python 轮询，长轮询

Posted 2022-12-24 huay

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轮询相关

用于消息和投票等

轮询

1.采用js 定时请求。

html

<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <style>
        li
            cursor: pointer;
        
    </style>
</head>
<body>
    <ul id="userList">
        % for key,val in users.items() %
            <li uid="key">val.name (val.count)</li>
        % endfor %
    </ul>

    <script src="https://cdn.bootcss.com/jquery/3.3.0/jquery.min.js"></script>
    <script>

        $(function () 
            $(‘#userList‘).on(‘dblclick‘,‘li‘,function () 
                var uid = $(this).attr(‘uid‘);
                $.ajax(
                    url:‘/vote‘,
                    type:‘POST‘,
                    data:uid:uid,
                    success:function (arg) 
                        console.log(arg);
                    
                )
            );

        );


        /*
        获取投票信息
         */
        function get_vote() 
            $.ajax(
                url:‘/get/vote‘,
                type:"GET",
                dataType:‘JSON‘,
                success:function (arg) 
                    $(‘#userList‘).empty();
                    $.each(arg,function (k,v) 
                        var li = document.createElement(‘li‘);
                        li.setAttribute(‘uid‘,k);
                        li.innerText = v.name + "(" + v.count + ‘)‘ ;
                        $(‘#userList‘).append(li);
                    )

                
            )
        


        setInterval(get_vote,3000);

    </script>
</body>
</html>

View Code

python

from flask import Flask,render_template,request,jsonify


app = Flask(__name__)


USERS = 
    ‘1‘:‘name‘:‘jack‘,‘count‘:1,
    ‘2‘:‘name‘:‘rose‘,‘count‘:0,
    ‘3‘:‘name‘:‘anner‘,‘count‘:0,


@app.route(‘/user/list‘)
def user_list():
    import time
    return render_template(‘user_list.html‘,users=USERS)

@app.route(‘/vote‘,methods=[‘POST‘])
def vote():
    uid = request.form.get(‘uid‘)
    USERS[uid][‘count‘] += 1
    return "投票成功"

@app.route(‘/get/vote‘,methods=[‘GET‘])
def get_vote():

    return jsonify(USERS)


if __name__ == ‘__main__‘:
    # app.run(host=‘192.168.13.253‘,threaded=True)
    app.run(threaded=True)

View Code

长轮询

1.采用队列，递归，多线程实现。

html

<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <style>
        li
            cursor: pointer;
        
    </style>
</head>
<body>
    <ul id="userList">
        % for key,val in users.items() %
            <li uid="key">val.name (val.count)</li>
        % endfor %
    </ul>

    <script src="https://cdn.bootcss.com/jquery/3.3.0/jquery.min.js"></script>
    <script>

        $(function () 
            $(‘#userList‘).on(‘click‘,‘li‘,function () 
                var uid = $(this).attr(‘uid‘);
                $.ajax(
                    url:‘/vote‘,
                    type:‘POST‘,
                    data:uid:uid,
                    success:function (arg) 
                        console.log(arg);
                    
                )
            );
            get_vote();
        );

        /*
        获取投票信息
         */
        function get_vote() 
            $.ajax(
                url:‘/get/vote‘,
                type:"GET",
                dataType:‘JSON‘,
                success:function (arg) 
                    if(arg.status)
                        $(‘#userList‘).empty();
                            $.each(arg.data,function (k,v) 
                                var li = document.createElement(‘li‘);
                                li.setAttribute(‘uid‘,k);
                                li.innerText = v.name + "(" + v.count + ‘)‘ ;
                                $(‘#userList‘).append(li);
                            )
                    
                    get_vote();

                
            )
        

    </script>
</body>
</html>

View Code

python

from flask import Flask,render_template,request,jsonify,session
import uuid
import queue

app = Flask(__name__)
app.secret_key = ‘asdfasdfasd‘


USERS = 
    ‘1‘:‘name‘:‘jack‘,‘count‘:1,
    ‘2‘:‘name‘:‘rose‘,‘count‘:0,
    ‘3‘:‘name‘:‘anner‘,‘count‘:0,


QUEQUE_DICT = 
    # ‘asdfasdfasdfasdf‘:Queue()


@app.route(‘/user/list‘)
def user_list():
    user_uuid = str(uuid.uuid4())
    QUEQUE_DICT[user_uuid] = queue.Queue()

    session[‘current_user_uuid‘] = user_uuid
    return render_template(‘user_list.html‘,users=USERS)

@app.route(‘/vote‘,methods=[‘POST‘])
def vote():
    uid = request.form.get(‘uid‘)
    USERS[uid][‘count‘] += 1
    for q in QUEQUE_DICT.values():
        q.put(USERS)
    return "投票成功"


@app.route(‘/get/vote‘,methods=[‘GET‘])
def get_vote():
    user_uuid = session[‘current_user_uuid‘]
    q = QUEQUE_DICT[user_uuid]

    ret = ‘status‘:True,‘data‘:None
    try:
        users = q.get(timeout=5)
        ret[‘data‘] = users
    except queue.Empty:
        ret[‘status‘] = False

    return jsonify(ret)



if __name__ == ‘__main__‘:
    app.run(host=‘192.168.3.10‘,threaded=True)
    # app.run(threaded=True)

View Code

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