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Diffstat (limited to 'tvix/docs/src')
| -rw-r--r-- | tvix/docs/src/SUMMARY.md | 1 | ||||
| -rw-r--r-- | tvix/docs/src/TODO.md | 129 |
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diff --git a/tvix/docs/src/SUMMARY.md b/tvix/docs/src/SUMMARY.md index f9b069d42c5a..b0e47a001108 100644 --- a/tvix/docs/src/SUMMARY.md +++ b/tvix/docs/src/SUMMARY.md @@ -2,6 +2,7 @@ # Tvix - [Architecture & data flow](./architecture.md) +- [TODOs](./TODO.md) # Nix - [Specification of the Nix Language](./language-spec.md) diff --git a/tvix/docs/src/TODO.md b/tvix/docs/src/TODO.md new file mode 100644 index 000000000000..6644bb6bac03 --- /dev/null +++ b/tvix/docs/src/TODO.md @@ -0,0 +1,129 @@ +# TODO + +This contains a rough collection of ideas on the TODO list, trying to keep track +of it somewhere. + +Of course, there's no guarantee these things will get addressed, but it helps +dumping the backlog somewhere. + +Feel free to add new ideas. Before picking something, ask in `#tvix-dev` to make +sure noone is working on this, or has some specific design in mind already. + +## Cleanups + - move some of the rstest cases in `tvix-glue` to the `.nix`/`.exp` mechanism. + - Parts requiring test fixtures need some special convention. + Some of these also cannot be checked into the repo, like the import tests + adding special files to test filtering. + - add `nix_oracle` mechanism from `tvix-eval` to `tvix-glue`. + +## Fixes towards correctness + - `builtins.toXML` is missing string context. See b/398. + - `builtins.toXML` self-closing tags need to be configurable in a more granular + fashion, requires third-party crate support. See b/399. + - `rnix` only supports string source files, but `NixString` uses bytes (and Nix + source code might be no valid UTF-8). + +## Documentation +Extend the other pages in here. Some ideas on what should be tackled: + - Document what Tvix is, and what it is not yet. What it is now, what it is not + (yet), explaining some of the architectural choices (castore, more hermetic + `Build` repr), while still being compatible. Explain how it's possible to + plug in other frontends, and use `tvix-{[ca]store,build}` without Nixlang even. + And how `nix-compat` is a useful crate for all sorts of formats and data + types of Nix. + - Update the Architecture diagram to model the current state of things. + There's no gRPC between Coordinator and Evaluator. + - Add a dedicated section/page explaining the separation between tvix-glue and + tvix-eval, and how more annoying builtins get injected into tvix-eval through + tvix-glue. + Maybe restructure to only explain the component structure potentially + crossing process boundaries (those with gRPC), and make the rest more crate + and trait-focused? + - Restructure docs on castore vs store, this seems to be duplicated a bit and + is probably still not too clear. + - Describe store composition(s) in more detail. There's some notes on granular + fetching which probably can be repurposed. + - Absorb the rest of //tvix/website into this. + +## Features + +### CLI + - `nix repl` can set variables and effectively mutates a global scope. We + should update the existing / add another repl that allows the same. We don't + want to mutate the evaluator, but should construct a new one, passing in the + root scope returned from the previous evaluation. + +### Fetchers +Some more fetcher-related builtins need work: + - `fetchGit` + - `fetchTree` (hairy, seems there's no proper spec and the URL syntax seems + subject to change/underdocumented) + +### Convert builtins:fetchurl to Fetches +We need to convert `builtins:fetchurl`-style calls to `builtins.derivation` to +fetches, not Derivations (tracked in `KnownPaths`). + +### Derivation -> Build +While we have some support for `structuredAttrs` and `fetchClosure` (at least +enough to calculate output hashes, aka produce identical ATerm), the code +populating the `Build` struct doesn't exist it yet. + +Similarly, we also don't properly populate the build environment for +`fetchClosure` yet. (Note there already is `ExportedPathInfo`, so once +`structuredAttrs` is there this should be easy. + +### Builders +Once builds are proven to work with real-world builds, and the corner cases +there are ruled out, adding other types of builders might be interesting. + + - bwrap + - gVisor + - Cloud Hypervisor (using similar technique as `//tvix//boot`). + +Long-term, we want to extend traits and gRPC protocol to expose more telemetry, +logs etc, but this is something requiring a lot of designing. + +### Store composition + - Combinators: list-by-priority, first-come-first-serve, cache + - How do describe hierarchies. URL format too one-dimensional, but we might get + quite far with a similar "substituters" concept that Nix uses, to construct + the composed stores. +### Store Config + There's already serde for some store options (bigtable uses `serde_qs`). + We might also have common options global over all backends, like chunking + parameters for chunking blobservices. Think where this would fit in. + - Rework the URL syntax for object_store. We should support the default s3/gcs + URLs at least. + +### BlobService + - On the trait side, currently there's no way to distinguish reading a + known-chunk vs blob, so we might be calling `.chunks()` unnecessarily often. + At least for the `object_store` backend, this might be a problem. + - While `object_store` recently got support for `Content-Type` + (https://github.com/apache/arrow-rs/pull/5650), there's no support on the + local filesystem yet. We'd need to add support to this (through xattrs). + +### DirectoryService + - Add an `object_store` variant, storing a Directory *closure* keyed by the + root `Directory` digest. This won't allow indexing intermediate Directory + nodes, but once we have `DirectoryService` composition, it shouldn't be an + issue. + - [redb](https://www.redb.org/) backend + +### PathInfoService + - [redb](https://www.redb.org/) backend + - sqlite backend (different schema than the Nix one, we need the root nodes data!) + +### Nix-compat +- Async NAR reader (@edef?) + +### Nix Daemon protocol +- Some work ongoing on the worker operation parsing. Partially blocked on the async NAR reader. + +### O11Y + - gRPC trace propagation (cl/10532) + - `tracing-tracy` (cl/10952) + - `[tracing-]indicatif` for progress/log reporting (floklis stash) + - unification into `tvix-tracing` crate, currently a lot of boilerplate + in `tvix-store` CLI entrypoint, and half of the boilerplate copied over to + `tvix-cli`. |