46.1Mb 的文件 传过去只有34Mb,用同步写入文件是完整的，问下老师这应该怎么解决啊
后端代码：

# demo.py
from sanic import Sanic
from sanic.response import json
import aiofiles

app = Sanic(__name__)

@app.route("/")
async def test(request):
    return json({"hello": "world"})
    
@app.post('/upload')
async def upload(request):
    # 获取文件信息
    upfile = request.files.get('file',None)
    filename = upfile.name
    filetype = upfile.type
    fileBody = upfile.body
    # 同步写入 文件完整可行
    #with open(f"./img/{filename}", 'ab+') as fp:
        #fp.write(fileBody)
    # 异步写入 文件不完整
    async with aiofiles.open(f"./img/{fileName}", 'ab+') as fp:
        await fp.write(fileBody)
    return json({"status":'success'})
    
if __name__ == "__main__":
    app.run(host="127.0.0.1", port=8000)

前端代码：
npm install vue-simple-uploader -S

main.js:

import uploader from "vue-simple-uploader";
Vue.use(uploader)

App.vue:

<template>
	<div id="app">
		<h1>hello vue.js app </h1>
		<uploader :options="options" class="uploader-example">
			<uploader-unsupport></uploader-unsupport>
			<uploader-drop>
				<p>拖动文件到此处上传</p>
				<uploader-btn>选择文件</uploader-btn>
				<uploader-btn :attrs="attrs">选择图片</uploader-btn>
				<uploader-btn :directory="true">选择文件夹</uploader-btn>
			</uploader-drop>
			<uploader-list></uploader-list>
		</uploader>
	</div>
</template>

<script>
  export default {
    name: "App",
    data () {
      return {
        options: {
          target: '//localhost:8000/upload',
          testChunks: false
        },
        attrs: {
          accept: 'image/*'
        }
      }
    }
  }
</script>

<style scoped lang="css">
	.uploader-example {
		width: 880px;
		padding: 15px;
		margin: 40px auto 0;
		font-size: 12px;
		box-shadow: 0 0 10px rgba(0, 0, 0, .4);
	}
	.uploader-example .uploader-btn {
		margin-right: 4px;
	}
	.uploader-example .uploader-list {
		max-height: 440px;
		overflow: auto;
		overflow-x: hidden;
		overflow-y: auto;
	}
</style>