一在网络编程中,如何处理TCP粘包问题?#

const net = require('net');
const { Buffer } = require('buffer');

// 假设消息头为4字节，存储消息体的长度
function readHeader(socket) {
    let headerBuffer = Buffer.alloc(4);
    let received = 0;

    return new Promise((resolve, reject) => {
        const readHandler = socket.on('data', (chunk) => {
            chunk.copy(headerBuffer, received, 0, chunk.length);
            received += chunk.length;

            if (received === 4) {
                socket.removeListener('data', readHandler);
                const msgLength = headerBuffer.readUInt32BE(0);
                resolve(msgLength);
            }
        });

        socket.on('end', () => {
            reject(new Error('Socket ended before receiving complete header.'));
        });
    });
}

async function readMessage(socket, msgLength) {
    let messageBuffer = Buffer.alloc(msgLength);
    let received = 0;

    return new Promise((resolve, reject) => {
        const dataHandler = socket.on('data', (chunk) => {
            let chunkLength = Math.min(chunk.length, msgLength - received);
            chunk.copy(messageBuffer, received, 0, chunkLength);
            received += chunkLength;

            if (received === msgLength) {
                socket.removeListener('data', dataHandler);
                resolve(messageBuffer);
            }
        });

        socket.on('end', () => {
            reject(new Error('Socket ended before receiving complete message.'));
        });
    });
}

const server = net.createServer(socket => {
    console.log('Client connected.');

    (async function handleMessages() {
        try {
            while (true) {
                const msgLength = await readHeader(socket);
                const message = await readMessage(socket, msgLength);
                console.log(`Received message: ${message.toString()}`);
            }
        } catch (error) {
            console.error(error.message);
            socket.end();
        }
    })();

    socket.on('end', () => {
        console.log('Client disconnected.');
    });
});

server.listen(3000, () => {
    console.log('Server listening on port 3000');
});