wroclaw-git-backups/nix
1
0
Fork 0
mirror of https://github.com/NixOS/nix synced 2025-07-01 12:37:59 +02:00
Code Activity

Revert "Revert "Use template structs instead of phantoms""

Browse source 
This is the more typically way to do [Argument-dependent
lookup](https://en.cppreference.com/w/cpp/language/adl)-leveraging
generic serializers in C++. It makes the relationship between the `read`
and `write` methods more clear and rigorous, and also looks more
familiar to users coming from other languages that do not have C++'s
libertine ad-hoc overloading.

I am returning to this because during the review in
https://github.com/NixOS/nix/pull/6223, it came up as something that
would make the code easier to read --- easier today hopefully already,
but definitely easier if we were have multiple codified protocols with
code sharing between them as that PR seeks to accomplish.

If I recall correctly, the main criticism of this the first time around
(in 2020) was that having to specify the type when writing, e.g.
`WorkerProto<MyType>::write`, was too verbose and cumbersome. This is
now addressed with the `workerProtoWrite` wrapper function.

This method is also the way `nlohmann::json`, which we have used for a
number of years now, does its serializers, for what its worth.

This reverts commit 45a0ed82f0. That
commit in turn reverted 9ab07e99f5.
This commit is contained in:
John Ericson 2023-05-17 22:04:59 -04:00
parent 684e9be8b9
commit cb5052d98f
10 changed files with 182 additions and 151 deletions
Download patch file Download diff file Expand all files Collapse all files

4
src/libstore/derivations.cc
View file

@ -748,7 +748,7 @@ Source & readDerivation(Source & in, const Store & store, BasicDerivation & drv,
drv.outputs.emplace(std::move(name), std::move(output));
}
drv.inputSrcs = worker_proto::read(store, in, Phantom<StorePathSet> {});
drv.inputSrcs = WorkerProto<StorePathSet>::read(store, in);
in >> drv.platform >> drv.builder;
drv.args = readStrings<Strings>(in);
@ -796,7 +796,7 @@ void writeDerivation(Sink & out, const Store & store, const BasicDerivation & dr
},
}, i.second.raw());
}
worker_proto::write(store, out, drv.inputSrcs);
workerProtoWrite(store, out, drv.inputSrcs);
out << drv.platform << drv.builder << drv.args;
out << drv.env.size();
for (auto & i : drv.env)