uWebSockets && uSockets 代碼分析----------3.主要數據結構轉換函數

void *us_loop_ext(struct us_loop_t *loop) {
    return loop + 1;
}

void *us_socket_ext(int ssl, struct us_socket_t *s) {
#ifndef LIBUS_NO_SSL
    if (ssl) {
        return us_internal_ssl_socket_ext((struct us_internal_ssl_socket_t *) s);
    }
#endif

    return s + 1;
}

void *us_internal_ssl_socket_ext(struct us_internal_ssl_socket_t *s) {
    return s + 1;
}

// same here, should or shouldn't it contain s?
struct us_internal_ssl_socket_t {
    struct us_socket_t s;
    SSL *ssl;
    int ssl_write_wants_read; // we use this for now
};

struct us_loop_t *us_socket_context_loop(int ssl, struct us_socket_context_t *context) {
    return context->loop;
}

struct us_socket_context_t *us_create_socket_context(int ssl, struct us_loop_t *loop, int context_ext_size, struct us_socket_context_options_t options) {
#ifndef LIBUS_NO_SSL
    if (ssl) {
        return (struct us_socket_context_t *) us_internal_create_ssl_socket_context(loop, context_ext_size, options);
    }
#endif

    struct us_socket_context_t *context = malloc(sizeof(struct us_socket_context_t) + context_ext_size);
    context->loop = loop;
    context->head = 0;
    context->iterator = 0;
    context->next = 0;
    context->ignore_data = default_ignore_data_handler;

    us_internal_loop_link(loop, context);
    return context;
}

struct us_socket_context_t *us_create_child_socket_context(int ssl, struct us_socket_context_t *context, int context_ext_size) {
#ifndef LIBUS_NO_SSL
    if (ssl) {
        return (struct us_socket_context_t *) us_internal_create_child_ssl_socket_context((struct us_internal_ssl_socket_context_t *) context, context_ext_size);
    }
#endif

    /* For TCP we simply create a new context as nothing is shared */
    struct us_socket_context_options_t options = {0};
    return us_create_socket_context(ssl, context->loop, context_ext_size, options);
}

void *us_socket_context_ext(int ssl, struct us_socket_context_t *context) {
#ifndef LIBUS_NO_SSL
    if (ssl) {
        return us_internal_ssl_socket_context_ext((struct us_internal_ssl_socket_context_t *) context);
    }
#endif

    return context + 1;
}

struct us_socket_context_t *us_socket_context(int ssl, struct us_socket_t *s) {
    return s->context;
}

struct us_loop_t *us_create_loop(void *hint, void (*wakeup_cb)(struct us_loop_t *loop), void (*pre_cb)(struct us_loop_t *loop), void (*post_cb)(struct us_loop_t *loop), unsigned int ext_size) {
    struct us_loop_t *loop = (struct us_loop_t *) malloc(sizeof(struct us_loop_t) + ext_size);

    loop->uv_loop = hint ? hint : uv_loop_new();
    loop->is_default = hint != 0;

    loop->uv_pre = malloc(sizeof(uv_prepare_t));
    uv_prepare_init(loop->uv_loop, loop->uv_pre);
    uv_prepare_start(loop->uv_pre, prepare_cb);
    uv_unref((uv_handle_t *) loop->uv_pre);
    loop->uv_pre->data = loop;

    loop->uv_check = malloc(sizeof(uv_check_t));
    uv_check_init(loop->uv_loop, loop->uv_check);
    uv_unref((uv_handle_t *) loop->uv_check);
    uv_check_start(loop->uv_check, check_cb);
    loop->uv_check->data = loop;

    // here we create two unreffed handles - timer and async
    us_internal_loop_data_init(loop, wakeup_cb, pre_cb, post_cb);

    // if we do not own this loop, we need to integrate and set up timer
    if (hint) {
        us_loop_integrate(loop);
    }

    return loop;
}