mercurial --> plain text --> mercurial

[Ondrej Certik]

On Thu, Mar 27, 2008 at 5:09 PM, Matt Mackall <mpm at selenic.com> wrote:
>
>  On Thu, 2008-03-27 at 14:24 +0000, didier deshommes wrote:
>  > Hi everyone,
>  > Sage (http://www.sagemath.org/) uses hg for its source control and recently a
>  > question has come up about the possibility of doing the following:
>  >
>  >  (1) export everything in the .hg repo to something (perhaps a ton of
>  > stuff) in plain text format,
>  >  (2) delete .hg/ directory
>  >  (3) do something that recovers the .hg/ directory from the output of (1).
>
>  This will work for the export side:
>
>  #!/usr/bin/env python
>  import sys
>  from mercurial import revlog, node
>
>  for f in sys.argv[1:]:
>     r = revlog.revlog(open, f)
>     print "file:", f
>     for i in xrange(r.count()):
>         n = r.node(i)
>         p = r.parents(i)
>         d = r.revision(n)
>         print "node:", node.hex(n)
>         print "linkrev:", r.linkrev(n)
>         print "parents:", node.hex(p[0]), node.hex(p[1])
>         print "length:", len(d)
>         print "-start-"
>         print d
>         print "-end-"
>
>  Then you can do something like:
>
>  find .hg/store -name "*.i" | xargs ./dumprevlog > repo.dump
>
>  This will make a nice flat, uncompressed file with everything you need
>  to reconstruct a repo. But it'll be huge. The mercurial repo goes from
>  11MB to 435MB. Other projects will get -much- bigger; I've seen large
>  revlogs with compression ratios of > 1000:1.
>
>  I'm too busy to write the import side of this today, but it'll be about
>  as long. And you shouldn't actually need that piece if you only need to
>  scan the dump.

They also want to make sure, there are no "hidden" things in the
mercurial repo, so the reconstruction is needed too.

Thanks a lot for the patch.

Ondrej