Re[2]: [ZODB-Dev] lazy BTreeItems
Hello Dieter Maurer,
Saturday, December 10, 2005, 12:32:35 AM, you wrote:
DM l = range(10)
DM for f in l: l.remove(f)
DM l
-- [1, 3, 5, 7, 9]
DM Due to the much more complex BTree structures, the results
DM of modifications during iteration might be even more surprising.
I know about this
Hello Tim Peters,
Saturday, December 10, 2005, 1:08:55 AM, you wrote:
TP The .keys(), .values(), and .items() methods of BTrees are very different
TP from those methods on dicts in that the BTree methods return lazy iterators
TP but the dict methods return lists.
I undestand that i need keys|values|items cast to list, and from this new list
get the new iterator.
And a funny situation
Starting debugger (the name app is bound to the top-level Zope object)
from OFS.ObjectManager import ObjectManager
from OFS.SimpleItem import SimpleItem
m = ObjectManager()
m._setObject('1',SimpleItem())
'1'
m._setObject('2',SimpleItem())
'2'
o_ids = m.objectIds()
o_ids
['1', '2']
m._delObject('1')
o_ids
['1', '2']
from Products.BTreeFolder2.BTreeFolder2 import BTreeFolder2
m = BTreeFolder2()
m._setObject('1',SimpleItem())
'1'
m._setObject('2',SimpleItem())
'2'
o_ids = m.objectIds()
o_ids
OOBTreeItems object at 0x4015dca0
list(o_ids)
['1', '2']
m._delObject('1')
list(o_ids)
['2']
I`ll want to migrate my large object containers from Folder to BTreeFolder2,
but my
code have many next places:
for id in container.objectIds():
if some_condition:
container._delObject(id)
or
container.manage_delObjects( container.objectIds() )
Be careful with migration of such type.
--
Best regards,
Victor Safronovich
NauMen.NauDoc.SoftwareDeveloper http://www.naumen.ru
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Re[2]: [ZODB-Dev] Deferred notifing from one thread to another.
Hello Dieter Maurer, Saturday, December 10, 2005, 12:34:48 AM, you wrote: DM Victor Safronovich wrote at 2005-12-9 14:33 +0500: ... But when T2 still not commiting its transaction, dispatcher not see new element :(. DM Any transaction will only see committed changes. DM Only at transaction boundaries will a connection cache be updated DM for modifications by other transactions. Dieter, i know about this. Have you some situations, when you need to know if transaction of thread1 commited, but you are in thread2? In other words How can i receive the signal that transaction in another thread commited( or aborted, but this is another question)? -- Best regards, Victor Safronovich NauMen.NauDoc.SoftwareDeveloper http://www.naumen.ru ___ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev
[ZODB-Dev] Deferred notifing from one thread to another.
Hello zodb-dev! I have a some problem, and don`t know how to solve it :(. I have a scheduler dispatcher thread with run method def run(self): app = Zope2.bobo_application() try: scheduler = app.unrestrictedTraverse( self.scheduler_path, None ) queue = scheduler.getEventQueue( reset=True ) while not DieEvent.isSet(): if ResetEvent.isSet(): ResetEvent.clear() app._p_jar.sync() # refresh the queue and set new expires time queue.refresh() event = queue.getNextEvent() if event and event.waitTillStart( ResetEvent ): EventSemaphore.acquire() event.setDaemon(True) event.setSemaphore( EventSemaphore ) event.start() elif not ResetEvent.isSet(): # No events left in the queue. # Just waiting for the queue to expire. delay = queue.expires - now() ResetEvent.wait( delay.seconds ) ResetEvent.set() finally: app._p_jar.close() and a Scheduler class with addScheduleElement method class Scheduler(BTreeFolder2): def addScheduleElement(self, **options): self._setObject(self.generateId(), ScheduleElement(**options)) ResetEvent.set() addScheduleElement is called from ZServer thread. for instance dispather thread is 'T1', and ZServer thread is 'T2'. addScheduleElement sets ResetEvent and dispatcher refreshed queue, dispatcher called app._p_jar.sync() to see modifications from other threads. But when T2 still not commiting its transaction, dispatcher not see new element :(. I thinks if there is an afterCommitHook at transaction, i`ll use it, but it is not exist. Of course i may write time.sleep( SLEEP_CONSTANT ) before app._p_jar.sync(), but is this a good solution? -- Best regards, Victor Safronovich NauMen.NauDoc.SoftwareDeveloper http://www.naumen.ru ___ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev
Re[2]: [ZODB-Dev] Deferred notifing from one thread to another.
