# Description
This PR adds a new method to `EngineInterface`: `register_ctrlc_handler`
which takes a closure to run when the plugin's driving engine receives a
ctrlc-signal. It also adds a mirror of the `signals` attribute from the
main shell `EngineState`.
This is an example of how a plugin which makes a long poll http request
can end the request on ctrlc:
https://github.com/cablehead/nu_plugin_http/blob/main/src/commands/request.rs#L68-L77
To facilitate the feature, a new attribute has been added to
`EngineState`: `ctrlc_handlers`. This is a Vec of closures that will be
run when the engine's process receives a ctrlc signal.
When plugins are added to an `engine_state` during a `merge_delta`, the
engine passes the ctrlc_handlers to the plugin's
`.configure_ctrlc_handler` method, which gives the plugin a chance to
register a handler that sends a ctrlc packet through the
`PluginInterface`, if an instance of the plugin is currently running.
On the plugin side: `EngineInterface` also has a ctrlc_handlers Vec of
closures. Plugin calls can use `register_ctrlc_handler` to register a
closure that will be called in the plugin process when the
PluginInput::Ctrlc command is received.
For future reference these are some alternate places that were
investigated for tying the ctrlc trigger to transmitting a Ctrlc packet
through the `PluginInterface`:
- Directly from `src/signals.rs`: the handler there would need a
reference to the Vec<Arc<RegisteredPlugins>>, which would require us to
wrap the plugins in a Mutex, which we don't want to do.
- have `PersistentPlugin.get_plugin` pass down the engine's
CtrlcHandlers to .get and then to .spawn (if the plugin isn't already
running). Once we have CtrlcHandlers in spawn, we can register a handler
to write directly to PluginInterface. We don't want to double down on
passing engine_state to spawn this way though, as it's unpredictable
because it would depend on whether the plugin has already been spawned
or not.
- pass `ctrlc_handlers` to PersistentPlugin::new so it can store it on
itself so it's available to spawn.
- in `PersistentPlugin.spawn`, create a handler that sends to a clone of
the GC event loop's tx. this has the same issues with regards to how to
get CtrlcHandlers to the spawn method, and is more complicated than a
handler that writes directly to PluginInterface
# User-Facing Changes
No breaking changes
---------
Co-authored-by: Ian Manske <ian.manske@pm.me>
# Description
Adds functionality to the plugin interface to support calling internal
commands from plugins. For example, using `view ir --json`:
```rust
let closure: Value = call.req(0)?;
let Some(decl_id) = engine.find_decl("view ir")? else {
return Err(LabeledError::new("`view ir` not found"));
};
let ir_json = engine.call_decl(
decl_id,
EvaluatedCall::new(call.head)
.with_named("json".into_spanned(call.head), Value::bool(true, call.head))
.with_positional(closure),
PipelineData::Empty,
true,
false,
)?.into_value()?.into_string()?;
let ir = serde_json::from_value(&ir_json);
// ...
```
# User-Facing Changes
Plugin developers can now use `EngineInterface::find_decl()` and
`call_decl()` to call internal commands, which could be handy for
formatters like `to csv` or `to nuon`, or for reflection commands that
help gain insight into the engine.
# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`
# After Submitting
- [ ] release notes
- [ ] update plugin protocol documentation: `FindDecl`, `CallDecl`
engine calls; `Identifier` engine call response
# Description
This allows plugins to report their version (and potentially other
metadata in the future). The version is shown in `plugin list` and in
`version`.
The metadata is stored in the registry file, and reflects whatever was
retrieved on `plugin add`, not necessarily the running binary. This can
help you to diagnose if there's some kind of mismatch with what you
expect. We could potentially use this functionality to show a warning or
error if a plugin being run does not have the same version as what was
in the cache file, suggesting `plugin add` be run again, but I haven't
done that at this point.
It is optional, and it requires the plugin author to make some code
changes if they want to provide it, since I can't automatically
determine the version of the calling crate or anything tricky like that
to do it.
Example:
```
> plugin list | select name version is_running pid
╭───┬────────────────┬─────────┬────────────┬─────╮
│ # │ name │ version │ is_running │ pid │
├───┼────────────────┼─────────┼────────────┼─────┤
│ 0 │ example │ 0.93.1 │ false │ │
│ 1 │ gstat │ 0.93.1 │ false │ │
│ 2 │ inc │ 0.93.1 │ false │ │
│ 3 │ python_example │ 0.1.0 │ false │ │
╰───┴────────────────┴─────────┴────────────┴─────╯
```
cc @maxim-uvarov (he asked for it)
# User-Facing Changes
- `plugin list` gets a `version` column
- `version` shows plugin versions when available
- plugin authors *should* add `fn metadata()` to their `impl Plugin`,
but don't have to
# Tests + Formatting
Tested the low level stuff and also the `plugin list` column.
