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>
This commit is contained in:
Ian Manske
2024-05-16 14:11:18 +00:00
committed by GitHub
parent 1b8eb23785
commit 6fd854ed9f
210 changed files with 3955 additions and 4012 deletions

View File

@ -313,7 +313,7 @@ where
// Unwrap the PipelineData from input, consuming the potential stream, and pass it to the
// simpler signature in Plugin
let span = input.span().unwrap_or(call.head);
let input_value = input.into_value(span);
let input_value = input.into_value(span)?;
// Wrap the output in PipelineData::Value
<Self as SimplePluginCommand>::run(self, plugin, engine, call, &input_value)
.map(|value| PipelineData::Value(value, None))

View File

@ -345,7 +345,7 @@ impl InterfaceManager for EngineInterfaceManager {
});
Ok(PipelineData::ListStream(stream, meta))
}
PipelineData::Empty | PipelineData::ExternalStream { .. } => Ok(data),
PipelineData::Empty | PipelineData::ByteStream(..) => Ok(data),
}
}
}
@ -850,7 +850,7 @@ impl EngineInterface {
let input = input.map_or_else(|| PipelineData::Empty, |v| PipelineData::Value(v, None));
let output = self.eval_closure_with_stream(closure, positional, input, true, false)?;
// Unwrap an error value
match output.into_value(closure.span) {
match output.into_value(closure.span)? {
Value::Error { error, .. } => Err(*error),
value => Ok(value),
}
@ -920,7 +920,7 @@ impl Interface for EngineInterface {
});
Ok(PipelineData::ListStream(stream, meta))
}
PipelineData::Empty | PipelineData::ExternalStream { .. } => Ok(data),
PipelineData::Empty | PipelineData::ByteStream(..) => Ok(data),
}
}
}

View File

@ -4,10 +4,9 @@ use super::{EngineInterfaceManager, ReceivedPluginCall};
use nu_plugin_core::{interface_test_util::TestCase, Interface, InterfaceManager};
use nu_plugin_protocol::{
test_util::{expected_test_custom_value, test_plugin_custom_value, TestCustomValue},
CallInfo, CustomValueOp, EngineCall, EngineCallId, EngineCallResponse, EvaluatedCall,
ExternalStreamInfo, ListStreamInfo, PipelineDataHeader, PluginCall, PluginCallResponse,
PluginCustomValue, PluginInput, PluginOutput, Protocol, ProtocolInfo, RawStreamInfo,
StreamData,
ByteStreamInfo, CallInfo, CustomValueOp, EngineCall, EngineCallId, EngineCallResponse,
EvaluatedCall, ListStreamInfo, PipelineDataHeader, PluginCall, PluginCallResponse,
PluginCustomValue, PluginInput, PluginOutput, Protocol, ProtocolInfo, StreamData,
};
use nu_protocol::{
engine::Closure, Config, CustomValue, IntoInterruptiblePipelineData, LabeledError,
@ -158,16 +157,9 @@ fn manager_consume_all_propagates_message_error_to_readers() -> Result<(), Shell
test.add(invalid_input());
let stream = manager.read_pipeline_data(
PipelineDataHeader::ExternalStream(ExternalStreamInfo {
PipelineDataHeader::ByteStream(ByteStreamInfo {
id: 0,
span: Span::test_data(),
stdout: Some(RawStreamInfo {
id: 0,
is_binary: false,
known_size: None,
}),
stderr: None,
exit_code: None,
trim_end_newline: false,
}),
None,
)?;
@ -1046,7 +1038,7 @@ fn interface_eval_closure_with_stream() -> Result<(), ShellError> {
true,
false,
)?
.into_value(Span::test_data());
.into_value(Span::test_data())?;
assert_eq!(Value::test_int(2), result);

View File

@ -30,7 +30,7 @@ pub use interface::{EngineInterface, EngineInterfaceManager};
/// This should be larger than the largest commonly sent message to avoid excessive fragmentation.
///
/// The buffers coming from external streams are typically each 8192 bytes, so double that.
/// The buffers coming from byte streams are typically each 8192 bytes, so double that.
#[allow(dead_code)]
pub(crate) const OUTPUT_BUFFER_SIZE: usize = 16384;