Hello Tim Peters, Friday, December 9, 2005, 9:18:26 PM, you wrote: TP [Victor Safronovich] ... Of course i may write time.sleep( SLEEP_CONSTANT ) before app._p_jar.sync(), but is this a good solution? TP I can't make time to understand your problem (sorry!) Tim, thank you for your answer. TP , but I can make time TP to tell you that a bare time.sleep() is almost never a good solution to TP thread problems. time.sleep() in a _loop_ can be reliable, provided you can TP write code to recognize when what you're waiting for has happened; this TP approach is called polling. TP while what I'm waiting for hasn't happened: TP time.sleep(WHATEVER) TP For example, when you change a persistent object, its ._p_changed attribute TP gets set to a true value. When the change gets committed, ._p_changed is TP reset to a false value. So _perhaps_ (I'm not sure -- being sure would TP require understanding all of your problem) you could poll waiting for some TP specific object's _p_changed to become false. Supper, I do the next def reset_hook( scheduler ): while scheduler._p_changed: time.sleep(0.05) # again time sleep :)) ResetEvent.set() and def addSchedulerElement(self, **options): self._setObject(self.generateId(), ScheduleElement(**options)) Thread(target=reset_hook, args=(self,)) Tommorow, i`ll check how this works :). -- Best regards, Victor Safronovich NauMen.NauDoc.SoftwareDeveloper http://www.naumen.ru ___ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev
Re: [ZODB-Dev] Class Versioning?
Hello Chris Spencer, Saturday, October 29, 2005, 7:16:43 AM, you wrote: CS Would it be possible to support some system of class versioning in ZODB, CS to aid to handling modifications to source code? For instance, suppose CS each class definition has a __version__ attribute. Upon serialization, CS this version is saved for each instance. Then, if the class is updated, CS signified by incrementing the class's __version__, ZODB could take CS action, for example, by executing an optional __upgrade_to_x(self) in CS the new class definition. you can easily derive your own class from Persistent class, and add some system of class versioning to them. for example ( untested ) class Persistent(_Persistent): # attributes for version tag support _class_version = None _class_tag = None _version_tag = None def __class_init__(self): # works only for extension classes tags = [ self._class_version ] for base in self.__bases__: if hasattr( base, '_class_tag' ): tags.append( base._class_tag ) self._class_tag = hash( tuple(tags) ) def __setstate__( self, state ): _Persistent.__setstate__( self, state ) if self.tagChanged(): self.doSomething() def doSomething(self): self._version_tag = self._class_tag def tagChanged(self): return self._version_tag self._class_tag class A(Persistent): _class_version = 1.3 class B(A): _class_version = 1.45 -- Best regards, Victor Safronovich NauMen.NauDoc.SoftwareDeveloper http://www.naumen.ru ___ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev
Re[2]: [ZODB-Dev] know the state of an object
Hello Jim Fulton, Friday, October 14, 2005, 7:01:00 PM, you wrote: JF The long term solution to these are other related use cases is to start JF using events in ZODB. That is, ZODB should use zope.event to report JF happenings of potential interest to applications. Then applications JF can use the event system to be notified and provide additional JF functionality. May be usefull to add some simple workflow to Persistent class with states: GHOST UPTODATE CHANGED STICKY transitions: activate deactivate ghostify unghostify changed invalidate and others and to be able to add hooks to before and after transition. -- Best regards, Victor Safronovich NauMen.NauDoc.SoftwareDeveloper http://www.naumen.ru ___ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev
Re[2]: [ZODB-Dev] afterCommitHook
