#twisted

hi, i have a serial connection which can handle approx 40 frames per second. my routine can calculate approx 2000 frames per second. is there any best practice or convenience for only accepting as much data as can be handeled?

hey all, looking for some advice here. I'm building an app that has a mail server via internet.TCPServer(port, SMTPFactory(...)) and I'd like the port # to be variable via a config file. The app gets pkgd up as an RPM and I have a systemd .service file that runs twisted and my app. Ideally, being that it's a mail server, it'd run on port 25. The docs show me how to do the socket activation, but given that it's in the .service file

rnix, twisted has a "producer/consumer" pattern, but tbh that's largely just a technique of structuring code, rather than a library that you can use https://twistedmatrix.com/documents/current/cor...

in the future, tubes ( https://github.com/twisted/tubes ) will hopefully make it easier to build systems with backpressure like that

fwiw, I have stumbled across this: http://superuser.com/a/892391, but I have to set that privilege on the python interpreter used to run twistd and that just feels wrong.

SirScott, i think irc cut your first line; "but given that it's in the .service file"..

asdf: oh, thanks!

asdf: thx, will take a look

... .service file, I lose the ability to change the port with a config file. Any suggestions for how I might allow execution on 25, but switching to a diff # if the user desires?

asdf: maybe best is to store a timestamp when the last frame has been calculated and skip calculation for this connection in calculation loop as long as my connections is not ready to receive

SirScott: you probably want systemd itself to bind the socket using a .socket file, in which case you change the port by changing the systemd configuration file.

SirScott: that is, the port config is in the .socket file and that's what the user should be changing in order to change the configuration.

foom: Yeah, hoping to have the configuration of the app in one location though, e.g. /etc/myapp/app.conf and not have them go change the .service file also.

foom: but if there's simply no way to consolidate, then that's just the way it is!

SirScott: well, if you don't want socket activation, you can have systemd run twistd as root. twistd can drop privs after loading all the python code and running a bunch of startup grunk -- which includes binding ports -- but before actually starting serving.

foom: interesting idea. Right now i have systemd doing that privilege dropping. Is it just the -u and -g args to twistd?

Yes. Although i'd really recommend having systemd do it for you, it's much simpler to drop privs *before* loading a mass of code than after.

(Just on general principles, I mean.)

Maybe allowing python to listen on privileged ports isn't such a big deal afterall.

pawelmhm submitted <https://tm.tl/#8212>; - Invalid HTTP header not handled properly in HTTP client (unassigned) for review

I have some data to send, like 100MB.

how can I send it in a row ?

callLater with the delay as 0 ?

introom: that would work

how does the reactor queue the callbacks ?

say, for example, if 3 different functions all do a reactor.callLater(0, func{a,b,c})

which func gets called first ?

you shouldn't rely on the order

so "doesn't matter"

pawelmhm submitted <https://tm.tl/#8110>; - setting `t.i.b.DelayedCall.debug = True` causes all tests to fail in Python 3 (unassigned) for review

Hello

i have a little question, regarding a basic TCP server using a Factory object which creates Protocols objects. I am looking for a way to make another instanciated object available to every instanciated Protocol objected... i am not good at Object Oriented Programming... neither i am to programming... but i would love to know if someone can explain me basically what "design pattern" i have to use for such a thing