websocket

 

更正   127时，取8个字节为字符长度

　　

flask示例：由js生成WebSocket对象

from flask import Flask, render_template, request
from geventwebsocket.handler import WebSocketHandler
from geventwebsocket.websocket import WebSocket
from gevent.pywsgi import WSGIServer
import json

app = Flask(__name__)

USERS = {
    '1': {'name': '钢弹', 'count': 0},
    '2': {'name': '铁锤', 'count': 0},
    '3': {'name': '贝贝', 'count': 100},
}


# http://127.0.0.1:5000/index
@app.route('/index')
def index():
    return render_template('index.html', users=USERS)


# http://127.0.0.1:5000/message
WEBSOCKET_LIST = []


@app.route('/message')
def message():
    ws = request.environ.get('wsgi.websocket')  # type:WebSocket
    if not ws:
        print('http')
        return '您使用的是Http协议'
    WEBSOCKET_LIST.append(ws)
    while True:
        cid = ws.receive()
        if not cid:
            WEBSOCKET_LIST.remove(ws)
            ws.close()
            break
        old = USERS[cid]['count']
        new = old + 1
        USERS[cid]['count'] = new
        for client in WEBSOCKET_LIST:
            client.send(json.dumps({'cid': cid, 'count': new}))


if __name__ == '__main__':
    http_server = WSGIServer(('0.0.0.0', 5000), app, handler_class=WebSocketHandler)
    http_server.serve_forever()
flask.py
<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body>
    <h1>投票系统</h1>
    <ul>
        {% for k,v in users.items() %}
            <li onclick="vote({{k}})" id="id_{{k}}">{{v.name}}<span>{{v.count}}</span></li>
        {% endfor %}
    </ul>

    <script src="{{ url_for('static',filename='jquery-3.3.1.min.js')}}"></script>
    <script>
        var ws = new WebSocket('ws://192.168.13.253:5000/message');
        ws.onmessage = function (event) {
            /* 服务器端向客户端发送数据时，自动执行 */
            // {'cid':cid,'count':new}
            var response = JSON.parse(event.data);
            $('#id_'+response.cid).find('span').text(response.count);

        };

        function vote(cid) {
            ws.send(cid)
        }
    </script>
</body>
</html>
index.html

 

 

 

Websocket原理：

import base64
import hashlib
import socket
import struct


def get_headers(data):
    """
    将请求头格式化成字典
    :param data:
    :return:
    """
    header_dict = {}
    data = str(data, encoding='utf-8')
    header, body = data.split('\r\n\r\n', 1)
    header_list = header.split('\r\n')
    for i in range(0, len(header_list)):
        if i == 0:
            if len(header_list[i].split(' ')) == 3:
                header_dict['method'], header_dict['url'], header_dict['protocol'] = header_list[i].split(' ')
        else:
            k, v = header_list[i].split(':', 1)
            header_dict[k] = v.strip()
    return header_dict


def send_msg(conn, msg_bytes):
    """
    WebSocket服务端向客户端发送消息
    :param conn: 客户端连接到服务器端的socket对象,即： conn,address = socket.accept()
    :param msg_bytes: 向客户端发送的字节
    :return:
    """

    token = b"\x81"
    length = len(msg_bytes)
    if length < 126:
        token += struct.pack("B", length)
    elif length <= 0xFFFF:
        token += struct.pack("!BH", 126, length)
    else:
        token += struct.pack("!BQ", 127, length)

    msg = token + msg_bytes
    conn.send(msg)


sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind(('127.0.0.1', 8002))
sock.listen(5)
# 1. 等待用户连接
conn, address = sock.accept()

# 2. 接收验证消息
msg = conn.recv(8096)
msg_dict = get_headers(msg)

# 3. 对数据加密
value = msg_dict['Sec-WebSocket-Key'] + '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'
ac = base64.b64encode(hashlib.sha1(value.encode('utf-8')).digest())
# print(ac,type(ac))
# 4. 将加密后的结果返回给小强
response_tpl = "HTTP/1.1 101 Switching Protocols\r\n" \
               "Upgrade:websocket\r\n" \
               "Connection: Upgrade\r\n" \
               "Sec-WebSocket-Accept: %s\r\n" \
               "WebSocket-Location: ws://127.0.0.1:8002\r\n\r\n"
response = response_tpl % (ac.decode('utf-8'),)
conn.send(response.encode('utf-8'))

# 5. 接收小强发送的数据
while True:
    """
    info = conn.recv(8096)

    payload_len = info[1] & 127
    if payload_len == 127:
        extend_payload_len = info[2:10]
        mask = info[10:14]
        decoded = info[14:]
    elif payload_len == 126:
        extend_payload_len = info[2:4]
        mask = info[4:8]
        decoded = info[8:]
    else:
        extend_payload_len = None
        mask = info[2:6]
        decoded = info[6:]

    bytes_list = bytearray()
    for i in range(len(decoded)):
        chunk = decoded[i] ^ mask[i % 4]
        bytes_list.append(chunk)
    body = str(bytes_list, encoding='utf-8')
    print(body)
    """
    import time

    time.sleep(2)
    send_msg(conn, b'123123123')
<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body>
    <script>
        var ws = new WebSocket("ws://127.0.0.1:8002/xxxx");

        ws.onmessage = function (event) {
            /* 服务器端向客户端发送数据时，自动执行 */
            console.log(event.data);
        };
    </script>
</body>
</html>

 

posted @ 2018-10-14 15:26  慕沁  阅读(117)  评论(0)    收藏  举报