MySQL CHAR 会补齐空格吗？

void run_upload(const char *ftp_url) {
    CircularQueue queue;
    // 初始化环形队列
    for (int i = 0; i < QUEUE_SIZE; i++) {
        queue.items[i].data = malloc(BUFFER_SIZE);
        if (queue.items[i].data == NULL) {
            fprintf(stderr, "Failed to allocate memory for queue item %d\n", i);
            exit(EXIT_FAILURE);
        }
        queue.items[i].total_size = BUFFER_SIZE;
    }
    queue.head = 0;
    queue.tail = 0;
    queue.download_finished = 0;
    pthread_t receive_tid, upload_tid;
    pthread_mutex_init(&queue.lock, NULL);
    pthread_cond_init(&queue.cond, NULL);
    if (pthread_create(&receive_tid, NULL, receive_thread, (void *)&queue) != 0) {
        fprint