The existing header is a bit too big. Now the following use-cases are
separated, and get their own headers:
- Using or implementing an arbitrary store: remaining `store-api.hh`
This is closer to just being about the `Store` (and `StoreConfig`)
classes, as one would expect.
- Opening a store from a textual description: `store-open.hh`
Opening an aribtrary store implementation like this requires some sort
of store registration mechanism to exists, but the caller doesn't need
to know how it works. This just exposes the functions which use such a
mechanism, without exposing the mechanism itself
- Registering a store implementation: `store-registration.hh`
This requires understanding how the mechanism actually works, and the
mechanism in question involves templated machinery in headers we
rather not expose to things that don't need it, as it would slow down
compilation for no reason.
For example, instead of doing
#include "nix/store-config.hh"
#include "nix/derived-path.hh"
Now do
#include "nix/store/config.hh"
#include "nix/store/derived-path.hh"
This was originally planned in the issue, and also recent requested by
Eelco.
Most of the change is purely mechanical. There is just one small
additional issue. See how, in the example above, we took this
opportunity to also turn `<comp>-config.hh` into `<comp>/config.hh`.
Well, there was already a `nix/util/config.{cc,hh}`. Even though there
is not a public configuration header for libutil (which also would be
called `nix/util/config.{cc,hh}`) that's still confusing, To avoid any
such confusion, we renamed that to `nix/util/configuration.{cc,hh}`.
Finally, note that the libflake headers already did this, so we didn't
need to do anything to them. We wouldn't want to mistakenly get
`nix/flake/flake/flake.hh`!
Progress on #7876
The short answer for why we need to do this is so we can consistently do
`#include "nix/..."`. Without this change, there are ways to still make
that work, but they are hacky, and they have downsides such as making it
harder to make sure headers from the wrong Nix library (e..g.
`libnixexpr` headers in `libnixutil`) aren't being used.
The C API alraedy used `nix_api_*`, so its headers are *not* put in
subdirectories accordingly.
Progress on #7876
We resisted doing this for a while because it would be annoying to not
have the header source file pairs close by / easy to change file
path/name from one to the other. But I am ameliorating that with
symlinks in the next commit.
Following what is outlined in #10766 refactor the uds-remote-store such
that the member variables (state) don't live in the store itself but in
the config object.
Additionally, the config object includes a new necessary constructor
that takes a scheme & authority.
Tests are commented out because of linking errors with the current config system.
When there is a new config system we can reenable them.
Co-authored-by: John Ericson <John.Ericson@Obsidian.Systems>
Progress towards #10766
I thought that #10768 achieved, but when I went to use this stuff (in
Hydra), turns out it did not. (Those `using FooConfig;` lines were not
working --- they are so finicky!) This PR gets the job done, and adds
some trivial unit tests to make sure I did what I intended.
I had to add add a header to expose `SSHStoreConfig`, after which the
preexisting `ssh-store-config.*` were very confusingly named files, so I
renamed them to `common-ssh-store-config.hh` to match the type defined
therein.
By moving `host` to the config, we can do a lot further cleanups and
dedups. This anticipates a world where we always go `StoreReference` ->
`*StoreConfig` -> `Store*` rather than skipping the middle step too.
Progress on #10766
Progress on https://github.com/NixOS/hydra/issues/1164
In particular `local://<path>` and `unix://` (without any path) now
work, and mean the same things as `local` and `daemon`, respectively. We
thus now have the opportunity to desguar `local` and `daemon` early.
This will allow me to make a change to
https://github.com/NixOS/nix/pull/9839 requested during review to
desugar those earlier.
Co-authored-by: Théophane Hufschmitt <7226587+thufschmitt@users.noreply.github.com>
This avoids split-on-whitespace errors:
- No more `bash -c` needed
- No more `shellEscape` needed
- `remote-program` ssh store setting also cleanly supports args (e.g.
`nix daemon`)
- `ssh` uses `--` to separate args for SSH from args for the command to
run.
and will help with Hydra dedup.
Some code taken from #6628.
Co-Authored-By: Alexander Bantyev <balsoft@balsoft.ru>
Pass this around instead of `Source &` and `Sink &` directly. This will
give us something to put the protocol version on once the time comes.
