Re: [Gnu-arch-users] [BUG] FEATURE PLANS: "perfect" summary deltas

[Aaron Bentley]

Tom Lord wrote:

>     > The archive.h-level stuff needs to be of the form "what are you willing 
>     > to give me that can get me from here to here."  
>
> It does not.  This has been discussed in the past.   Gah... I wish you
> were near enough that we could sit down at a pub table with a sheet of
> paper: I'm increasingly getting the impression that there's some
> disconnect between us about builder issues that needs to be debugged.
>
> In some cases a server may decide that the delta from X to Y is best
> provided as a list of composable deltas, but their composition should
> take place behind the archive.h scene.

When we trace a path, we get a list of deltas like this:

address@hidden/tla--devo--1.1--patch-287
address@hidden/tla--devo--1.2--base-0
address@hidden/tla--devo--1.2--patch-1
...
address@hidden/tla--devo--1.2--patch-115
address@hidden/tla--devo--1.3--base-0
address@hidden/tla--devo--1.3--patch-1
...
address@hidden/tla--devo--1.3--patch-26
address@hidden/tla--devo--1.3--patch-27
address@hidden/tla--devo--1.3--patch-28

The first line is the first FROM revision, and the second line is the 
first TO revision.

So it's a list of deltas, where each delta is the delta between adjacent 
revisions.

Of course, right now, we just apply-or reverse-apply revision 
changesets.  But I expected that we'd be changing things so that the 
list was a true list of deltas later.

Now, I suppose it's possible that, having generated all this, we can 
throw most of it away, and just do

arch_apply_delta(tree, arch, 
"address@hidden/tla--devo--1.1--patch-287", 
"address@hidden/tla--devo--1.3--patch-28")

For pfs archives, we'd have to rescan the archive to generate the same 
list.  So that's clearly bogus.

So I guess we're left with
arch_apply_deltas(tree, arch, delta_list)

And then have the smart server do what you want, rather than what you 
asked for.

Is that what you have in mind?

Aaron