Mailman 3 March 2011 - Twisted-web

Test
by Philippe Lafoucrière 05 Aug '21

05 Aug '21

Hi all just a test

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integrating inotify into a protocol
by Jason Pepas 30 Mar '11

30 Mar '11

hey guys, I'm new to twisted, and I'm trying to figure out how to integrate the inotify support into a client protocol. let's say I have a client protocol which connects to a server and stays connected, like the "Echo" example here: http://twistedmatrix.com/documents/10.2.0/core/howto/clients.html#auto3 I've taken that example a tweaked it so that it echos back to the server, rather than to stdout (see echo.py, attached), and takes its port number as sys.argv[1]. now, I can start the "server": $ cat | socat - tcp4-listen:1234 and start the client: $ python echo.py 1234 Started to connect. Connected. and if I type something into the server, it gets printed on client's stdout, and then echoed back to the server: $ cat | socat - tcp4-listen:1234 blah blah $ python foo.py 1234 Started to connect. Connected. blah life is good. now, let's say I want to integrate inotify support into my persistent client. let's say that whenever a new file appears in /tmp, I want to client to announce this file to the server, over its persistent connection. accordingly, I've added 'def announceNewFile()' to the Echo() protocol class (see echo_inotify, attached). but herein lies the rub: the inotify notifier just takes a list of callback functions, not a list of objects. so how can I get the notifier to call a method on my Echo protocol object? another way to say this is that the protocol/client/factory side of things is all object-oriented, but the inotify side of things is just procedural. n'ere the twain shall meet? specifically, the notifier expects the callback to accept 3 args: _Watch object, path, and mask. so, when you try to pass in a class method as one of its callbacks, you get something like this: exceptions.TypeError: unbound method announceNewFile() must be called with Echo instance as first argument (got _Watch instance instead) halp? -jason

2 2

Question regarding callLater() and service creation
by Eric Chamberlain 09 Mar '11

09 Mar '11

I'm creating a service using Twisted. It has nothing to do with networking (I know that Twisted is an event-driven networking engine... stay with me here :). It's simply polling a database every 30 seconds. I'm using callLater() once the work has been completed. My question is does the reactor spawn a new thread once the callLater() timeout has been reached? If so, this would mean that the work being done may be effected by the GIL, correct? I may make more services like this where Twisted is used to create the service. These services may do a lot of heavy lifting... and may have nothing to do with networking. However, I like the fact that Twisted gives me a base for creating services. I also like the fact that if I do any network related services I'm using the same lib... which will use the same method to launch the service, etc. Even with all of these pros I still feel like I may be using the wrong tool for the job. Maybe I answered my own question... for non-network related services, services that will do a lot of heavy lifting, etc. fork a process (there are plenty of classes out there that daemonize scripts easily enough) and use Twisted for all event-driven networking related services. I'd be interested to know what you guys think. Thanks in an advance! Eric Chamberlain Confidentiality Notice: This e-mail may contain proprietary information some of which may be legally privileged. It is for the intended recipient(s) only. If you believe that it has been sent to you in error, please notify the sender by reply e-mail and delete the message. Any disclosure, copying, distribution or use of this information by someone other than the intended recipient(s) is prohibited and may be unlawful.

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Twisted-web March 2011