To do this ergonomically, we need to expose `RemoteStore::Connection`,
so do that too. Give it some more API docs while we are at it.
Continue progress on #5729.
Just as I hoped, this uncovered an issue: the daemon protocol is missing
a way to query build logs. This doesn't effect `unix://`, but does
effect `ssh://`. A FIXME is left for this, so we come back to it later.
This is important if the remote side *does* execute
nix-store/nix-daemon successfully, but stdout is polluted
(e.g. because the remote user's bashrc script prints something to
stdout). In that case we have to shutdown the write side to force the
remote nix process to exit.
This is already used by Hydra, and is very useful when materializing
a remote builder list from service discovery. This allows the service
discovery tool to only sync one file instead of two.
We embrace virtual the rest of the way, and get rid of the
`assert(false)` 0-param constructors.
We also list config base classes first, so the constructor order is
always:
1. all the configs
2. all the stores
Each in the same order
Rework the `Store` hierarchy so that there's now one hierarchy for the
store configs and one for the implementations (where each implementation
extends the corresponding config). So a class hierarchy like
```
StoreConfig-------->Store
| |
v v
SubStoreConfig----->SubStore
| |
v v
SubSubStoreConfig-->SubSubStore
```
(with virtual inheritance to prevent DDD).
The advantage of this architecture is that we can now introspect the configuration of a store without having to instantiate the store itself
Add a new `init()` method to the `Store` class that is supposed to
handle all the effectful initialisation needed to set-up the store.
The constructor should remain side-effect free and just initialize the
c++ data structure.
The goal behind that is that we can create “dummy” instances of each
store to query static properties about it (the parameters it accepts for
example)
Directly register the store classes rather than a function to build an
instance of them.
This gives the possibility to introspect static members of the class or
choose different ways of instantiating them.
Add a fallback path in `queryPartialDerivationOutputMap` for daemons
that don't support it.
Also upstreams a couple methods from `SSHStore` to `RemoteStore` as this
is needed to handle the fallback path.
Brings the functionality of ssh-ng:// in sync with the legacy ssh://
implementation. Specifying the remote store uri enables various useful
things. eg.
$ nix copy --to ssh-ng://cache?remote-store=file://mnt/cache --all
Most functions now take a StorePath argument rather than a Path (which
is just an alias for std::string). The StorePath constructor ensures
that the path is syntactically correct (i.e. it looks like
<store-dir>/<base32-hash>-<name>). Similarly, functions like
buildPaths() now take a StorePathWithOutputs, rather than abusing Path
by adding a '!<outputs>' suffix.
Note that the StorePath type is implemented in Rust. This involves
some hackery to allow Rust values to be used directly in C++, via a
helper type whose destructor calls the Rust type's drop()
function. The main issue is the dynamic nature of C++ move semantics:
after we have moved a Rust value, we should not call the drop function
on the original value. So when we move a value, we set the original
value to bitwise zero, and the destructor only calls drop() if the
value is not bitwise zero. This should be sufficient for most types.
Also lots of minor cleanups to the C++ API to make it more modern
(e.g. using std::optional and std::string_view in some places).
For instance, this reduced the memory consumption of
$ nix copy --from ssh://localhost --to ~/my-nix /nix/store/1n7x0yv8vq6zi90hfmian84vdhd04bgp-blender-2.79a
from 632 MiB to 16 MiB.
This can be iterated on and currently leaves out settings we know we
want to forward, but it fixes#1713 and fixes#1935 and isn't
fundamentally broken like the status quo. Future changes are suggested
in a comment.
The typical use is to inherit Config and add Setting<T> members:
class MyClass : private Config
{
Setting<int> foo{this, 123, "foo", "the number of foos to use"};
Setting<std::string> bar{this, "blabla", "bar", "the name of the bar"};
MyClass() : Config(readConfigFile("/etc/my-app.conf"))
{
std::cout << foo << "\n"; // will print 123 unless overriden
}
};
Currently, this is used by Store and its subclasses for store
parameters. You now get a warning if you specify a non-existant store
parameter in a store URI.
