use crate::input_handler::{operate, CmdArgument};
use nu_engine::CallExt;
use nu_protocol::ast::{Call, CellPath};
use nu_protocol::engine::{Command, EngineState, Stack};
use nu_protocol::{
Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
};
struct Arguments {
pattern: Vec<u8>,
end: bool,
all: bool,
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 BytesIndexOf;
impl Command for BytesIndexOf {
fn name(&self) -> &str {
"bytes index-of"
}
fn signature(&self) -> Signature {
Signature::build("bytes index-of")
.input_output_types(vec![
(Type::Binary, Type::Int),
(Type::Binary, Type::List(Box::new(Type::Int))),
])
.required(
"pattern",
SyntaxShape::Binary,
"the pattern to find index of",
)
.rest(
"rest",
SyntaxShape::CellPath,
"for a data structure input, find the indexes at the given cell paths",
)
.switch("all", "returns all matched index", Some('a'))
.switch("end", "search from the end of the binary", Some('e'))
.category(Category::Bytes)
}
fn usage(&self) -> &str {
"Returns start index of first occurrence of pattern in bytes, or -1 if no match"
}
fn search_terms(&self) -> Vec<&str> {
vec!["pattern", "match", "find", "search"]
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
let pattern: Vec<u8> = call.req(engine_state, stack, 0)?;
let cell_paths: Vec<CellPath> = call.rest(engine_state, stack, 1)?;
let cell_paths = (!cell_paths.is_empty()).then_some(cell_paths);
let arg = Arguments {
pattern,
end: call.has_flag("end"),
all: call.has_flag("all"),
cell_paths,
};
operate(index_of, arg, input, call.head, engine_state.ctrlc.clone())
}
fn examples(&self) -> Vec<Example> {
vec![
Example {
description: "Returns index of pattern in bytes",
example: " 0x[33 44 55 10 01 13 44 55] | bytes index-of 0x[44 55]",
result: Some(Value::test_int(1)),
},
Example {
description: "Returns index of pattern, search from end",
example: " 0x[33 44 55 10 01 13 44 55] | bytes index-of -e 0x[44 55]",
result: Some(Value::test_int(6)),
},
Example {
description: "Returns all matched index",
example: " 0x[33 44 55 10 01 33 44 33 44] | bytes index-of -a 0x[33 44]",
result: Some(Value::List {
vals: vec![Value::test_int(0), Value::test_int(5), Value::test_int(7)],
span: Span::test_data(),
}),
},
Example {
description: "Returns all matched index, searching from end",
example: " 0x[33 44 55 10 01 33 44 33 44] | bytes index-of -a -e 0x[33 44]",
result: Some(Value::List {
vals: vec![Value::test_int(7), Value::test_int(5), Value::test_int(0)],
span: Span::test_data(),
}),
},
Example {
description: "Returns index of pattern for specific column",
example: r#" [[ColA ColB ColC]; [0x[11 12 13] 0x[14 15 16] 0x[17 18 19]]] | bytes index-of 0x[11] ColA ColC"#,
result: Some(Value::List {
vals: vec![Value::Record {
cols: vec!["ColA".to_string(), "ColB".to_string(), "ColC".to_string()],
vals: vec![
Value::test_int(0),
Value::Binary {
val: vec![0x14, 0x15, 0x16],
span: Span::test_data(),
},
Value::test_int(-1),
],
span: Span::test_data(),
}],
span: Span::test_data(),
}),
},
]
}
}
fn index_of(val: &Value, args: &Arguments, span: Span) -> Value {
match val {
Value::Binary {
val,
span: val_span,
} => index_of_impl(val, args, *val_span),
Value::Error { .. } => val.clone(),
other => Value::Error {
error: ShellError::OnlySupportsThisInputType(
"binary".into(),
other.get_type().to_string(),
span,
other.expect_span(),
),
},
}
}
fn index_of_impl(input: &[u8], arg: &Arguments, span: Span) -> Value {
if arg.all {
search_all_index(input, &arg.pattern, arg.end, span)
} else {
let mut iter = input.windows(arg.pattern.len());
if arg.end {
Value::Int {
val: iter
.rev()
.position(|sub_bytes| sub_bytes == arg.pattern)
.map(|x| (input.len() - arg.pattern.len() - x) as i64)
.unwrap_or(-1),
span,
}
} else {
Value::Int {
val: iter
.position(|sub_bytes| sub_bytes == arg.pattern)
.map(|x| x as i64)
.unwrap_or(-1),
span,
}
}
}
}
fn search_all_index(input: &[u8], pattern: &[u8], from_end: bool, span: Span) -> Value {
let mut result = vec![];
if from_end {
let (mut left, mut right) = (
input.len() as isize - pattern.len() as isize,
input.len() as isize,
);
while left >= 0 {
if &input[left as usize..right as usize] == pattern {
result.push(Value::Int {
val: left as i64,
span,
});
left -= pattern.len() as isize;
right -= pattern.len() as isize;
} else {
left -= 1;
right -= 1;
}
}
Value::List { vals: result, span }
} else {
let (mut left, mut right) = (0, pattern.len());
let input_len = input.len();
let pattern_len = pattern.len();
while right <= input_len {
if &input[left..right] == pattern {
result.push(Value::Int {
val: left as i64,
span,
});
left += pattern_len;
right += pattern_len;
} else {
left += 1;
right += 1;
}
}
Value::List { vals: result, span }
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_examples() {
use crate::test_examples;
test_examples(BytesIndexOf {})
}
}