nushell/crates/nu-command/tests/format_conversions
Ian Manske 6fd854ed9f
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>
2024-05-16 07:11:18 -07:00
..
csv.rs Replace ExternalStream with new ByteStream type (#12774) 2024-05-16 07:11:18 -07:00
html.rs Remove feat extra and include in default (#12140) 2024-03-10 17:29:02 +01:00
json.rs Avoid taking unnecessary ownership of intermediates (#12740) 2024-05-04 00:53:15 +00:00
markdown.rs Clean up tests containing unnecessary cwd: tokens (#9692) 2023-07-17 18:43:51 +02:00
mod.rs Msgpack commands (#12664) 2024-04-26 06:23:16 -05:00
msgpack.rs Msgpack commands (#12664) 2024-04-26 06:23:16 -05:00
msgpackz.rs Msgpack commands (#12664) 2024-04-26 06:23:16 -05:00
nuon.rs Deprecate register and add plugin use (#12607) 2024-04-23 06:37:50 -05:00
ods.rs Add long options for formats (#10645) 2023-10-08 19:07:09 +02:00
ssv.rs Avoid taking unnecessary ownership of intermediates (#12740) 2024-05-04 00:53:15 +00:00
toml.rs Clean up tests containing unnecessary cwd: tokens (#9692) 2023-07-17 18:43:51 +02:00
tsv.rs Replace ExternalStream with new ByteStream type (#12774) 2024-05-16 07:11:18 -07:00
url.rs Rename to url command to url build-query (#7702) 2023-01-15 10:16:29 -08:00
xlsx.rs Add date support in from xlsx (#11952) 2024-02-24 07:25:51 -06:00
xml.rs Add self-closed tag support for to xml (#11577) 2024-01-19 05:35:29 -06:00
yaml.rs Clean up tests containing unnecessary cwd: tokens (#9692) 2023-07-17 18:43:51 +02:00