tornado流式接收上传文件

问题

上传的文件放在表单上传如果过大，会导致服务端内存溢出，所以需要客户端将参数放到header里，文件放到body里传输，服务端流式接收body的内容

• 客户端代码

data = {'file_size':'xxxx','file_md5':'xxxx','file_id':'xxxxx'}
filename=‘xxxxx’
storage_url = "http://xxx" 
with open(filename, 'rb') as f:
    res = requests.post(storage_url, headers=data, data=f)

• 服务端代码

  需要使用到 tornado.web.stream_request_body 装饰器

@tornado.web.stream_request_body
class BigformUploadHandler(web.RequestHandler):
    executor = ThreadPoolExecutor(thread_pool_size)
    save_name = None
    save_seek = 0

    def prepare(self):
        try:
            headers = self.request.headers
            print(headers)
            file_id = headers["file_id"]
            redis_data = loads(redis_ins.get(file_id))
            if redis_data:
                storage_path = redis_data["storage_path"]
                self.save_name = os.path.join(storage_path, file_id)
        except Exception:
            run_log.error(traceback.format_exc())

    def data_received(self,chunk):
        if self.save_name:
            if not os.path.exists(self.save_name):
                with open(self.save_name, 'wb+') as up:
                    pass
            with open(self.save_name, 'rb+') as up:
                up.seek(self.save_seek)
                up.write(chunk)
                self.save_seek = self.save_seek + len(chunk)

    @tornado.web.asynchronous
    @tornado.gen.coroutine
    def post(self):
        values = {}
        result = {"return_code": 500,"error_info":""}
        try:
            headers = self.request.headers
            values["file_md5"] = headers["file_md5"]
            values["file_size"] = headers["file_size"]
            values["file_id"] = headers["file_id"]
            # 从redis获取存储路径
            redis_data = loads(redis_ins.get(values["file_id"]))
            values["storage_path"] = redis_data["storage_path"]
            filename = os.path.join(values["storage_path"], values["file_id"])
            values["filename"] = filename

            result = yield self.do_upload_form(values)
        except Exception:
            run_log.error(traceback.format_exc())
        finally:
            if result["return_code"] == 200:
                self.write(dumps(result))
            else:
                self.set_status(500)

    @run_on_executor
    def do_upload_form(self, values):
        result = {"return_code": 500, "error_info": ""}
        try:
            if os.path.exists(values["filename"]):
                md5 = str(get_md5(values["filename"]))
                if values["file_md5"] == md5:
                    result['return_code']=200
        except Exception:
            run_log.error(traceback.format_exc())
        finally:
            return result