psuedocode for kernelcorn

gistfile1.c

struct query {
    struct event * r_pipe_ev;
    int            r_pipe;       /* response pipe */
    int            q_pipe;       /* query pipe */
    int            response[256];
};

static void
read_response(int sock, short events, void * arg) {
    struct query * q = (struct query *)arg;
    ssize_t        nread;


    if ((nread = read(q->r_pipe, q->response, sizeof(q->response))) == -1) {
        fprintf(stderr, "whoah nelly %s\n", strerror(errno));
        goto done;
    }

    /* XXX: don't know if you need it, but add logic to make sure we get the whole response,
     * and if we didn't, we need a buffering mechanism, and return here if not complete.
     *
     * Like
     *
     * nread = read(q->r_pipe &q->response_buffer[q->buffer_idx], ...);
     * if (p->response_len < expected_response_len) {
     *    return;
     * }
     *
     */

    q->response[nread] = '\0';

    fprintf(stderr, "response: %s\n", q->response);

done:
    close(q->r_pipe);
    close(q->q_pipe);

    event_free(q->r_pipe_ev);
    free(q);
}

static void
do_query(struct event_base * evbase, const char * path) {
    struct query * q;

    q            = calloc(1, sizeof(struct query));
    q->r_pipe    = open("/tmp/tor-onions-response", O_NONBLOCK);
    q->q_pipe    = open("/tmp/tor-onions-query", O_NONBLOCK);
    q->r_pipe_ev = event_new(evbase, q->r_pipe, EV_READ | EV_PERSIST, read_response, q);

    /* in reality we need to make this another event if we get a -1 and an errno that
     * is retry-able.
     */
    write(q->q_pipe, path, strlen(path) + 1);

    /* now we add the event for reading the response and return. the function read_response
     * will execute once data is ready.
     */

    event_add(q->r_pipe, NULL);
}