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/* This file is part of the Project Athena Zephyr Notification System.
* It is one of the source files comprising zwgc, the Zephyr WindowGram
* client.
*
* Created by: Marc Horowitz <marc@athena.mit.edu>
*
* $Id$
*
* Copyright (c) 1989 by the Massachusetts Institute of Technology.
* For copying and distribution information, see the file
* "mit-copyright.h".
*/
#if (!defined(lint) && !defined(SABER))
static const char rcsid_string_dictionary_aux_c[] = "$Id$";
#endif
/*
* string_dictionary_aux - a module implementing convenience routines for use
* with string_dictionarys
*
* Overview:
*
* This module implements Fetch and Set operations on
* string_dictionaries which take the place of Define and Lookup for
* most uses. The importance difference between them and Define and
* Lookup is that they maintain the invariant that all the value strings
* in a string_dictionary are on the heap. In particular, they do
* free's and string_Copy's whenever needed. Also implemented is
* SafeDestroy which does a Destroy after freeing all the value strings
* in a string_dictionary.
*/
#include <sysdep.h>
#include "new_memory.h"
#include "string_dictionary.h"
#include "string_dictionary_aux.h"
/*
* void string_dictionary_Set(string_dictionary d, string key,string value):
* Modifies: d
* Effects: Binds key to value in d. Automatically free's the
* previous value of key, if any. Value is copied on the
* heap.
*/
void
string__dictionary_Set(string_dictionary d,
string key,
string value)
{
string_dictionary_binding *binding;
int already_exists;
binding = string_dictionary_Define(d, key, &already_exists);
if (already_exists)
free(binding->value);
binding->value = string_Copy(value);
}
/*
* char *string_dictionary_Fetch(string_dictionary d, string key)
* Effects: If key is not bound in d, returns 0. Otherwise,
* returns the value that key is bound to.
* Note that the returned string if any should not be
* freed or modified in any way. Note also that it may
* disappear later if key is rebound.
*/
char *
string_dictionary_Fetch(string_dictionary d,
string key)
{
string_dictionary_binding *binding;
binding = string_dictionary_Lookup(d, key);
if (!binding)
return(0);
return(binding->value);
}
/*
* void string_dictionary_SafeDestroy(string_dictionary d)
* Modifies: d
* Effects: Like string_dictionary_Destroy except first frees
* all value's in the dictionary.
*/
static void
free_value_of_binding(string_dictionary_binding *b)
{
free(b->value);
}
void
string_dictionary_SafeDestroy(string_dictionary d)
{
string_dictionary_Enumerate(d, free_value_of_binding);
string_dictionary_Destroy(d);
}
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