使用SocketIO上传文件时Flask request.stream.read()停止

from flask import Flask, request
from flask_socketio import SocketIO, emit

app = Flask(__name__)
socketio = SocketIO(app)

@socketio.on('upload')
def handle_upload(data):
    # 获取文件名和文件内容
    filename = data['filename']
    filedata = data['filedata']

    # 逐块保存文件内容
    with open(filename, 'ab') as f:
        f.write(filedata)

    # 发送上传进度给客户端
    emit('progress', {'progress': len(filedata)})

if __name__ == '__main__':
    socketio.run(app)

var socket = io.connect('http://localhost:5000');

function uploadFile(file) {
    var chunkSize = 1024; // 每次发送的块大小
    var offset = 0; // 文件偏移量

    // 逐块发送文件内容
    while (offset < file.size) {
        var chunk = file.slice(offset, offset + chunkSize);
        socket.emit('upload', {
            filename: file.name,
            filedata: chunk
        });
        offset += chunkSize;
    }
}