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Merge pull request #284 from onthebridgetonowhere/port_first_command

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Add back binary support for the first command
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JT 2021-11-04 15:42:57 +13:00 committed by GitHub
commit f6d7df5a45
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1 changed files with 72 additions and 13 deletions
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75
crates/nu-command/src/filters/first.rs
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@ -2,7 +2,7 @@ use nu_engine::CallExt;
use nu_protocol::ast::Call;
use nu_protocol::engine::{Command, EngineState, Stack};
use nu_protocol::{
Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
};
#[derive(Clone)]
@ -62,26 +62,85 @@ fn first_helper(
) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
let head = call.head;
let rows: Option<i64> = call.opt(engine_state, stack, 0)?;
let rows_desired: usize = match rows {
let mut rows_desired: usize = match rows {
Some(x) => x as usize,
None => 1,
};
if rows_desired == 1 {
let mut input_peek = input.into_iter().peekable();
match input_peek.next() {
Some(val) => Ok(val.into_pipeline_data()),
None => Err(ShellError::AccessBeyondEndOfStream(head)),
if input_peek.peek().is_some() {
match input_peek.peek().unwrap().get_type() {
Type::Binary => {
match &mut input_peek.next() {
Some(v) => match &v {
Value::Binary { val, .. } => {
let bytes = val;
if bytes.len() >= rows_desired {
// We only want to see a certain amount of the binary
// so let's grab those parts
let output_bytes = bytes[0..rows_desired].to_vec();
Ok(Value::Binary {
val: output_bytes,
span: head,
}
.into_pipeline_data())
} else {
Ok(Value::List {
vals: input.into_iter().take(rows_desired).collect(),
// if we want more rows that the current chunk size (8192)
// we must gradually get bigger chunks while testing
// if it's within the requested rows_desired size
let mut bigger: Vec<u8> = vec![];
bigger.extend(bytes);
while bigger.len() < rows_desired {
match input_peek.next() {
Some(Value::Binary { val, .. }) => bigger.extend(val),
_ => {
// We're at the end of our data so let's break out of this loop
// and set the rows_desired to the size of our data
rows_desired = bigger.len();
break;
}
}
}
let output_bytes = bigger[0..rows_desired].to_vec();
Ok(Value::Binary {
val: output_bytes,
span: head,
}
.into_pipeline_data())
}
}
_ => todo!(),
},
None => Ok(Value::List {
vals: input_peek.into_iter().take(rows_desired).collect(),
span: head,
}
.into_pipeline_data()),
}
}
_ => {
if rows_desired == 1 {
match input_peek.next() {
Some(val) => Ok(val.into_pipeline_data()),
None => Err(ShellError::AccessBeyondEndOfStream(head)),
}
} else {
Ok(Value::List {
vals: input_peek.into_iter().take(rows_desired).collect(),
span: head,
}
.into_pipeline_data())
}
}
}
} else {
Err(ShellError::UnsupportedInput(
String::from("Cannot perform into string on empty input"),
head,
))
}
}
#[cfg(test)]
mod test {
use super::*;