4 Commits

Author	SHA1	Message	Date
Stefan Holderbach	076a29ae19	Document public types in nu-protocol (#12906) ... - **Doc-comment public `nu-protocol` modules** - **Doccomment argument/signature/call stuff** - **Doccomment cell path types** - **Doccomment expression stuff** - **Doccomment import patterns** - **Doccomment pattern matching AST nodes**	2024-07-11 13:30:12 +02:00
Devyn Cairns	d7392f1f3b	Internal representation (IR) compiler and evaluator (#13330) ... # Description This PR adds an internal representation language to Nushell, offering an alternative evaluator based on simple instructions, stream-containing registers, and indexed control flow. The number of registers required is determined statically at compile-time, and the fixed size required is allocated upon entering the block. Each instruction is associated with a span, which makes going backwards from IR instructions to source code very easy. Motivations for IR: 1. **Performance.** By simplifying the evaluation path and making it more cache-friendly and branch predictor-friendly, code that does a lot of computation in Nushell itself can be sped up a decent bit. Because the IR is fairly easy to reason about, we can also implement optimization passes in the future to eliminate and simplify code. 2. **Correctness.** The instructions mostly have very simple and easily-specified behavior, so hopefully engine changes are a little bit easier to reason about, and they can be specified in a more formal way at some point. I have made an effort to document each of the instructions in the docs for the enum itself in a reasonably specific way. Some of the errors that would have happened during evaluation before are now moved to the compilation step instead, because they don't make sense to check during evaluation. 3. **As an intermediate target.** This is a good step for us to bring the [`new-nu-parser`](https://github.com/nushell/new-nu-parser) in at some point, as code generated from new AST can be directly compared to code generated from old AST. If the IR code is functionally equivalent, it will behave the exact same way. 4. **Debugging.** With a little bit more work, we can probably give control over advancing the virtual machine that `IrBlock`s run on to some sort of external driver, making things like breakpoints and single stepping possible. Tools like `view ir` and [`explore ir`](https://github.com/devyn/nu_plugin_explore_ir) make it easier than before to see what exactly is going on with your Nushell code. The goal is to eventually replace the AST evaluator entirely, once we're sure it's working just as well. You can help dogfood this by running Nushell with `$env.NU_USE_IR` set to some value. The environment variable is checked when Nushell starts, so config runs with IR, or it can also be set on a line at the REPL to change it dynamically. It is also checked when running `do` in case within a script you want to just run a specific piece of code with or without IR. # Example ```nushell view ir { |data| mut sum = 0 for n in $data { $sum += $n } $sum } ``` ```gas # 3 registers, 19 instructions, 0 bytes of data 0: load-literal %0, int(0) 1: store-variable var 904, %0 # let 2: drain %0 3: drop %0 4: load-variable %1, var 903 5: iterate %0, %1, end 15 # for, label(1), from(14:) 6: store-variable var 905, %0 7: load-variable %0, var 904 8: load-variable %2, var 905 9: binary-op %0, Math(Plus), %2 10: span %0 11: store-variable var 904, %0 12: load-literal %0, nothing 13: drain %0 14: jump 5 15: drop %0 # label(0), from(5:) 16: drain %0 17: load-variable %0, var 904 18: return %0 ``` # Benchmarks All benchmarks run on a base model Mac Mini M1. ## Iterative Fibonacci sequence This is about as best case as possible, making use of the much faster control flow. Most code will not experience a speed improvement nearly this large. ```nushell def fib [n: int] { mut a = 0 mut b = 1 for _ in 2..=$n { let c = $a + $b $a = $b $b = $c } $b } use std bench bench { 0..50 | each { |n| fib $n } } ``` IR disabled: ``` ╭───────┬─────────────────╮ │ mean │ 1ms 924µs 665ns │ │ min │ 1ms 700µs 83ns │ │ max │ 3ms 450µs 125ns │ │ std │ 395µs 759ns │ │ times │ [list 50 items] │ ╰───────┴─────────────────╯ ``` IR enabled: ``` ╭───────┬─────────────────╮ │ mean │ 452µs 820ns │ │ min │ 427µs 417ns │ │ max │ 540µs 167ns │ │ std │ 17µs 158ns │ │ times │ [list 50 items] │ ╰───────┴─────────────────╯ ```  ## [gradient_benchmark_no_check.nu](https://github.com/nushell/nu_scripts/blob/main/benchmarks/gradient_benchmark_no_check.nu) IR disabled: ``` ╭───┬──────────────────╮ │ 0 │ 27ms 929µs 958ns │ │ 1 │ 21ms 153µs 459ns │ │ 2 │ 18ms 639µs 666ns │ │ 3 │ 19ms 554µs 583ns │ │ 4 │ 13ms 383µs 375ns │ │ 5 │ 11ms 328µs 208ns │ │ 6 │ 