As I said, all numbers are fanciful. I just wanted to get a discussion started.

From our point of view I would prefer a much much smaller limit. There needs to be limits so that we can design interface around these attributes, and it seems also for technical reasons on the size of an attribute. I think that the way to go about this is to talk this back and forth here for a bit, then have someone go and write some code to implement the guidelines and turn them into a nice cocoa api. For instance, one thing that I run into with tags is that some programs/ users enter (say 6) tags as a comma delimited string, and this gets stored as a single string in an array of length one. It's not impossible to catch this sort of thing and deal with it, but if it were all in one open sourced class, it would be a lot easier and more consistent.

Suggested Fields
---------------
Tags
Authors
URLs
Character encoding for text files
Checksum

+ application defined?

It seems like a small well defined set of attributes to use would be better than a larger set. At least as a first step.

Where are the maximum xattr lengths documented? I read on a wiki page that HFS+ limits xattrs to 'one b-tree node' which I take it is 4k.
http://en.wikipedia.org/wiki/Extended_file_attributes

--Tom
On 8-Jul-08, at 10:59 AM, Mac QA wrote:
On Tue, Jul 8, 2008 at 10:45 AM, Tom Andersen <[EMAIL PROTECTED]> wrote:
User Entered tags:
--------------------------
stored: under the keyword: kXATTR_UserTags
value: NSArray of NSStrings. No hierarchy, maximum tag length 100 chars, maximum number of tags 100, Guidelines: tags should be entered by the user,
and not be things like GUIDs, paths, etc.

You want all of this in one extended attribute? Even assuming no
overhead for NSArray or NSStrings, wouldn't 100 chars/tag * 100 tags
already be about 2-3 times the maximum amount of storage currently
allowed in one generic extended attribute? As I understand the maximum
is roughly 4K, with the ResourceFork being a special case clearly.


On 8-Jul-08, at 10:59 AM, Mac QA wrote:

On Tue, Jul 8, 2008 at 10:45 AM, Tom Andersen <[EMAIL PROTECTED]> wrote:
User Entered tags:
--------------------------
stored: under the keyword: kXATTR_UserTags
value: NSArray of NSStrings. No hierarchy, maximum tag length 100 chars, maximum number of tags 100, Guidelines: tags should be entered by the user,
and not be things like GUIDs, paths, etc.

You want all of this in one extended attribute? Even assuming no
overhead for NSArray or NSStrings, wouldn't 100 chars/tag * 100 tags
already be about 2-3 times the maximum amount of storage currently
allowed in one generic extended attribute? As I understand the maximum
is roughly 4K, with the ResourceFork being a special case clearly.

_______________________________________________

Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com

This email sent to [EMAIL PROTECTED]

Reply via email to