python 中 websocket實現消息定時推送

一、socket服務端 websocket_util.py

import socket
import base64
import hashlib
from threading import Thread
import struct
import copy
import json
import time

from XX.redis_db import RedisDb

from utils.summary import summary
from utils.redis_util import RedisUtil
import config

redis_db = RedisDb(config.REDIS)
redis_util = RedisUtil()


class WebSocketUtil(object):

    global users
    users = set()

    def __init__(self, port=config.SOCKET_PORT, max_wait_user=5):
        self.sock = socket.socket()
        self.sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.sock.bind(("0.0.0.0", port))
        self.sock.listen(max_wait_user)

    # 請求頭轉換格式爲字典
    def get_headers(self, data):
        """將請求頭轉換爲字典"""
        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[0].split(" ")) == 3:
                    header_dict['method'], header_dict['url'], header_dict['protocol'] = header_list[0].split(" ")
            else:
                k, v = header_list[i].split(":", 1)
                header_dict[k] = v.strip()
        return header_dict

    # 等待用戶連接
    def socket_connect(self):
        conn, addr = self.sock.accept()
        users.add(conn)
        # 獲取握手消息，magic string ,sha1加密  發送給客戶端  握手消息
        data = conn.recv(8096)
        headers = self.get_headers(data)
        # 對請求頭中的sec-websocket-key進行加密
        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://%s%s\r\n\r\n"

        magic_string = '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'
        value = headers['Sec-WebSocket-Key'] + magic_string
        ac = base64.b64encode(hashlib.sha1(value.encode('utf-8')).digest())
        response_str = response_tpl % (ac.decode('utf-8'), headers['Host'], headers['url'])

        # 響應握手信息
        conn.send(bytes(response_str, encoding='utf-8'), )

        # 新的連接成功立馬發一次數據
        data = summary()
        self.send_msg(conn, bytes(json.dumps(data), encoding="utf-8"))

        # 添加redis,保存該連接最近推送消息的時間戳
        redis_key = redis_util.get_md5_key(str(conn))
        redis_db.str_set(redis_key, int(time.time()))

    def get_data(self, info):
        payload_len = info[1] & 127
        if payload_len == 126:
            extend_payload_len = info[2:4]
            mask = info[4:8]
            decoded = info[8:]
        elif payload_len == 127:
            extend_payload_len = info[2:10]
            mask = info[10:14]
            decoded = info[14:]
        else:
            extend_payload_len = None
            mask = info[2:6]
            decoded = info[6:]

        bytes_list = bytearray()  # 這裏我們使用字節將數據全部收集，再去字符串編碼，這樣不會導致中文亂碼
        for i in range(len(decoded)):
            chunk = decoded[i] ^ mask[i % 4]  # 解碼方式
            bytes_list.append(chunk)
        body = str(bytes_list, encoding='utf-8')
        return body

    # 向客戶端發送數據
    def send_msg(self, conn, msg_bytes):
        """
        WebSocket服務端向客戶端發送消息
        :param conn: 客戶端連接到服務器端的socket對象,即： conn,address = socket.accept()
        :param msg_bytes: 向客戶端發送的字節
        :return:
        """
        token = b"\x81"  # 接收的第一字節，一般都是x81不變
        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
        # 如果出錯就是客戶端斷開連接
        try:
            conn.send(msg)
        except Exception as e:
            # 刪除斷開連接的記錄
            users.remove(conn)

    # 循環等待客戶端建立連接
    def wait_socket_connect(self):
        while True:
            self.socket_connect()

    # socket服務端監聽客戶端連接並批量推送數據
    def start_socket_server(self):
        # 啓線程循環等待客戶端建立連接
        Thread(target=self.wait_socket_connect).start()
        # 消息推送
        while True:
            # 判斷是否有客戶端連接，有才推送消息
            if len(users):
                send_users = copy.copy(users)
                # 自定義的消息內容
                data = summary()
                # 遍歷
                for user in send_users:
                    # 判斷該連接是否最近5s推送消息(可配置時間)，有就跳過
                    if self.get_connect_last_send_time(user):
                        self.send_msg(user, bytes(json.dumps(data), encoding="utf-8"))
                    else:
                        pass
                time.sleep(config.FLUSH_TIME)

