human.c

/*-
 * Copyright (c) 2012 valsorym <[email protected]>.
 * All rights reserved.
 *
 * Discussion on the forums.freebsd.org.
 *  url: http://forums.freebsd.org/showthread.php?p=177208
 */

/*
 * Very simple class, for example OOD in ANSI C.
 */

#include <stdio.h>
#include <string.h>
#include <memory.h>

#include "human.h"

/* INTERFACES */

/* Private:
 * For the experiment, the method of Private.
 */
static int goodage(int );

/* Public: */
/* Constructor & Destructor */
static struct w_human *create(int , char *);
static void destroy(struct w_human *);

/* To access the data, we use the methods. */
static int  setage(struct w_human *, int );
static int  getage(struct w_human *);
static char *setname(struct w_human *, char *);
static char *getname(struct w_human *);

/* Initialization (constructor / destructor). */
const struct w_human_vtable w_human = {
    .create  = create,  .destroy = destroy,
    .setage  = setage,  .getage  = getage,
    .setname = setname, .getname = getname
};

/* IMPLEMENTATIONS */
/* Private: */
/*
 * In this class, the method gooage() determines whether the normal
 * age of a person.
 */
static int
goodage(int age)
{
    if (age >= 0 && age <= 120)
        return 1;

    return 0;
}

/* Public: */
/*
 * The constructor, allocates memory to accommodate the class,
 * initialize its elements.
 */
static struct w_human
*create(int age, char *name)
{
    struct w_human *self = (struct w_human *)malloc(sizeof(struct w_human));

    /* Private data. */
    w_human.setage(self, age);
    w_human.setname(self, name);

    return self;
}

/*
 * The destructor frees the allocated memory in self class.
 */
static void
destroy(struct w_human *self)
{
    if (self) {
        if (self->name)
            free(self->name);

        free(self);
    }
}

/*
 * Set a person's age.
 */
static int
setage(struct w_human *self, int age)
{
    if (self) {
        if (goodage(age) == 0) /* Use function of private sector. */
            return 0;

        self->age = age;
    }

    return self->age;
}

/*
 * Get the person's age.
 */
static int
getage(struct w_human *self)
{
    if (self)
        return self->age;

    return 0;
}

/*
 * Set the name of the person.
 */
static char
*setname(struct w_human *self, char *name)
{
    int name_len = strlen(name) + 1;

    if (self) {
        if (self->name)
            free(self->name);

        self->name = (char *)malloc(name_len * sizeof(char));
        strncpy(self->name, name, name_len);

        return self->name;
    }

    return NULL;
}

/*
 * Get the name of the person.
 */
static char
*getname(struct w_human *self)
{
    if (self)
        return self->name;

    return NULL;
}

/* The End. */