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Singleton DA possible?
by Brad Clements 17 Jul '02

17 Jul '02

The gvibDA interbase adapter really must have exactly one database connection shared among all threads. Even though the DA is derived from THUNKED_TM, there are still multiple instances of the DA created, one for each thread (depending on server load). What I really want is "one DA" that is controlled through a thread-lock for all threads. I realize I may need to create a proxy object.. any suggestions on how best to design this? -- Also, even running Zope with -t 1, I still sometimes get 2 DA objects. I can even see that the __del__ method on the earlier DA instance is being called. But that still messes it up. Brad Clements, bkc(a)murkworks.com (315)268-1000 http://www.murkworks.com (315)268-9812 Fax AOL-IM: BKClements

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Confusing segfault for Zope2 head on RH7.3
by barry＠zope.com 17 Jul '02

17 Jul '02

Working on the Zope 2.7 branch I noticed a very strange crash while running the test suite. I re-checked out the Zope 2 cvs head, rebuilt everything from scratch and I still get the crash. I'm about out of ideas so I thought I'd post what I know here in case anyone else can confirm or give clues. First off, I'm using a fresh checkout of the Zope 2 cvs head with a virgin Python 2.1.3 (although a cvs head of the Python 2.1 maintenance branch has the same problem). I've rebuilt Python 2.1.3 with only the -g option (no -O, although it makes no difference), and I've rebuilt Zope using this command: % python2.1 setup.py build_ext -i which also builds with just the -g option, although that also makes no difference. Note that I've also built using "python2.1 wo_pcgi.py" and that also makes no difference. I then run the test suite like so: % PYTHONPATH=lib/python python2.1 utilities/testrunner -a and I reliably get a crash in ISO_8859_1_Splitter.c I've boiled it down to the following simplified test case: -------------------- snip snip --------------------crash.py from Products.PluginIndexes.TextIndex.Splitter.ISO_8859_1_Splitter.ISO_8859_1_Splitter import ISO_8859_1_Splitter x = ISO_8859_1_Splitter('hello world') list(x) -------------------- snip snip -------------------- run it like so: % PYTHONPATH=lib/python python2.1 crash.py The top of the backtrace is: #0 PyErr_SetString (exception=0x6e727574, string=0x402660dc "Splitter index out of range") at Python/errors.c:69 #1 0x402658af in ISO_Splitter_item (self=0x843ed98, i=2) at Products/PluginIndexes/TextIndex/Splitter/ISO_8859_1_Splitter/src/ISO_8859_1_Splitter.c:357 #2 0x0808b98d in PySequence_List (v=0x843ed98) at Objects/abstract.c:1258 #3 0x080b934f in builtin_list (self=0x0, args=0x810137c) at Python/bltinmodule.c:1357 ... (I hacked the C code to rename Splitter_item() in ISO_8859_1_Splitter.c to ISO_Splitter_item() for ease of setting the break point.) Here's the deal. Splitter_item() cruises along as expected until it hits the end of the text. word is Py_None and it drops into the clause that sets the IndexError exception. AFAICT, there are no reference counting bugs in the code. At the PyErr_SetString() call PyExc_IndexError is a perfectly valid PyObject*, but just one stack frame later, inside the PyErr_SetString, the exception object is a completely bogus address. PyErr_SetString() is not getting the same object that Splitter_item() is providing in the first argument. Note that the second argument, a char* is just fine. Stepping through the code with gdb gives no help. I can set break points and inspect all the objects created and decref'd and everything appears okay. Printing PyExc_IndexError right before the call shows nothing strange, but stepping into PyErr_SetString() shows the first arg is corrupted. I don't get it. I've show the other PLabbers and it perplexes them too. :) To make matters weirder, we've tested this on various Linux flavors and versions. On RH6.1 and MD8.{0,1} it works just fine -- no crash. The /only/ system that I've seen the crash is RedHat 7.3, and there it crashes on both of my up-to-date RH7.3 systems, every time, and reliably. I think I've eliminated gcc as a culprit because most of our Linux boxes are using the same gcc version, according to gcc -v: Reading specs from /usr/lib/gcc-lib/i386-redhat-linux/2.96/specs gcc version 2.96 20000731 (Red Hat Linux 7.3 2.96-110) i.e 2.96 20000731. The /only/ difference that I can tell is the glibc version. My RH7.3 systems have glibc 2.2.5 and on all the other systems glibc's are older; no system with glibc 2.2.4 or earlier exhibits the crash. I have not tested gcc 3.1 and I have not tried other glibc's on RH7.3. I'd really like to know if anybody else on RH7.3 either sees the same crash or doesn't. And if so <wink> what version of gcc and glibc you've got. I'm starting to suspect a glibc bug, but it's dang strange. -Barry

