Re: [ZODB-Dev] I would like to know if api exists nowadays to get list of all objects which where modified in a transaction ?
Le 26/07/2011 09:55, Stéphane Klein a écrit : Hi, some time ago, someone ask how to get list of all objects which where modified in a transaction : http://article.gmane.org/gmane.comp.web.zope.zodb/5734 Jim Fulton said « there isn't a public API for this ». I would like to know if this api exists nowadays ? No idea ? -- Stéphane Klein steph...@harobed.org blog: http://stephane-klein.info Twitter: http://twitter.com/klein_stephane pro: http://www.is-webdesign.com ___ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org https://mail.zope.org/mailman/listinfo/zodb-dev
Re: [ZODB-Dev] Twisted, ZODB and zc.twist
Hello Erik. As the author, I'll suggest that you move on to a ZODB connection pool used by the usual Twisted-provided thread pool. zc.twist is maybe interesting and maybe clever, but of very limited usefulness. I suspect it is only used in zc.async, and that's probably as it should be. It's a case of premature generalization. If you are going to use Twisted in anything like a normal way, and the ZODB in anything like a normal way, use a connection pool and threads. Best, Gary On Jul 28, 2011, at 4:12 PM, Erik Allik wrote: Hello everyone, I hope this is the right mailing list to post this question to. I'm trying to build an Twisted application that uses ZODB and I've also found zc.twist. I've read its README as well as the source code to try to understand how exactly and why I should use zc.twist, and also asked the same questions on irc.freenode.net #zope but without a conclusive answer. What I'm not able to understand is whether using zc.twist will allow me to do all ZODB access in the main Twisted thread, or if still need to set up a thread pool and deferToThread any code that accesses the DB. The README of zc.twist has: Everything can be done within the main thread, so it can be full-bore Twisted usage, without threads. However, looking at the source code of zc.twist, I cannot find any reference to async communication (callbacks/polling) with ZODB, so it's difficult to conclude that all DB access is non-blocking and can be done in a single thread. Also, there are some examples with threads in the README. I would highly appreciate if somebody with a clearer understanding of this could explain to me whether I in fact need to set up a thread pool, and in any case, what exactly is zc.twist for regardless of whether it needs to be used with a threadpool or not. Thanks in advance! Regards, Erik Allik P.S. I'd be very thankful for any references to open source projects/code using ZODB with Twisted, or even zc.twist (besides zc.async). ___ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org https://mail.zope.org/mailman/listinfo/zodb-dev ___ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org https://mail.zope.org/mailman/listinfo/zodb-dev
Re: [ZODB-Dev] Twisted, ZODB and zc.twist
Gary, since you're the author of zc.twist (as I understand), I take this as an exhaustive answer, and thank you :) However, I'm still curious to know zc.twist would provide any benefit when used together with a thread pool. The thread examples in its README (which I find hard to understand) indicate that there must be some meaning to using zc.twist with threads. Thanks again and best regards, Erik 2011/7/29 Gary Poster gary.pos...@gmail.com: Hello Erik. As the author, I'll suggest that you move on to a ZODB connection pool used by the usual Twisted-provided thread pool. zc.twist is maybe interesting and maybe clever, but of very limited usefulness. I suspect it is only used in zc.async, and that's probably as it should be. It's a case of premature generalization. If you are going to use Twisted in anything like a normal way, and the ZODB in anything like a normal way, use a connection pool and threads. Best, Gary On Jul 28, 2011, at 4:12 PM, Erik Allik wrote: Hello everyone, I hope this is the right mailing list to post this question to. I'm trying to build an Twisted application that uses ZODB and I've also found zc.twist. I've read its README as well as the source code to try to understand how exactly and why I should use zc.twist, and also asked the same questions on irc.freenode.net #zope but without a conclusive answer. What I'm not able to understand is whether using zc.twist will allow me to do all ZODB access in the main Twisted thread, or if still need to set up a thread pool and deferToThread any code that accesses the DB. The README of zc.twist has: Everything can be done within the main thread, so it can be full-bore Twisted usage, without threads. However, looking at the source code of zc.twist, I cannot find any reference to async communication (callbacks/polling) with ZODB, so it's difficult to conclude that all DB access is non-blocking and can be done in a single thread. Also, there are some examples with threads in the README. I would highly appreciate if somebody with a clearer understanding of this could explain to me whether I in fact need to set up a thread pool, and in any case, what exactly is zc.twist for regardless of whether it needs to be used with a threadpool or not. Thanks in advance! Regards, Erik Allik P.S. I'd be very thankful for any references to open source projects/code using ZODB with Twisted, or even zc.twist (besides zc.async). ___ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org https://mail.zope.org/mailman/listinfo/zodb-dev ___ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org https://mail.zope.org/mailman/listinfo/zodb-dev
Re: [ZODB-Dev] Twisted, ZODB and zc.twist
On Jul 28, 2011, at 6:38 PM, Erik Allik wrote: Gary, since you're the author of zc.twist (as I understand), I take this as an exhaustive answer, and thank you :) However, I'm still curious to know zc.twist would provide any benefit when used together with a thread pool. The thread examples in its README (which I find hard to understand) indicate that there must be some meaning to using zc.twist with threads. The threads in the README are there to let me explore a running reactor within the doctest. They are not anything to emulate. The README overstates zc.twist's usefulness. As you point out, it blocks. If you assume that the ZODB is functioning normally, it won't block much but with standard definitions of blocking, it fails. For zc.async, that's fine--but a while True loop and a time.sleep() to give some breathing room probably would have been fine, with hindsight, and much simpler. The use of Twisted is a very questionable convenience, and the way zc.async uses Twisted is not to be copied 99% or more of the time. Gary Thanks again and best regards, Erik 2011/7/29 Gary Poster gary.pos...@gmail.com: Hello Erik. As the author, I'll suggest that you move on to a ZODB connection pool used by the usual Twisted-provided thread pool. zc.twist is maybe interesting and maybe clever, but of very limited usefulness. I suspect it is only used in zc.async, and that's probably as it should be. It's a case of premature generalization. If you are going to use Twisted in anything like a normal way, and the ZODB in anything like a normal way, use a connection pool and threads. Best, Gary On Jul 28, 2011, at 4:12 PM, Erik Allik wrote: Hello everyone, I hope this is the right mailing list to post this question to. I'm trying to build an Twisted application that uses ZODB and I've also found zc.twist. I've read its README as well as the source code to try to understand how exactly and why I should use zc.twist, and also asked the same questions on irc.freenode.net #zope but without a conclusive answer. What I'm not able to understand is whether using zc.twist will allow me to do all ZODB access in the main Twisted thread, or if still need to set up a thread pool and deferToThread any code that accesses the DB. The README of zc.twist has: Everything can be done within the main thread, so it can be full-bore Twisted usage, without threads. However, looking at the source code of zc.twist, I cannot find any reference to async communication (callbacks/polling) with ZODB, so it's difficult to conclude that all DB access is non-blocking and can be done in a single thread. Also, there are some examples with threads in the README. I would highly appreciate if somebody with a clearer understanding of this could explain to me whether I in fact need to set up a thread pool, and in any case, what exactly is zc.twist for regardless of whether it needs to be used with a threadpool or not. Thanks in advance! Regards, Erik Allik P.S. I'd be very thankful for any references to open source projects/code using ZODB with Twisted, or even zc.twist (besides zc.async). ___ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org https://mail.zope.org/mailman/listinfo/zodb-dev ___ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org https://mail.zope.org/mailman/listinfo/zodb-dev
