mirror of
https://github.com/nushell/nushell.git
synced 2025-07-12 12:26:05 +02:00
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>
40 lines
610 B
Rust
40 lines
610 B
Rust
// `example` command - just suggests to call --help
|
|
mod main;
|
|
|
|
pub use main::Main;
|
|
|
|
// Basic demos
|
|
mod one;
|
|
mod three;
|
|
mod two;
|
|
|
|
pub use one::One;
|
|
pub use three::Three;
|
|
pub use two::Two;
|
|
|
|
// Engine interface demos
|
|
mod config;
|
|
mod disable_gc;
|
|
mod env;
|
|
mod view_span;
|
|
|
|
pub use config::Config;
|
|
pub use disable_gc::DisableGc;
|
|
pub use env::Env;
|
|
pub use view_span::ViewSpan;
|
|
|
|
// Stream demos
|
|
mod collect_bytes;
|
|
mod echo;
|
|
mod for_each;
|
|
mod generate;
|
|
mod seq;
|
|
mod sum;
|
|
|
|
pub use collect_bytes::CollectBytes;
|
|
pub use echo::Echo;
|
|
pub use for_each::ForEach;
|
|
pub use generate::Generate;
|
|
pub use seq::Seq;
|
|
pub use sum::Sum;
|