Mailman 3 June 2004 - Twisted

RE: [Twisted-Python] Local IP and factory shutdown
by Gill, Mandeep 24 Jun '04

24 Jun '04

>Gill, Mandeep wrote: >> Hi, >> I'm in the process of finishing a multicasting RTP streaming media >> server and client in Twisted but have encountered several issues that I >> can't figure out, > >Neat. Note that shtoom (shtoom.divmod.org) also has an RTP >implementation in Twisted - if you're planning to release your >code, there may be stuff we can borrow from each other. > Actually I extensively studied the Shtoom code before I started as it contained many ideas I could use and explained a lot of Twisted subtleties - I must thank you for that, it's well written and extremely easy to learn from. The RTP code is borrowed from Shtoom with a few changes to make it support other media formats in an independent manner - at the moment I'm multicasting 5 different MP3 streams around the house with it and it works fine. The system is my undergrad project, however once it's marked I plan to release the code, there's definitely stuff that can borrowed either way. >> Firstly, Is there any way to determine your own IP address from with >> Twisted, I've looked around everywhere and can't find away to achieve >> this except by setting up a loopback connection and reading it from the >> transport - but that only gives 127.0.0.1. Is there any way to determine >> all available local IPs? > >One trick I do in shtoom is put in a ConnectedUDP to the other end, then >read the local address off that. It's ugly, but gives me the IP of the >local interface that's being used for this connection. You could also >use STUN for this, of course. But that won't give you _all_ interfaces. > >I don't believe that this is possible in a portable way. Yeah, I saw that code in Shtoom, however when I tried it I only got '0.0.0.0' - dunno what was going on there. i think at the moment I'll just stick with gethostbyname(gethostname()) for internal IPs and leave the rest for now - NAT seems like too much pain. >> Oh yeah, there seem to be a few bugs in the current wxreactor support, >> most notably with any custom dialog boxes - the OK/Cancel return doesn't >> seem to be processed on time and causes a wxDateTime assertion error, >> does it work for anyone else? > >Neither wxsupport or wxreactor are suitable for heavy lifting. wxsupport >blocks whenever wx spawns a sub-event-loop (for dialogs, menus, and the >like) and wxreactor can give no better than the wxTimer's granularity. >The wx docs promise "no worse than 1s" granularity. On Linux, it doesn't >seem to be a problem. On Windows, tho, you're boned. > >Run the wx mainloop in your main thread, and spawn a second thread to >run the twisted event loop. You then use callFromThread() to pass things >to the twisted event loop, and you can make your own shim to pass stuff >back to the wx event loop. Again, shtoom has this code, in >shtoom/ui/wxui/ (thanks to Andy Hird for writing this). > > >Anthony wxreactor seems to be ok for most tasks, I have a fairly complex dynamic GUI running here, however the most random actions will just bring it down. I saw the threaded code in Shtoom and guess that’s the way to go, it just seems a lot of work if wxreactor can be fixed. Mandeep

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RE: [Twisted-Python] processProtocol woes and a plea for aid
by Gary Coulbourne 24 Jun '04

24 Jun '04

>It sounds like maybe the program you're calling isn't flushing its writes >to stdout. If it doesn't, there's no way for Twisted to see its output >until the program's output buffer overflows. Thanks! I suspect that's exactly it... he's just printing to stdout. It's easy enough to throw a flush in there. Great idea! Thanks again, as I would not have considered that otherwise. Peace, Gary This e-mail message is intended only for the personal use of the recipient(s) named above. This message should be considered a confidential communication, and as such is not subject to disclosure to anyone who is not an intended recipient. If you are not an intended recipient, you may not legally review, copy or distribute this message. If you have received this communication in error, please notify the sender(s) immediately by e-mail and delete the original message from your computer system.

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[Twisted-Python] Re: information
by glyph＠twistedmatrix.com 23 Jun '04

23 Jun '04

incest?

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RE: [Twisted-Python] Local IP and factory shutdown
by Gill, Mandeep 23 Jun '04

23 Jun '04

> >Have you looked at shtoom? http://www.divmod.org/Home/Projects/Shtoom/ >If your traffic is UDP, I'd recommend using STUN for the client. For >the server, "all available local IPs" is a fairly vague question. >IPv4? IPv6? With or without internet connectivity? Internal or >external IPs? Some of these questions aren't even answerable. Usually >if you want to provide advanced server configuration informations with >regard to domain names and IP addresses you need to tell the server >about them directly, with a config file of some sort. It varies by >protocol what that file has to say. > Thanks yeah I've looked quite a bit at Shtoom. I guess my question was fairly vague, I simply meant a method to determine all available internal IP4 addresses. I did consider systems such as STUN and such, however I am multicasting so the system won't work across the Internet or NAT anyway (thankfully as it makes it all lot simpler).