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Adding Items to Object Manager and Folders
by Ross Boylan 17 Jul '02

17 Jul '02

The Zope Developer's Guide and the API docs (Zope 2.5) present different stories about how to add things to object managers. I don't really follow what the API stuff is doing. This is a request for clarification. Devguide says do def addFunction(dispatcher, id): "Create object and add to self" p = SomeProduct(id) dispatcher.Destination()._setObject(id, p) This makes sense, though, as commented at http://www.zope.org//Members/michel/Projects/Interfaces/ObjectManager, it relies on a private, undocumented method. addFunction is in outer scope of a module, and is hooked up wtih various calls in ___init__.py. On the other hand, the ObjectManager API says to do self.manage_addProduct['OFSP'].manage_addFolder(id, title). First, what scope should that be done in? Second, this seems to create one product (OFSP) and then add a folder to it, so that it creates two, nested products. The API for Folder mentions manage_addFolder as a constructor, but again the scope is unclear to me. Presumably it needs to know what to add it to, but that is not passed in. Finally, the use of id in two places in the first code snippet (one apparently associated with the container, the other with the object) seems like an invitation to trouble. Why is it done that way? One reason I want to know this is that I'm considering having a container that would automatically label (or set id) of its contents (e.g., 'a' is first, 'b' is second....). Thanks for any light you can shed.

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Re: [Zope-CMF] CMF Usabiltiy
by Tim Hoffman 16 Jul '02

16 Jul '02

Hi For what it is worth here are some code snippets from the monkeypatch that adds the basics to show what I have been doing. It is a bit messy and probably not the best way to do it, but this gives you the gist of what is going on. First off I have been monkeypatching the DefaultDublinCoreImpl and adding the following field and method. I also override the behaviour of manageAfterClone # UniqueId ----------------------------------------------------- security.declarePublic( 'UniqueId' ) def UniqueID( self ): '''Designing Futures element - UniqueID''' try: return self.unique_id except: return "" #------------------------------------------------------------------ import md5, base64, time, string def ETIMakeUniqueID(id): ''' Generate a unique id ''' oid=md5.new() oid.update(id) oid.update(str(time.time())) oid=oid.digest() oid=string.strip(base64.encodestring(oid)) return 'DF_OID_'+oid.replace('/','$') I need to extend the functionality of manage_afterClone so that if an object is cloned/copied it needs to have the UniqueID regenerated, otherwise we will end up with duplicate ID's (not a good thing) def manage_afterClone(self,obj): obj.unique_id = ETIMakeUniqueID(obj.title_or_id()) Overide the __init__ method in DefaultDublinCoreImpl to include self.unique_id = ETIMakeUniqueID(title) So that the unique id is initialised on object creation. The bind/rebind these methods to the base classes, so that all content types will exhibit this behaviour. DefaultDublinCoreImpl.UniqueID = UniqueID DefaultDublinCoreImpl.__init__ = __init__ Item.manage_afterClone = manage_afterClone Then I set up an Index and Metadata for UniqeID in the portal_catalog. Now any object can be found by UniquID. Irrespective of whats it's path is, by using the catalog. I find also that an awfull lot of the time the metadata is often sufficient without having to retrieve the object. Regards Tim On Fri, 2002-07-12 at 23:44, J C Lawrence wrote: > On 12 Jul 2002 14:43:23 +0800 > Tim Hoffman <timhoffman(a)cams.wa.gov.au> wrote: > > > This is a feature I too wanted, and my solution was to to give every > > object a unique object ID (new metadata field) which get's updated if > > the object is cloned. This Object ID is then catalogued, and then > > content which needs links uses the object Id plus a retrieval > > method. This way doc's can move anywhere and no broken links. > > Neat. Smart. Might be a good idea to throw the details and a sample > code blob up on the Collector for others to follow. > > -- > J C Lawrence > ---------(*) Satan, oscillate my metallic sonatas. > claw(a)kanga.nu He lived as a devil, eh? > http://www.kanga.nu/~claw/ Evil is a name of a foeman, as I live.

