python基于FastAPI实现一个简易的在线用户统计功能

pip install fastapi uvicorn

python main.py

uvicorn main:app --reload --host 0.0.0.0 --port 8001

from fastapi import FastAPI, Request, Depends, HTTPException
from collections import defaultdict
from datetime import datetime, timedelta
import asyncio
import json
import os

app = FastAPI()

# 存储客户端的心跳数据
clients_last_heartbeat = defaultdict(datetime)

# 每个IP请求时间间隔限制为1秒
last_request_time = defaultdict(datetime)

# 在线客户端统计
online_clients = set()

# 心跳超时时间设置为1分钟
HEARTBEAT_TIMEOUT = timedelta(minutes=10)

# 用户数据文件路径
USER_DATA_FILE = "users_data.json"

# 加载用户数据
def load_user_data():
    if os.path.exists(USER_DATA_FILE):
        with open(USER_DATA_FILE, "r") as f:
            return json.load(f)
    return {}

# 保存用户数据
def save_user_data(data):
    with open(USER_DATA_FILE, "w") as f:
        json.dump(data, f)

# 初始化用户数据
all_users = load_user_data()

@app.on_event("startup")
async def startup_event():
    # 启动后台任务，每1分钟检查一次在线设备
    asyncio.create_task(remove_offline_clients())

async def remove_offline_clients():
    """
    定时任务：移除超过心跳超时时间未发送心跳的客户端
    """
    while True:
        await asyncio.sleep(HEARTBEAT_TIMEOUT.total_seconds())
        now = datetime.utcnow()
        # 找出超过超时时间未发送心跳的设备，并将其从在线列表中移除
        offline_clients = {ip for ip, last_heartbeat in clients_last_heartbeat.items()
                           if now - last_heartbeat > HEARTBEAT_TIMEOUT}
        
        # 从在线设备中移除离线的客户端
        for client in offline_clients:
            online_clients.discard(client)
            del clients_last_heartbeat[client]  # 删除心跳记录

        print(f"清除离线客户端, 当前在线客户端数量: {len(online_clients)}")

# 请求频率限制，1秒内只能请求一次
def request_limit(request: Request):
    client_ip = request.client.host
    now = datetime.utcnow()
    
    if client_ip in last_request_time and (now - last_request_time[client_ip]).total_seconds() < 1:
        raise HTTPException(status_code=429, detail="Too Many Requests")
    
    last_request_time[client_ip] = now

@app.post("/heartbeat")
async def receive_heartbeat(request: Request, limit: None = Depends(request_limit)):
    """
    接受客户端的心跳包
    """
    client_ip = request.client.host
    now = datetime.utcnow()
    # 更新心跳时间并将客户端标记为在线
    clients_last_heartbeat[client_ip] = now
    online_clients.add(client_ip)
    
    # 更新所有用户数据并保存到文件
    all_users[client_ip] = now.isoformat()
    save_user_data(all_users)
    
    return {"message": "Heartbeat received", "ip": client_ip}

@app.get("/online_clients")
async def get_online_clients(request: Request, limit: None = Depends(request_limit)):
    """
    获取当前在线客户端数量
    """
    return {"online_clients_count": len(online_clients)}

@app.post("/online_clients")
async def get_online_clients2(request: Request, limit: None = Depends(request_limit)):
    """
    获取当前在线客户端数量
    """
    return {"online_clients_count": len(online_clients)}

@app.get("/total_users")
async def get_total_users(days: int = 7, request: Request = None, limit: None = Depends(request_limit)):
    """
    获取最近n天活跃的用户数
    """
    now = datetime.utcnow()
    cutoff_date = now - timedelta(days=days)
    
    # 筛选最近n天活跃的用户
    recent_users_count = sum(
        1 for last_seen in all_users.values()
        if datetime.fromisoformat(last_seen) >= cutoff_date
    )
    
    return {"recent_users_count": recent_users_count, "days": days}

if __name__ == '__main__':
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=8001)