[Monotone-devel] Re: How to apply "automate get_revision" data

[Brian Downing]

Brian Downing wrote:
> Nathaniel Smith wrote:
> > In general, there is no order you can apply them in; they are to be
> > applied "all at once".  It's more like a declarative description of
> > how two trees map to each other than it is a procedural description
> > of how to produce one tree from another.  The algorithm for working
> > with such things is a little subtle; the best description I know of
> > is:
> >   
> > http://mebentley.blogspot.com/2005/12/tree-transforms-on-posix-filesystems.html 
> >
> > (This is Aaron Bentley talking about bzr, but mtn and bzr
> > independently invented identical algorithms here, so it still
> > applies.)
>
> Interesting.  I'll see if that'll be too complex for me to implement.

In case anybody's interested, this turned out to be very easy for Git's 
case, since it doesn't care about rename identity or directories.

a) Move all renamed paths to temporary paths, longest pathname first.
b) Delete all paths, longest pathname first.
c) Move all temporary paths to new paths, shortest pathname first.
d) Apply all new and patched files.

These rules yield an identical Git repository for net.venge.monotone as 
one imported with manifests, and runs a whole lot faster.

-bcd