Re: Guix to participate in the Google Summer of Code

[Ricardo Wurmus]

Hi Alex,

>> The reference scanner is already implemented in the form of grafts.  The
>> code opens each file and searches efficiently for store references.
>>
> Does this mean we have procedure to do a single find-reference and the
> remaining work is to build a recursive find-reference?

The current way to obtain references is through the daemon.  In (guix
store) there is a procedure “references” that is used whenever we want
to get a list of references for a store item.  But how does the daemon
itself obtain those references in the first place?

“nix/libstore/references.cc” implements a reference scanner and it is
quite similar to how “replace-store-references” in (guix build graft)
works.

So a first step towards an implementation of the reference scanner would
be to liberate “replace-store-references” from its grafting context;
possibly turn it into a higher order function that finds references and
optionally invokes a function when a reference is found.  Then it could
be used for grafting as well as for collecting references in the daemon.

But I would recommend to revive the work from the last GSoC first.

--
Ricardo

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