    # 獲取該連接最近推送消息的時間戳並判斷是否在閥值內
    def get_connect_last_send_time(self, conn, time_threshold=config.TIME_THRESHOLD):
        try:
            redis_key = redis_util.get_md5_key(str(conn))
            last_send_time = int(redis_db.str_get(redis_key) or 0)
            return True if time.time() - last_send_time > time_threshold else False
        except Exception as e:
            return True


if __name__ == '__main__':
    web = WebSocketUtil(port=8005)
    web.start_socket_server()

二、 socket 客戶端 websocket_client.py, 可同時多個連接，可以通過服務端sock.listen(5)調整可等待連接數

import websocket
import json

ws = websocket.create_connection("ws://127.0.0.1:8080/")

while True:
    data = ws.recv()
    print(json.loads(str(data, encoding="utf-8")))

    
三、 前端測試 test.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

</body>
</html>
<script>
    ws =new WebSocket("ws://127.0.0.1:8005/");
    ws.onopen = function(ev){
        console.log("連接成功")
    };
    ws.onmessage = function (ev){
        console.log("接收消息爲:");
        console.log(ev);
    }
</script>

四、在flask項目結合使用websocket

    1、只需要在flask項目啓動時啓一個線程來調用 websocket_util.py中的start_socket_server()
    2、例子：
      

		# 線程啓動socket服務端
		from utils.websocket_util import WebSocketUtil
		import config
		import threading
		try:
			# uwsgi啓動socket服務，只選其中一個進程啓動，多個會報端口占用錯誤
			import uwsgi
			if uwsgi.worker_id() == 2:
				# uwsgi啓動socket服務，默認端口爲8003
				web_socket = WebSocketUtil(port=config.SOCKET_PORT)
				threading.Thread(target=web_socket.start_socket_server).start()
				print("socket server uwsgi啓動成功")
				print("服務端推送間隔爲：" + str(config.FLUSH_TIME) + "s")
		except Exception as e:
			print(e)
			print("socket server uwsgi啓動失敗")
			try:
				# 如果報錯，證明是本地遠程啓動項目，直接啓動socket服務 8004端口
				web_socket = WebSocketUtil(port=8004)
				threading.Thread(target=web_socket.start_socket_server).start()
				print("socket server 本地遠程啓動成功")
				print("服務端推送間隔爲：" + str(config.FLUSH_TIME) + "s")
			except Exception as e:
				print("socket server 本地遠程啓動失敗")

五、Nginx配置websocket反向代理

	# 第一種：另起一個server端口代理
		map $http_upgrade $connection_upgrade { 
			default upgrade; 
			'' close; 
		} 
		upstream wsbackend{ 
			server ip1:8003; 
			keepalive 1000; 
		} 
		 
		server { 
			listen 8003; 
			location /{ 
				proxy_http_version 1.1; 
				proxy_pass http://wsbackend; 
				proxy_redirect off; 
				proxy_set_header Host $host; 
				proxy_set_header X-Real-IP $remote_addr; 
				proxy_read_timeout 3600s; 
				proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; 
				proxy_set_header Upgrade $http_upgrade; 
				proxy_set_header Connection $connection_upgrade; 
			} 
		}

	# 第二種：在原來的server中添加一個location，將"ws://127.0.0.1:8080/websocket/"轉成"ws://127.0.0.1:8003/"
		# web socket location
        location ~ /websocket/ {
            proxy_http_version 1.1;
            proxy_pass http://127.0.0.1:8003;
            proxy_redirect off;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_read_timeout 3600s;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection $connection_upgrade;
        }

  以上也是借鑑了網友的分享再加上自己的一點優化，僅供參考。