Linked by Thom Holwerda on Mon 6th Aug 2012 13:16 UTC
Mac OS X How this passed through Apple's Mountain Lion testing is beyond me. "If one edits a document, then chooses Save As, then BOTH the edited original document and the copy are saved, thus not only saving a new copy, but silently saving the original with the same changes, thus overwriting the original." Just goes to show: do not mess with my ability to save my stuff. There is no one-size-fits-all for this kind of delicate stuff.
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RE[5]: file versioning
by Tony Swash on Mon 6th Aug 2012 22:11 UTC in reply to "RE[4]: file versioning"
Tony Swash
Member since:
2009-08-22

Can't see how data isn't been lost cumulatively. Don't use mac but from what I understand you to mean a file is in a liner process of change and unless you remembered to copy the file from the beginning you have 2 versions, the present and the previous 'save-as' as the bak which is whatever variable of 'save-as's' from the original.


Actually what Auto Save does is take regular snapshots of a document as you make changes and saves multiple backups going back in time which can be easily browsed and from which any number of earlier version can be retrieved.

It's a bit eerie at first, once you first save a document in an app like TextEdit that implements Auto Save there is no longer a save item in the menu, you just open the document or close it with no dialogue asking if you want to save it. But hidden in the background and instantly accessible there is the previous version as it was before you opened it and made the changes, plus all previous versions.

Personally I think it's great feature but it's in it's infancy, I am sure eventually all apps will work like this. The problem now is how would such a system cope with say a large photoshop file, or a video being edited, but that all comes down to system resources, storage, speed etc, and we all know that eventually system resources limitations get overcome.

Reply Parent Score: 2

RE[6]: file versioning
by darknexus on Tue 7th Aug 2012 07:53 in reply to "RE[5]: file versioning"
darknexus Member since:
2008-07-15

Actually what Auto Save does is take regular snapshots of a document as you make changes and saves multiple backups going back in time which can be easily browsed and from which any number of earlier version can be retrieved.


What I want to know is where are these previous versions stored? In the document? The file metadata? Some special folder? Obviously they cannot be stored in the file proper, as if they were, most other operating systems probably wouldn't recognize the file and would fail to open it. It concerns me because I have one small system drive and several large data drives. If the version information is stored in the file's metadata (those annoy extra files you sometimes get when mixing OS X with other operating systems) then that's all well and good, but if it's using a special folder on my system drive, I'll eventually accidentally end up with my system drive filled and that will cause other problems. I know that applications' save states are saved in ~/Library/Saved Application State/, and that makes me wonder where versions are stored.

Reply Parent Score: 2

RE[7]: file versioning
by dnebdal on Tue 7th Aug 2012 09:03 in reply to "RE[6]: file versioning"
dnebdal Member since:
2008-08-27

From some quick googling, it seems to be storing them in /.DocumentRevisions-V100/ .

This reminds me of something VMS (and several others) does: Say you create a new file called "myfile.txt". Editing and saving that creates "myfile.txt;1", and saving again creates "myfile.txt;2". Opening "myfile.txt" grabs the one with the highest number - and increments that again when saving. File managers and the shells and such know about this system, and only show the newest version.

It's not as automatic (you have to manually save), and it does require extra space (I think each version is a complete copy - at least there's a purge command that removes all but the newest versions) - but the basic idea was and still is nice.

Reply Parent Score: 2