Building derivations is a lot harder, but the downloading goals is
portable enough.
The "common channel" code is due to Volth. I wonder if there is a way we
can factor it out into separate functions / files to avoid some
within-function CPP.
Co-authored-by: volth <volth@volth.com>
At this point many features are stripped out, but this works:
- Can run libnix{util,store,expr} unit tests
- Can run some Nix commands
Co-Authored-By volth <volth@volth.com>
Co-Authored-By Brian McKenna <brian@brianmckenna.org>
Most of this is a `catch SysError` -> `catch SystemError` sed. This
is a rather pure-churn change I would like to get out of the way. **The
intersting part is `src/libutil/error.hh`.**
On Unix, we will only throw the `SysError` concrete class, which has
the same constructors that `SystemError` used to have.
On Windows, we will throw `WinError` *and* `SysError`. `WinError`
(which will be created in a later PR), will use a `DWORD` instead of
`int` error value, and `GetLastError()`, which is the Windows equivalent
of the `errno` machinery. Windows will *also* use `SysError` because
Window's "libc" (MSVCRT) implements the POSIX interface, and we use it
too.
As the docs describe, while we *throw* one of the 3 choices above (2
concrete classes or the alias), we should always *catch* `SystemError`.
This ensures no matter how the implementation changes for Windows (e.g.
between `SysError` and `WinError`) the catching logic stays the same
and stays correct.
Co-Authored-By volth <volth@volth.com>
Co-Authored-By Eugene Butler <eugene@eugene4.com>
more buffers that can be uninitialized and on the stack. small
difference, but still worth doing.
before:
Benchmark 1: nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'
Time (mean ± σ): 6.963 s ± 0.011 s [User: 5.330 s, System: 1.421 s]
Range (min … max): 6.943 s … 6.974 s 10 runs
after:
Benchmark 1: nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'
Time (mean ± σ): 6.952 s ± 0.015 s [User: 5.294 s, System: 1.452 s]
Range (min … max): 6.926 s … 6.974 s 10 runs
This is the core functionality but just unit-tested and not yet made
part of the store layer. This is because there is some tech debt around
(a) repeated boilerplate hashing objects (b) better integration of the
new `SourceAccessor` type that needs to be cleaned up first.
Part of RFC 133
Co-Authored-By: Matthew Bauer <mjbauer95@gmail.com>
Co-Authored-By: Carlo Nucera <carlo.nucera@protonmail.com>
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
Co-authored-by: Florian Klink <flokli@flokli.de>
All OS and IO operations should be moved out, leaving only some misc
portable pure functions.
This is useful to avoid copious CPP when doing things like Windows and
Emscripten ports.
Newly exposed functions to break cycles:
- `restoreSignals`
- `updateWindowSize`
The `write` name is ambiguous and could lead to some funny bugs like
https://github.com/NixOS/nix/pull/8173#issuecomment-1500009480. So
rename it to the more explicit `writeUnbuffered`.
Besides, this method shouldn't be (and isn't) used outside of the class
implementation, so mark it `protected`.
This makes it more symetrical to `BufferedSource` which uses a
`protected readUnbuffered` method.
Changes:
* The divider lines are gone. These were in practice a bit confusing,
in particular with --show-trace or --keep-going, since then there
were multiple lines, suggesting a start/end which wasn't the case.
* Instead, multi-line error messages are now indented to align with
the prefix (e.g. "error: ").
* The 'description' field is gone since we weren't really using it.
* 'hint' is renamed to 'msg' since it really wasn't a hint.
* The error is now printed *before* the location info.
* The 'name' field is no longer printed since most of the time it
wasn't very useful since it was just the name of the exception (like
EvalError). Ideally in the future this would be a unique, easily
googleable error ID (like rustc).
* "trace:" is now just "…". This assumes error contexts start with
something like "while doing X".
Example before:
error: --- AssertionError ---------------------------------------------------------------------------------------- nix
at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix
6|
7| x = assert false; 1;
| ^
8|
assertion 'false' failed
----------------------------------------------------- show-trace -----------------------------------------------------
trace: while evaluating the attribute 'x' of the derivation 'hello-2.10'
at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix
191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) {
192| name = "${attrs.pname}-${attrs.version}";
| ^
193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
Example after:
error: assertion 'false' failed
at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix
6|
7| x = assert false; 1;
| ^
8|
… while evaluating the attribute 'x' of the derivation 'hello-2.10'
at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix
191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) {
192| name = "${attrs.pname}-${attrs.version}";
| ^
193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
Crucially this introduces BoehmGCStackAllocator, but it also
adds a bunch of wiring to avoid making libutil depend on bdw-gc.
Part of the solutions for #4178, #4200
I got it to just become `LocalStore::addToStoreFromDump`, cleanly taking
a store and then doing nothing too fancy with it.
`LocalStore::addToStore(...Path...)` is now just a simple wrapper with a
bare-bones sinkToSource of the right dump command.
In particular this causes copyStorePath() from HttpBinaryCacheStore to
only start a download if needed. E.g. if the destination LocalStore
goes to sleep waiting for the path lock and another process creates
the path, then LocalStore::addToStore() will never read from the
source so we don't have to do the download.
copyStorePath() now pipes the output of srcStore->narFromPath()
directly into dstStore->addToStore(). The sink used by the former is
converted into a source usable by the latter using
boost::coroutine2. This is based on [1].
This reduces the maximum resident size of
$ nix build --store ~/my-nix/ /nix/store/b0zlxla7dmy1iwc3g459rjznx59797xy-binutils-2.28.1 --substituters file:///tmp/binary-cache-xz/ --no-require-sigs
from 418592 KiB to 53416 KiB. (The previous commit also reduced the
runtime from ~4.2s to ~3.4s, not sure why.) A further improvement will
be to download files into a Sink.
[1] https://github.com/NixOS/nix/compare/master...Mathnerd314:dump-fix-coroutine#diff-dcbcac55a634031f9cc73707da6e4b18
Issue #1969.