5ms 659µs 542ns │ ╰───┴──────────────────╯ ``` IR enabled: ``` ╭───┬──────────────────╮ │ 0 │ 22ms 662µs │ │ 1 │ 17ms 221µs 792ns │ │ 2 │ 14ms 786µs 708ns │ │ 3 │ 13ms 876µs 834ns │ │ 4 │ 13ms 52µs 875ns │ │ 5 │ 11ms 269µs 666ns │ │ 6 │ 6ms 942µs 500ns │ ╰───┴──────────────────╯ ``` ## [random-bytes.nu](https://github.com/nushell/nu_scripts/blob/main/benchmarks/random-bytes.nu) I got pretty random results out of this benchmark so I decided not to include it. Not clear why. # User-Facing Changes - IR compilation errors may appear even if the user isn't evaluating with IR. - IR evaluation can be enabled by setting the `NU_USE_IR` environment variable to any value. - New command `view ir` pretty-prints the IR for a block, and `view ir --json` can be piped into an external tool like [`explore ir`](https://github.com/devyn/nu_plugin_explore_ir). # Tests + Formatting All tests are passing with `NU_USE_IR=1`, and I've added some more eval tests to compare the results for some very core operations. I will probably want to add some more so we don't have to always check `NU_USE_IR=1 toolkit test --workspace` on a regular basis. # After Submitting - [ ] release notes - [ ] further documentation of instructions? - [ ] post-release: publish `nu_plugin_explore_ir`	2024-07-10 17:33:59 -07:00
Ian Manske	399a7c8836	Add and use new Signals struct (#13314) ... # Description This PR introduces a new `Signals` struct to replace our adhoc passing around of `ctrlc: Option<Arc<AtomicBool>>`. Doing so has a few benefits: - We can better enforce when/where resetting or triggering an interrupt is allowed. - Consolidates `nu_utils::ctrl_c::was_pressed` and other ad-hoc re-implementations into a single place: `Signals::check`. - This allows us to add other types of signals later if we want. E.g., exiting or suspension. - Similarly, we can more easily change the underlying implementation if we need to in the future. - Places that used to have a `ctrlc` of `None` now use `Signals::empty()`, so we can double check these usages for correctness in the future.	2024-07-07 22:29:01 +00:00
Ian Manske	6fd854ed9f	Replace ExternalStream with new ByteStream type (#12774) ... # Description This PR introduces a `ByteStream` type which is a `Read`-able stream of bytes. Internally, it has an enum over three different byte stream sources: ```rust pub enum ByteStreamSource { Read(Box<dyn Read + Send + 'static>), File(File), Child(ChildProcess), } ``` This is in comparison to the current `RawStream` type, which is an `Iterator<Item = Vec<u8>>` and has to allocate for each read chunk. Currently, `PipelineData::ExternalStream` serves a weird dual role where it is either external command output or a wrapper around `RawStream`. `ByteStream` makes this distinction more clear (via `ByteStreamSource`) and replaces `PipelineData::ExternalStream` in this PR: ```rust pub enum PipelineData { Empty, Value(Value, Option<PipelineMetadata>), ListStream(ListStream, Option<PipelineMetadata>), ByteStream(ByteStream, Option<PipelineMetadata>), } ``` The PR is relatively large, but a decent amount of it is just repetitive changes. This PR fixes #7017, fixes #10763, and fixes #12369. This PR also improves performance when piping external commands. Nushell should, in most cases, have competitive pipeline throughput compared to, e.g., bash. | Command | Before (MB/s) | After (MB/s) | Bash (MB/s) | | -------------------------------------------------- | -------------:| ------------:| -----------:| | `throughput \| rg 'x'` | 3059 | 3744 | 3739 | | `throughput \| nu --testbin relay o> /dev/null` | 3508 | 8087 | 8136 | # User-Facing Changes - This is a breaking change for the plugin communication protocol, because the `ExternalStreamInfo` was replaced with `ByteStreamInfo`. Plugins now only have to deal with a single input stream, as opposed to the previous three streams: stdout, stderr, and exit code. - The output of `describe` has been changed for external/byte streams. - Temporary breaking change: `bytes starts-with` no longer works with byte streams. This is to keep the PR smaller, and `bytes ends-with` already does not work on byte streams. - If a process core dumped, then instead of having a `Value::Error` in the `exit_code` column of the output returned from `complete`, it now is a `Value::Int` with the negation of the signal number. # After Submitting - Update docs and book as necessary - Release notes (e.g., plugin protocol changes) - Adapt/convert commands to work with byte streams (high priority is `str length`, `bytes starts-with`, and maybe `bytes ends-with`). - Refactor the `tee` code, Devyn has already done some work on this. --------- Co-authored-by: Devyn Cairns <devyn.cairns@gmail.com>	2024-05-16 07:11:18 -07:00