointer to the entry as its argument. The ptr argument is passed
/* on to the action function.
/*
/* nvtable_list() returns a null-terminated list of pointers to
/* all elements in the named table. The list should be passed to
/* myfree().
/* RESTRICTIONS
/* A callback function should not modify the attribute list that is
/* specified to its caller.
/* DIAGNOSTICS
/* The following conditions are reported and cause the program to
/* terminate immediately: memory allocation failure; an attempt
/* to delete a non-existent entry.
/* SEE ALSO
/* mymalloc(3) memory management wrapper
/* htable(3) hash table manager
/* LICENSE
/* .ad
/* .fi
/* The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/* Wietse Venema
/* IBM T.J. Watson Research
/* P.O. Box 704
/* Yorktown Heights, NY 10598, USA
/*--*/
/* C library */
#include <sys_defs.h>
/* Utility library. */
#include <mymalloc.h>
#include <htable.h>
#include <nvtable.h>
/* nvtable_update - update or enter (key, value) pair */
NVTABLE_INFO *nvtable_update(NVTABLE * table, const char *key, const char *value)
{
NVTABLE_INFO *ht;
if ((ht = htable_locate(table, key)) != 0) {
myfree(ht->value);
} else {
ht = htable_enter(table, key, (void *) 0);
}
ht->value = mystrdup(value);
return (ht);
}
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