[Zope3-dev] Re: [Checkins] SVN: z3c.extfile/ initial import of the z3c.extfile package

[Florent Guillaume]

On 10 Aug 2006, at 19:39, Bernd Dorn wrote:
> On 10.08.2006, at 19:09, Florent Guillaume wrote:
>> On 10 Aug 2006, at 18:28, Bernd Dorn wrote:
>>>
>>>   initial import of the z3c.extfile package
>>
>> Does this package tie into the transaction manager? I couldn't see  
>> any reference to transactions.
>
> short answer - no
>
> files are stored based on their sha digest, so it does not matter  
> if the transaction fails after the file is saved, because we do not  
> have to delete it immediatly.
>
> concurrency is also possible, because when the file is commited, it  
> is moved to its final location, if another process uploads the same  
> file and the same file exists (hash), it gets silently deleted,  
> because a file only has to exist one time on the system.
>
> i plan to implement some kind of pack mechanism, which searches for  
> such properties in the zodb and then deletes all files which are  
> not used anymore

IMHO it would be better and more efficient to register a data manger  
with the transaction when a file operation is done, and cleanup when  
the transaction commits/aborts.
But then I'm not the one coding this :)

Flornet

-- 
Florent Guillaume, Nuxeo (Paris, France)   Director of R&D
+33 1 40 33 71 59   http://nuxeo.com   fg at nuxeo.com