Geografic-Information-System/lib/gis/key_value1.c

/*!
   \file key_value1.c

   \brief Key_Value management.

   (C) 2001-2008 by the GRASS Development Team

   This program is free software under the 
   GNU General Public License (>=v2). 
   Read the file COPYING that comes with GRASS
   for details.

   \author CERL
 */

#include <string.h>
#include <stdlib.h>
#include <grass/gis.h>

/*!
   \brief Allocate and initialize Key_Value structure

   \return poiter to allocated Key_Value structure
 */
struct Key_Value *G_create_key_value(void)
{
    struct Key_Value *kv;

    kv = (struct Key_Value *)G_malloc(sizeof(struct Key_Value));
    if (kv == NULL)
	return NULL;

    kv->nitems = 0;
    kv->nalloc = 0;
    kv->key = (char **)NULL;
    kv->value = (char **)NULL;

    return kv;
}

/*!
   \brief Set value for given key

   If key has spaces in it, this will break the logic 
   so rule is: NO SPACES IN key.

   \param[in] key key to be set up
   \param[in] value value for given key
   \param[in,out] kv Key_value structure to be modified

   \return 0 no memory
   \return 1 ok, but key was NULL or "" so ignored
   \return 2 ok
 */
int G_set_key_value(const char *key, const char *value, struct Key_Value *kv)
{
    int n;
    int size;

    if (key == NULL || key == 0)
	return 1;

    for (n = 0; n < kv->nitems; n++)
	if (strcmp(key, kv->key[n]) == 0)
	    break;

    if (n == kv->nitems) {
	if (n >= kv->nalloc) {
	    if (kv->nalloc <= 0) {
		kv->nalloc = 8;
		size = kv->nalloc * sizeof(char *);
		kv->key = (char **)G_malloc(size);
		kv->value = (char **)G_malloc(size);
	    }
	    else {
		kv->nalloc *= 2;
		size = kv->nalloc * sizeof(char *);
		kv->key = (char **)G_realloc(kv->key, size);
		kv->value = (char **)G_realloc(kv->value, size);
	    }

	    if (kv->key == NULL || kv->value == NULL) {
		if (kv->key) {
		    G_free(kv->key);
		    kv->key = NULL;
		}
		if (kv->value) {
		    G_free(kv->value);
		    kv->value = NULL;
		}
		kv->nitems = kv->nalloc = 0;
		return 0;
	    }
	}
	kv->value[n] = NULL;
	kv->key[n] = G_malloc(strlen(key) + 1);
	if (kv->key[n] == NULL)
	    return 0;
	strcpy(kv->key[n], key);
	kv->nitems++;
    }
    if (value == NULL)
	size = 0;
    else
	size = strlen(value);
    if (kv->value[n] != NULL)
	G_free(kv->value[n]);
    if (size > 0) {
	kv->value[n] = G_malloc(size + 1);
	if (kv->value[n] == NULL)
	    return 0;
	strcpy(kv->value[n], value);
    }
    else
	kv->value[n] = NULL;
    return 2;
}

/*!
   \brief Find given key

   \param[in] key key to be found
   \param[in] kv Key_value structure

   \return poiter to value of key
   \return NULL if no key found
 */
char *G_find_key_value(const char *key, const struct Key_Value *kv)
{
    int n;

    for (n = 0; n < kv->nitems; n++)
	if (strcmp(key, kv->key[n]) == 0)
	    return kv->value[n][0] ? kv->value[n] : NULL;
    return NULL;
}

/*!
   \brief Free allocated Key_Value structure

   \param[in] kv Key_Value structure

   \return
 */
void G_free_key_value(struct Key_Value *kv)
{
    int n;

    for (n = 0; n < kv->nitems; n++) {
	G_free(kv->key[n]);
	G_free(kv->value[n]);
    }
    G_free(kv->key);
    G_free(kv->value);
    kv->nitems = 0;		/* just for safe measure */
    kv->nalloc = 0;
    G_free(kv);
}