void client_read_cb(uv_stream_t *tcp, ssize_t nread, const uv_buf_t *buf) {
    client_t *client = (client_t*)tcp->data;
    int ret;

    if(nread<0) {
        if(buf->base) {
            free(buf->base);
        }
        free(base);
        uv_close((uv_handle_t*)tcp, client_close_cb);
        return;
    } else if(nread == 0) {
        if(buf->base) {
            free(buf->base);
        }
        free(base);
        return;
    }

    if(nread + client->cur_buf > client->buf.len) {
        size_t s = ((nread + client->cur_buf)/client->buf.len)+1;
        s = s*client->buf.len;
        char *c = memcpy(malloc(s), client->buf.base, client->cur_buf);
        free(client->buf.base);
        client->buf = uv_buf_init(c, s);
    }
    memcpy(client->buf.base + client->cur_buf, buf->base, nread);
    client->cur_buf += nread;
    free(buf->base);
    free(buf);

    if(client->read_len < 0) {
        ret = mcp_decode_varint(&client->read_len, (uint8_t*)client->buf.base);
        if(ret<0) {
            client->read_len = -1;
            return;
        }
        client->cur_buf -= ret;
        memmove(client->buf.base, client->buf.base + ret, client->cur_buf);
    }
    if(client->cur_buf < client->read_len) {
        return;
    }

    int32_t packet_id;
    ret = mcp_decode_varint(&packet_id, (uint8_t*)client->buf.base);
}