flexarray.c

/* Implemantation of header file for flexarray.
 * 11/09/17
 * Authors: Taylor Manning, Callan Taylor, Luke Falvey
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "mylib.h"
#include "flexarray.h"

/* Structure of a 'flexarray', holds variables
 * of capacity, itemcount and the array of items.
 */
struct flexarrayrec {
    /* capacity is the amount of items the current items array can hold. */
    int capacity;
    /* itemcount is the amount of items currently in the flexarray. */
    int itemcount;
    /* items is the actual array of items. */
    char **items;
};

/* Creates new flexarray, initialises all the values and
 * allocates memory for the array of items.
 * Returns:  the flexarray just created.
 */
flexarray flexarray_new() {
    flexarray result = emalloc(sizeof *result);
    result->capacity = 2;
    result->itemcount = 0;
    result->items = emalloc(result->capacity * sizeof result->items[0]);
    return result;
}

/* Searches through a flexarray and returns whether an item is present.
 * Parameters: f is the flexarray to search.
 * Parameters: target is the item being searched for.
 * Returns:  1 if present, 0 if not.
 */
int flexarray_is_present(flexarray f, char *target) {
    int i;
    for (i = 0; i < f->itemcount; i++) {
        if (strcmp(f->items[i], target) == 0) {
            return 1;
        }	
    }
    return 0;
}

/* Performs a given function on a given flexarray.
 * Parameters: f is flexarray to visit
 * Parameters: func is the function to apply to each item
 */
void flexarray_visit(flexarray f, void func(char *str)) {
    int i;
    for (i = 0; i < f->itemcount; i++) {
        func(f->items[i]);
    }
}

/* Adds an item to array, if the array is full,
 * then a new array of same size is appended to
 * the end to allow room.
 * Parameters: f is the flexarray bein added to.
 * Parameters: item is the string being added.
*/
void flexarray_append(flexarray f, char *item) {
    if (f->itemcount == f->capacity) {
        f->capacity += f->capacity;
        f->items = erealloc(f->items, f->capacity * sizeof f->items[0]);
    }
    f->items[f->itemcount] = emalloc((strlen(item)+1) * sizeof f->items[0][0]);
    strcpy(f->items[f->itemcount], item);
    f->itemcount++;
}

/* Frees all the memory the flex array is using.
 * Parameters: f is the flexarray using the memory.
 */
void flexarray_free(flexarray f) {
    int i;
    for (i = 0; i < f->itemcount; i++) {
    	free(f->items[i]);
    }
    free(f->items);
    free(f);
}