[Sugar-devel] [PATCH] Share Journal entries over external devices #1636

[Simon Schampijer]

On 11/30/2010 11:01 AM, Simon Schampijer wrote:
> On 11/26/2010 04:33 PM, Sascha Silbe wrote:
>> Excerpts from simon's message of Thu Nov 25 10:51:16 +0100 2010:
>>
>>> metadata and preview of an entry are stored in hidden files. For example
>>> when copying an entry homework.pdf to the device a file called
>>> .homework.pdf.metadata and .homework.pdf.preview will be stored on the
>>> device as well. Those will be read in when copying an entry from the
>>> external device to a Journal.
>>
>> I'm not yet convinced of that approach. How do you detect and handle
>> "stale" metadata and preview files? Especially since you "hide" the
>> files (how do non-Unix OSs handle dot-files, BTW?)
>
> On a Windows XP machine I had access to the dot-files. Windows does
> handle the visibility of a file with an attribute. On OSX the dot-files
> are not shown.
>
> Regards,
> Simon

Note about the hidden files on windows: I looked a bit around, and there 
is no way to set that attribute on Linux, AFAIK. To reduce the number of 
visible secondary files on the stick, we could pack them into one hidden 
folder as well.

We discussed the two approaches (hidden files with the metadata per 
entry vs archived file (like JEBs [1])) a bit yesterday. Here is a short 
summary:

Use Cases:

* share a Journal entry with your classmate using a storage device 
(alternatives are here the file transfer option in the Journal)

* backup your Journal entry on a storage device, or transfer it over a 
storage device to another machine, this includes writing and reading 
(alternatives here are the Server side backup)

* the backup/restore has to be possible over several Sugar versions 
(upgrade path)

* copy the picture you painted to your storage device and show it to 
your mom on her computer


Current status:

AFAIK the school server currently handles the backup by rsync [2] 
(Martin?). Are there future plans for fine grained backup (per entry)?

Sascha seem to use the JEB in his activities for backup and restore 
[3][4]. Sascha are those used in a distribution already? Used by a 
deployment?

It seem as well that some work has been going into Dextrose to provide 
backing up functionality [5]. Bernie, is this actually available in 
Dextrose?

Regards,
    Simon

[1] http://wiki.laptop.org/go/Journal_entry_bundles
[2] 
http://wiki.laptop.org/go/XS_Blueprints:Datastore_Simple_Backup_and_Restore
[3] http://activities.sugarlabs.org/en-US/sugar/addon/4326
[4] http://activities.sugarlabs.org/en-US/sugar/addon/4327
[5] http://wiki.sugarlabs.org/go/Features/Backup_and_Restore