Dynamic header structs

dynamic.c

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

typedef struct Header {
    char *key;
    char *value;
} Header;

typedef struct Response {
    Header **headers;
    int headers_count;
} Response;

Header *
header_create(const char *key, char *value)
{
    Header *header = malloc(sizeof(Header));

    header->key = calloc(strlen(key) + 1, sizeof(char));
    strncpy(header->key, key, strlen(key));

    header->value = calloc(strlen(value) + 1, sizeof(char));
    strncpy(header->value, value, strlen(value));

    return header;
}

void
header_free(Header *header)
{
    free(header->key);
    free(header->value);
    free(header);
}

Response *
response_create()
{
    Response *response = malloc(sizeof(Response));
    
    response->headers       = NULL;
    response->headers_count = 0;

    return response;
}

void
response_header_add(Response *response, const char *key, char *value)
{
    // This is inefficient since we only grow the allocation by 1, would be better to allocate multiple
    // blocks at the same time and keep track of count vs. allocated, but that's premature optimization
    // for this example.
    response->headers = realloc(response->headers, (response->headers_count + 1) * sizeof(Header *));
    
    response->headers[response->headers_count] = header_create(key, value);
    response->headers_count++;
}

void response_free(Response *response)
{
    int i = 0;
    
    for (i = 0; i < response->headers_count; i++) {
        header_free(response->headers[i]);
    }

    free(response->headers);
    free(response);
}

int
main(void)
{
    int i = 0;

    Response *response = response_create();
    
    response_header_add(response, "Content-Type", "text/html");
    response_header_add(response, "Content-Length", "1337");
    response_header_add(response, "Connection", "close");
    
    for (i = 0; i < response->headers_count; i++) {
        printf("Header at position %d is: %s: %s\n", i, response->headers[i]->key, response->headers[i]->value);
    }

    response_free(response);

    return 0;
}