如何在不停止 discord.py 中其余脚本的情况下运行循环

Question

我试图制作一个类似于 Minecraft 服务器控制台的不和谐机器人，但是，我觉得这是一个非常基本的问题，我希望机器人继续发送 Minecraft 服务器的输出并通过消息写入输入一个特定的通道，但当然，如果你有一个循环运行程序的其余部分没有运行，我尝试了多进程和多线程，但由于异步函数它没有工作。 这是我的代码：

minecraft_dir = r"C:\Users\Pablo\Desktop\1.18 server - Copy"
executable = r'java -Xms4G -Xmx4G -jar "C:\Users\Pablo\Desktop\1.18 server - Copy\server.jar" java'
process = None

async def start_serv(msg):
  os.chdir(minecraft_dir)
  process = subprocess.Popen(executable,stdin=PIPE,stdout=PIPE, text=True)
  for line in process.stdout:
    await msg.channel.send(line)

def serv_cmd(cmd):
  if cmd == "stop":
    process = None
  cmd = cmd + "\n"
  cmd = cmd.encode()
  process.stdin.write(cmd)
  process.stding.flush()

@client.event
async def on_message(message):
  global process
  if message.author.id != client.user.id and message.channel.name == "mc-server-console":
    command = message.content
    command=command.lower()
    if command == "start":
      if process == None:
        await message.channel.send("yessir")
    if process != None:
      serv_cmd(command)

这是我的多线程尝试：

async def start_serv():
  os.chdir(minecraft_dir)
  process = subprocess.Popen(executable,stdin=PIPE,stdout=PIPE, text=True)
  for line in process.stdout:
    await channel.send(line)
    time.sleep(0.1)

def serv_cmd(cmd):
  if cmd == "stop":
    process = None
  cmd = cmd + "\n"
  cmd = cmd.encode()
  process.stdin.write(cmd)
  process.stding.flush()

def main():
  @client.event
  async def on_message(message):
    global process
    if message.author.id != client.user.id and message.channel.name == "mc-server-console":
      command = message.content
      command=command.lower()
      if command == "start":
        if process == None:
          await message.channel.send("yessir")
          thread2.start()
      if process != None:
        serv_cmd(command)

thread1 = threading.Thread(target=main)
thread1.start()
thread2 = threading.Thread(target=start_serv)

如果有人知道只在服务器输出更新时发送消息的方法，我认为这也可以。

Answer 1

线程实际上在这里并不是一个好的举措。大多数时候discord.py 的线程不会是“线程安全的”。你可以弄乱Lock's，但尽可能避免它们更容易。请注意这是一个原型，因为我没有测试过任何一个（我没有 MC）。我会把它当作一个概念，用它来指导你

让我们介绍一种在不阻塞事件循环的情况下做你想做的事的方法。

import os
import subprocess
import aiohttp
import discord
from discord.ext import commands
from typing import TYPE_CHECKING, Generic, TypeVar, Any

if TYPE_CHECKING:
    from asyncio import AbstractEventLoop
    
B = TypeVar('B', bound='commands.Bot')

# We'll make a class caleld MinecraftRunner
# to hold all minecraft based operations
    
class MinecraftRunner(Generic[B]):
    def __init__(self, bot: B) -> None:
        self.bot: commands.Bot = bot
        self.loop: AbstractEventLoop = bot.loop
        self.session: aiohttp.ClientSession = getattr(bot, 'session', aiohttp.ClientSession())
        
        self.minecraft_dir: str = r"C:\Users\Pablo\Desktop\1.18 server - Copy"
        self.executable: str = r'java -Xms4G -Xmx4G -jar "C:\Users\Pablo\Desktop\1.18 server - Copy\server.jar" java'
        
        # We'll use webhooks to send to the channel instead of `channel.send`. 
        # This will not rate-limit our bot.
        self.webhook_url: str = '' 
        
        # Using loop.create_task will allow us to not block
        # the main event loop.
        self.runner_task = self.loop.create_task(self.main_loop())
        
    async def send_to_webhook(self, *args, **kwargs) -> discord.WebhookMessage:
        if not (webhook := getattr(self, 'webhook', None)):
            self.webhook = webhook = await (discord.Webhook.from_url(self.webhook_url, session=self.session, bot_token=self.bot.http.token)).fetch()

        return await webhook.send(*args, **kwargs)
    
    async def main_loop(self) -> None:
        await self.bot.wait_until_ready() # Don't do anything until our bot is ready to do work.
        
        os.chdir(self.minecraft_dir)
        self.process = process = subprocess.Popen(self.executable,stdin=subprocess.PIPE,stdout=subprocess.PIPE, text=True)
        
        for line in process.stdout:
            await self.send_to_webhook(line)
    
# Let's put our on_message into a simple cog as well
class MinecraftListener(commands.Cog):
    def __init__(self, bot: commands.Bot) -> None:
        self.bot: commands.Bot = bot
        self.minecraft_runner = MinecraftRunner(bot)
        
    def cog_unload(self) -> None:
        self.minecraft_runner.runner_task.cancel()
        
        try:
            delattr(self.minecraft_runner, 'runner_task')
        except AttributeError:
            pass
        
    async def send_command(self, command: str) -> None:
        command += '\n'
        command.encode()
        self.minecraft_runner.process.stdin.write(command)
        self.minecraft_runner.process.stdin.flush()
    
    @commands.Cog.listener()
    async def on_message(self, message: discord.Message) -> Any:
        if message.author.bot: # This message was sent from a bot.
            return
        if message.webhook_id: # This message is a webhook message.
            return
        
        command = message.content.lower()
        channel = message.channel
        
        if command == 'start':
            if not hasattr(self.minecraft_runner, 'runner_task'):
                self.minecraft_runner.runner_task = self.minecraft_runner.loop.create_task(self.minecraft_runner.main_loop())
                return await channel.send('The process has been started.')
            
            return await channel.send('The process is already started.')
                
        elif command == 'stop': # Stop the process
            if not hasattr(self.minecraft_runner, 'runner_task'):
                return await channel.send('The process is not running!')
            
            return self.cog_unload()
        
        # This isn't a custom command, send it to the minecraft process
        await self.send_command(command)