tvl-depot/tvix
Aspen Smith 201173afac fix(tvix): Represent strings as byte arrays
C++ nix uses C-style zero-terminated char pointers to represent strings
internally - however, up to this point, tvix has used Rust `String` and
`str` for string values. Since those are required to be valid utf-8, we
haven't been able to properly represent all the string values that Nix
supports.

To fix that, this change converts the internal representation of the
NixString struct from `Box<str>` to `BString`, from the `bstr` crate -
this is a wrapper around a `Vec<u8>` with extra functions for treating
that byte vector as a "morally string-like" value, which is basically
exactly what we need.

Since this changes a pretty fundamental assumption about a pretty core
type, there are a *lot* of changes in a lot of places to make this work,
but I've tried to keep the general philosophy and intent of most of the
code in most places intact. Most notably, there's nothing that's been
done to make the derivation stuff in //tvix/glue work with non-utf8
strings everywhere, instead opting to just convert to String/str when
passing things into that - there *might* be something to be done there,
but I don't know what the rules should be and I don't want to figure
them out in this change.

To deal with OS-native paths in a way that also works in WASM for
tvixbolt, this also adds a dependency on the "os_str_bytes" crate.

Fixes: b/189
Fixes: b/337
Change-Id: I5e6eb29c62f47dd91af954f5e12bfc3d186f5526
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10200
Reviewed-by: tazjin <tazjin@tvl.su>
Reviewed-by: flokli <flokli@flokli.de>
Reviewed-by: sterni <sternenseemann@systemli.org>
Autosubmit: aspen <root@gws.fyi>
Tested-by: BuildkiteCI
2024-01-31 14:51:49 +00:00
..
.vscode chore(tvix): fix vscode rust-analyzer recommendation 2022-10-15 16:54:28 +00:00
boot refactor(tvix/nar-bridge): mv nar-bridge{,-http} 2023-10-05 06:17:10 +00:00
build feat(tvix/build): add CLI entrypoint 2024-01-15 18:54:35 +00:00
build-go chore(3p/sources): Bump channels & overlays 2024-01-19 21:47:32 +00:00
castore feat(tvix/castore): process_entry cannot process unsupported nodes 2024-01-22 14:15:42 +00:00
castore-go chore(3p/sources): Bump channels & overlays 2024-01-19 21:47:32 +00:00
cli fix(tvix): Represent strings as byte arrays 2024-01-31 14:51:49 +00:00
docs docs(tvix/docs): add document about drvPath differences 2023-08-20 22:08:02 +00:00
eval fix(tvix): Represent strings as byte arrays 2024-01-31 14:51:49 +00:00
glue fix(tvix): Represent strings as byte arrays 2024-01-31 14:51:49 +00:00
nar-bridge feat(tvix/store/nar-info): Support async blob upload 2024-01-23 17:01:16 +00:00
nix-compat fix(nix-compat): accept SRI hashes of invalid length 2024-01-20 17:14:30 +00:00
nix-lang-test-suite docs(tvix): initial notes on a possible generic Nix lang test suite 2024-01-22 14:21:19 +00:00
scripts chore(tvix): Run criterion benchmarks for the whole workspace 2023-12-20 18:04:43 +00:00
serde fix(tvix): Represent strings as byte arrays 2024-01-31 14:51:49 +00:00
store chore(tvix/store): Use BoxStream type alias 2024-01-21 19:41:02 +00:00
store-go chore(3p/sources): Bump channels & overlays 2024-01-19 21:47:32 +00:00
tools feat(tvix/tools/crunch-v2): add CLI args 2024-01-27 18:40:48 +00:00
verify-lang-tests test(tvix/eval): add test case for b/339 2023-12-12 14:26:46 +00:00
website feat(tvix/website): Link to windtunnel results page 2023-12-23 17:12:25 +00:00
.gitignore chore(tvix): add /*.sled to .gitignore 2023-09-24 17:05:48 +00:00
buildkite.yml chore(tvix): move buildkite.yml from views/tvix to tvix/ 2023-10-25 08:22:57 +00:00
Cargo.lock fix(tvix): Represent strings as byte arrays 2024-01-31 14:51:49 +00:00
Cargo.nix fix(tvix): Represent strings as byte arrays 2024-01-31 14:51:49 +00:00
Cargo.toml chore(tvix): switch to upstream futures 0.3.30 2023-12-24 21:45:04 +00:00
clippy.toml chore(tvix): add missing clippy attributes & config 2023-11-05 20:28:38 +00:00
crate-hashes.json chore(tvix): switch to upstream futures 0.3.30 2023-12-24 21:45:04 +00:00
default.nix refactor(tools): move crate2nix generate here 2024-01-18 15:02:15 +00:00
LICENSE chore(tvix): Bootstrap Tvix folder 2021-03-27 00:09:49 +00:00
logo.webp refactor(tvix): move logo to //tvix:logo 2023-09-10 13:13:14 +00:00
OWNERS chore(depot): update OWNERS files for aspen 2023-12-20 18:35:58 +00:00
README.md refactor(tools): move crate2nix generate here 2024-01-18 15:02:15 +00:00
shell.nix chore(tvix/shell): add cargo-expand to debug proc-macro 2024-01-18 12:29:46 +00:00


