Messages in this thread | | | Date | Fri, 8 Apr 2005 08:50:21 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: Kernel SCM saga.. |
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On Fri, 8 Apr 2005 ross@jose.lug.udel.edu wrote: > > Here's a partial solution. It does depend on a modified version of > cat-file that behaves like cat. I found it easier to have cat-file > just dump the object indicated on stdout. Trivial patch for that is included.
Your trivial patch is trivially incorrect, though. First off, some files may be binary (and definitely are - the "tree" type object contains pathnames, and in order to avoid having to worry about special characters they are NUL-terminated), and your modified "cat-file" breaks that.
Secondly, it doesn't check or print the tag.
That said, I think I agree with your concern, and cat-file should not use a temp-file. I'll fix it, but I'll also make it verify the tag (so you'd now have to know the tag in advance if you want to cat the data).
Something like
cat-file -t <sha1> # output the tag cat-file <tag> <sha1> # output the data
or similar. Easy enough. That way you can do
torvalds@ppc970:~/git> ./cat-file -t `cat .dircache/HEAD ` commit
and
torvalds@ppc970:~/git> ./cat-file commit `cat .dircache/HEAD `
tree ca30cdf8df2f31545cc1f2c1be62619111b6f6aa parent c2474b336d7a96fb4e03e65d229bcddc62b244fc author Linus Torvalds <torvalds@ppc970.osdl.org> Fri Apr 8 08:16:38 2005 committer Linus Torvalds <torvalds@ppc970.osdl.org> Fri Apr 8 08:16:38 2005
Make "cat-file" output the file contents to stdout.
New syntax: "cat-file -t <sha1>" shows the tag, while "cat-file <tag> <sha1>" outputs the file contents after checking that the supplied tag matches.
I'll rsync the .dircache directory to kernel.org. You'll need to update your scripts.
> Now to see what I come up with for commit, push, and pull...
A "commit" (*) looks roughly like this:
# check with "show-diff" what has changed, and check if # you need to add any files..
update-cache <list of files that have been changed/added/deleted>
# check with "show-diff" that it all looks right
oldhead=$(cat .dircache/HEAD) newhead=$(commit-tree $(write-tree) -p $oldhead < commit-message)
# update the head information if [ "$newhead" != "" ] ; then echo $newhead > .dircache/HEAD; fi
(*) I call this "commit", but it's really something much simpler. It's really just a "I now have <this directory state>, I got here from <collection of previous directory states> and the reason was <reason>".
The "push" I use is
rsync -avz --exclude index .dircache/ <destination-dir>
and you can pull the same way, except when you pull you should save _your_ HEAD file first (and then you're screed. There's no way to merge. If you've made changes and committed them, your changes are still there, but they are now on a different HEAD than the new one).
That, btw, is kind of the design. "git" really doesn't care about things like merges. You can use _any_ SCM to do a merge. What "git" does is track directory state (and how you got to that state), and nothing else. It doesn't merge, it doesn't really do a whole lot of _anything_.
So when you "pull" or "push" on a git archive, you get the "union" of all directory states in the destination. The HEAD thing is _one_ pointer into the "sea of directory states", but you really have to use something else to merge two directory states together.
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