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[Twisted-Python] processProtocol woes and a plea for aid
by Gary Coulbourne 23 Jun '04

23 Jun '04

Howdy! I'm using processProtocol to talk to a program written by a coworker. It handles things fine, but it is asynchronous in that when I send a response to it, it may send several responses back, or it may just randomly send back a response. If I were handling this output a line at a time, it would be fine, but processProtocol seems to put all of the responses together... each response is followed by a \n. I naively assumed that each time a line was complete, Twisted would call my outRecieved. It seems, though, that dozens of respopnses can build up in the buffer before it was called. I'm certain I am missing out on something basic. Is there any way to set processProtocol to look at the \n as a signal to call outRecieved rather than to call it at some arbitrary time? I didn't see anything quickly obvious in the source, so I thought I would ask for advice. Thanks in advance for any help or suggestions! Peace, Gary This e-mail message is intended only for the personal use of the recipient(s) named above. This message should be considered a confidential communication, and as such is not subject to disclosure to anyone who is not an intended recipient. If you are not an intended recipient, you may not legally review, copy or distribute this message. If you have received this communication in error, please notify the sender(s) immediately by e-mail and delete the original message from your computer system.

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Re: [Twisted-Python] processProtocol woes and a plea for aid
by Phillip J. Eby 23 Jun '04

23 Jun '04

At 01:34 PM 6/23/04 -0400, Gary Coulbourne wrote: >Howdy! > >I'm using processProtocol to talk to a program written by a coworker. It >handles things fine, but it is asynchronous in that when I send a response >to it, it may send several responses back, or it may just randomly send >back a response. If I were handling this output a line at a time, it >would be fine, but processProtocol seems to put all of the responses >together... each response is followed by a \n. I naively assumed that >each time a line was complete, Twisted would call my outRecieved. It >seems, though, that dozens of respopnses can build up in the buffer before >it was called. > >I'm certain I am missing out on something basic. Is there any way to set >processProtocol to look at the \n as a signal to call outRecieved rather >than to call it at some arbitrary time? I didn't see anything quickly >obvious in the source, so I thought I would ask for advice. It sounds like maybe the program you're calling isn't flushing its writes to stdout. If it doesn't, there's no way for Twisted to see its output until the program's output buffer overflows. One quick way to check: are you always getting the messages in blocks of roughly N bytes, (except perhaps for the last block before the program exits)? If so, you need to get your coworker to flush his output buffer. Alternatively, depending on your platform, creating a pty (aka pseudoterminal) may be an option. This would be to convince your co-worker's program that it's talking to a console, and therefore should output data as it becomes available instead of buffering it. But that depends somewhat on the language/libraries being used by the program.

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[Twisted-Python] Calling Oracle stored procedure using adbapi
by Faisal Shibley 22 Jun '04

22 Jun '04

Hello Everybody, I have a stored procedure named test1() which I want to call from Twisted code using adbapi. Can anybody help me out with this problem. Some sample code could help me the best. Faisal Abdullah Shibley

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Re: [Twisted-Python] Re: Twisted-Python Digest, Vol 3, Issue 17
by dave＠krondo.com 22 Jun '04

22 Jun '04

You will want to use runInteraction. See the example here: http://twistedmatrix.com/pipermail/twisted-python/2004-June/007995.html The 'trans' object is just a wrapper around a DB API cursor, so you can do something like: return trans.callproc(procname, arg1, arg2, ...) dave ---- Original Message ---- From: Faisal Shibley Date: Tue 6/22/04 2:04 To: twisted-python(a)twistedmatrix.com Subject: [Twisted-Python] Re: Twisted-Python Digest, Vol 3, Issue 17 Hello everybody I want to call a Stored Procedure of Oracle using adbapi. can anyone help me in this? if someone can give me some sample code along with the description, I would be highly benifited Faisal Abdullah Shibley

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[Twisted-Python] Newbie Question: Running Twisted in a thread?
by brett hartshorn 22 Jun '04

22 Jun '04

Hello, So Twisted can not be run inside a thread, and must be 'on top' and start my other threads? After reading: http://twistedmatrix.com/documents/current/howto/threading it looks like i will have to schedule my own threads to be run inside the twisted main event loop. What is the best way to make my threads thread safe? Will the code below work? from twisted.internet import reactor def myThread(value): print value time.sleep(1) reactor.callInThread(myThread, 1) reactor.run() so when reactor enters its mainloop via reactor.run() it will call once per loop myThread, is this correct? Will the call to myThread block all other threads, and it should be thread safe then, correct? Is there a way to have myThread called at a certian time interval? I'd like to update it at 30hz. My old code just looked like this: def myThread(value): time.sleep(0.333333) while 1: scene.render() thanks for the help, -brett __________________________________ Do you Yahoo!? Yahoo! Mail Address AutoComplete - You start. We finish. http://promotions.yahoo.com/new_mail

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[Twisted-Python] duh--2.3.4
by Bill la Forge 22 Jun '04

22 Jun '04

I must have Python 2.4 on my mind. Sorry 'bout that! Bill ________________________________________________________________________ Yahoo! India Matrimony: Find your partner online. http://yahoo.shaadi.com/india-matrimony/

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Twisted June 2004