# After Submitting
- [ ] update plugin guide docs
- [ ] update plugin protocol docs (`Metadata` call & response)
- [ ] update plugin template (`fn metadata()` should be easy)
- [ ] release notes
# 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>
# Description
This allows plugins to view the source code of spans.
Requested by @ayax79 for implementing `polars ls`. Note that this won't
really help you find the location of the span. I'm planning to add
another engine call that will return information more similar to what
shows up in the miette diagnostics, with filename / line number / some
context, but I'll want to refactor some of the existing logic to make
that happen, so it was easier to just do this first. I hope this is
enough to at least have something somewhat useful show up for `polars
ls`.
# User-Facing Changes
- Example plugin: added `example view span` command
# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`
# After Submitting
- [ ] Add to plugin protocol reference
# Description
This is something that was discussed in the core team meeting last
Wednesday. @ayax79 is building `nu-plugin-polars` with all of the
dataframe commands into a plugin, and there are a lot of them, so it
would help to make the API more similar. At the same time, I think the
`Command` API is just better anyway. I don't think the difference is
justified, and the types for core commands have the benefit of requiring
less `.into()` because they often don't own their data
- Broke `signature()` up into `name()`, `usage()`, `extra_usage()`,
`search_terms()`, `examples()`
- `signature()` returns `nu_protocol::Signature`
- `examples()` returns `Vec<nu_protocol::Example>`
- `PluginSignature` and `PluginExample` no longer need to be used by
plugin developers
# User-Facing Changes
Breaking API for plugins yet again 😄
# Description
As suggested by @WindSoilder, since plugins can now contain both simple
commands that produce `Value` and commands that produce `PipelineData`
without having to choose one or the other for the whole plugin, this
change merges `stream_example` into `example`.
# User-Facing Changes
All of the example plugins are renamed.
# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`
# After Submitting
- [ ] Check nushell/nushell.github.io for any docs that match the
command names changed
[Context on
Discord](https://discord.com/channels/601130461678272522/855947301380947968/1216517833312309419)
# Description
This is a significant breaking change to the plugin API, but one I think
is worthwhile. @ayax79 mentioned on Discord that while trying to start
on a dataframes plugin, he was a little disappointed that more wasn't
provided in terms of code organization for commands, particularly since
there are *a lot* of `dfr` commands.
This change treats plugins more like miniatures of the engine, with
dispatch of the command name being handled inherently, each command
being its own type, and each having their own signature within the trait
impl for the command type rather than having to find a way to centralize
it all into one `Vec`.
For the example plugins that have multiple commands, I definitely like
how this looks a lot better. This encourages doing code organization the
right way and feels very good.
For the plugins that have only one command, it's just a little bit more
boilerplate - but still worth it, in my opinion.
The `Box<dyn PluginCommand<Plugin = Self>>` type in `commands()` is a
little bit hairy, particularly for Rust beginners, but ultimately not so
bad, and it gives the desired flexibility for shared state for a whole
plugin + the individual commands.
# User-Facing Changes
Pretty big breaking change to plugin API, but probably one that's worth
making.
```rust
use nu_plugin::*;
use nu_protocol::{PluginSignature, PipelineData, Type, Value};
struct LowercasePlugin;
struct Lowercase;
// Plugins can now have multiple commands
impl PluginCommand for Lowercase {
type Plugin = LowercasePlugin;
// The signature lives with the command
fn signature(&self) -> PluginSignature {
PluginSignature::build("lowercase")
.usage("Convert each string in a stream to lowercase")
.input_output_type(Type::List(Type::String.into()), Type::List(Type::String.into()))
}
// We also provide SimplePluginCommand which operates on Value like before
fn run(
&self,
plugin: &LowercasePlugin,
engine: &EngineInterface,
call: &EvaluatedCall,
input: PipelineData,
) -> Result<PipelineData, LabeledError> {
let span = call.head;
Ok(input.map(move |value| {
value.as_str()
.map(|string| Value::string(string.to_lowercase(), span))
// Errors in a stream should be returned as values.
.unwrap_or_else(|err| Value::error(err, span))
}, None)?)
}
}
// Plugin now just has a list of commands, and the custom value op stuff still goes here
impl Plugin for LowercasePlugin {
fn commands(&self) -> Vec<Box<dyn PluginCommand<Plugin=Self>>> {
vec![Box::new(Lowercase)]
}
}
fn main() {
serve_plugin(&LowercasePlugin{}, MsgPackSerializer)
}
```
Time this however you like - we're already breaking stuff for 0.92, so
it might be good to do it now, but if it feels like a lot all at once,
it could wait.
# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`
# After Submitting
- [ ] Update examples in the book
- [x] Fix#12088 to match - this change would actually simplify it a
lot, because the methods are currently just duplicated between `Plugin`
and `StreamingPlugin`, but they only need to be on `Plugin` with this
change
