Node.js WebSocket 数据发送函数：分块发送文件并通知结束

function sendData(path, step) {\n const fs = require("fs");\n const WebSocketUtil = require("WebSocketUtil");\n const sleep = require("util").promisify(setTimeout);\n\n const inputStream = fs.createReadStream(path);\n const data = Buffer.alloc(step);\n let readSize = 0;\n\n inputStream.on("data", function(chunk) {\n chunk.copy(data);\n readSize = chunk.length;\n WebSocketUtil.sendBinaryMessage(data);\n sleep(200);\n });\n\n inputStream.on("end", function() {\n const closebytes = Buffer.from("{"end": "true"}");\n WebSocketUtil.sendBinaryMessage(closebytes);\n });\n}