8 Commits

Author SHA1 Message Date
Bahex
f63cecc316
add metadata access command (#13785)
# Description
Add `metadata access`, which allows accessing/inspecting the metadata of
a stream in a closure.
```nu
ls | metadata access {|meta|
    ...
}
```

- The metadata is provided as an argument to the closure, identical to
the record obtained with `metadata` command.

- `metadata access` passes its input stream into the closure as it is.

- Within the closure, both the metadata and the stream are available.
The closure may modify, collect or pass the stream as it is.

# Motivation
- Without this command, nu code can't act on metadata without losing the
stream, use cases requiring both the stream and metadata must be
implemented either as a built-in or a plugin.

- This command allows users to enhance presentation of data, similar to
`table` coloring the output of `ls`.
2024-09-11 12:44:06 -05:00
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] │
╰───────┴─────────────────╯
```

![explore ir
view](https://github.com/nushell/nushell/assets/10729/d7bccc03-5222-461c-9200-0dce71b83b83)

##
[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
Darren Schroeder
7fe2e60af7
add ability to set metadata (#12564)
# Description

This PR adds the ability to set metadata. This is especially useful for
activating LS_COLORS when using table literals.


![image](https://github.com/nushell/nushell/assets/343840/feef6433-f592-43ea-890a-38cb2df35686)

You can also set the filepath metadata, although I'm not really user how
useful this is. We may end up removing this option entirely.
```nushell
❯ "crates" | metadata set --datasource-filepath $'(pwd)/crates' | metadata
╭────────┬───────────────────────────────────╮
│ source │ /Users/fdncred/src/nushell/crates │
╰────────┴───────────────────────────────────╯
```

No file paths are checked. You could also do this.
```nushell
❯ "crates" | metadata set --datasource-filepath $'a/b/c/d/crates' | metadata
╭────────┬────────────────╮
│ source │ a/b/c/d/crates │
╰────────┴────────────────╯
```

The command name and parameter names are still WIP. We could change
them.

There are currently 3 kinds of metadata in nushell.
```rust
pub enum DataSource {
    Ls,
    HtmlThemes,
    FilePath(PathBuf),
}
```

I've skipped adding `HtmlThemes` because it seems to be specific to our
`to html` command only.
2024-04-19 09:03:59 +08:00
Jakub Žádník
14d1c67863
Debugger experiments (#11441)
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# Description
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This PR adds a new evaluator path with callbacks to a mutable trait
object implementing a Debugger trait. The trait object can do anything,
e.g., profiling, code coverage, step debugging. Currently,
entering/leaving a block and a pipeline element is marked with
callbacks, but more callbacks can be added as necessary. Not all
callbacks need to be used by all debuggers; unused ones are simply empty
calls. A simple profiler is implemented as a proof of concept.

The debugging support is implementing by making `eval_xxx()` functions
generic depending on whether we're debugging or not. This has zero
computational overhead, but makes the binary slightly larger (see
benchmarks below). `eval_xxx()` variants called from commands (like
`eval_block_with_early_return()` in `each`) are chosen with a dynamic
dispatch for two reasons: to not grow the binary size due to duplicating
the code of many commands, and for the fact that it isn't possible
because it would make Command trait objects object-unsafe.

In the future, I hope it will be possible to allow plugin callbacks such
that users would be able to implement their profiler plugins instead of
having to recompile Nushell.
[DAP](https://microsoft.github.io/debug-adapter-protocol/) would also be
interesting to explore.

Try `help debug profile`.

## Screenshots

Basic output:

![profiler_new](https://github.com/nushell/nushell/assets/25571562/418b9df0-b659-4dcb-b023-2d5fcef2c865)

To profile with more granularity, increase the profiler depth (you'll
see that repeated `is-windows` calls take a large chunk of total time,
making it a good candidate for optimizing):

![profiler_new_m3](https://github.com/nushell/nushell/assets/25571562/636d756d-5d56-460c-a372-14716f65f37f)

## Benchmarks

### Binary size

Binary size increase vs. main: **+40360 bytes**. _(Both built with
`--release --features=extra,dataframe`.)_

### Time

```nushell
# bench_debug.nu
use std bench

let test = {
    1..100
    | each {
        ls | each {|row| $row.name | str length }
    }
    | flatten
    | math avg
}

print 'debug:'
let res2 = bench { debug profile $test } --pretty
print $res2
```

```nushell
# bench_nodebug.nu
use std bench

let test = {
    1..100
    | each {
        ls | each {|row| $row.name | str length }
    }
    | flatten
    | math avg
}

