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https://github.com/nushell/nushell.git
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6fd854ed9f
# 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>
107 lines
3.0 KiB
Rust
107 lines
3.0 KiB
Rust
//! Test support for [Nushell](https://nushell.sh) plugins.
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//!
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//! # Example
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//!
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//! ```rust
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//! use std::sync::Arc;
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//!
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//! use nu_plugin::*;
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//! use nu_plugin_test_support::PluginTest;
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//! use nu_protocol::{
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//! Example, IntoInterruptiblePipelineData, LabeledError, PipelineData, ShellError, Signature,
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//! Span, Type, Value,
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//! };
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//!
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//! struct LowercasePlugin;
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//! struct Lowercase;
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//!
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//! impl PluginCommand for Lowercase {
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//! type Plugin = LowercasePlugin;
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//!
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//! fn name(&self) -> &str {
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//! "lowercase"
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//! }
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//!
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//! fn usage(&self) -> &str {
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//! "Convert each string in a stream to lowercase"
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//! }
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//!
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//! fn signature(&self) -> Signature {
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//! Signature::build(self.name()).input_output_type(
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//! Type::List(Type::String.into()),
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//! Type::List(Type::String.into()),
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//! )
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//! }
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//!
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//! fn examples(&self) -> Vec<Example> {
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//! vec![Example {
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//! example: r#"[Hello wORLD] | lowercase"#,
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//! description: "Lowercase a list of strings",
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//! result: Some(Value::test_list(vec![
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//! Value::test_string("hello"),
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//! Value::test_string("world"),
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//! ])),
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//! }]
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//! }
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//!
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//! fn run(
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//! &self,
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//! _plugin: &LowercasePlugin,
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//! _engine: &EngineInterface,
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//! call: &EvaluatedCall,
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//! input: PipelineData,
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//! ) -> Result<PipelineData, LabeledError> {
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//! let span = call.head;
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//! Ok(input.map(
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//! move |value| {
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//! value
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//! .as_str()
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//! .map(|string| Value::string(string.to_lowercase(), span))
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//! // Errors in a stream should be returned as values.
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//! .unwrap_or_else(|err| Value::error(err, span))
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//! },
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//! None,
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//! )?)
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//! }
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//! }
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//!
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//! impl Plugin for LowercasePlugin {
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//! fn commands(&self) -> Vec<Box<dyn PluginCommand<Plugin=Self>>> {
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//! vec![Box::new(Lowercase)]
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//! }
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//! }
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//!
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//! // #[test]
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//! fn test_examples() -> Result<(), ShellError> {
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//! PluginTest::new("lowercase", LowercasePlugin.into())?
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//! .test_command_examples(&Lowercase)
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//! }
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//!
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//! // #[test]
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//! fn test_lowercase() -> Result<(), ShellError> {
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//! let input = vec![Value::test_string("FooBar")].into_pipeline_data(Span::test_data(), None);
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//! let output = PluginTest::new("lowercase", LowercasePlugin.into())?
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//! .eval_with("lowercase", input)?
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//! .into_value(Span::test_data())?;
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//!
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//! assert_eq!(
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//! Value::test_list(vec![
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//! Value::test_string("foobar")
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//! ]),
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//! output
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//! );
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//! Ok(())
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//! }
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//! #
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//! # test_examples().unwrap();
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//! # test_lowercase().unwrap();
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//! ```
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mod diff;
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mod fake_persistent_plugin;
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mod fake_register;
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mod plugin_test;
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mod spawn_fake_plugin;
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pub use plugin_test::PluginTest;
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