Well, the compression is the last thing I am talking about. It is important, but not essential.
I am talking about several people working on one file and then fossil merging the changes automatically (of course if there is no conflicts in the edits). On Tue, 20 Dec 2016 16:58:18 -0700 Warren Young <war...@etr-usa.com> wrote: > On Dec 20, 2016, at 3:57 PM, Warren Young <war...@etr-usa.com> wrote: > > > >> What if I design some text file format (containing only ascii characters) > >> and > >> it can't be properly processed by fossil? > > > > Then you should post it as a replicable test case for our study. > > I decided to take up my own challenge. Consider: > > ## Create new repo; note initial size > $ f init ../x.fossil > $ ls -lh ../x.fossil > -rw-r--r-- 1 me group 212K Dec 20 16:13 ../x.fossil > > ## Go grab a free PNG file, and re-save it with Photoshop’s > ## Save for Web function to reduce unnecessary differences > $ wget > https://upload.wikimedia.org/wikipedia/commons/thumb/3/31/Topographic_Map_of_Bulgaria_Bulgarian.png/120px-Topographic_Map_of_Bulgaria_Bulgarian.png > $ open -a 'Adobe Photoshop CC 2017' > 120px-Topographic_Map_of_Bulgaria_Bulgarian.png > $ ls -lh 120px-Topographic_Map_of_Bulgaria_Bulgarian.png > -rw-r--r-- 1 me group 23K Dec 20 16:12 > 120px-Topographic_Map_of_Bulgaria_Bulgarian.png > > ## Add it to repo; notice that repo size goes up by 20 kB, > ## showing that Fossil’s internal compression managed to > ## squeeze an additional 3 kB over what Photoshop gives, > ## probably due to metadata compression > $ f add 120px-Topographic_Map_of_Bulgaria_Bulgarian.png > $ f ci -m initial > $ f rebuild --compress --vacuum > $ ls -lh ../x.fossil > -rw-r--r-- 1 me group 232K Dec 20 16:13 ../x.fossil > > ## Change upper left corner pixel, amounting to only several > ## bits of difference in the raw data > $ open -a 'Adobe Photoshop CC 2017' > 120px-Topographic_Map_of_Bulgaria_Bulgarian.png > $ ls -lh 120px-Topographic_Map_of_Bulgaria_Bulgarian.png > -rw-r--r-- 1 me group 23K Dec 20 16:14 > 120px-Topographic_Map_of_Bulgaria_Bulgarian.png > > ## Check change in; notice that roughly a dozen bits of change in > ## the raw data became 28 kB of difference in the repo size! > $ f ci -m '1 px change’ > $ f rebuild --compress --vacuum > $ ls -lh ../x.fossil > -rw-r--r-- 1 me group 260K Dec 20 16:14 ../x.fossil > > > Repeating that test with TIFF and PSD files didn’t give as small a difference > in the resulting Fossil repos size between checkins as I’d expected, but on > investigating I found that Photoshop writes a bunch of stuff into the > metadata that change on every save (e.g. timestamps, UUIDs…) which balloons > the diffs. > > Switching to Windows BMP fixes this: a 1px change results in a negligible > change in the repo size, because only about a dozen bits change in the raw > data. (Windows BMP has very little metadata.) > _______________________________________________ > fossil-users mailing list > fossil-users@lists.fossil-scm.org > http://lists.fossil-scm.org:8080/cgi-bin/mailman/listinfo/fossil-users -- http://fresh.flatassembler.net http://asm32.info John Found <johnfo...@asm32.info> _______________________________________________ fossil-users mailing list fossil-users@lists.fossil-scm.org http://lists.fossil-scm.org:8080/cgi-bin/mailman/listinfo/fossil-users