print 'no debug:'
let res1 = bench { do $test } --pretty
print $res1
```

`cargo run --release -- bench_debug.nu` is consistently 1--2 ms slower
than `cargo run --release -- bench_nodebug.nu` due to the collection
overhead + gathering the report. This is expected. When gathering more
stuff, the overhead is obviously higher.

`cargo run --release -- bench_nodebug.nu` vs. `nu bench_nodebug.nu` I
didn't measure any difference. Both benchmarks report times between 97
and 103 ms randomly, without one being consistently higher than the
other. This suggests that at least in this particular case, when not
running any debugger, there is no runtime overhead.

## API changes

This PR adds a generic parameter to all `eval_xxx` functions that forces
you to specify whether you use the debugger. You can resolve it in two
ways:
* Use a provided helper that will figure it out for you. If you wanted
to use `eval_block(&engine_state, ...)`, call `let eval_block =
get_eval_block(&engine_state); eval_block(&engine_state, ...)`
* If you know you're in an evaluation path that doesn't need debugger
support, call `eval_block::<WithoutDebug>(&engine_state, ...)` (this is
the case of hooks, for example).

I tried to add more explanation in the docstring of `debugger_trait.rs`.

## TODO

- [x] Better profiler output to reduce spam of iterative commands like
`each`
- [x] Resolve `TODO: DEBUG` comments
- [x] Resolve unwraps
- [x] Add doc comments
- [x] Add usage and extra usage for `debug profile`, explaining all
columns

# User-Facing Changes
<!-- List of all changes that impact the user experience here. This
helps us keep track of breaking changes. -->

Hopefully none.

# Tests + Formatting
<!--
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Make sure you've run and fixed any issues with these commands:

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mode](https://learn.microsoft.com/en-us/windows/apps/get-started/developer-mode-features-and-debugging))
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crates/nu-std"` to run the tests for the standard library

> **Note**
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> use toolkit.nu # or use an `env_change` hook to activate it
automatically
> toolkit check pr
> ```
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# After Submitting
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2024-03-08 20:21:35 +02:00
Jakub Žádník
a35ecb4837
Finish removing profile command and related data (#10807) 2023-10-22 14:06:53 +03:00
Darren Schroeder
1f62024a15
add a debug info command to show memory info (#10711)
# Description

This PR adds a new command called `debug info`. I'm not sure if the name
is right but we can rename it if needed. The purpose of this command is
to show a user how much memory nushell is using. This is what the output
looks like.

I feel like the further we go with nushell, the more we'll need to
easily monitor the memory usage. With this command, we should easily be
able to do that with scripts or just running the command.

```nushell
❯ debug info | table -e
╭─────────┬──────────────────────────────────────────────────────────────────────╮
│pid      │31036                                                                 │
│ppid     │29388                                                                 │
│         │╭─────────────────┬────────────────────────────────────────────────╮  │
│process  ││memory           │63.5 MB                                         │  │
│         ││virtual_memory   │5.6 GB                                          │  │
│         ││status           │Runnable                                        │  │
│         ││root             │C:\cartar\debug                                 │  │
│         ││cwd              │C:\Users\us991808\source\repos\forks\nushell\   │  │
│         ││exe_path         │C:\cartar\debug\nu.exe                          │  │
│         ││command          │c:\cartar\debug\nu.exe -l                       │  │
│         ││name             │nu.exe                                          │  │
│         ││environment      │{record 110 fields}                             │  │
│         │╰─────────────────┴────────────────────────────────────────────────╯  │
│         │╭────────────────┬───────╮                                            │
│system   ││total_memory    │17.1 GB│                                            │
│         ││free_memory     │5.9 GB │                                            │
│         ││used_memory     │11.3 GB│                                            │
│         ││available_memory│5.9 GB │                                            │
│         │╰────────────────┴───────╯                                            │
╰─────────┴──────────────────────────────────────────────────────────────────────╯
```
> [!NOTE]
The `process.environment` is not the nushell `$env` but the environment
that the process was created with at launch time.
# User-Facing Changes
<!-- List of all changes that impact the user experience here. This
helps us keep track of breaking changes. -->

# Tests + Formatting
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2023-10-14 12:28:48 -05:00
Darren Schroeder
d5ce509e3a
move ast command to the debug group (#8077)
# Description

This PR tweaks how `ast` works a tiny bit by outputting values in stead
of eprintln!'s. It also moves the `ast` command into the folder with the
rest of the debug commands and changes the category to debug.

I started adding some tests but couldn't figure out a good way to do it
since every `ast` command contains spans that will be different on each
invocation.

# User-Facing Changes



# Tests + Formatting

Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass

# After Submitting

If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.
2023-02-14 18:47:34 +00:00
Darren Schroeder
4c787af26d
relocate debug commands (#8071)
# Description

Now that we've landed the debug commands we were working on, let's
relocate them to an easier place to find all of them. That's what this
PR does.

The only actual code change was changing the `timeit` command to a
`Category::Debug` command. The rest is just moving things around and
hooking them up.

# User-Facing Changes



# Tests + Formatting

Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass

# After Submitting

If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.
2023-02-13 16:39:07 +00:00