On 29.11.2013 20:42, Ivan Zhakov wrote:
> On 29 November 2013 22:22, <br...@apache.org> wrote:
>> Author: brane
>> Date: Fri Nov 29 18:22:00 2013
>> New Revision: 1546619
>>
>> URL: http://svn.apache.org/r1546619
>> Log:
>> * branches/fsfs-ucsnorm/BRANCH-README: New file.
>>
>> Added:
>> subversion/branches/fsfs-ucsnorm/BRANCH-README (with props)
>>
>> Added: subversion/branches/fsfs-ucsnorm/BRANCH-README
>> URL:
>> http://svn.apache.org/viewvc/subversion/branches/fsfs-ucsnorm/BRANCH-README?rev=1546619&view=auto
>> ==============================================================================
>> --- subversion/branches/fsfs-ucsnorm/BRANCH-README (added)
>> +++ subversion/branches/fsfs-ucsnorm/BRANCH-README [UTF-8] Fri Nov 29
>> 18:22:00 2013
>> @@ -0,0 +1,66 @@
>> +The purpose of this [fsfs-ucsnorm] branch is to implement two optional
>> +checks related to Unicode normalisation to FSFS.
>> +
>> +
>> +Option: Prevent name collisions
>> +===============================
>> +
>> +If this option is enabled, FSFS will reject operations that would
>> +create two different representations of the same name in the same
>> +directory. This will prevent situations where a user could see more
>> +than one form of the name in a directory listing:
> Nice feature, but why in FS layer? May be it's better to implement
> this feature on svn_repos layer?
It's not, for at least two reasons:
* Users of the FS API must have the same constraints as repository
clients, otherwise the whole thing falls on its face.
* The repos layer cannot implement this optimally; at a rough guess,
it would have to double the number of lookups performed:
o The node cache in an FSFS implementation detail, and this option
will affect how cache keys are generated.
o Likewise for actual lookups into the on-disk representation.
-- Brane
--
Branko Čibej | Director of Subversion
WANdisco // Non-Stop Data
e. br...@wandisco.com