Hello Chris Withers, Friday, September 23, 2005, 9:12:19 PM, you wrote: CW Why not just use MaildropHost? 1. Because it is *nix only, it use os.fork(), using Thread.setDaemon(1) is more friendly for me. 2. Because it takes all his options from Config file, not Zodb objects. 3. Because there is imposible to import mainloop from Products.MaildropHost.maildrop.maildrop, because Products.MaildropHost.maildrop is not package. 4. Because mainloop is the huge function, MainLoop class with small methods is more friendly for me, to subclassing from it. But MaildropHost is a wonderful product, and thanks to its author. This topic is not a zodb-dev problem and should be moved to zope-dev. -- Best regards, Victor Safronovich NauMen.NauDoc.SoftwareDeveloper http://www.naumen.ru ___ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev
Re[2]: [ZODB-Dev] BTrees and setdefault
Hello zodb-dev, [Tim Peters] TP Despite that the message I linked to above was written last October, there TP are still only about a dozen total uses of setdefault() in the Python core, TP and there are still many more lines of code in the core implementing the TP thing than there are lines of code using it. I remain -0 on the idea (which TP means it's OK by me, I just prefer not to bother). Jim's +1 wipes out any TP number of -0 votes ;-). +1 for adding setdefault for BTrees. the code below if not self._index.has_key(comp): self._index[comp] = IOBTree() if not self._index[comp].has_key(level): self._index[comp][level] = IITreeSet() self._index[comp][level].insert(id) may change to comp = self._index.setdefault( comp, IOBTree() ) level = comp.setdefault( level, IITreeSet() ) level.insert( id ) which looks much better. -- Best regards, Victor Safronovich NauMen.NauDoc.SoftwareDeveloper http://www.naumen.ru ___ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev
Re: [ZODB-Dev] PersistentMapping glitches
Hello Tim Peters,
Monday, August 22, 2005, 8:44:08 PM, you wrote:
from BTrees.OOBTree import OOBTree
b = OOBTree()
b.update(pm)
TP Traceback (most recent call last):
TP File stdin, line 1, in ?
TP File C:\python23\lib\UserDict.py, line 19, in __getitem__
TP def __getitem__(self, key): return self.data[key]
TP KeyError: 0
Some workaround for me(the Collector 1873 poster) was to use data attribute of
the UserDict instances.
from ZODB.PersistentMapping import PersistentMapping
from BTrees.OOBTree import OOBTree
r = OOBTree()
r.update( PersistentMapping({1:1}).data)
dict(r)
{1: 1}
i am using isinstance(obj, UserDict) condition now.
--
Best regards,
Victor Safronovich
NauMen.NauDoc.SoftwareDeveloper http://www.naumen.ru
___
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[ZODB-Dev] Reloading product in 2.8
[11211695992112010853]
Function variables:
meta=(class 'Products.Transience.TransientObject.TransientObject', ())
klass=class 'Products.Transience.TransientObject.TransientObject'
[TransientObject]
newargs=built-in method __getnewargs__ of TransientObject object at
0x02F4A170 [__getnewargs__]
Module ZODB.serialize, line 339, in _dump
Line 7 of function _dump:
self._p.dump(state)
Function arguments:
self=ZODB.serialize.ObjectWriter instance at 0x03B21030
classmeta=(class 'Products.Transience.TransientObject.TransientObject',
())
state={'_last_accessed': 1121169672.484, '_last_modified':
1121169672.655, 'token': '74187034A16XXKS7Ut0', '_created': 1121169599.296,
'_container': {('explorer', '351409078'): {'title_field': None, 'ca
PicklingError: Can't pickle class
'Products.CMFNauTools.Explorer.FolderExplorer': it's not the same object as
Products.CMFNauTools.Explorer.FolderExplorer
previous Zope version, which I used, was 2.6.1, but it was very old version and
I decided to jump to 2.8.0. I took problems with autorefresh. What can I do to
solve
my problems?
p.s. sorry for my english.
--
Best regards,
Victor Safronovichmailto:[EMAIL PROTECTED]
NauMen.NauDoc.SoftwareDeveloper http://www.naumen.com
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