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rfc1123_date
by Magnus Heino 15 Jul '02

15 Jul '02

Why is rfc1123_date a method in App.Common, and not a method on DateTime.DateTime? How am I supposed to use it from dtml/zpt? /Magnus

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creating products
by Dirk Datzert 14 Jul '02

14 Jul '02

Hi, I want to write a simple product which saves some data. Which base python-zope class is necessary to store user-structured data in the following format: zope-container non-zope structure object 1 non-zope object-container non-zope structure object 2 ... Which base class must be the zope-container ? SimpleItem, PropertyManager, ObjectManager, or what. Which base class must the non-zope structured data ? Persistent, PropertyManager, SimpleItem Regards, Dirk

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Tracker-Catalog
by Sebastian Sippl 12 Jul '02

12 Jul '02

Hi, Is there a way to access the Trackers(TrackerBase-Product) Catalog(and its contents) via DTML-var or Python script? Sebastian

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?determine if x is a string or array in PythonScript
by Tim Hoffman 12 Jul '02

12 Jul '02

Hi I must be stupid or something, but I can't for the life of me work out a simple way of determining if a variable contains a string or array, in a PythonScript in Zope. I can't import type and or use type() function. isinstance doesn't work because I can't give a type as the second arg. I obviously just can't see the wood for the trees, can anyone help out this silly individual ? Rgds Tim

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vulnerability in stock Zope
by seb bacon 11 Jul '02

11 Jul '02

Production sites running a stock Zope are vulnerable to abuse of their server if they have not removed the 'Examples' folder. For example, anyone could use http://notcarefulenough.com/Examples/FileLibrary as a warez repository. I propose changing the 'View' permission on the entire folder to 'Manager'-only to protect some of us from ourselves ;-) Any objections? seb

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IIS / login bug
by seb bacon 11 Jul '02

11 Jul '02

There is a bug in IIS[1] which causes cookies to be dropped during a redirect. The result in the CMF is that a login fails when it is combined with a redirect, as happens following an attempted access of a forbidden resource when using the CookieCrumbler. Now, I'm not too familiar with the pcgi mechanism, or IIS, and not having my own Windows development machine makes debugging a bit problematic. So I'd appreciate advice from IIS / pcgi savants (there must be some, somewhere ;-) M$ says the workaround is to rename the zope.pcgi script to nhp-zope.pcgi, which indicates to IIS that it should pass on all HTTP headers untouched. The problem here is that the ZPublisher defers to the server to produce some of the relevant HTTP headers, namely the protocol version / status header ('HTTP/1.1 200 OK'). Without this header, browsers display all the headers as if they are part of the body. My solution is to alter the pcgi_publisher.py script so that it passes the publish_module a ZServerHTTPResponse object - which *will* add all the relevant server headers [2]. However, altering the pcgi_publisher script seems to have no effect, whatsoever, on anything. Should my approach work? Are there better workarounds? Thanks, seb -- References [1] http://support.microsoft.com/default.aspx?scid=kb;EN-US;q176113 [2] pcgi_publisher.py patch (watch for line wraps) *** pcgi_publisher.py Thu Sep 7 17:40:07 2000 --- nhp-pcgi_publisher.py Thu Jul 11 09:56:42 2002 *************** *** 294,306 **** ### IIS hack to fix broken PATH_INFO ### taken from Mike Fletcher's win_cgi_module_publisher import string if env.has_key('SERVER_SOFTWARE') and string.find(env['SERVER_SOFTWARE'],'Microsoft-IIS') != -1: script = filter(None,string.split(string.strip(env['SCRIPT_NAME']),'/')) path = filter(None,string.split(string.strip(env['PATH_INFO']),'/')) env['PATH_INFO'] = string.join(path[len(script):],'/') ! try: ! self.publish_module(self.moduleName,stdin=stdin,stdout=stdout,stderr=stderr,environ=env) except: self.fatalError("unable to publish module") --- 294,308 ---- ### IIS hack to fix broken PATH_INFO ### taken from Mike Fletcher's win_cgi_module_publisher import string + from ZServer.HTTPResponse import ZServerHTTPResponse + iis-nhp-response = None if env.has_key('SERVER_SOFTWARE') and string.find(env['SERVER_SOFTWARE'],'Microsoft-IIS') != -1: script = filter(None,string.split(string.strip(env['SCRIPT_NAME']),'/')) path = filter(None,string.split(string.strip(env['PATH_INFO']),'/')) env['PATH_INFO'] = string.join(path[len(script):],'/') ! iis-nhp-response = ZServerHTTPResponse(stdout=stdout, stderr=stderr) try: ! self.publish_module(self.moduleName,stdin=stdin,stdout=stdout,stderr=stderr,environ=env,response=iis-nhp-response) except: self.fatalError("unable to publish module")

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