To start, it is just a clone of the common protocol. But now that we
have the separate protocol implementations, we can add versioning
information without the versions of one protocol leaking into another.
Using the infrastructure from the previous commit, we don't have to
duplicate code for shared behavior.
Motivation: No more perverse incentives. [0] did some awkward things
because the serialisers did not store the version. I don't want anyone
making changes to be pushed towards keeping the serialization logic with
the core data types just because it's easier or the alternative is
tedious.
The actual versioning of the Worker and Serve protocol serialisers
(Common remains unversioned as the underlying mini-protocols are not
versioned) will happen in subsequent commits / PRs.
[0]: fe1f34fa60
Copy the relevant tests to ensure the new interfaces added in the last
commit are tested.
Perhaps I should try to deduplicat these tests some more. However its
not clear how to do that outside of a big ugly C++ macro.
https://github.com/google/googletest/blob/main/docs/advanced.md has some
stuff but it is cumbersome and I didn't figure it out yet.
This is done in a separate commit in order to be sure that the first
commit really didn't change any behavior; if we changed the
implementation and the tests at once, it would be harder to tell whether
or not some behavioral changes slipped in what is supposed to be a "pure
refactor".
Co-Authored-By: Valentin Gagarin <valentin.gagarin@tweag.io>
This introduces some shared infrastructure for our notion of protocols.
We can then define multiple protocols in terms of that notion.
We an also express how particular protocols depend on each other.
For example, we can define a common protocol and a worker protocol,
where the second depends on the first in terms of the data types it can
read and write.
The "serve" protocol can just use the common one for now, but will
eventually need its own machinary just like the worker protocol for
version-aware serialisers
For people working on Nix with `nix develop`, it's better to just use
`autoreconfPhase` and `configurePhase`, which is standard Nixpkgs / nix
shell make from Nixpkgs practice --- it is good to emphasize the degree
to which Nix is *just* a regular C++ project which can be worked on in
the regular way.
(For people running `nix-shell`, the story is similar, except
`configurePhase` would use non-writable store paths, which matters for
hte times we use output paths before `make install`, so I kept the
existing `./configure ...` instruction.)
For people building Nix without Nix (e.g. packaging it for another
distro) they also don't need `bootstrap.sh`, and can just run
`autoreconf -vfi` directly. (More likely, they have their own idioms to
do this just as we have `autoreconfPhase`.)
I was sleepy and confused that "interpolated expression" was a new type of thing at first. This nudges the reader to understand that its just a regular expression, and these conditions are imposed by the interpolation operation.
Additionally this skipping of the building is reimplemented to be a bit
more robust and use the same idioms as the functionality for skipping
the tests. In particular, it will now work even if the source files
exist, so we can do this during development too.
I think the our `flake.nix` is currently too large and too scary looking.
I think this matters --- if Nix cannot dog-food itself in a way that is
elegant, why should other people have confidence that their own code can
be elegant and easy to maintain?
We could do this at many points in time, but I think around now, when we
are thinking about stabilizing parts of Flakes, is an especially good
time.
This is a first step to make the `flake.nix` smaller, and make
individual components responsible for their own packaging. I hope we can
do this many more follow-ups like it, until the top-level `flake.nix` is
very small and just coordinates between other things.
I think it is bad for these reasons when `tests/` contains a mix of
functional and integration tests
- Concepts is harder to understand, the documentation makes a good
unit vs functional vs integration distinction, but when the
integration tests are just two subdirs within `tests/` this is not
clear.
- Source filtering in the `flake.nix` is more complex. We need to
filter out some of the dirs from `tests/`, rather than simply pick
the dirs we want and take all of them. This is a good sign the
structure of what we are trying to do is not matching the structure
of the files.
With this change we have a clean:
```shell-session
$ git show 'HEAD:tests'
tree HEAD:tests
functional/
installer/
nixos/
```
A couple of tests require building some libraries that depend on Nix,
and assume it to be built locally.
Don't run these if we only want to run the install tests.
This prevents the CI from rebuilding several times Nix (like in
https://github.com/NixOS/nix/actions/runs/6404422275/job/17384964033#step:6:6412), thus removing a fair amount of build time.
