nonsensebot/app/modules/latency.py

"""
This module simply returns the latency between a message being sent and the bot receiving it.

It also supports a rudimentary federation latency check, by sending a request to the target homeserver.
"""
import urllib.parse

import niobot
import time
import httpx


class LatencyModule(niobot.Module):

    @niobot.command("latency", aliases=["ping"])
    async def latency(self, ctx: niobot.Context, homeserver: str = None):
        """
        See the bot's latency.
        
        If you supply a homeserver, it will also show the federation latency to that homeserver.
        """
        latency = ctx.latency

        homeserver = homeserver or ctx.message.sender.split(":")[1]
        if not homeserver.startswith("http"):
            homeserver = f"https://{homeserver}"

        parsed = urllib.parse.urlparse(homeserver)
        loc = "https://" + parsed.netloc
        try:
            start_resolv = time.perf_counter()
            homeserver = await niobot.resolve_homeserver(parsed.netloc)
            end_resolv = time.perf_counter()
            resolv = round(end_resolv - start_resolv, 2)
        except ValueError as e:
            await ctx.respond("\N{WARNING SIGN} Failed to resolve homeserver: " + str(e))
            homeserver = loc
            resolv = -1

        async with httpx.AsyncClient(headers={"User-Agent": niobot.__user_agent__}) as client:
            timings = []
            for rnd in range(5):
                start = time.perf_counter()
                try:
                    res = await client.get(f"{homeserver}/_matrix/federation/v1/version")
                    res.raise_for_status()
                except httpx.HTTPError:
                    timings.append(-1)
                else:
                    end = time.perf_counter()
                    timings.append(end - start)
            fed_latency = sum(timings) / len(timings) * 1000

        hs_target = homeserver[8:]
        return await ctx.respond(
            "Latency: {:,.2f}ms ({:,.2f}ms to resolve homeserver, federation latency to {!r}: {:,.2f}ms)".format(
                latency,
                resolv * 1000,
                hs_target,
                fed_latency
            )
        )