Flask长轮询即时消息

轮询是每隔多久的时间请求一次
长轮询是请求到来就夯住，并设置超时时间，有值就瞬间返回。

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


app = Flask(__name__)
app.secret_key = str(uuid.uuid4())


USERS = {
    '1': {'name': '小黑', 'count': 1},
    '2': {'name': '小胖', 'count': 0},
    '3': {'name': '小铁锤', 'count': 0},
}

QUEUE_DICT = {
    # 'uuid': Queue()队列   格式
}


@app.route("/user/list")
def user_list():
    user_uuid = str(uuid.uuid4())               # 生成用户随机字符串
    QUEUE_DICT[user_uuid] = queue.Queue()        # 引用队列消息
    session["current_user_uuid"] = user_uuid    # session存放uuid字符串
    return render_template("user_list.html", users=USERS)


@app.route("/vote", methods=["POST"])
def vote():
    uid = request.form.get('uid')     # 获取uuid值
    USERS[uid]['count'] += 1         # 让字典中的值自增
    for q in QUEUE_DICT.values():     # 循环获取队列中的值并添加到USERS
        q.put(USERS)
    return "投票成功"


@app.route("/get/vote", methods=["get"])
def get_vote():
    user_uuid = session["current_user_uuid"]    # 获取session中的存储的uuid值
    q = QUEUE_DICT[user_uuid]                  # 获取字典中uuid对应的Q()

    ret = {"status": True, "data": None}    # 返回状态码
    try:
        users = q.get(timeout=5)     # 异常就夯(hang)住5秒
        ret["data"] = users
    except queue.Empty:
        ret["status"] = False
    return jsonify(ret)

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