nushell/crates/nu-command/src/conversions/into/glob.rs
Ian Manske 9996e4a1f8
Shrink the size of Expr (#12610)
# Description
Continuing from #12568, this PR further reduces the size of `Expr` from
64 to 40 bytes. It also reduces `Expression` from 128 to 96 bytes and
`Type` from 32 to 24 bytes.

This was accomplished by:
- for `Expr` with multiple fields (e.g., `Expr::Thing(A, B, C)`),
merging the fields into new AST struct types and then boxing this struct
(e.g. `Expr::Thing(Box<ABC>)`).
- replacing `Vec<T>` with `Box<[T]>` in multiple places. `Expr`s and
`Expression`s should rarely be mutated, if at all, so this optimization
makes sense.

By reducing the size of these types, I didn't notice a large performance
improvement (at least compared to #12568). But this PR does reduce the
memory usage of nushell. My config is somewhat light so I only noticed a
difference of 1.4MiB (38.9MiB vs 37.5MiB).

---------

Co-authored-by: Stefan Holderbach <sholderbach@users.noreply.github.com>
2024-04-24 15:46:35 +00:00

128 lines
3.5 KiB
Rust

use nu_cmd_base::input_handler::{operate, CmdArgument};
use nu_engine::command_prelude::*;
struct Arguments {
cell_paths: Option<Vec<CellPath>>,
}
impl CmdArgument for Arguments {
fn take_cell_paths(&mut self) -> Option<Vec<CellPath>> {
self.cell_paths.take()
}
}
#[derive(Clone)]
pub struct SubCommand;
impl Command for SubCommand {
fn name(&self) -> &str {
"into glob"
}
fn signature(&self) -> Signature {
Signature::build("into glob")
.input_output_types(vec![
(Type::String, Type::Glob),
(
Type::List(Box::new(Type::String)),
Type::List(Box::new(Type::Glob)),
),
(Type::table(), Type::table()),
(Type::record(), Type::record()),
])
.allow_variants_without_examples(true) // https://github.com/nushell/nushell/issues/7032
.rest(
"rest",
SyntaxShape::CellPath,
"For a data structure input, convert data at the given cell paths.",
)
.category(Category::Conversions)
}
fn usage(&self) -> &str {
"Convert value to glob."
}
fn search_terms(&self) -> Vec<&str> {
vec!["convert", "text"]
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
glob_helper(engine_state, stack, call, input)
}
fn examples(&self) -> Vec<Example> {
vec![
Example {
description: "convert string to glob",
example: "'1234' | into glob",
result: Some(Value::test_glob("1234")),
},
Example {
description: "convert filepath to glob",
example: "ls Cargo.toml | get name | into glob",
result: None,
},
]
}
}
fn glob_helper(
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
let head = call.head;
let cell_paths = call.rest(engine_state, stack, 0)?;
let cell_paths = (!cell_paths.is_empty()).then_some(cell_paths);
let args = Arguments { cell_paths };
match input {
PipelineData::ExternalStream { stdout: None, .. } => {
Ok(Value::glob(String::new(), false, head).into_pipeline_data())
}
PipelineData::ExternalStream {
stdout: Some(stream),
..
} => {
// TODO: in the future, we may want this to stream out, converting each to bytes
let output = stream.into_string()?;
Ok(Value::glob(output.item, false, head).into_pipeline_data())
}
_ => operate(action, args, input, head, engine_state.ctrlc.clone()),
}
}
fn action(input: &Value, _args: &Arguments, span: Span) -> Value {
match input {
Value::String { val, .. } => Value::glob(val.to_string(), false, span),
x => Value::error(
ShellError::CantConvert {
to_type: String::from("glob"),
from_type: x.get_type().to_string(),
span,
help: None,
},
span,
),
}
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn test_examples() {
use crate::test_examples;
test_examples(SubCommand {})
}
}