Tvix is a new implementation of the Nix language and package manager. See the announcement post for information about the background of this project.

Tvix is developed by TVL in our monorepo, the depot, at //tvix. Code reviews take place on Gerrit, bugs are filed in our issue tracker.

For more information about Tvix, feel free to reach out. We are interested in people who would like to help us review designs, brainstorm and describe requirements that we may not yet have considered.

Most of the discussion around development happens on our IRC channel, which you can join in several ways documented on tvl.fyi, or on our mailing list.

Contributions to Tvix follow the TVL review flow and contribution guidelines.

WARNING: Tvix is not ready for use in production. None of our current APIs should be considered stable in any way.

WARNING: Any other instances of this project or repository are josh-mirrors. We do not accept code contributions or issues outside of the tooling and communication methods outlined above.

Components

This folder contains the following components:

  • //tvix/castore - subtree storage/transfer in a content-addressed fashion
  • //tvix/cli - preliminary REPL & CLI implementation for Tvix
  • //tvix/eval - an implementation of the Nix programming language
  • //tvix/nar-bridge
    • nar-bridge-http: A HTTP webserver providing a Nix HTTP Binary Cache interface in front of a tvix-store
  • //tvix/nix-compat - a Rust library for compatibility with C++ Nix, features like encodings and hashing schemes and formats
  • //tvix/serde - a Rust library for using the Nix language for app configuration
  • //tvix/store - a "filesystem" linking Nix store paths and metadata with the content-addressed layer

Some additional folders with auxiliary things exist and can be explored at your leisure.

Building the CLI

The CLI can also be built with standard Rust tooling (i.e. cargo build), as long as you are in a shell with the right dependencies.

  • If you cloned the full monorepo, it can be provided by mg shell //tvix:shell.
  • If you cloned the tvix workspace only (git clone https://code.tvl.fyi/depot.git:workspace=views/tvix.git), nix-shell provides it.

If you're in the TVL monorepo, you can also run mg build //tvix/cli (or mg build from inside that folder) for a more incremental build.

Please follow the depot-wide instructions on how to get mg and use the depot tooling.

Compatibility

Important note: We only use and test Nix builds of our software against Nix 2.3. There are a variety of bugs and subtle problems in newer Nix versions which we do not have the bandwidth to address, builds in newer Nix versions may or may not work.

Rust projects, crate2nix

Some parts of Tvix are written in Rust. To simplify the dependency management on the Nix side of these builds, we use crate2nix in a single Rust workspace in //tvix to maintain the Nix build configuration.

When making changes to Cargo dependency configuration in any of the Rust projects under //tvix, be sure to run mg run //tools:crate2nix-generate in //tvix itself and commit the changes to the generated Cargo.nix file. This only applies to the full TVL checkout.

License structure

All code implemented for Tvix is licensed under the GPL-3.0, with the exception of the protocol buffer definitions used for communication between services which are available under a more permissive license (MIT).

The idea behind this structure is that any direct usage of our code (e.g. linking to it, embedding the evaluator, etc.) will fall under the terms of the GPL3, but users are free to implement their own components speaking these protocols under the terms of the MIT license.